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Antinoise or distortion (includes predistortion)

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375 - Pulse or digital communications

375295000 - TRANSMITTERS

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Class / Patent application numberDescriptionNumber of patent applications / Date published
375297000 Power amplifier 103
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DocumentTitleDate
20090010358Methods and apparatus to pre-compensate for I/Q distortion in quadrature transmitters - Methods and apparatus to pre-compensate for in-phase/quadrature (I/Q) distortion in quadrature transmitters are disclosed. A disclosed example method comprises coupling a portion of an analog baseband in-phase signal to an analog baseband quadrature signal through an impedance, and selecting a resistance value for the impedance to pre-distort the analog baseband quadrature signal to compensate for an error introduced by modulation of the analog baseband in-phase signal and the analog baseband quadrature signal.01-08-2009
20110002415WIRELESS COMMUNICATION MOBILE STATION DEVICE AND METHOD FOR USING PRECODING MATRIX - Provided is a wireless communication mobile station device capable of suppressing an increase in an SRS resource even when the mobile station is provided with a plurality of antennas. In the device, a weighting section (01-06-2011
20130028348DISCRETE DIGITAL TRANSMITTER - A transmitter includes a conversion module, a sample and hold module, and a discrete time bandpass filter module. The conversion module is operable to convert an outbound baseband signal into outbound frequency domain pulse signal. The sample and hold module is operable to sample and hold the outbound frequency domain pulse signal to produce a frequency domain sample pulse train, wherein the sample and hold module is clocked at a rate corresponding to a frequency component of an outbound wireless signal. The discrete time bandpass filter module is operable to bandpass filter the frequency domain sample pulse train to produce the outbound wireless signal.01-31-2013
20130028349MULTIPLE OUTPUT DISCRETE DIGITAL TRANSMITTER - A transmitter includes a conversion module, a sample and hold module, and a discrete time bandpass filter module. The conversion module is operable to convert a first outbound baseband signal into a first outbound frequency domain pulse signal and to convert a second outbound baseband signal into a second outbound frequency domain pulse signal. The sample and hold module operable to sample and hold the first outbound frequency domain pulse signal and the second outbound frequency domain pulse signal to produce a frequency domain sample pulse train. The discrete time bandpass filter module is operable to filter the frequency domain sample pulse train to produce a first outbound wireless corresponding to the first baseband signal and to produce a second outbound wireless signal corresponding to the second inbound baseband signal.01-31-2013
20100061482Method for transmitting data using phase shift based precoding and transceiver supporting the same - A method of transmitting data using cyclic delay in a multi-antenna system using a plurality of subcarriers and a transceiver supporting the same are disclosed. More particularly, a method of selecting a matrix (second matrix) for transforming a precoding matrix (first matrix) into a unitary matrix from a codebook by a prescribed reference is disclosed. An index for selecting the second matrix is calculated by a prescribed modulo operation in an open loop system or delivered as feedback information in a closed loop system. Diversity can be obtained by switching each column of the selected second matrix in accordance with time. In a multi-user system, a single second matrix can be determined by combining columns of the second matrix selected by each user.03-11-2010
20090196374Minimal dead time digitally compensated process transmitter - A process transmitter includes a sensor for producing an analog process signal as a function of a process parameter. The uncompensated analog process signal is digitized by an A/D converter and digitally compensated by a digital processor. The digitized signal from the analog-to-digital converter is also band pass filtered. The digitally compensated signal and the band pass filtered signal are combined to produce a transmitter output.08-06-2009
20110194649Method of Precoding with a Codebook for a Wireless System With Multiple Transmission Ranks and a Quantized Beamforming Matrix - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.08-11-2011
20090122911System and Method for Corrected Modulation with Nonlinear Power Amplification - A system and method for modulating and amplifying an input signal are provided in a communication transmitter. The transmitter includes a pre-distortion lookup table containing pre-distortion lookup data. An auto-calibration module is in communication with the pre-distortion lookup table. The auto-calibration module is configured to operate during a closed-loop auto-calibration interval and to calibrate the pre-distortion lookup data to compensate for a non-linearity in the transmitter. A baseband processor is in communication with the pre-distortion lookup table. The baseband processor is configured to receive an input signal and to generate a pre-distorted baseband I/Q signal pair. The pre-distortion is based on the pre-distortion lookup data during an open-loop operational interval. An I/Q modulator is in communication with the baseband processor. The I/Q modulator is configured to modulate an RF carrier signal based on the pre-distorted baseband I/Q signal pair and to generate a pre-distorted, modulated RF carrier signal. A power amplifier is in communication with the baseband processor and the I/Q modulator. The power amplifier is configured to amplify the corrected, modulated RF carrier signal and to generate an amplified RF signal. A digital feedback path in communication with the power amplifier and the baseband processor. The digital feedback path is configured to provide a feedback signal to the baseband processor during the closed-loop auto-calibration interval.05-14-2009
20120177142PRECODING PROCESS FOR A TRANSMITTER OF A MU-MIMO COMMUNICATION SYTSTEM - A Precoding process for a transmitter of a MU-MIMO communication system comprising M antennas in the transmitter and K User Equipments (UE), said precoding being based on a Regularized Zero Forcing (R-ZF) linear precoding.07-12-2012
20100119007PRECODER CIRCUIT - A disclosed precoder circuit is used for differential phase shift keying and includes multiple levels of parallel precoder units, each of which is configured to perform a precoding operation using a data signal having multiple symbols and one of a fixed value and a one-symbol preceding modulated signal output from a preceding-level parallel precoder unit so as to obtain a modulated signal, precoding operations of the parallel precoder units being simultaneously performed in a parallel fashion; multiple levels of re-timing units configured to synchronize modulated signals output from the parallel precoder units; and multiple levels of offset units, each of which is configured to add a phase difference between the fixed value and the one-symbol preceding modulated signal to the modulated signals output from the corresponding re-timing units.05-13-2010
20100074368ASYNCHRONOUS DELTA-SIGMA MODULATOR AND A METHOD FOR THE DELTA-SIGMA MODULATION OF AN INPUT SIGNAL - An asynchronous delta-sigma modulator is proposed that comprises an input port, a filter, an envelope path, a phase path, an amplifier, and a feedback path that conveys the amplifier output signal to the filter. The envelope path extracts an envelope from the signal provided by the filter and issues an envelope signal. The phase path processes or processes a phase from the signal provided by the filter and issues a phase signal. The amplifier comprises input ports for the envelope signal and the phase signal. The amplifier issues an amplifier output signal based on said envelope signal and said phase signal. The feedback path conveys the amplifier output signal to the filter. The feedback signal contains both amplitude information and phase information. A corresponding method and computer-program products usable for production and operation of the delta-sigma modulator are also disclosed.03-25-2010
20130077712ECHO CANCELLATION IN WIRELESS INBAND SIGNALING MODEM - An inband signaling modem receives digital user data for transmission to a remote location, via wireless and land line telecommunication networks. The modem converts the user data into audio tones for transmission, and encodes the audio tones into digital form suitable for transmission through a voice channel call session of a digital wireless network. After establishing a voice channel call session on a digital wireless network, the modem disables any echo cancellation or echo suppression means that may be encountered in the voice channel call session; and then transmits the user data audio tones. Preferably, disabling the echo cancellation or echo suppression means comprises transmitting a predetermined tone in the voice channel call session. Further, the modem preferably repeats the tone, to again disable echo cancellation or echo suppression means, at the beginning of each data burst during the call session.03-28-2013
20100046667WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATING METHOD - A wireless communication apparatus of a base station uses antennas for multiple systems, forms a multi-beam, transmits data to a mobile station, and includes a code book configured to store therein beamforming information; a pre-coder that reads the code book and executes a process of forming a given beam for the data; a control unit that, based on feedback information to correct variations in phase occurring at transmitting circuits respectively corresponding to each of the systems, performs control such that the beamforming information to correct the variations in phase is read from the code book; and a phase correcting unit that corrects a phase of the multi-beam formed by the pre-coder, based on the feedback information and such that relations among the phases of the multi-beam become substantially linear.02-25-2010
20100046666SIGNAL PROCESSING WITH CHANNEL EIGENMODE DECOMPOSITION AND CHANNEL INVERSION FOR MIMO SYSTEMS - Techniques for processing a data transmission at a transmitter and receiver, which use channel eigen-decomposition, channel inversion, and (optionally) “water-pouring”. At the transmitter, (1) channel eigen-decomposition is performed to determine eigenmodes of a MIMO channel and to derive a first set of steering vectors, (2) channel inversion is performed to derive weights (e.g., one set for each eigenmode) used to minimize ISI distortion, and (3) water-pouring may be performed to derive scaling values indicative of the transmit powers allocated to the eigenmodes. The first set of steering vectors, weights, and scaling values are used to derive a pulse-shaping matrix, which is used to precondition modulation symbols prior to transmission. At the receiver, channel eigen-decomposition is performed to derive a second set of steering vectors, which are used to derive a pulse-shaping matrix used to condition received symbols such that orthogonal symbol streams are recovered.02-25-2010
20100046665Method and apparatus for performing sequential closed loop multiple input multiple output (MIMO) - In a communication system using closed loop MIMO, beam forming information may be fed back from a receiver to a transmitter sequentially over a number of frames. The beam forming matrices that are fed back may be quantized.02-25-2010
20130034187PRECODING WEIGHT GENERATION METHOD AND CONTROL APPARATUS - To reduce interference among mobile station apparatuses even when the CSI is not transmitted from all mobile station apparatuses as feedback in an environment where Joint Transmission is performed, a channel matrix is generated which is comprised of the CSI from a plurality of mobile station apparatuses (UEs) undergoing spatial multiplexing for each of coordinated cells, and based on the channel matrix, precoding weights are generated successively starting from a cell having the highest number of mobile station apparatuses (UEs) that transmit the CSI as feedback. When data transmission is targeted for a mobile station apparatus (UE#02-07-2013
20130034185WIRELESS COMMUNICATION DEVICE AND WIRELESS COMMUNICATION METHOD - A wireless communication device includes a mixer that multiplies quadrature-modulated transmission data by a local oscillation frequency signal and outputs a high-frequency signal; a distributor that distributes the high-frequency signal; a detector circuit that detects a direct current component included in the high-frequency signal, based on the high-frequency signal distributed by the distributor; a correction signal generating unit that generates a correction signal for removing the direct current component from the high-frequency signal, based on the direct current component detected by the detector circuit; a correction unit that corrects the high-frequency signal by the correction signal generated by the correction signal generating unit; and a transmission unit that transmits the high-frequency signal that has been corrected by the correction unit.02-07-2013
20130034186OFDM MODULATED WAVE TRANSMITTER APPARATUS, OFDM MODULATED WAVE TRANSMISSION METHOD, AND PROGRAM - In an orthogonal frequency division multiplex (OFDM) modulated wave transmitter apparatus, a symbol mapping circuit and a serial/parallel (S/P) converter generate an OFDM symbol signal from transmission data. An inverse fast Fourier transform (IFFT) circuit, a parallel/serial (P/S) converting and guard interval (GI) adding circuit, a timing adjusting circuit, a digital/analog (D/A) converter, a frequency converter, a local oscillator and an analog filter generate an OFDM modulated wave signal from the OFDM symbol signal. A power amplifier (PA) control circuit limits a band of the OFDM symbol signal and generates a PS control signal and a PA control signal. A PA designates a voltage supplied from a DC/DC converter as a PS voltage and amplifies and outputs the OFDM modulated wave signal based on the PA control signal.02-07-2013
20100074367ADAPTIVE COMBINER ERROR CALIBRATION ALGORITHMS IN ALL-DIGITAL OUTPHASING TRANSMITTER - Systems and methods may include a signal component separator that receives a non-constant envelope input signal and at least one phase offset value, and generates first digital phase data and second digital phase data; at least one digital phase modulator that receives the first phase data and the second phase data and operates with a frequency synthesizer to generate a first component signal having a first constant envelope and a second component signal having a second constant envelope; at least one power amplifier that amplifies the first component signal and the second component signal; a non-isolated power combiner that combines the first amplified component signal and the second amplified component signal to generate an output signal having a non-constant envelope; and a mismatch compensator that monitors the output signal to determine the at least one phase offset value, where the at least one phase offset value is utilized by the signal component separator for phase adjustment.03-25-2010
20090116581PRE-CODING APPARATUS ON ACCOUNT OF ADAPTIVE ESTIMATION - A pre-coding process and apparatus on account of adaptive estimation is provided, which comprises a plurality of channel state information detectors, a reduction sampler, a plurality of adaptive estimators, an error-estimation averager, and a parallel/serial transducer. The pre-coding implementation of the present apparatus can be divided in an initial stage of acquisition and a following tracking stage. The present invention can be applied to Single-Input Single-Output (SISO) antenna system and Multiple-Input Multiple-Output (MIMO) antenna system, in order to advance the dependability and stability of the system, which also have advantage in further decreasing the complexity, power consumption and cost of the end-user host receiver, easy implementation, and high immunity from channel noise interference.05-07-2009
20100111224METHOD FOR TRANSMITTING COMMON FEEDBACK CHANNEL AND TRANCEIVER THEREFOR - Disclosed is a method for generating feedback signal patterns of common feedback channels using cyclic shift in a multiple access system, and a transceiver therefore. A method for generating feedback signal patterns includes generating first transmission symbols by adding a cyclic prefix to transmission symbols of feedback signals, and generating second and subsequent transmission symbols by cyclically shifting the first transmission symbols and then adding the cyclic prefix.05-06-2010
20100111221OPTIMIZED DIGITAL CORRECTION FOR POWER AMPLIFIER DISTORTION AND QUADRATURE ERROR - A method, wireless device, and wireless communication system manage quadrature and non-linear distortions in a transmitter system (05-06-2010
20100104043POWER AMPLIFIER - A switched mode class-S power amplifier comprises a sigma-delta modulator with a digital input, a power switch connected to the output of the sigma-delta modulator providing the power amplifier output, and a feedback mechanism. The sigma-delta modulator has a high-pass transfer function and uses an offset switching frequency to remove an unwanted image over half of the switching frequency. The amplifier may have a filter to remove unwanted fold-over image. There may be at least two modulators arranged in parallel, and there may be a complex filter for constructively combining the modulator outputs.04-29-2010
20120183098DIGITAL BROADCASTING SYSTEM AND DATA PROCESSING METHOD - A transmitting system and method therein are disclosed, by which mobile service data is received and processed. The transmitting system includes an encoder, a signaling encoder, a group formatter, a transmission unit. The encoder encodes mobile data and the signaling encoder encodes signaling information. The group formatter forms data groups having the encoded mobile and signaling information. The data groups have a plurality of data blocks and specific data blocks of the plurality of data blocks include known data sequences. The transmission unit transmit broadcast signal including a parade that includes a collection of data groups having same FEC parameters. And the signaling information includes information identifying the parade and first assigned data group number for the parade to which a first assigned data group belongs.07-19-2012
20130070870DIGITAL PRE-DISTORTION FILTER SYSTEM AND METHOD - A digital predistorter for improving the performance of a narrow passband filter near the output is disclosed. The digital predistorter provides amplitude correction to the signal based on the characteristics of the passband filter. A filter group delay predistorter may also be employed to correct group delay variation introduced by the narrow passband filter.03-21-2013
20120219091METHOD AND TRANSMITTER FOR TRANSMITTING FOR TRANSMITTING SIGNAL AND RECEIVER THEREOF IN WIRELESS COMMUNICATION SYSTEM - The present invention relates to precoding the signal in wireless communication system.08-30-2012
20120219090APPARATUSES, SYSTEMS, AND METHODS FOR REDUCING SPURIOUS EMISSIONS RESULTING FROM CARRIER LEAKAGE - An exemplary apparatus includes a modulator configured to modulate a data signal onto a carrier signal to generate a modulated signal having a transmit frequency within a predefined frequency range adjacent to and within a boundary of an uplink frequency band, a filter configured to at least partially remove a carrier frequency component from the modulated signal to produce a filtered modulated signal, and an antenna configured to transmit the filtered modulated signal.08-30-2012
20120219089TRANSMISSION METHOD AND TRANSMISSION APPARATUS - All data symbols used in data transmission of a modulated signal are precoded by switching between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol along the frequency axis and the time axis all differ. A modulated signal with such data symbols arranged therein is transmitted.08-30-2012
20120219088Signal Processing Circuit and Method - A signal processing circuit for providing a modulated analog transmit signal on the basis of a digital transmit data signal is configured to vary a resolution in dependence on a detected or predefined parameter when providing the modulated analog transmit signal.08-30-2012
20130070871RECEIVING APPARATUS, TRANSMITTING APPARATUS AND WIRELESS COMMUNICATION SYSTEM USING THEM - When spatial multiplexing is performed to any of a plurality of receiving antennas included in each terminal, it becomes possible to obtain excellent receiving characteristics by combining signals received by all antennas appropriately. A receiving antenna unit 03-21-2013
20110058626Ultra Wideband Interference Cancellation for Orthogonal Frequency Division Multiplex Transmitters by Protection-Edge Tones - A transmitter and communication system are disclosed. A first component operable to determine an active interference cancellation value for each of a plurality of active interference cancellation tones and a protection-edge value for each of a plurality of protection-edge tones based on optimizing active interference cancellation, and further based on constraining an average power of the active interference cancellation values and the protection-edge values to less than or equal to a maximum power level, and on a plurality of data values. A second component is operable to transform a sequence of tones to a time domain signal, the sequence of tones comprised of the active interference cancellation tones, the protection-edge tones, and a plurality of data tones, the data tones containing the data values. A third component operable to transmit an orthogonal frequency division multiplex signal based on the time domain signal.03-10-2011
20130058433PRE-CODING METHOD, PRE-DECODING METHOD, TRANSMITTER AND MOBILE TERMINAL BASED ON INTERFERENCE ALIGNMENT - The transmitter and a mobile terminal based on interference alignment use pre-coding and pre-decoding methods. An antenna mapping matrix is computed according to a downlink channel state information, wherein the antenna mapping matrix is used for antenna mapping for the current transmitter to perform interference alignment. A multi-cell pre-coding matrix according to the downlink channel state information and the antenna mapping matrix; a single cell multi-user pre-coding matrix and pre-coding user data using the single cell multi-user pre-coding matrix and the multi-cell pre-decoding matrix and performing an antenna mapping using the antenna mapping matrix are computed. A system which cannot use the interference alignment method directly may be transformed to use the interference alignment method directly. In addition, the interference suppression between cells and the interference management inside cells are two separate processes, in which different linear pre-coding and decoding methods may be used.03-07-2013
20130058434DEVICE AND METHOD FOR PRECODING VECTORS IN A COMMUNICATION SYSTEM - A device and method for precoding vectors in a communication system is provided. A transmitter may precode a data vector using information regarding a communication channel prior to transmitting the data vector. The transmitter may precode the data vector in a manner that reduces an energy value of a resulting transmit data vector so as to minimize interference in a received signal at a receiver. The transmitter may perturb entries of the data vector one-by-one in an iterative fashion until a minimum in an energy value of the transmit data vector is obtained.03-07-2013
20120307938CODES AND PREAMBLES FOR SINGLE CARRIER AND OFDM TRANSMISSIONS - Certain aspects of the present disclosure relate to a method for generating a frame structure suitable for use in both single carrier (SC) and Orthogonal Frequency Division Multiplexing (OFDM) transmission modes, while ensuring accurate channel estimation at a receiver.12-06-2012
20110013725REDUCTION OF AGGREGATE EMI EMISSIONS OF MULTIPLE TRANSMITTERS - A power efficient and reduced electromagnetic interference (EMI) emissions multi-transmitter system for unshielded twisted pair (UTP) data communication applications. For each transmitter, digital transmit data is converted to a current-mode differential signal analog waveform by a digital-to-analog converter (DAC). The output current from each DAC is used to generate the required transmit voltage on the respective UTP line. Timing circuitry staggers the time base of each transmitter to reduce the aggregate EMI emissions of the multi-transmitter system.01-20-2011
20130058432WIRELESS TRANSMISSION DEVICE, WIRELESS TRANSMISSION METHOD, WIRELESS TRANSMISSION PROGRAM, AND WIRELESS COMMUNICATION SYSTEM - A wireless transmission device is characterized by including: first interference suppression processing means 03-07-2013
20090067540METHOD FOR CONSTRUCTING RACH PREAMBLE AND METHOD FOR TRANSMITTING RACH SIGNAL - A wireless communication system is disclosed. A method for constructing a RACH preamble according to a cell radius of a base station (BS) irrespective of a guard time (GT) and a method for allocating the RACH preamble are disclosed. A method for constructing a preamble of a random access channel (RACH) includes acquiring time-length information of a predetermined cyclic prefix (CP) for each cell radius of a base station (BS), acquiring sequence time-length information of a single sequence or a repeated sequence, and constructing the preamble using the predetermined CP time-length information and the sequence time-length information, irrespective of a time length of a guard time (GT).03-12-2009
20100091905Low overhead MIMO scheme - Systems and methods are disclosed for use in a communications network that includes transmitting a set of known precodes on a plurality of subbands and storing a correlation of transmitted precodes with a time of transmission of the precodes. These systems and methods also include receiving a set of channel quality indicators (CQI) that correspond to the time of transmission of the precodes and determining which precodes may be used in communication based upon the received CQIs and the correlation of the transmitted precodes with the time of transmission of the precodes.04-15-2010
20100091904WIRELESS COMMUNICATIONS APPARATUS - A block of information is processed before transmission thereof in a block transmission based communication. This comprises inserting a cyclic prefix and a cyclic suffix into the block of information before applying a time reversal based prefilter prior to transmission to the data after cyclic prefix and cyclic suffix insertion, the prefilter being configured on the basis of knowledge of the condition of the channel over which communication is to be effected. Then, at the receiver, a removal operation is operable to remove the effect of cyclic prefix and suffix insertion, leaving a circulant shifted version of the original block. This can be decoded using a diagonal matrix containing frequency domain channel coefficients on its diagonal entries after FFT. For systems with more than two transmit antennas, this facilities the use of full rate OSTBC, regardless of whether real or complex signalling is transmitted.04-15-2010
20130064324Digital Modulation With Arbitrary Input Sampling and Output Modulation Frequencies - An arbitrary modulation frequency of a modulating signal is selected. The modulating signal is applied to an information-bearing signal, where such modulation is carried out through digital signal processing operations. The digitally modulated signal is resolution-reduced and the quantization noise introduced by such is shaped to locate a spectral null in the noise transfer function of the resolution reducing modulator at the modulation frequency. Thus, the modulation frequency can be selected independently of the clock frequency at which the resolution-reduced samples are converted to an analog signal.03-14-2013
20120195392PREDISTORTION IN SPLIT-MOUNT WIRELESS COMMUNICATION SYSTEMS - A transmitter includes an Outdoor Unit (ODU) including circuitry, and an Indoor Unit (IDU) that is configured to predistort a signal based on a non-linearity model of the circuitry having one or more model parameters, and to forward the predistorted signal to the ODU. The ODU is configured to accept the predistorted signal from the IDU, to amplify and transmit the predistorted signal using the circuitry, to estimate the non linearity model parameters, and to send the estimated model parameters to the IDU so as to cause the IDU to apply the model parameters in predistoring the signal.08-02-2012
20090238305METHOD, APPARATUS AND SYSTEM FOR HIGH-SPEED TRANSMISSION - Multi-carrier modulation systems constructed using a series of electrical carriers, modulating the data on the electrical carriers and combining the carriers to form a wideband signal. Multi-carrier modulation may be applied to existing channels, which may be of lower quality. An adaptive multi-carrier modulation transmitter may characterize an existing channel and ascertain the overall characteristics of the channel. The transmitter and receiver can then be configured to use various bandwidths and various modulations in order to match the transfer characteristic of the channel. A series of adaptive multi-carrier modulation transmitters and receivers can be integrated on a single integrated circuit. If multiple adaptive receivers and transmitters are integrated on a single integrated circuit, they may be used to upgrade existing networks to achieve any capacity desired. Each receiver and transmitter may characterize the channel and may configure the modulation and bandpass to the channel's characteristics.09-24-2009
20120114074System and Method for Reducing Peak-To-Average Power Ratio For Multi-Carrier Communication Systems - The present disclosure presents a predictive signal producing method that effectively levels transmitter output power in a multi-carrier communication system and results in approaching amplifier performance normally associated with constant carrier waveforms. Embodiments of the disclosed solution offers >10 dB reduction in the peak-to-average power required to support the transmission of, for example, orthogonal frequency division modulation (“OFDM”) modulation techniques. Embodiments of the novel system and method maximize peak-to-average power ratio (“PAPR”) reduction with selective mapping and soft clipping, which may include filtering, combined. This novel approach also minimizes overhead, bit error rate, retransmissions, and increases latency as well as implementing processing cycles with a number of iterations. The disclosed system and method improves the total system DC power efficiency and provides an optimal solution for PAPR reduction in multi-carrier communication systems such as, for example, OFDM.05-10-2012
20120114072SUCCESSIVE TRANSMIT BEAMFORMING METHODS FOR MULTIPLE-ANTENNA ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) SYSTEMS - An improvement in a method of transmit beamforming between a transmitter and a receiver in an OFDM wireless system having a plurality of subcarriers for a time varying fading channel comprises performing successive beamforming for each of the plurality of subcarriers using less than complete knowledge of the previous fading blocks for the subcarriers by beamforming an adaptive codebook, C=(C05-10-2012
20120269290SIX TRANSMIT ANTENNA CODEBOOK DESIGN - A method of wireless data transmission includes a base station having six antennas and at least one user equipment. The base station forms at least one layer of data stream including modulated symbols, precodes the at least one layer of data stream via multiplication with consecutive first and second precoding matrices and transmit the precoded data stream to the at least one user equipment via the six antennas. The first precoding matrix W10-25-2012
20120269289METHODS AND APPARATUSES FOR DATA TRANSMISSION - Methods and devices are disclosed involving crosstalk reduction depending on weighting factors or grouping of transmission channels. In other embodiments, other methods or devices may be used.10-25-2012
20120269288SYSTEM AND METHOD FOR SIMULTANEOUS MIMO SIGNAL TESTING WITH SINGLE VECTOR SIGNAL ANALYZER - Signal conversion circuitry and method for converting a multiple input, multiple output (MIMO) packet data signal transmission to a plurality of complex data samples for processing by shared test equipment, e.g., a single vector signal analyzer (VSA).10-25-2012
20110044405CODING METHOD, DECODING METHOD, APPARATUSES THEREOF, PROGRAMS THEREOF, AND RECORDING MEDIUM - A coding method with a small error is provided. In the coding method of the present invention, a normalization value obtained from an input signal is corrected for an error calculated from an input and output in vector quantization and is then quantized. The coding method includes a normalization stage of normalizing the input signal in accordance with the normalization value of the input signal, calculated in each frame; a dividing stage of dividing the normalized frame into divided input signal sequences in accordance with a predetermined rule; a vector quantization stage of applying vector quantization to the divided input signal sequences to generate a vector quantization index; and a normalization value correction stage of correcting the normalization value of the input signal for the error obtained from the input and output in the vector quantization stage.02-24-2011
20110122968Method and Apparatus for using Factorized Precoding - According to one or more aspects, the teachings herein improve user equipment (UE) Channel State Information (CSI) feedback, by letting the precoder part of a CSI feedback report comprise factorized precoder feedback. In one or more such embodiments, the factorized precoder feedback corresponds to at least two precoder matrices, including a recommended “conversion” precoder matrix and a recommended “tuning” precoder matrix. The recommended conversion precoder matrix restricts the number of channel dimensions considered by the recommended tuning precoder matrix and, in turn, the recommended tuning precoder matrix matches the recommended precoder matrix to an effective channel that is defined in part by said recommended conversion precoder matrix.05-26-2011
20100008446TRANSCEIVER ARCHITECTURE WITH COMBINED SMART ANTENNA CALIBRATION AND DIGITAL PREDISTORTION - A method, apparatus, and electronic device for using digital predistortion are disclosed. A first transmitter 01-14-2010
20090310704Low Complexity Systems and Methods for Peak-to-Average Ratio (PAR) Reduction Using Reserved Tones - Systems and methods for reducing the peak-to-average ratio (PAR) at the transmitter can reduce the dynamic range required in various analog components. PAR can be reduced by applying a time-domain compensation signal which reduces the magnitude of peaks in the time-domain signal prior to transmission where the time-domain compensation signals use tones that are reserved for the purpose of reducing the PAR. The reservation of these reserved tones for PAR can be implemented by altering the typical startup procedures in a digital subscriber line (xDSL) system. The use of the reserved tones to reduce the PAR can be implemented using a low complexity algorithm or using an adaptive technique.12-17-2009
20100310006Signal processing apparatus, test system, distortion detecting apparatus, signal compensation apparatus, analytic signal generating apparatus, recording medium and analytic signal generating method - Provided is a reference data converting section that rearranges each of a plurality of frequency components along the frequency axis such that (i) a fundamental wave component and harmonic wave components of a reference digital signal are within a first Nyquist region of a spectrum of the reference digital signal and (ii) image components of the fundamental wave component and the harmonic wave components are within a second Nyquist region of the spectrum; and a distortion detecting section that detects the non-linear distortion of the reference digital signal caused by each harmonic wave component, based on each harmonic wave component having a prescribed order number in the spectrum in which each frequency component has been rearranged by the reference data converting section.12-09-2010
20090310705OFDM-MODULATED-WAVE OUTPUT UNIT AND DISTORTION COMPENSATING METHOD - OFDM (orthogonal frequency division multiplex)-modulated wave output unit. An amplitude extraction section (12-17-2009
20110142165Flexible self-adaptive differential system to improve transmission efficiency - A system and method for transmitting data. The system and method is configured to dynamically implement one of a differential signaling method or a single-ended signaling method during a transmission of data. The signaling method is selected based on a measured interference level during the transmission of data. The implementation of the signaling method is performed without interrupting the data transmission.06-16-2011
20120288029TRANSMITTER, TRANSMISSION METHOD, RECEIVER, RECEPTION METHOD, PROGRAM, AND INTEGRATED CIRCUIT - A transmitter 11-15-2012
20120288028Digital Pre-Distortion With Carrier Cancellation - A non-linear power amplifier generates an amplified output signal based on a pre-distorted signal generated by a digital pre-distorter (DPD) based on an input signal. A feedback path generates a feedback signal based on the amplified output signal. The feedback signal is aligned with the input signal, or vice versa, and the aligned signals are used to adaptively update the DPD processing. In particular, a linear FIR filter is estimated to minimize a cost function based on the input and feedback signals. Depending on how the filter is generated, the filter is applied to the input signal or to the feedback signal to generate the aligned input and feedback signals.11-15-2012
20120099673METHODS AND APPARATUSES FOR COMPENSATION OF I/Q IMBALANCE - Methods for compensation of imbalance between I (In-phase) and Q (Quadrature) signal paths (04-26-2012
20110299627TRANSMITTER PRE-DISTORTION ACROSS WIDE TRANSMIT POWER DYNAMIC RANGE - An integrated circuit radio transceiver and method therefor includes an integrated circuit radio transceiver operable to provide pre-distortion settings that correspond to specified analog transmit path gain levels. Further, a change in gain is provided solely through digital gain when the new gain is within a specified range. If the gain change is not within the specified range, the gain is provided by a new transmit path gain module and, if necessary, with additional digital gain. Additionally, a new pre-distortion setting is applied to correspond to the new analog transmit path gain setting.12-08-2011
20110286550PREDICTIVE CLIPPING IN MULTI-CARRIER WIRELESS COMMUNICATION SYSTEMS - A method and apparatus for selectively clipping waveforms prior to transmission in a multi-carrier wireless communication system is provided. The design includes estimating peak values of the composite multi-carrier signal, determining a local threshold set including one local threshold for each carrier based on a configurable total threshold representing a maximum aggregate signal level for a sum of all signals to be transmitted over the multiple carriers, and clipping one signal to be transmitted over one carrier when the signal exceeds a corresponding local threshold and a sum of all signals to be transmitted over multiple carriers exceed the total threshold. Alternately, the design may include estimating peak signal values for signals to be transmitted in the multi-carrier system, and selectively clipping any signal wherein at least one peak signal value exceeds a local threshold and peak signal values for a sum of all signals to be transmitted exceed a global threshold.11-24-2011
20110293039NON-CONTACT WIRELESS COMMUNICATION APPARATUS, METHOD OF WAVEFORM-SHAPING ENVELOPE CURVE, AND MOBILE ELECTRONIC DEVICE - A non-contact wireless communication apparatus that includes: an antenna section configured to receive a carrier wave; an envelope-curve shaping section configured to shape a falling waveform of an envelope curve of the carrier wave into a gradual falling waveform; and a demodulation section configured to extract the envelope curve shaped by the envelope-curve shaping section and perform envelope-curve detection by binarizing the envelope curve with a predetermined threshold value.12-01-2011
20110002414 Method Of And A Device For Precoding Transmit Data Signals In A Wireless MIMO Communication System - A method of and a precoding device and a communication device for precoding transmit data signals in a wireless Multiple-Input Multiple-Output, MIMO, channel transmission scheme for maximizing channel capacity of the MIMO system given available amounts of transmit power. The precoding is expressed in a complex precoding matrix (W), which is calculated involving individual transmit power constraints of the multiple outputs (01-06-2011
20090034651METHOD FOR FAST CONVERGENCE CALIBRATION OF RADIO-FREQUENCY TRANSCEIVERS - To more efficiently compensate for modulation imbalance, a mobile device modulates and demodulates a calibration tone and generates digital data representing modulation imbalance effects on the calibration tone. Using digital data enables modulation imbalance effects to be quickly estimated using digital signal processing techniques, increasing the number of estimates of modulation imbalance effects calculated. The modulation imbalance estimates are used to refine one or more compensation parameters which are applied to transmitted and/or received signals to compensate for errors caused by modulation.02-05-2009
20080310548ORTHOGONAL FREQUENCY DIGITAL MULTIPLEXING CORRELATION CANCELLER - A correlation canceller modulates a communication signal over a plurality of channels and an epoch aperture by a plurality of interference response signals corresponding to linear response by one or more filtering effects to generate an inversely correlated communication signal.12-18-2008
20080310547Multi-code precoding for sequence modulation - In accordance with an exemplary embodiment of the invention a method is provided to reduce a peak to average ratio with a multi-code transmission. The method includes precoding a plurality of symbols, modulating the precoded plurality of symbols using multi-codes including a plurality of orthogonal codes, and transmitting a signal comprising the modulated precoded plurality of symbols, where precoding is performed to reduce the peak to average ratio of the transmitted signal.12-18-2008
20100014608DATA TRANSMITTING AND RECEIVING METHOD USING PHASE SHIFT BASED PRECODING AND TRANSCEIVER SUPPORTING THE SAME - A method for performing a precoding based on a generalized phase shift or a precoding based on an extended phase shift in a Multi-Input Multi-Output (MIMO) system employing several sub-carriers, and a transceiver for supporting the same are disclosed. A phase-shift-based precoding matrix is generalized by multiplying a diagonal matrix for a phase shift by a unitary matrix for maintaining orthogonality between sub-carriers. In this case, a diagonal matrix part may be extended by multiplying a precoding matrix for removing interference between sub-carriers by a diagonal matrix for a phase shift. By generalization and extension of the phase-shift-based precoding, a transceiver is more simplified, and communication efficiency increases.01-21-2010
20090279640TRANSMISSION APPARATUS AND METHOD, RECEPTION APPARATUS AND METHOD, AND PROGRAM - A transmission apparatus includes a modulating section configured to modulate a baseband signal by using a carrier wave; a determining section configured to determine a pattern of the carrier wave, in accordance with a characteristic of a transmission channel on which a waveform represented by a signal value of a specific symbol is stationarily distorted according to a value of a symbol transmitted before or after the specific symbol; and a transmitting section configured to transmit a modulation signal through the transmission channel, the modulation signal being obtained by modulation using the determined carrier-wave pattern.11-12-2009
20100027713METHOD AND APPARATUS FOR SELECTING PRE-CODING VECTORS - To optimize the selection of pre-coding vectors in a multi-user MIMO system, the present invention provides a method for selecting pre-coding vectors in a base station, comprising the steps of: transmitting a plurality of pilot signals without being precoded to the plurality of terminals; receiving a plurality of feedback signals from the plurality of terminals, wherein at least one feedback signal includes a plurality of recommended pre-coding vector information and a plurality of channel status information, and each of the channel status information corresponds to a recommended pre-coding vector information; generate a pre-coding codebook based on the plurality feedback signals, wherein at least one pre-coding vector in the pre-coding codebook is determined based on a correlation coefficient between at least two recommended pre-coding vectors; and performing a transmission operation using the pre-coding codebook. Through considering the correlation among pre-coding vectors and different channel status information corresponding to different pre-coding vectors, be used to extend the selection range of pre-coding vectors and improve the total transmission rate of the whole system and system capacity.02-04-2010
20090245416INPUT/OUTPUT DRIVER SWING CONTROL AND SUPPLY NOISE REJECTION - In general, in one aspect, the disclosure describes an apparatus having an averager to receive differential output voltages of a transmitter and generate an average transmitter output voltage. A comparator is to compare the average transmitter output voltage to a reference voltage and generate a difference therebetween. An integrator is to integrate the difference between the average transmitter output voltage and the reference voltage over time. The integrated difference is fed back to the transmitter to bias the transmitter.10-01-2009
20100124298DATA TRANSMITTING SYSTEM - A data transmitting system is provided that includes a transmitter that suppresses coupling noise by being operated using a differential voltage driving scheme at the time of transmitting data and being operated using a common voltage driving scheme by equalizing potential of a pair of transmission lines during a transition interval; and a receiver that is connected to the transmitter through the pair of transmission lines and recovers the data by sensing the voltage difference in signals of the pair of transmission lines.05-20-2010
20120033760EXTENDED NON-RETURN-TO-ZERO SERIAL CHANNEL SIGNALING - Methods and apparatus for serial channel operation are disclosed. An N+1-level signaling scheme is used to transmit N staggered but overlapping NRZ sub-sequences concurrently on a serial channel. Each sequence has a bit rate R and an essential bandwidth of R Hz. The combined bit rate of the channel is N×R, but due to a lack of correlation between the sub-sequences, the essential bandwidth remains approximately R Hz. The signaling scheme also contains redundancy that allows some errors to be detected and/or corrected. Other embodiments are also described and claimed.02-09-2012
20100195764OFDM TRANSMISSION APPARATUS, OFDM RECEIVING APPARATUS AND INTERLEAVING METHOD - In order to provide a simpler interleaving operation of an OFDM (Orthogonal Frequency Division Multiplexing) operation than conventional techniques, and in order to improve practical effectiveness of the retransmission, an OFDM transmission apparatus which transmits transmission data after conducting OFDM operation, includes: an interleave portion which, in a step before a serial/parallel conversion for a carrier modulation, the transmission data is randomized based on a random number generated by using a predetermined random number generation method; and a control portion which controls the interleave portion to conduct different randomization operations on the transmission data with regard to a retransmission and initial transmission.08-05-2010
20090207936REAL AND COMPLEX SPECTRAL SHAPING FOR SPECTRAL MASKS IMPROVEMENTS - An integrated circuit radio transceiver and method therefor includes an integrated circuit radio transceiver operable to provide specified gain levels and transmit path filter responses to correspond with a selected power spectral density mask. Changes in gain may be provided solely digital gain changes or may include analog gain module gain changes. A transmitter selects from one of at least three masks to reduce or eliminate spectral regrowth out of band to satisfy EVM requirements. Non-symmetric masks may also be selected for special circumstances to prevent out of band spectral regrowth. Additionally, pre-distortion settings are applied to in-band frequencies to correspond to the selected PSD mask.08-20-2009
20090207935TRANSMITTER PRE-DISTORTION ACROSS WIDE TRANSMIT POWER DYNAMIC RANGE - An integrated circuit radio transceiver and method therefor includes an integrated circuit radio transceiver operable to provide pre-distortion settings that correspond to specified analog transmit path gain levels. Further, a change in gain is provided solely through digital gain when the new gain is within a specified range. If the gain change is not within the specified range, the gain is provided by a new transmit path gain module and, if necessary, with additional digital gain. Additionally, a new pre-distortion setting is applied to correspond to the new analog transmit path gain setting.08-20-2009
20090207938Method and apparatus for distorting input signal of digital predistortion (DPD) power amplifier in wireless communication system - A predistortion apparatus of a Digital Pre-Distortion (DPD) power amplifier in a wireless communication system is provided. A method for predistorting an input signal at the predistortion apparatus of the DPD power amplifier includes dividing one or more bits constituting the input signal into upper bits and lower bits; generating two successive address values using the upper bits; generating distortion values of the upper bits corresponding to the address values; calculating a distortion value of the lower bits; and calculating a distortion signal value corresponding to the input signal using the distortion values of the upper bits and the distortion bit of the lower bits. Hence, the time taken to update the LUT can be shortened, the cost can be lowered by the reduced memory capacity, and the power consumption can be decreased.08-20-2009
20090207937Method and System for Optimizing Quantization for Noisy Channels - Methods are described for configuring a quantizer to achieve improved end-to-end distortion performance when transmitting encoded source data over a noisy channel. The codebook and partitioning are selected using an iterative process of determining an updated codebook and an updated partition space, where the updated codebook is based, in part, on the average symbol error probability of the channel. Complete knowledge of the transitional probabilities of the channel is not required. Variants of the iterative process are described.08-20-2009
20090225899Compensation of Diagonal ISI in OFDM Signals - A method and apparatus for compensating for ISI is described herein. A transmitter and receiver work together to develop pulse shaped OFDM symbols with reduced inter-channel ISI between pulse-shaped OFDM symbols transmitted on different sub-carriers at the same time, and inter-block ISI between pulse-shaped OFDM symbols transmitted on the same sub-carrier at different times. In addition, a pre-compensation element in the transmitter and/or a post-compensation element in the receiver compensate for diagonal ISI occurring between pulse-shaped OFDM symbols transmitted on different sub-carriers at different times.09-10-2009
20110170633TRANSMISSION METHOD TAKING ECHO INTO ACCOUNT - A transmission method and device are provided for taking account of an echo. The method and the device adapt the send power mask to take account of an echo's power estimated on the basis of an echo function, the echo being due to the transmission by a transmission channel of a sequence sent by the sender device.07-14-2011
20110170631METHOD AND APPARATUS FOR MAPPING/DEMAPPING RESOURCE IN WIRELESS COMMUNICATION SYSTEM - A method and apparatus for mapping/demapping a resource efficiently in a wireless communication system are provided. A resource mapping method of a transmitter in a wireless communication system includes precoding pairs of symbols, arranging the pairs of precoded symbols adjacently in a resource block, and transmitting the pairs of precoded symbols in the resource block.07-14-2011
20080317167Generation of a Transmission Signal - The present disclosure relates to different techniques of generation of a transmission signal, as for example, a transmitting apparatus for transmitting a communication signal and a method for transmitting a communication signal.12-25-2008
20090262861Feedback Compensation Detector For A Direct Conversion Transmitter - A feedback compensation detector for a direct conversion transmitter includes a baseband processor, a direct up-converter, an antenna, and an impairment detection and compensation feedback circuit. The baseband processor generates an in-phase (I) baseband signal and a quadrature-phase (Q) baseband signal. The direct up-converter is coupled to the baseband processor, and combines the I and Q baseband signals with an RF carrier signal to generate an RF output signal. The antenna is coupled to the direct up-converter, and transmits the RF output signal. The impairment detection and compensation feedback circuit is coupled to the RF output signal and the I and Q baseband signals. The impairment detection and compensation feedback circuit down-converts the RF output signal to generate an intermediate frequency (IF) signal, measures as least one signal impairment in the IF signal, and pre-distorts the I and Q baseband signals to compensate for the measured signal impairment.10-22-2009
20110170632Digital Up-Converter and N-Channel Modulator With Flexible Association of QAM Generation Resources to Narrowcast and Broadcast Frequencies - Embodiments of a digital up-converter and an N-channel modulator are provided herein. The embodiments of the digital up-converter, in combination with the N-channel modulator, are capable of efficiently filling the spectrum of one or more RF signals with one or more types of information signals. For example, the digital up-converter can fill the spectrum of one or more RF signals with both broadcast and narrowcast video and data signals. In addition, the digital up-converter is capable of flexibly mapping the information signals to one or more channels of the one or more RF signals using a novel, three-level switching architecture.07-14-2011
20110170630Digital Predistortion Training System - Techniques are provided herein for training a digital predistortion module in a wireless communication device. At a controller apparatus that is capable of communicating with a plurality of wireless devices, a particular wireless device that requires adjustment of predistortion parameters is identified. The controller also identifies one or more participating wireless devices to participate in a training session during which the particular wireless device makes test transmissions and the one or more participating wireless devices make measurements based on reception of the test transmissions sent by the particular wireless device. The controller apparatus sends commands to the particular wireless device and to the one or more participating wireless devices to initiate the training session. The controller receives measurement data from the one or more participating wireless devices based on reception of the test transmissions from the particular wireless device during the training session. The controller apparatus determines predistortion parameters for use by the particular wireless device based on the measurement data received from the one or more participating wireless devices.07-14-2011
20090296854RADIO WAVE GENERATOR, WIRELESS COMMUNICATION SYSTEM, RADIO INTERFERENCE PREVENTION CONTROL METHOD, AND RADIO INTERFERENCE PREVENTION CONTROL PROGRAM - The present invention is to provide a wireless communication system that is capable of preventing occurrence of radio interference caused by radio wave used by a radio wave generator without requiring any improvement of existing wireless devices. The wireless communication system of the present invention includes: a radio wave generator (12-03-2009
20090296853Rotation Direction Control for Phase Modulation - A transmitter architecture and method of modulation that include a rotation-direction control circuit for varying the direction of rotation of phase transitions of a phase modulation based on the occurrence of a predetermined pattern of input data. This variation of rotation direction by the rotation-direction control circuit maintains the output spectrum of a modulated signal within the spectral mask requirements of an associated communications standard and thereby enables the use of non-linear power amplifiers in applications that generally require linear amplifiers.12-03-2009
20100111223METHOD AND APPARATUS FOR CHOOSING A MODULATION AND CODING RATE IN A MULTI-USER, MIMO COMMUNICATION SYSTEM - A method and apparatus for choosing a modulation and coding rate in a MU-MIMO communication system is provided herein. During operation, a node will determine the MCR to feed back to the base even though the mobile does not know which of the possible interferers (if any) will be using the same time/frequency resources as the mobile. This takes place via the mobile node calculating best antenna weights (codebook choice) for each group of subcarriers that can be potentially used by the mobile. Transmit weights v for each interferer are then determined and the weights are utilized to determine a best modulation and coding rate for the mobile.05-06-2010
20100111222Digital Modulation Jitter Compensation for Polar Transmitter - This disclosure relates to clock jitter suppression in digital to analog converter generated pulses for a polar transmitter.05-06-2010
20110200141METHOD AND SYSTEM FOR AN EFFICIENT CHANNEL QUANTIZATION METHOD FOR MIMO PRE-CODING SYSTEMS - A method and system for processing communication signals is provided and may comprise, minimizing a cost function in a MIMO pre-coding system by choosing a smallest scalar cost from a plurality of scalar costs, wherein each one of the scalar costs is generated from one or more sums and one or more products of elements of a product matrix, and wherein the product matrix is generated from one of the plurality of unitary matrices, a matrix comprising the channel estimate, and their respective Hermitian Transposes. The codebook is selected based on the minimized cost function. The channel estimate is quantized onto the selected codebook.08-18-2011
20080212712Power Control Device - The invention relates to a power control device for a power output stage. A forward signal corresponding to a wave advancing on a wall feed line and a return signal corresponding to a wave returning on the wave feed line is obtained by means of a directional coupler and is supplied to a controller after narrow-band selection for controlling the output of the power output stage. Narrow-band selection is not carried out in the baseband but on an intermediate frequency level above the baseband.09-04-2008
20110268225ORTHOGONAL DIFFERENTIAL VECTOR SIGNALING - Using a transformation based at least in part on a non-simple orthogonal or unitary matrix, data may be transmitted over a data bus in a manner that is resilient to one or more types of signal noise, that does not require a common reference at the transmission and acquisition points, and/or that has a pin-efficiency that is greater than 50% and may approach that of single-ended signaling. Such transformations may be implemented in hardware in an efficient manner. Hybrid transformers that apply such transformations to selected subsets of signals to be transmitted may be used to adapt to various signal set sizes and/or transmission environment properties including noise and physical space requirements of given transmission environments.11-03-2011
20100220812MULTI-CARRIER TRANSMISSION APPARATUS AND PEAK SUPPRESSION METHOD - Peak power is reduced without causing degradation of EVM. A multi-carrier transmission apparatus comprises: a first amplitude suppression unit suppressing amplitude of an oversampled multi-carrier signal; a first Fourier transform unit transforming an output signal of the first amplitude suppression unit into a frequency domain; a first signal suppression unit suppressing a signal outside a band of the output signal from the first Fourier transform unit under a predetermined condition; and a first inverse Fourier transform unit receiving a multi-carrier signal with respect to a signal within the band, receiving the output signal of the first signal suppression unit with respect to a signal outside the band, and inverse Fourier transforming these received signals.09-02-2010
20080273624METHOD AND SYSTEM FOR CQI/PMI FEEDBACK FOR PRECODED MIMO SYSTEMS UTILIZING DIFFERENTIAL CODEBOOKS - Aspects of a method and system for CQI/PMI feedback for precoded MIMO systems utilizing differential codebooks may include generating one or more feedback messages for one or more Channel Quality Indicator (CQI) reporting units based on at least channel state information associated with the one or more CQI reporting units. One or more differential feedback messages may be generated for one or more Pre-coding Matrix Index (PMI) reporting units based on at least channel state information associated with the one or more PMI reporting units, wherein the one or more PMI reporting units span a useable bandwidth. A bandwidth and a feedback period may be assigned to each of the one or more CQI reporting units and the one or more PMI reporting units to define the one or more CQI reporting units and the one or more PMI reporting units.11-06-2008
20100002802OFDM TRANSMITTING AND RECEIVING SYSTEMS AND METHODS THEREOF - An orthogonal frequency division multiplexing (OFDM) transmission system is provided which includes a data processing unit which generates a transmission signal using a plurality of tones including a reserved tone, a storage unit which stores Peak Reduction Kernel information according to the type of data symbol, and a compensation unit which retrieves the Peak Reduction Kernel information according to the type of data symbol from the storage unit and causes the retrieved information to be carried by the reserved tone included in the transmission signal. Therefore, a Peak-to-Average Power Ratio (PAPR) can be efficiently compensated.01-07-2010
20080240287Transmitter - A transmitter capable of suppressing a peak of a transmission signal includes a frequency domain acquisition unit for obtaining a frequency domain signal from the signal for transmission; and a level control unit for controlling a level of the frequency domain signal obtained by the frequency domain acquisition unit to suppress a peak in a time domain transmission signal. Further, the transmitter includes a time domain conversion unit for converting the frequency domain signal into the time domain transmission signal whose level has been controlled by the level control unit; and a transmission unit for transmitting the time domain transmission signal.10-02-2008
20130010894Selective Peak Power Reduction - A communication system comprising signal processing circuitry and up-conversion circuitry. The signal processing circuitry is configured to: i) generate a first signal of a first modulation type and a second signal of a second modulation type; ii) combine the first and second signals to form a combined input signal; iii) generate peak reduction distortion based on the combined input signal; iv) select a portion of the peak reduction distortion that corresponds to a first frequency band; and v) apply the selected portion of the peak reduction distortion in the first frequency band of the combined input signal to provide a combined output signal. The up-conversion circuitry up-converts the combined output signal to an RF signal for transmission.01-10-2013
20100142643MULTI-CARRIER SIGNAL TRANSMITTER, MULTI-CARRIER SIGNAL RECEIVER, AND METHOD OF TRANSMITTING AND RECEIVING MULTI-CARRIER SIGNAL - A multi-carrier signal transmitter includes a multi-carrier modulation circuit, a power converter, a frequency converter and an interference protection determination circuit, and that the interference protection determination circuit determines a difference in power levels between a higher layer component and a lower layer component of multi-carrier signals in a manner to avoid digital interference. The power converter converts a power level of the multi-carrier signals when necessary based on a data of the determination, and the frequency converter converts a center frequency band of the multi-carrier signals when necessary based on the data of the determination. The digital interference of the hierarchical multi-carrier signals can be prevented.06-10-2010
20080240286SIGNAL TRANSMISSION SYSTEM, METHOD AND APPARATUS - The invention discloses a signal transmission system, method and apparatus, and relates to the fields of communications and broadcast television. It is intended to reduce the hardware cost of the signal transmitting system. The system according to the invention is based on a personal computer operating system, and comprises a computer and a transmitting equipment, said computer comprising a signal source processing module for processing a signal source, a channel encoding and modulating module for channel encoding and modulating of the processed signal source, and an interface module for outputting the data encoded and modulated by the channel encoding and modulating module, and said transmitting equipment being arranged to receive data from the interface module, process the received data into a radio frequency RF signal, and then transmit the RF signal. The invention may be applicable to a transmitter of broadcast television.10-02-2008
20110268226MEMORY EFFECT CANCELLER, TRANSMITTER, AND MEMORY EFFECT CANCELLING METHOD - A memory effect canceller includes a sample obtaining section that obtains a plurality of discrete-time samples of a transmission signal supplied to a power amplifier that amplifies a transmission signal, a signal generation section that generates a correction signal that is a weighted linear combination, using given weighting coefficients, of partial derivatives of a transfer function of the power amplifier, wherein the transfer function has been defined in advance with a plurality of discrete-time samples as input variables, and wherein the partial derivatives are based on the discrete-time samples obtained by the sample obtaining section at respective times, and a signal correction section that corrects an output signal of the power amplifier based on the correction signal.11-03-2011
20120140850Codebook Method for a Multiple Input Multiple Output Wireless System - A method for wireless encoding includes encoding wireless multiple input and multiple output signals in accordance with a codebook being one of a discrete codebook restricting elements of codebook entries to be within a predetermined finite set of complex numbers and a constant amplitude codebook including each entry in its codebook having equal column norm and equal row norm. In a preferred embodiment the digital codebook further includes restricting elements of a finite set in the discrete codebook to be in the form of k06-07-2012
20120069931MULTI-BAND POWER AMPLIFIER DIGITAL PREDISTORTION SYSTEM AND METHOD - Traditionally, for multi-band communication systems, independent signal chains for each of the different bands are employed. By using such an architecture, there are a large number of components, and there is substantial power consumption. Here, transmit processor is provided that enables transmission across multiple bands using few components (namely, fewer signal chains), while also provided for digital predistortion.03-22-2012
20080317165Systems and methods of calibrating a transmitter - In one embodiment the present invention includes a method of calibrating the frequency response of a transmitter comprising generating a plurality of calibration tones across a frequency range, coupling the plurality of calibration tones to an input of said transmitter, detecting the plurality of calibration tones at an output in said transmitter, and in accordance therewith, generating a plurality of calibration values, receiving digital data to be transmitted, the digital data comprising a plurality of frequency components in said frequency range, and calibrating said frequency components of said digital data using the calibration values.12-25-2008
20110222629PRE-CODING FOR DOWNLINK CONTROL CHANNEL - Precoding information is provided (implicitly or explicitly) to a particular user equipment UE. Closed-loop spatial coding for a control channel is selected for the particular user equipment, and at least one control channel element CCE is determined within the particular user equipment's search space of the control channel that is associated with the provided precoding information. The determined at least one CCE is spatially encoded using the provided precoding information to schedule radio resources for the particular user equipment. The UE determines a search space for a control channel, and from received radio resource control signaling determines at least one CCE within the search space that is to be encoded with closed-loop spatial coding. The UE decodes the determined at least one CCE within the search space using a closed-loop spatial decoding with precoding information associated with the at least one CCE to find radio resources scheduled for the particular UE.09-15-2011
20090052574MEDIA ACCESS CONTROL ADAPTATION METHOD FOR MICROWAVE INTERFERENCE - Disclosed is a Media Access Control (MAC) adaptation method for adapting transmission of packets by a wireless device in response to interference in a wireless medium. On detecting interference in the wireless medium, the wireless device triggers sensing of wireless spectrum to determine presence of a periodic interference signal. A first energy level and a second energy level of the periodic interference signal are estimated and a threshold energy level is set between the first energy level and the second energy level for transmission of packets by the wireless device. Based on the threshold energy level and a current energy level in the wireless medium, the wireless device transmits packets over the wireless medium.02-26-2009
20090097590Distortion-Compensated RF Transmitter and Method Therefor - An RF transmitter (04-16-2009
20130121439Design of a Global Codebook for Coordinated Multi-Point Processing - In accordance with one or more embodiments of the present disclosure a method for generating a codebook comprises generating a plurality of wireless communication channel representations. The method further comprises generating a precoding matrix for each of the plurality of wireless communication channel representations. The method additionally comprises performing a clustering operation on the precoding matrices to determine a plurality of centroids associated with the precoding matrices. Also the method includes determining codewords based on the centroids and generating a codebook based on the codewords.05-16-2013
20130121440METHOD AND APPARATUS FOR IMPLEMENTING DIGITAL BASEBAND PREDISTORTION - An apparatus for implementing digital baseband predistortion includes a transmission channel including a digital-to-analog converter, a modulator, an amplifier and a power amplifier, and further includes a feedback channel analog part including a diode detector, a filter and an analog-to-digital converter, and a feedback channel digital part including a predistorter, a mode obtaining unit, a predistortion coefficient generator and a feedback correcting unit. The diode detector is configured to obtain an envelope of an output signal of the power amplifier. Embodiments of the present invention further provide a method for implementing digital baseband predistortion by applying the foregoing single-chip. Due to a simple structure of the diode detector, not only the number of radio frequency devices on the feedback channel is reduced, implementation complexity of hardware is lowered, power consumption is reduced, but also a feedback channel analog part may be integrated onto the single-chip.05-16-2013
20130121441TRANSMISSION METHOD, TRANSMISSION DEVICE, RECEPTION METHOD, AND RECEPTION DEVICE - Provided is a precoding method for generating, from a plurality of baseband signals, a plurality of precoded signals to be transmitted over the same frequency bandwidth at the same time, including the steps of selecting a matrix F[i] from among N matrices, which define precoding performed on the plurality of baseband signals, while switching between the N matrices, i being an integer from 0 to N−1, and N being an integer at least two, generating a first precoded signal z05-16-2013
20110142166METHOD OF FEEDBACK INFORMATION TRANSMISSION, METHOD AND APPARATUS OF DATA TRANSMISSION IN A WIRELESS COMMUNICATION SYSTEM HAVING MULTIPLE ANTENNAS - A method of data transmission in a wireless communication system having multiple antennas is disclosed. A method of data transmission from a transmitter of a wireless communication system which uses multiple antennas comprises receiving identification information of a precoding matrix from a receiver, the precoding matrix being selected from a codebook generated using a plurality of first matrixes generated by multiplying a discrete fourier transform (DFT) matrix by each of a plurality of phase shift matrixes; precoding data to be transmitted, by using a precoding matrix indicated by the identification information; and transmitting the precoded data to the receiver by using the multiple antennas.06-16-2011
20100054364DIGITAL PRE-DISTORTION TECHNIQUE USING NONLINEAR FILTERS - A system and method for stabilizing a coefficient set used by a digital predistortion (DPD) engine to apply pre-distortion to a transmit signal and cancel distortion generated by a distorting element or distorting system when transmitting the transmit signal, including obtaining an initial coefficient set; rotating the initial coefficient set to maintain a phase of fundamental components (w03-04-2010
20090257525SOFTWARE-BASED SPREAD SPECTRUM SIGNAL PROCESSING - A proposed data processing device includes at least two processor units, which each is adapted to process digitized precorrelation navigation satellite signal data as well as to process alternative data and/or signals relating to at least one function being uncorrelated with the satellite signal data. The device includes at least one data buffer adapted to store data sets, where each set includes a number of instances of the satellite signal data. A control module in the device controls execution of a processing job with respect to a stored data set by allocating individual processing tasks to at least one of the at least two processor units based on a current processing load on each processor unit.10-15-2009
20120195395EVM Pooling for Multi-Standard and Multi-Carrier Systems - Error vector magnitude (EVM) is pooled and adaptively distributed among carriers in a multi-standard or multi-carrier system to reduce peak to average power ratios (PAPR) without exceeding EVM limits. Correction tone injection is used to reduce PAPR. The amplitude of each correction tone, and number of correction tones assigned to a carrier, are adjusted to control the EVM and out-of-band distortion of each carrier, to comply with EVM limits imposed by the respective radio access technology.08-02-2012
20120195394DIGITAL BROADCASTING SYSTEM AND METHOD OF PROCESSING DATA - A digital broadcast transmitter includes a block processor encoding mobile service data at a coding rate of 1/H and first interleaving the encoded mobile service data, wherein H is an integer equal to or greater than 2, a deinterleaver deinterleaving the first-interleaved mobile service data to output a first data group, an interleaver second interleaving the first data group to output a second data group including the mobile service data, a trellis encoding module trellis encoding data of the second data group, and a multiplexer multiplexing the trellis-encoded data with segment synchronization data and field synchronization data, wherein the block processor is concatenated with the trellis encoding module.08-02-2012
20120195393SUPPORT FOR RETRANSMITTING A TRANSPORT BLOCK WITH A DIFFERENT NUMBER OF LAYERS THAN A PREVIOUS TRANSMISSION ATTEMPT - A method of conveying transport block size (TBS) information includes determining TBS parameters for a wireless transmission of data between a first node and a second node based on a first number of transmission layers associated with the wireless transmission. The method also includes generating a control message indicating the TBS parameters and transmitting the control message to the second node. The method also includes transmitting a transport block to the second node in accordance with the TBS parameters indicated by the control message. The transport block is transmitted over a first number of transmission layers. The method also includes retransmitting the transport block to the second node in accordance with the TBS parameters indicated by the control message. The transport block is retransmitted over a second number of transmission layers that differs from the first number of transmission layers.08-02-2012
20120140848Transmitting Terminal and Transmit Antenna Selecting Method Thereof - A transmitting terminal includes a signal processing unit, M06-07-2012
20090316827AMPLITUDE SUPPRESSING APPARATUS AND SIGNAL TRANSMITTING APPARATUS - An amplitude suppressing apparatus includes a differential circuit that calculates a differential value of amplitude of an input signal at a point when the amplitude reaches a predetermined threshold. The amplitude suppressing apparatus also includes an amplitude suppressing circuit that suppresses the amplitude of the input signal on the basis of the differential value calculated by the differential circuit.12-24-2009
20100150265ANTENNA SELECTION METHOD AND RADIO COMMUNICATION DEVICE - There is provided an antenna selection method and others capable of reducing a transmission error ratio and a calculation amount. In this method, a reception side feeds back M-column channel estimation matrix H_e to a transmission side (ST06-17-2010
20090279639DIGITAL BRANCH CALIBRATOR FOR AN RF TRANSMITTER - The present invention provides a digital (computational) branch calibrator which uses a feedback signal sensed from an RF transmit signal path following the combining stage of LINC circuitry of a transmitter to compensate for gain and phase imbalances occurring between branch fragment signals leading to the combiner. The calibrator feeds a quiet (zero) base band signal through the transmit path during the calibration sequence (i.e. a period when data is not transmitted) and adjusts the phase and gain of the phasor fragment signals input thereto by driving the sensed output power to zero. The calibration is performed by alternating phase and gain adjustments with predetermined (programmable) and multiple update parameters stages (speeds). A baseband modulation is preferably used to distinguish false leakage (e.g. due to local oscillator, LO, feed through and DC offset in the base band Tx) from imbalance leakage.11-12-2009
20100183091METHOD FOR TUNING A DIGITAL COMPENSATION FILTER WITHIN A TRANSMITTER, AND ASSOCIATED DIGITAL COMPENSATION FILTER AND ASSOCIATED CALIBRATION CIRCUIT - A method for tuning a digital compensation filter within a transmitter includes: obtaining at least one loop gain calibration result by performing loop gain calibration based upon signals of at least a portion of the transmitter, and obtaining at least one resistance-capacitance (RC) detection result by performing RC detection on the portion of the transmitter without individually measuring resistance values of resistors therein and capacitance values of capacitors therein, wherein the RC detection result corresponds to a detected value representing a product of a resistance value and a capacitance value, and the digital compensation filter includes a gain compensation module and an RC compensation module; and tuning the digital compensation filter by respectively inputting the loop gain calibration result and the RC detection result into the gain compensation module and the RC compensation module. An associated digital compensation filter and an associated calibration circuit are also provided.07-22-2010
20090116582INTERPOLATION METHOD AND APPARATUS FOR INCREASING EFFICIENCY OF CROSSTALK ESTIMATION - Techniques are disclosed that efficiently obtain channel crosstalk estimates in DSL systems and other communication systems that may include unsynchronized channels. For example, a method includes obtaining a first set of estimated measures of crosstalk for a first portion of a plurality of communication channels over which data signals are to be transmitted from a transmitter to a plurality of receivers, and interpolating a second set of estimated measures of crosstalk for a second portion of the plurality of communication channels based on the first set of estimated measures of crosstalk. The first portion of the plurality of communication channels may be a subset of the plurality of communication channels and the second portion of the plurality of communication channels is a remainder of the plurality of communication channels. Each estimated measure of crosstalk may relate to at least one tone associated with at least one of the plurality of communication channels.05-07-2009
20100183090MULTI-ANTENNA TRANSMITTER FOR MULTI-TONE SIGNALING - Embodiments of a communication circuit are described. This communication circuit includes an input node (07-22-2010
20090116583HDMI communication over twisted pairs - A method of transmitting a data stream over a communication channel, the method comprising: providing symbol sets having different numbers of symbols; modulating data in the data stream that warrant different degrees of protection against noise onto symbols from symbol sets having different numbers of symbols, wherein which symbol set given data in the stream is modulated onto is independent of symbol sets onto which other data in the data stream is modulated onto; and transmitting the symbols.05-07-2009
20090046806WIRELESS COMMUNICATION METHOD IN MULTIANTENNA COMMUNICATION SYSTEM - A wireless communication method in which use of the HERQ technique brings about an improved throughput of data transmission. In this method, if the number of retransmissions n is equal or below an upper limit value (ST02-19-2009
20100177847DYNAMICALLY SELECTING METHODS TO REDUCE DISTORTION IN MULTI-CARRIER MODULATED SIGNALS RESULTING FROM HIGH PEAK-TO-AVERAGE POWER RATIOS - In one embodiment, an algorithm dynamically selects a method for reducing distortion in a multi-carrier modulated signal, such as an orthogonal frequency division multiplexing (OFDM) signal. The algorithm directs a transmitter to transmit peak-to-average power ratio (PAPR)-reduction signals over reserved tones (i.e., frequencies) if reserved tones are available. If reserved tones are not available, then the algorithm directs the transmitter to transmit PAPR-reduction symbols over free tones if free tones are available. If the free tones for this transmitter are used by adjacent transmitters, then interference-reduction techniques may be used to reduce interference with the adjacent transmitters. If reserved tones and free tones are not available, then the transmitter may use an alternative method to reduce distortion, such as successive clipping and filtering. In another embodiment, the transmitter may transmit PAPR-reduction symbols over both free and reserved tones, if available.07-15-2010
20130215999METHOD FOR COMPENSATING MISMATCH OF IN-PHASE SIGNAL AND QUADRATURE SIGNAL OF TRANSMITTER/RECEIVER - A method for compensating mismatches of an in-phase signal and a quadrature signal of a transmitter/receiver is provided. The method includes: receiving a plurality of test signals to generate two groups of factors, respectively, where each group of factors is applied to two multipliers utilized for compensating a gain mismatch and a phase mismatch of the in-phase signal and the quadrature signal of the transmitter/receiver; then calculating a delay mismatch of the in-phase signal and the quadrature signal according to the two groups of factors.08-22-2013
20100226458OFDM Spectral Control - A method and apparatus for configuring a variable filter in an OFDM transmitter based on the number of subcarrier frequencies selected for the input data block is described herein. An exemplary OFDM transmitter comprises a control unit, OFDM modulator, and variable filter. The control unit selects the number of subcarriers for the input data block, and configures one or more filter properties for the variable filter based on the selected number of subcarriers. The modulator, which has a size greater than the selected number of subcarriers, pads an input data block generated for the selected number of subcarriers to generate an expanded data block having a size equal to the size of the modulator, and modulates the expanded data block to generate an OFDM signal. The filter, as configured by the control unit, filters the OFDM signal.09-09-2010
20120140849FREQUENCY REUSE IN WIRELESS POINT-TO-POINT COMMUNICATION SYSTEMS - A method for interference reduction in transmission of at least two single carrier frequency continuous communication beams including producing a first communication signal for a first digital communication link, producing a second communication signal for a second digital communication link, transmitting the first communication signal over a first continuous communication beam at a first frequency, transmitting the second communication signal over a second continuous communication beam at the first frequency, characterized by modifying the first communication signal using transmitter interference cancellation.06-07-2012
20100208842DMT SYMBOL REPETITION IN THE PRESENCE OF IMPULSE NOISE - With the current initialization procedures defined in the VDSL and ADSL standards, even though the xDSL system could operate in Showtime in an impulse noise environment where symbols are being corrupted, the transceivers would not be able to reach Showtime because initialization would fail due to initialization message failure. Through the use of an improved initialization procedure for communication systems, operation in environments with higher levels of impulse noise is possible.08-19-2010
20120140851METHOD OF MAINTAINING COHERENCY OF A PRECODING CHANNEL IN A COMMUNICATION NETWORK AND ASSOCIATED APPARATUS - In prior art, selection of precoding granularity is affected by two inter-restricting factors, i.e., precoding accuracy and channel estimation at a mobile terminal. To solve this problem, the present invention provides a method of maintaining coherency of a precoding channel in a communication network and an associated apparatus. During precoding, this method takes into account both channel coherency and system capacity. A base station adjusts phase and/or amplitude of a precoding matrix corresponding to each precoded unit to maintain coherency of associated information of the overall precoding channel. The associated information of the precoding channel includes, for example, CSI or eigenvalue matrix of the precoding channel. Afterwards, a mobile terminal performs channel estimation based on reference signals of multiple precoded units, thereby eliminating the limitation in prior art that a mobile terminal can perform channel estimation only within one or more resource block limited by a precoding granularity.06-07-2012
20100246715WIRELESS COMMUNICATION METHOD AND APPARATUS - In a wireless communications system, a method of processing data prior to transmission thereof to a plurality of stations. The method includes determining a channel matrix using a plurality of weighted channel responses, each of which is associated with one of the plurality of stations and weighted by a gain factor corresponding to the station, wherein the gain factor is inversely proportional to a noise power of the station. The data is then processed in accordance with a precoding scheme using the determined channel matrix.09-30-2010
20110235749ACTIVE ANTENNA ARRAY HAVING ANALOGUE TRANSMITTER LINEARISATION AND A METHOD FOR PREDISTORTION OF RADIO SIGNALS - An active antenna array for a mobile communications network comprising: a digital signal processor connected to a plurality of digital-to-analogue conversion blocks; a plurality of antenna elements; a plurality of transmission paths, whereby an individual one of the plurality of transmission paths is connected between an individual one of the digital-to-analogue conversion blocks and an individual one of the plurality of antenna elements, whereby an individual one of the plurality of transmission paths comprises a predistorter and a coupler; a plurality of paths connected between an individual one of the couplers and a single combiner; a single feedback path connected between the single combiner and a predistorter coefficient calculation unit; and a coefficient update path connected between the predistorter coefficient calculation unit and at least an individual one of the predistorters.09-29-2011
20090323856TRANSMIT-CANCELING TRANSCEIVER RESPONSIVE TO HEAT SIGNAL AND METHOD THEREFOR - A transmit-canceling transceiver (12-31-2009
20110033010APPARATUS AND METHOD FOR SELECTION OF PRECODING MATRIX - The present invention relates to an apparatus and a method for selection of a precoding matrix. In the present invention, a precoding matrix to enable an effective signal-to-noise ratio (ESNR) to have a maximum value with respect to a signal vector that requires retransmission is selected in a codebook and fed back to a transmitter. Accordingly, since the effective signal-to-noise ratio has the maximum value after the signal vector is retransmitted, it is possible to minimize a reception error probability of retransmission.02-10-2011
20090141828DISTORTION COMPENSATION CIRCUIT AND METHOD - The invention relates to methods and circuits for compensating linear in-band distortions such as those occurring in RF circuits of broad band communication systems. A low-rate sampling is used to collect statistical information about a modulated signal after it passed through the distorting circuits, which is then compared to reference statistical information for the modulated signal to iteratively adjust a frequency response of an equalizing linear filter inserted into the signal path so as to compensate for the distortions.06-04-2009
20090110112Method and Apparatus for Reducing Phase Noise in Orthogonal Frequency Division Multiplexing Systems - Method and apparatus for reducing phase noise from a multi-carrier modulation (MCM) system, such as an orthogonal frequency division multiplexing (OFDM) system, by transmitting known data on a sub-carrier at a power level adapted to allow for accurate estimation. Preferably, the sub-carrier is the DC sub-carrier.04-30-2009
20110235748ACTIVE ANTENNA ARRAY HAVING ANALOGUE TRANSMITTER LINEARISATION AND A METHOD FOR PREDISTORTION OF RADIO SIGNALS - An active antenna array comprises: a digital signal processor connected to a plurality of digital-to-analogue conversion blocks; a plurality of antenna elements; a plurality of transmission paths, whereby an individual one of the plurality of transmission paths is connected between an individual one of the plurality of digital-to-analogue conversion blocks and an individual one of the plurality of antenna elements, whereby an individual one of the plurality of transmission paths comprises a predistorter and a coupler; and a plurality of feedback paths connected between an individual one of the couplers and an individual one of the predistorters, wherein an individual one of the plurality of feedback paths comprises a predistorter coefficient calculation unit. A method for predistorting radio signals is also disclosed.09-29-2011
201301290163-LEVEL BRIDGE DRIVER WITH SINGLE SUPPLY AND LOW COMMON MODE EMI EMISSION - In one embodiment, a circuit, having a single supply, is provided to transmit a wireless signal with low common mode electromagnetic interference (EMI) emission. The circuit can achieve common mode attenuations of 40 dB or greater as a result of the symmetric built circuit. Also included is a system that includes a transmission circuit and a receiver circuit, and a method of using such a system.05-23-2013
20110235750BEAMFORMING METHOD AND APPARATUS USING A RATE SPLITTING SCHEME IN A MULTI-CELL MULTI-ANTENNA INTERFERENCE CHANNEL - A beamforming method and apparatus for using a rate splitting scheme in a multi-cell multi-antenna system, are provided. The multi-cell multi-antenna system determines transmission and reception beamforming vectors, thereby being divided into a plurality of pairs of single input and single output (SISO) interference channels. A rate splitting scheme may be applied to each of the plurality of pairs.09-29-2011
20100296605DETERMINING A LEVEL OF POWER REDUCTION FOR A TRANSMITTER - A level of power reduction for a transmitter arranged to transmit signals modulated according to one of a number of modulation configurations via radio channels in a digital wireless communications system is estimated. Modulation dependent data comprising a term calculated from a third order product of a signal modulated according to a modulation configuration are provided, and a power reduction estimate for transmission of signals modulated according to said modulation configuration is calculated there from. The modulation dependent data are provided to comprise, in addition to the term calculated from a third order product, at least one term calculated from a higher order product. Further, transmitter dependent data are provided, and the estimate is calculated from said modulation dependent and transmitter dependent data. Thus a more accurate method of determining a power reduction is achieved, which also allows different operating conditions for the transmitter to be considered.11-25-2010
20100310007Filter Device - An input signal to a filter device is allowed to be written into one of a plurality of sequentially connected cells if the input signal is not the zero-valued sample. Each cell receives the input signal and multiplies the input signal by one of a plurality of weight coefficients. The input signal is stopped to be written into any of the cells if the input signal is the zero-valued sample. A result of a filtering operation is output from the last cell.12-09-2010
20100322345METHOD AND SYSTEM FOR BANDWIDTH CALIBRATION FOR A PHASE LOCKED LOOP (PLL) - Aspects of a method and system for bandwidth calibration for a phase locked loop are presented. Aspects of the method may include generating one or more carrier signals based on one or more corresponding calibration signals. A pre-distortion function may be computed based on the generated one or more carrier signals for the phase locked loop circuit. An output radio frequency (RF) synthesized signal generated by the phase locked loop circuit may be modified based on the computed pre-distortion function and a subsequent output RF synthesized signal generated based on the modified output RF synthesized signal.12-23-2010
20110007838TRANSMITTER - This application relates to an apparatus comprising a signal generator configured to generate a signal. The apparatus encompasses a predistortion unit configured to pre-distort the generated signal. The apparatus includes a pulse width modulating unit configured to modulate the pre-distorted signal into at least two signals. The apparatus comprises at least two amplifying units each configured to amplify one of the two modulated signals.01-13-2011
20110007839SPUR CANCELLATION IN A DIGITAL BASEBAND TRANSMIT SIGNAL USING CANCELLING TONES - A method for reducing spurs within a transmit signal is disclosed. A cancelling tone is determined. The cancelling tone is added to a baseband transmit signal in the digital domain to obtain a baseband transmit signal with cancelling tone. A spur in the transmit signal is reduced using the cancelling tone. The transmit signal with the reduced spur is transmitted using an antenna.01-13-2011
20110007840TRANSMISSION DEVICE AND MODULATION METHOD - A transmission device includes an RQAM modulating unit that has an S/P that divides a transmitting signal indicating information to be transmitted into a first signal and a second signal, a mapping unit that maps the first signal into a first in-phase component and a second in-phase component and the second signal into a first orthogonal component and a second orthogonal component by a predetermined mapping system, a P/S that generates a first modulated signal including the first in-phase component and the first orthogonal component and a second modulated signal including the second in-phase component and the second orthogonal component, an IFFT that transmits the first modulated signal and the second modulated signal, a DAC, an LPF, a Mixer, a BPF, and a LOCAL.01-13-2011
20090067539Wireless Personal Area Network Communication Systems, Apparatus and Methods with Fast Adaptive Beamforming - An embodiment of the present invention provides a method for communicating in a wireless personal area network, comprising using adaptive beamforming configured for a low-rate mode for reliable low-rate communications and a high-rate mode for high-rate communications and using a fast algorithm to perform antenna beamforming for the high rate mode, wherein the fast algorithm includes training performed on a block-by-block basis with decision feedback from a receiver (RX) to a transmitter (TX) about the usefulness of further training stages.03-12-2009
20100080323Methods and apparatus for partial interference reduction within wireless networks - Methods and apparatus that enable one or more wireless networks to minimize inter-cellular interference (ICI) at a receiver. In one embodiment, the network comprises an OFDM-based cellular network, and the method comprises utilizing a priori knowledge of non-data portions of signals from multiple base stations in order to schedule transmissions. In one variant, these non-data portions comprise pilot tones; the pilot tones can be scheduled onto various time-frequency resources of the network so as to minimize ICI. The mobility context of the receiver can also be used as a basis for dynamically adjusting the pilot tone density. In another variant, precoding (e.g., Tomlinson-Harashima preceding) can be applied to “shape” the non-data portions of the transmitted signals so as to mitigate ICI. In yet other variants, frame preambles and learning sequences are used as the basis for invoking selective transmission time shifts across the potentially interfering base stations so as to minimize ICI.04-01-2010
20110019770METHODS AND APPARATUS FOR MEASURING, COMMUNICATING AND/OR USING INTERFERENCE INFORMATION - Wireless communications methods and apparatus are described. A communications apparatus, e.g., a base station, measures interference information, e.g., other sector interference information. The communications apparatus generates a preamble which includes a plurality of pilot symbols and at least one of the pilot symbols includes interference information. In some embodiments, the preamble is part of a superframe structure, e.g., a recurring superframe structure, including the preamble and a plurality of frames, at least some of the frames used to convey traffic data. The communications apparatus transmits the preamble, thus broadcasting the interference information to access terminals in the vicinity. An access terminal receives the preamble including a plurality of pilot signals, at least one of the pilot signals including interference information. The access terminal recovers the interference information from the received preamble and controls signal transmission based on the recovered interference information.01-27-2011
20110019769MULTI STAGE CODE GENERATOR AND DECODER FOR COMMUNICATION SYSTEMS - A method of encoding data for transmission from a source to a destination over a communications channel is provided. A plurality of redundant symbols are generated from an ordered set of input symbols to be transmitted. A plurality of output symbols are generated from a combined set of symbols including the input symbols and the redundant symbols, wherein the number of possible output symbols is much larger than the number of symbols in the combined set of symbols, wherein at least one output symbol is generated from more than one symbol in the combined set of symbols and from less than all of the symbols in the combined set of symbols, and such that the ordered set of input symbols can be regenerated to a desired degree of accuracy from any predetermined number, N, of the output symbols.01-27-2011
20090034652DIGITAL BROADCASTING SYSTEM AND DATA PROCESSING METHOD - A digital broadcasting system and a method of processing data are disclosed, which are robust to error when mobile service data are transmitted. To this end, additional encoding is performed for the mobile service data, whereby it is possible to strongly cope with fast channel change while giving robustness to the mobile service data.02-05-2009
20100172437Signal pre-processor for an amplifying system - A signal pre-processor, for at least partially correcting non-linear performance of a high power amplifier (“HPA”), operates on an over-sampled signal in complex form in the digital domain. By converting the over-sampled signal to amplitude values, the pre-processor is enabled to apply correction values, based on the amplitude values, which correction values incorporate both amplitude and phase correction in respect of distortion generated in the HPA. The use of an over-sampled signal allows out-of-band correction values to be applied to correct out-of-band distortion arising in the signal processing path, for instance in the linearization process itself. The out-of-band distortion can otherwise alias back in-band, creating noise at the HPA.07-08-2010
20110116573Methods and Systems for Adaptive Communication - One embodiment of the present invention relates to a method of transferring data in a communication system. In the method, an initial impulse noise protection value is determined. A number of redundancy bits is added to blocks of data to form codewords as a function of the initial impulse noise protection value, where the impulse noise protection value corresponds to a number of consecutive symbols that can be corrected. The number of symbols that can be correctly transmitted is changed by changing only the number of redundancy bits added to each block of data.05-19-2011
20110085618METHOD FOR SEMI-STATICALLY ADAPTING UPLINK MULTIPLE-INPUT MULTIPLE-OUTPUT TRANSMISSION - A method, a wireless terminal device, and a base station are disclosed. A receiving unit 04-14-2011
20110243272Precoder Codebooks for Effective Channels with Structured Frequency-Selectivity - A precoder for an effective channel linking a wireless receiver to a wireless transmitter includes a precoder report and a precoder update report, the effective channel including a propagation channel, transmit filters and receive filters. A structured frequency-selectivity of the effective channel is determined, the structured frequency-selectivity being induced by one or more long term and/or persistent parameters of the effective channel. The precoder update report is generated based on the structured frequency-selectivity. The precoder update report includes frequency-dependent phase compensation which accounts for the structured frequency-selectivity. The precoder report is generated for the effective channel based on channel state information determined for the effective channel. The precoder report and the precoder update report are transmitted to the wireless transmitter. The transmitter determines a transmission operation based on the precoder report and the precoder update report, and transmits data to the wireless receiver in accordance with the transmission operation.10-06-2011
20100239047WIRELESS APPARATUS AND DISTORTION COMPENSATION METHOD USED ON TIME DIVISION DUPLEX SYSTEM - There is provided a wireless apparatus in which a distortion compensation loop is formed so as to compensate nonlinear distortion of a transmission amplifier, being used on a time division duplex system on which a wireless signal is transmitted in a transmission time period with same frequency as being received, the wireless apparatus used on the time division duplex system including a combining section to combine a feedback signal into which a return signal generated by reflection of a transmission signal at a antenna leaks and the return signal processed by a reception unit to process a reception signal from the antenna in the transmission time period so as to cancel the return signal leaked into the feedback signal.09-23-2010
20120134442DATA FORMAT CONVERSION FOR ELECTRONIC DEVICES - Format converters and methods of performing data format conversion are provided. The format converters may convert compressed data into a different compressed format that is compatible with the Bluetooth transmission standard. The format converter may decompose the compressed data into frequency domain data streams of different frequency sub-bands. The format converter may transform each data stream of frequency domain information from a first encoding scheme to a second encoding scheme, and may then quantize the transformed data steams based on bit allocation information for each sub-band. The format converters may also include a bit allocation component which computes the bit allocation information for each sub-band based on an unfiltered version of the compressed data.05-31-2012
20110135034Digital Pre-Distortion of Non-Linear Systems with Reduced Bandwidth Feedback - Embodiments of the invention provide a DPD system where the transmit reference signal is transformed, including sub-sampling, frequency translation, and the like, to match the feedback signal, which goes thru a similar transformation process, to obtain an error signal. The same transformation is applied to a system model, which may be Jacobian, Hessian, Gradient, or the like, in an adaptation algorithm to minimize error.06-09-2011
20090213960TRANSMITTER - There are provided a BPF (08-27-2009
20100054362PREAMBLE NOISE CANCELLATION CIRCUIT - A preamble noise cancellation circuit according to an aspect of the invention may include: a coupler dividing an input signal; a preamble noise detection unit subtracting a predetermined reference preamble signal from a received preamble signal output from the coupler to detect preamble noise included in the received preamble signal; and a noise cancellation unit subtracting the preamble noise detected by the preamble noise detection unit from the received preamble signal output from the coupler.03-04-2010
20100054363Method and Device for the Noise Shaping of a Transmission Signal - A description is given of a device and a method for the noise shaping of a transmission signal such as are employed, for example, in a data transmission system.03-04-2010
20110249770 PASSIVE TRANSMITTER ARCHITECTURE WITH SWITCHABLE OUTPUTS FOR WIRELESS APPLICATIONS - A transmitter architecture having a single signal path or hardware to cover WCDMA/EDGE/GSM applications, and requires no SAW at the transmitter outputs. The transmitter architecture allows for a transmit convergence feature. A passive mixer with unique driver and furthermore using native devices available from the CMOS process for the mixer cores enables low voltage and low power design, low output noise and high linearity. A digital variable gain amplifier has the capability to cover wide output dynamic range operated from low supply voltage and interfaced digitally with the baseband circuit without DAC. A single transformer is used to combine the outputs from the WCDMA/EDGE and GSM drivers and subsequently convert the differential signal paths into a single-ended signal. RF switches are used to divert the output from the transformer to different bands and applications.10-13-2011
20110069783CHANNEL EQUALIZER AND METHOD OF PROCESSING BROADCAST SIGNAL IN RECEIVING SYSTEM - A channel equalizer for use in a receiving system includes an overlap unit, a first estimator, an interpolator, and a second estimator. The overlap unit overlaps a group of normal data packets including a head, a body, and a tail, and a known data region is periodically repeated in the body. The first estimator estimates CIRs of the known data regions according to a first algorithm, and the interpolator estimates CIRs of normal data regions in the body by interpolating the estimated CIRs of the known data regions. The second estimator estimates CIRs of normal data regions in the head and tail according to a second algorithm different from the first algorithm. A calculator calculates equalization coefficients based on the estimated CIRs and a compensator multiplies the overlapped data with the coefficients. A save unit saves the compensated data.03-24-2011
20110075762UPLINK INTERFERENCE MITIGATION METHOD AND APPARATUS - Disclosed is a method and apparatus for mitigating uplink interference in the wireless communication system, wherein the method comprises determining a loading-status value for each sector; if the loading-status value is not greater than the first threshold value, generating UL zone switch IE and UL allocation start IE to allocate data bursts of the sectors to different subchannels; and preparing an uplink map using the UL zone switch IE and UL allocation start IE for each sector, wherein the uplink duration indicates a duration where all the subchannels are used for allocation of the data burst.03-31-2011
20110075761DIFFERENTIAL SIGNAL TRANSMISSION SYSTEM AND METHOD - A transmission system for transmitting a first differential signal includes a transmitter, a transmission path, and a receiver. The transmitter transmits the first differential signal and a second differential signal. The transmission path transfers the first differential signal and the second differential signal. The receiver receives the first differential signal and the second differential signal. The transmitter includes a generator circuit and a switch. The generator circuit generates the second differential signal lower in baud rate than the first differential signal. The switch selects between the second differential signal and the first differential signal to output the selected differential signal to the transmission path. The receiver includes a detector circuit and a corrector circuit. The detector circuit detects a skew of the second differential signal. The corrector circuit corrects a skew of the first differential signal based by the detected skew of the second differential signal.03-31-2011
20110075760RADIO TRANSMISSION DEVICE AND RADIO COMMUNICATION METHOD - It is possible to provide a radio transmission device and a radio communication method which can reduce inter-sequence interference and reduce the circuit size and the calculation amount even when RS is transmitted with different transmission bandwidths. Sequence length decision units (03-31-2011
20110069784HYBRID HETERODYNE TRANSMITTERS AND RECEIVERS - Disclosed are hybrid heterodyne transmitters and receivers for use in communications systems, or other systems, and the corresponding methods for hybrid heterodyne transmitting and receiving. A heterodyne receiver for converting a continuous time modulated signal to a discrete time digital baseband signal includes a sigma-delta modulator. The sigma-delta modulator is a signal-delta analog-to-digital converter constructed and arranged to receive a modulated signal at an RF carrier frequency and provide a quantized output at a first intermediate frequency. The heterodyne receiver may also include a digital mixer constructed and arranged to receive a data stream quantized by the sigma-delta analog-to-digital converter and receive a signal at a second mixing frequency. The digital mixer then provides digital signals representative of a baseband signal suitable for digital signal processing.03-24-2011
20120201329TRANSMIT METHODS WITH DELAY DIVERSITY AND SPACE-FREQUENCY DIVERSITY - In this invention, several open-loop solutions that encompass the small delay CDD codeword cycling, codeword cycling between different re-transmissions of both small and large delay CDD are proposed. In addition, an open-loop codeword cycling method for SFBC+FSTD scheme, as well as its extension to SFBC+FSTD based HARQ, are proposed. In one method, a plurality of information bits are encoded, scrambled and modulated to generate a plurality of modulation symbols. The plurality of modulation symbols are mapped onto the subcarriers in at least one transmission layer of a transmission resource. The modulation symbols are then precoded by using a matrix for cyclic delay diversity and a set of codewords from a certain codebook to generate a plurality of precoded symbols. The codewords are cycled for every a certain number of subcarriers. Finally, the precoded symbols are transmitted via a plurality of transmission antennas.08-09-2012
20110150130ACTIVE ANTENNA ARRAY WITH MODULATOR-BASED PRE-DISTORTION - An active antenna array comprises a plurality of transmission paths, a predistortion modulation signal generator, and a predistortion modulation signal distribution structure. At least two of the plurality of transmission paths comprise a predistortion modulator for modulating a transmission path signal with a predistortion modulation signal generated by the predistortion modulation signal generator and distributed by predistortion modulation signal distribution structure to the at least two of the plurality of transmission paths. A method for predistorting at least two of a plurality of transmission path signals in an active antenna array and computer program products for manufacture and method execution are also claimed.06-23-2011
20110249771ADAPTIVE GAIN CONTROL BASED ON ECHO CANCELLER PERFORMANCE INFORMATION - A system and method for provide a stable gain from an adaptive gain control device in a signal path. An echo canceller is also located in the signal path, and is used to provide performance information regarding losses in the signal. This performance information is fed to the automatic gain control device via a connection. The automatic gain control device thereafter uses the performance information to determine a maximum gain that might be provided based upon losses cause by echo conditions. The gain however is limited in order to provide for a stable system. The performance information includes a loss rate that includes a combination of the echo return loss and the echo return loss enhancement.10-13-2011
20110249769METHOD AND APPARATUS OF COMPENSATION FOR AMPLITUDE AND PHASE DELAY USING SUB-BAND POLYPHASE FILTER BANK IN BROADBAND WIRELESS COMMUNICATION SYSTEM - Provided is a method and apparatus improving a deterioration of a gain flatness and a phase characteristic that may be incurred while a baseband signal is transformed into a immediate frequency (IF) signal and a radio frequency (RF) signal in a broadband wireless communication system. A sub-band extractor may divide the broadband signal into multiple sub-band signals, may pre-compensate for a gain and a phase delay of each sub-band signals in the baseband, and may combine the pre-compensated sub-band signals into the single broadband signal and thus, the deterioration of the gain flatness and a phase delay flatness that may be incurred while the broadband signal is transformed into the IF signal and the RF to signal, may be improved.10-13-2011
20100260288WIRELESS TRANSMISSION METHOD AND APPARATUS - According to one embodiment, a wireless transmission method is disclosed. The method can perform feedback loop processing including subtracting a feedback data signal obtained by multiplying a feedback processing data signal by a gain from an input data signal to generate the feedback processing data signal. The method can perform beam forming processing with respect to the feedback processing data signal and at least one pilot signal for channel estimation to generate a beam-formed signal. In addition, the method can transmit the beam-formed signal by a plurality of antennas. Precoding processing performed on the pilot signal is only beam forming processing.10-14-2010
20120033759Phase Calibration and Erroneous Cabling Detection for a Multi-Antenna Radio Base Station - A radio base station has at least two radio chains and a precoder for precoding information symbols by a precoding matrix for multi-antenna transmission to a number of user equipment terminals. Precoding matrix statistics representative of phase coherency between at least two radio chains is compiled based on feedback information representative of preferred precoding matrix from one or more user equipment terminals (S02-09-2012
20120033758SYSTEMS AND METHODS FOR CONTROLLING LOCAL OSCILLATOR FEED-THROUGH - A method for controlling local oscillator (LO) feed-through in a direct transmitter includes detecting a signal level corresponding to LO feed-through in a radio frequency (RF) signal that is output by a direct transmitter. Responsive to detecting the signal level corresponding to LO feed-through, DC offset levels are modified for an in-phase (I) signal and/or a quadrature-phase (Q) signal in the direct transmitter.02-09-2012
20110150131APPARATUS AND METHOD FOR PROCESSING DIGITAL TRANSMISSION/RECEPTION SIGNALS TO CORRECT IN-BAND GAIN FLATNESS - An apparatus for processing a digital transmission signal for a transmitter includes a transmission Finite Impulse Response (FIR) filter to perform shaping on initial setting data to convert the initial setting data into a signal having a predetermined passband, a comparator to compare the signal with data including degradation information provided as feedback by a receiver corresponding to the transmitter, to generate a control signal, and a band flatness correction filter to adjust a coefficient of the band flatness correction filter in response to the control signal, and to correct an in-band flatness.06-23-2011
20100002801PRECODING IN HIGH-ORDER MIMO - A high-order Multiple-Input-Multiple-Output (MIMO) transmitter implementing a covariance-based precoding scheme that exploits transmit channel correlation and a method of operation thereof are provided. In one embodiment, covariance-based precoding is performed at the high-order MIMO transmitter based on feedback from a remote high-order MIMO receiver regarding a covariance-based precoding matrix. The covariance-based precoding matrix is, or is derived from, a transmit channel correlation matrix determined by the high-order MIMO receiver for the high-order MIMO transmitter. The covariance-based precoding provides a beam-forming effect when there is a relatively high degree of transmit channel correlation, thereby improving performance of the high-order MIMO transmitter. Further, because changes in the transmit channel correlation occur relatively slowly over time, feedback overhead requirements are substantially reduced as compared to that required for traditional MIMO precoding schemes.01-07-2010
20110150132METHOD TO GENERATE BEAMFORMING VECTOR AND PROVIDE THE INFORMATION FOR GENERATING BEAMFORMING VECTOR - A method to generate a beamforming vector by a terminal includes receiving information on a first precoding matrix and a second precoding matrix from a serving base station; and generating a beamforming vector by linearly combining the first precoding matrix and the second precoding matrix.06-23-2011
20080310546Method for Adapting Digital Data Transmission Parameters to Measured Repetitive Noise - Following a transmission comprising a plurality of symbols, an error measurement is generated for each symbol, so that one may distinguish between symbols having a relatively low error and symbols having a relatively high error. A bit rate to be used for subsequent transmission is determined as a function of error measurements of those symbols that have relatively low error and as a function also of the proportion of symbols having a relatively high error, such that the bit rate reduces as the proportion increases. Measurement of the error rate and/or the durations of high and low error conditions may also be used to set other transmission parameters such as error-correcting code and interleaver settings.12-18-2008
20080253475Device and Method for Generating a Base Band Signal and Program Causing Computer to Execute the Method - There is disclosed a base band signal generation device and others for processing transmission data so that a reception side can restored the data without recognizing whether the data has been subjected to a processing and transmitting the data with an appropriate efficiency corresponding to the communication quality. A transmission device T judges the communication quality of a transmission path L. When the communication quality is preferable, a four-value FSK symbol is generated from the bit of the most significant part of the encoded voice data and the bit of the least significant part. When the communication quality is not preferable, a four-value FSK symbol is generated from the bit of the most significant part of the encoded voice data and a redundant bit of “0”. However, a symbol containing a redundant bit is set to the maximum value or the minimum value of the four values which the symbol value may have. Moreover, each bit of the encoded voice data has a value “0” when indicating that no component corresponding to the bit is present.10-16-2008
20080253476Method and System for Enabling Collusion Resistant Watermarking - A method and a system for modifying a bitstream signal for enabling collusion resistant bitstream watermarking. The method comprises dividing a bitstream spectral signal X[k] of the bitstream signal bx into a first signal (10-16-2008
20100329386Crosstalk Control Method and Apparatus Using a Bandwidth-Adaptive Precoder Interface - In a communication system, a precoder is coupled between first and second portions of each of a plurality of transmitters. The precoder is configured to receive an adaptive index representation of a scaled signal associated with the first portion of a first one of the transmitters, and to process the adaptive index representation using an adjusted precoder coefficient to generate a precompensation signal. The precompensation signal is supplied from the precoder to the second portion of a second one of the transmitters for use in precompensation of at least one signal to be transmitted by the second transmitter.12-30-2010
20100329387WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD - A wireless communication apparatus includes a transmission unit configured to convert an input signal into a transmission signal, and a correction unit configured to impart, to the input signal, characteristics opposite to group delay deviation derived from amplitude deviation of a reflective wave of the transmission signal reflected from a radio transmission filter, through which the transmission signal output from the transmission unit passes to arrive at an antenna.12-30-2010
20100246714METHOD AND SYSTEM FOR CREST FACTOR REDUCTION - An apparatus and system are provided for crest factor reduction (CFR). Preferably, a peak from the wideband signal is detected. A gain from the magnitude of the peak and a threshold can then be calculated. Based on this information, each carrier's contribution to the peak can be approximated, and a cancellation pulse coefficient for each carrier from its contribution to the peak can be calculated. A base cancellation pulse can be calculated from the cancellation pulse coefficients for each carrier, and a cancellation pulse can be calculated from the base cancellation pulse and the gain, which can then be applied to the wideband signal.09-30-2010
20120147991DISTORTION COMPENSATION DEVICE, DISTORTION COMPENSATION METHOD AND WIRELESS APPARATUS - A distortion compensation device includes a storage unit storing a plurality of distortion compensation coefficients associated with power values of transmission signals, a distortion compensation processing unit acquiring a distortion compensation coefficient corresponding to a power value of a received transmission signal from among the plurality of distortion compensation coefficients and subjecting the received transmission signal to a distortion compensation process on the basis of the acquired distortion compensation coefficient, a phase calculating unit calculating a phase correction value on the basis of the distortion compensation coefficients, a phase correcting unit generating a reference signal by correcting a phase of the received transmission signal on the basis of the phase correction value, and a correction processing unit performing a correction process for the transmission signal subjected to the distortion compensation process on the basis of the reference signal and a feedback signal from a transmission power amplifier.06-14-2012
20110096870METHOD AND APPARATUS FOR VECTORED DATA TRANSMISSION - An apparatus includes a transmitter configured to transmit data via a plurality of communication channels of a communication connection. The transmitter is further configured to transmit a same sequence for vector training on each of the communication channels. The sequences for at least two of the communication channels are shifted with respect to each other.04-28-2011
20110200140Systems and Methods for MIMO Precoding in an xDSL System - One embodiment is a method for precoding data for transmission in a discrete multi-tone (DMT) system to cancel self-induced far end crosstalk (self-FEXT). The method comprises learning, by the system, characteristics associated with a plurality of N users within a digital subscriber line (xDSL) system to determine an initial off-diagonal multiple input multiple output (MIMO) precoder (ODMP) for a given tone frequency and converging towards an ODMP from the initial ODMP to cancel self-FEXT for the plurality of N users, wherein the ODMP is represented as a zero diagonal matrix containing only off-diagonal terms.08-18-2011
20100215119RECEPTION APPARATUS - A reception apparatus includes a plurality of antennas for receiving modulation signals of channels in the same frequency band, an received signal strength intensity estimation unit for estimating the reception received signal strength intensity of each reception signal, transmission path fluctuation estimation units for estimating a transmission path fluctuation of each channel of the reception signal, phase difference estimation units for calculating a phase difference of the transmission path fluctuation estimation signal of a predetermined channel of each antenna and outputting it as a phase difference signal, and a signal selection unit for selecting and outputting a reception quadrate baseband signal for isolating a signal of each channel from the reception signals and a transmission path fluctuation estimation signal of each channel. Thus, by isolating and demodulating a plurality of multiplexed modulated signals received, it is possible to improve the data transmission rate.08-26-2010
20100166109RADIO STATION AND ACTIVE ANTENNA ARRAY - The present disclosure relates to a radio station providing a digital predistortion to be imposed on a payload signal. The digital predistortion is usable as a general predistortion for several transmit paths of the radio station. The radio station provides coupled transmit signals to be combined within a combiner forming a common feedback signal. The common feedback signal is relayed along a common feedback path. A digital predistortion update unit to updates the digital predistortion in order to linearise a transfer characteristics of the transmit paths. The disclosure relates to a method of digitally predistorting a payload signal in order to linearise a transmit characteristics of the transmit paths. The disclosure further relates to computer program products for the manufacture of the radio station and/or a computer product for the execution of the method digitally predistorting. The disclosure further relates to an antenna array comprising the radio station.07-01-2010
20100158154METHOD AND APPARATUS FOR GENERATING PREDISTORTION SIGNAL - Provided is a digital predistortion linearizer applicable to millimeter-wave band point-to-point communications. The digital predistortion linearizer includes a transmission unit and a reception unit. The reception unit receives a first signal including a transmission signal and a distortion signal through a millimeter-wave propagation environment, detects the distortion signal from the first signal, and transmits information on the detected distortion signal with the first signal to the transmission unit. The transmission unit generates a predistortion signal using the information on the distortion signal and the first signal received from the reception unit, couples the generated predistortion signal with the transmission signal, and outputs the coupled signal.06-24-2010
20110051843TRANSMISSION CIRCUIT - A transmission circuit includes: a first switch configured to select one of a first baseband signal and an oscillation signal; a second switch configured to select one of a second baseband signal and the oscillation signal; a first multiplier configured to multiply a first local frequency signal based on the oscillation signal by the signal selected by the first switch; a second multiplier configured to multiply a second local frequency signal based on the oscillation signal by the signal selected by the second switch; an adder configured to add an output from the first multiplier to an output from the second multiplier; and a correction circuit configured to correct one of the first baseband signal and the second baseband signal based on an output from the adder when the first switch and the second switch select the oscillation signal.03-03-2011
20100166110METHOD FOR DIGITALLY PREDISTORTING A PAYLOAD SIGNAL AND RADIO STATION INCORPORATING THE METHOD - A radio station providing a digital predistortion to be imposed on a payload signal is disclosed. The digital predistortion is usable as a digital predistortion for one or more of the transmit paths of the radio station. The radio station provides coupled transmit signals to be switched as a selected one of the coupled transmit signals along a common feedback path. A digital predistortion update unit is adapted to update the digital predistortions in order to linearise a transfer characteristics of the transmit paths according to a hierarchy of the transmit paths. A method of digitally predistorting a payload signal in order to linearise a transmit characteristics of the transmit paths is disclosed.07-01-2010
20100316163System and method for DIDO precoding interpolation in multicarrier systems - A system and machine-implemented method are described for performing precoding interpolation in a DIDO system which employs orthogonal frequency-division multiplexing (OFDM) and DIDO precoding to communicate with a plurality of distributed-input-distributed-output (DIDO) clients. For example, a system according to one embodiment of the invention comprises: selecting a first subset of ODFM tones to determine a first subset of precoding weights; deriving a second subset of precoding weights for a second subset of ODFM tones by interpolating between the first subset of precoding weights; and using a combination of the first subset of precoding weights and the second subset of precoding weights to precode a data stream prior to transmitting the data stream to a DIDO client.12-16-2010
20090316826PREDISTORTION AND POST-DISTORTION CORRECTION OF BOTH A RECEIVER AND TRANSMITTER DURING CALIBRATION - A post-distorter compensates for receiver nonlinearity in calibration mode. Linearized receiver-side output from the post-distorter is used to correctly compensate for transmitter-side nonlinearities in calibration mode. The post-distorter also compensates for receiver-side nonlinearities during normal receive mode. Thus, the post-distorter features dual modes of use, a calibration mode, wherein calibration signals received from the adjacent transmitter are linearized by the post-distorter and a normal receive mode, wherein communication signals from a remote transmitter are linearized by the post-distorter.12-24-2009
20120307937TRANSMITTER AND MIMO MUTLIPLEX TRANSMISSION METHOD - In MIMO multiplex transmission accompanied by precoding, a reduction of peak power is realized while minimizing deterioration of transmission quality. The present MIMO multiplex transmission method includes a step of generating transmission data corresponding to a plurality of streams to be transmitted simultaneously, a step of performing precoding so that the transmission data is received by a receiver as data orthogonal to each other, a step of applying amplitude clipping to the precoded transmission data in stream units to suppress peaks of the entire transmission power, and a step of suppressing allocation of interference power caused by the amplitude clipping to streams in a good channel state.12-06-2012
20110013724I/Q IMBALANCE ESTIMATION AND COMPENSATION FOR A TRANSMITTER AND A RECEIVER - Techniques for performing inphase/quadrature (I/Q) imbalance estimation and compensation are described. In one exemplary design, I/Q imbalances in a receiver may be estimated by (i) applying a continuous wave signal at different frequencies to the receiver and (ii) processing I and Q input samples from the receiver to determine I/Q imbalances at different frequencies. In another exemplary design, I/Q imbalances may be estimated by (i) downconverting an input RF signal with an LO signal that is offset in frequency from the input RF signal, (ii) transforming I and Q input samples from the receiver to the frequency domain to obtain I and Q symbols, and (iii) determining I/Q imbalances based on the I and Q symbols. In one exemplary design, I/Q imbalances may be corrected by compensating for frequency-dependent and frequency-independent I/Q imbalances separately. I/Q imbalances in a transmitter may also be estimated and compensated.01-20-2011
20110305299WIDEBAND CODEBOOK CONSTRUCTION AND APPLICATIONS - A precoding scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the multi antenna transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices that includes matrices having a structure matched to that of the eigenvectors of the spatial covariance matrix, wherein the spatial covariance matrix is modeled as a Hermitian and Toeplitz matrix parameterized by a single complex-valued scalar.12-15-2011
20110305298DIRTY PAPER PRECODING METHOD AND TRANSMITTER IMPLEMENTED BY USING PHASE RESHAPING - A dirty paper precoding method implemented by using phase reshaping at the transmitter side, wherein the method comprises: subtracting interference signal from intended signal to obtain difference signal; determining constellation size for constellation extension according to amplitude-related information of interference signal and intended signal; extendedly mapping original constellation block of the difference signal to extended constellation block having the determined constellation size by constellation extension processing, according to the determined constellation size for constellation extension, wherein, the extended constellation block being proportionally enlarged to be closer to origin of constellation coordinate compared with original constellation block; and performing phase reshaping of each constellation point of extended constellation block corresponding to the difference signal, wherein, the phase reshaping making constellation point of extended constellation block of difference signal corresponding to specific constellation point of intended signal to be mapped into the same constellation quadrant as that of the specific constellation point.12-15-2011
20130010895WIRELESS COMMUNICATION SYSTEM, BASE STATION, TERMINAL AND METHOD OF GENERATING CODEBOOK - The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which cotains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.01-10-2013
20120039416System and Method for Employing Six-Bit Rank 1 and 2 Codebooks for Four Transmit Antennas - A system and method is provided for employing six-bit rank 1 and 2 codebooks for multiple transmit antennas. A channel estimate is generated for a communications channel that can be established between a communications device and a controller serving the communications device. The channel estimate can be quantized using a codebook to produce a selected codeword. An index corresponding to the selected codeword can be transmitted to the controller. The codebook can include a plurality of first level codewords, with each first level codeword having a plurality of subsidiary codewords. The quantizing can be in the form of a search of the first level codewords followed by a search of a subset of a plurality of subsidiary codewords, and the codebook can be derived at least in part from a rank of communications between the communications device and the controller.02-16-2012
20120039415DISTORTION COMPENSATION AMPLIFIER DEVICE AND DISTORTION COMPENSATION METHOD - A distortion compensation amplifier device for compensating for distortion of a transmission signal generated by amplifying the transmission signal and for outputting the compensated transmission signal. The distortion compensation amplifier includes a storage unit that stores therein distortion compensation coefficients; a processor that performs distortion compensation processing on the transmission signal by using one of the distortion compensation coefficients; and an amplifier that amplifies the transmission signal that has been subjected to the distortion compensation processing; wherein the processor calculates an average value of the distortion compensation coefficients stored in the storage unit, and calculates the distortion compensation coefficient on the basis of the transmission signal, and the average value.02-16-2012
20120147992METHOD AND APPARATUS FOR CONSTRUCTING CODEBOOK, AND METHOD, APPARATUS AND SYSTEM FOR PRECODING - The present invention discloses a method and apparatus for constructing a codebook. The method comprises: receiving grouping information on a plurality of transmit antennas of a base station: obtaining a channel model for a channel between a mobile terminal and the base station; and determining an optimal precoding matrix corresponding to each antenna group according to the grouping information and the channel model, so as to construct a codebook used for precoding. The present invention further discloses a method and apparatus for selecting a precoding matrix, as well as a method, apparatus and system for precoding.06-14-2012
20120099674ANTENNA CONFIGURATION FOR CO-OPERATIVE BEAMFORMING - The present invention relates to a method for communicating in a network, the network comprising at least a first cell and a second cell including respectively a first primary station having a first antenna array dedicated to the first cell and a second primary station having a second antenna array dedicated to the second cell, for communicating with a plurality of secondary stations, the method comprising the step of (a) providing with a co-operative beamforming transmission from the first and second primary stations to at least one first secondary station, wherein step (a) includes (a1) the first secondary station signaling at least one channel matrix to at least one of the first and second primary stations, and (a2) the first and second primary stations applying a precoding matrix across both the first antenna array and the second antenna array, and wherein the precoding matrix comprises a first vector for the first cell and a second vector for the second cell, the precoding matrix being based on the at least one channel matrix.04-26-2012
20080279306PILOT TONES IN A MULTI-TRANSMIT OFDM SYSTEM USABLE TO CAPTURE TRANSMITTER DIVERSITY BENEFITS - In a wireless transmitter having a plurality of spatial streams differentiable at a receiver, wherein data is encoded and transmitted over a communication channel with pilot tones to provide the receiver with information about the effects of the communication channel and/or transmitter impairments and/or receiver impairments on the spatial streams transmitted, the benefits can be provided by identifying a plurality of symbol periods within which symbols representing some of the encoded data are to be transmitted, identifying pilot tone values for the plurality of symbol periods, wherein the identified pilot tone values are such that the receiver, when receiving at least some of the pilot tones having the identified pilot tone values, is provided with signals enabling the receiver to characterize the communication channel and/or transmitter impairments and/or receiver impairments to obtain transmit stream diversity gain, and transmitting the symbols and the pilot tones over the plurality of spatial streams for the plurality of symbol periods. In some embodiments, the pilot tones are orthogonal over space and time or over space and time and frequency, while in others they are semi-orthogonal. Pilot tone values might be of a constant amplitude and phase shifted, or might also have amplitude variations wherein at least two pilot tones are nonzero for spatial streams for a given symbol period.11-13-2008
20110317787TRANSMITTER SYSTEM FOR TRANSMITTING PARALLEL DATA BY COMPENSATING FOR CROSSTALK - A transmitter system for transmitting parallel data by compensating a crosstalk includes: first and second transmission lines parallel to each other; a first inverted crosstalk pulse generation unit configured to receive first transmission data and inverted first transmission data and output a first inverted crosstalk pulse according to a data mode; a second inverted crosstalk pulse generation unit configured to receive second transmission data transmitted in parallel to the first transmission data and inverted second transmission data and output a second inverted crosstalk pulse according to the data mode; a first addition unit configured to combine the first transmission data and the second inverted crosstalk pulse and output first compensation data to be transmitted to the first transmission line; and a second addition unit configured to combine the second transmission data and the first inverted crosstalk pulse and output second compensation data to be transmitted to the second transmission line.12-29-2011
20110317786System and Method for Estimating a Transmit Channel Response and/or a Feedback Channel Response Using Frequency Shifting - Systems and methods for identifying a transmission channel response and a feedback channel response from a plurality of composite system responses are disclosed. A plurality of shifted feedback signals are created by shifting a feedback signal frequency by a plurality of first offset values and/or by shifting a transmission signal frequency by a plurality of second offset values. The feedback signals are compared to an input signal to identify the transmission channel response and/or a feedback channel response. A control signal is generated for a pre-distortion circuit to modify the input signal by an inverse of the transmission channel response. The composite system response is measured at a plurality of operating frequencies and at the plurality of offset values. The measurements are stored in a matrix and singular value decomposition is applied to the matrix of measurements to calculate the transmission channel response and feedback channel response.12-29-2011
20120207243Precoder Selection For Precoder Cycling - From a set of X precoding matrix codewords, there is selecting a subset of N codewords so that each selected codeword is optimized for both a cross-polarized antenna array and a co-polarized linear antenna array. Each n08-16-2012
20120045019METHOD AND APPARATUS FOR DETERMINING A PRECODING MATRIX - Disclosed is a method for determining precoding matrix based on an open-loop MIMO scheme, which can enhance a diversity gain at a static communication environment or a low-mobility communication environment. The method for determining precoding matrix applies a first precoding matrix to downstream data to transmit the downstream data through a plurality of antennas, the first precoding matrix being selected from a codebook which comprises a plurality of precoding matrixes, and changes the first precoding matrix to a second precoding matrix per predetermined period, and applying the second precoding matrix to the downstream data to transmit the downstream data through the antennas. The second precoding matrix is a precoding matrix corresponding to an index which has been shifted by a certain value from an index of the first precoding matrix in a direction where an index of a precoding matrix increases, in the codebook02-23-2012
20120008716DIGITAL BROADCASTING SYSTEM AND METHOD OF PROCESSING DATA - A digital broadcasting system including a transmitting system and a receiving system, and a method of processing data are disclosed. A method of processing data of a transmitting system includes sequentially grouping N number of columns (Kc) configured of A number of enhanced data bytes having information included therein, thereby creating a frame having a size of N (rows)*Kc (columns), wherein N and A are integers, encoding the created frame, and multiplexing and transmitting enhanced data included in the encoded frame and main data.01-12-2012
20120008715Digital Phase Feedback for Determining Phase Distortion - A feedback loop is used to determine phase distortion created in a signal by directly extracting the phase distortion information from a feedback signal using original frequency modulation information.01-12-2012
20120057650TRANSMITTING A SIGNAL FROM A POWER AMPLIFIER - A method for limiting peak-to-average power of a signal transmitted from a power amplifier. The method comprises: applying a pulse-shape filter to a first signal, thereby generating a second signal being a filtered version of the first signal; and outputting the second signal for transmission from a power amplifier. The method further comprises: applying each of a plurality of predictor filters to a respective instance of the first signal, each predictor filter approximating the application of the pulse-shape filter to the first signal based on a different respective set of filter coefficients, and each thereby generating a respective third signal. The method also further comprises determining an indicator of amplitude of each of the third signals, selecting the indicator corresponding to the largest of those amplitudes, generating a modifier based on the selected indicator, and using the modifier to limit the first signal prior to applying the pulse-shape filter.03-08-2012
20120057651TRANSMISSION APPARATUS AND METHOD - A transmission apparatus selects a single transmission channel through which a transmission signal is to be transmitted from among unoccupied available channels, forms the transmission signal so as to alleviate interference with adjacent channels according to occupancy states of an upper adjacent channel and a lower adjacent channel adjacent to the transmission channel, and transmits the transmission signal.03-08-2012
20120114073SPECTRAL SHAPING OF MULTICARRIER SIGNALS - A method for generating and transmitting a multicarrier signal representing data symbols, where the multicarrier signal is a linear combination of subcarriers, is disclosed, as well as a transmission entity. The generation and transmission is characterized by 05-10-2012
20120014475MULTI-ANTENNA COMMUNICATION APPARATUS AND METHOD OF MULTI-ANTENNA COMMUNICATION - To reduce an error rate of received data, a MIMO processing unit receives data transmitted from a transmitter via antennas and separates packets of layers 01-19-2012
20120014474Method and Means for the Scalable Improvement of the Quality of a Signal Encoding Method - The invention relates to a method for the scalable improvement of the quality of an encoding method according to IT-U Recommendation G.722, including the following steps:-a digital error signal (E) derived from an input signal to be encoded and a prognosis signal is compared in sections to a number of M*LN different reference signals in an iterative process having a number of repeated steps depending on the scope of the expansion, and the reference signal having a minimum error signal of a prescribed error criteria is derived therefrom,-the reference signals are each made up of equidistant Dirac impulses δ(n) according to (I), wherein off=[0 . . . M−1], indicates the distance of the first impulse from a zero time point, α∈{α,α, . . . ,α} indicates the amplitude value, M the distance between the individual pulses, N the number of pulses, and L the number of different levels,-the information about the reference signal having the minimum error signal is transmitted.01-19-2012
20120014476Pilot Aided Data Transmission and Reception with Interference Mitigation in Wireless Systems - Embodiments disclosed herein reduce interference at pilot symbols and also enable good interference measurements by using a combination pilot tones and null tones along with null tones. In this type of system, the receivers can estimate tile channel state information without any interference from the remaining transmitters and at the same time the receiver can measure either the individual interference channel states or the interference covariances from the silent periods. The groups of transmitters are reused in geographically separated region using a frequency reuse structure. In a preferred implementation, pilot signal is precoded using a multi-antenna precoder. The precoder may be same for pilot and data.01-19-2012
20120057652CHANNEL EQUALIZER AND METHOD OF PROCESSING BROADCAST SIGNAL IN RECEIVING SYSTEM - A channel equalizer for use in a receiving system includes an overlap unit, a first estimator, an interpolator, and a second estimator. The overlap unit overlaps a group of normal data packets including a head, a body, and a tail, and a known data region is periodically repeated in the body. The first estimator estimates CIRs of the known data regions according to a first algorithm, and the interpolator estimates CIRs of normal data regions in the body by interpolating the estimated CIRs of the known data regions. The second estimator estimates CIRs of normal data regions in the head and tail according to a second algorithm different from the first algorithm. A calculator calculates equalization coefficients based on the estimated CIRs and a compensator multiplies the overlapped data with the coefficients. A save unit saves the compensated data.03-08-2012
20120057653METHOD FOR TUNING A DIGITAL COMPENSATION FILTER WITHIN A TRANSMITTER, AND ASSOCIATED DIGITAL COMPENSATION FILTER - A method for tuning a digital compensation filter within a transmitter includes: obtaining at least one resistance-capacitance (RC) detection result, wherein the digital compensation filter includes an RC compensation module; and tuning the digital compensation filter by inputting the RC detection result into the RC compensation module. For example, the RC detection result may correspond to a detected value representing a product of a resistance value and a capacitance value. In another example, the at least one RC detection result may be obtained by performing RC detection on at least a portion of the transmitter without individually measuring resistance values of resistors therein and capacitance values of capacitors therein. An associated digital compensation filter and an associated calibration circuit are also provided.03-08-2012
20110064162TRANSMITTING UNIT THAT REDUCES PAPR AND METHOD THEREFOR - A communication system (03-17-2011
20120063543Transmitted with Quantization Noise Compensation - The invention discloses a transmitter (03-15-2012
20120063542Novel Wide Null FOrming System with Beamforming - A novel wide null forming system achieves both wide bandwidth and beam width null through employing an antenna array to receive and transmit signals to which a complex null weight vector, calculated by perturbation program, is applied. The novel wide null forming system includes a multiple-element antenna array for receiving or transmitting signals. Multiple conditioning units matching the number of elements is present to condition the signals for proper reception and analysis, after which a series of complex multiplier processors adds complex weights. After being weighted each constituent beam is combined in an adding processor to form one composite beam for use by the user.03-15-2012
20090135949DIGITL PRE-DISTORTION FOR OTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM)SIGNALS05-28-2009
20120300877PRECODING METHOD, TRANSMITTING DEVICE, AND RECEIVING DEVICE - A transmission scheme for transmitting a first modulated signal and a second modulated signal in the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a precoding weight by a baseband signal after a first mapping and a baseband signal after a second mapping and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.11-29-2012
20120300876QUADRATURE MODULATOR, SIGNAL GENERATING DEVICE, AND QUADRATURE MODULATION METHOD - To provide a quadrature modulator, a signal generating device, and a quadrature modulation method capable of correcting a gain balance error, a zero offset error, and an orthogonality error that occur during quadrature modulation. The quadrature modulator 11-29-2012
20120106675DIGITAL BROADCAST SYSTEM FOR TRANSMITTING/RECEIVING DIGITAL BROADCAST DATA, AND DATA PROCESSING METHOD FOR USE IN THE SAME - The present invention is directed to a digital broadcast system and a data processing method. A broadcast signal in which mobile service data and main service data are multiplexed is transmitted and received. Then, in a broadcasting receiver, mobile service data identification information indicating whether the mobile service data of the broadcast signal provides an internet protocol (IP)-based service is parse from the broadcast signal. And the mobile service data is outputted by using the parsed mobile service data identification information.05-03-2012
20120106674RECEPTION APPARATUS AND TRANSMISSION APPARATUS FOR SUPPORTING SCALABLE BANDWIDTH IN CARRIER AGGREGATION ENVIRONMENT - Provided are a reception apparatus and transmission apparatus for supporting a scalable bandwidth in a carrier aggregation environment. The reception apparatus and transmission apparatus can link carrier aggregation technology and scalable bandwidth technology by supporting a scalable bandwidth having different bandwidths in size in a carrier aggregation environment, thereby enhancing compatibility between different wireless communication systems.05-03-2012
20100172439SYSTEMS AND METHODS FOR DESIGNING A SEQUENCE FOR CODE MODULATION OF DATA AND CHANNEL ESTIMATION - A method for using a numerical method to design a sequence for code modulating data is described. An input multiple input multiple output signal is determined. A nearest tight frame to one or more given structured vectors is obtained. One or more structured vectors is obtained from the nearest tight frame. The one or more structured vectors is projected onto the space of circulant matrices. One or more classes of matrices that indicates the design of the sequence is outputted. Data is code modulated using the designed sequence.07-08-2010
20100172438TRANSMISSION SIGNAL GENERATING APPARATUS, METHOD, AND PROGRAM - Data multiplexing subcarrier identification signal generating means generates a data multiplexing subcarrier identification signal that identifies subcarriers with which data signals are to be multiplexed. Transmission signal generating means generates transmission signals by multiplexing data signals with subcarriers according to the data multiplexing subcarrier identification signal. Peak reducing transmission signal generating means generates peak reducing transmission signals by reducing peak power of the transmission signals according to peak reducing signals in a combination of a first peak reducing process in which subcarriers with which the data signals are not multiplexed are used for the peak reducing signals and subcarriers with which the data signals are multiplexed are not used for the peak reducing signals, and a second peak reducing process in which both subcarriers with which the data signals are not multiplexed and the subcarriers with which the data signals are multiplexed are used for the peak reducing signals.07-08-2010
20090092203ADAPTIVE SELF-QUIETER SUPPRESSION FOR OFDM WIRELESS COMMUNICATION SYSTEMS - Various embodiments to provide cancellation techniques that can be used to address the self-quieter problem are described. For example, a receiver that includes a tone selector and a self-quieter suppressor is provided. The tone selector (04-09-2009
20120121037Apparatus and Method of Reducing Noise For Frequency Modulated Signals - Apparatus for reducing FM click noise on a demodulated FM signal, the apparatus comprising, filter means configured to produce a click detection signal according to the demodulated FM signal, click detection means configured to receive the click detection signal and produce a click occurrence signal, and click correction means configured to correct FM clicks on the de-modulated FM signal according to the click occurrence signal.05-17-2012
20120121040Apparatus for Transmitting and Receiving Data to Provide High-Speed Data Communication and Method Thereof - In the present invention, data generated from a source unit are distributed to at least one bandwidth; the data distributed to the respective bandwidths are encoded in order to perform an error correction; the encoded data are distributed to at least one antenna; a subcarrier is allocated to the data distributed to the respective antennas, and an inverse Fourier transform is performed; a short preamble and a first long preamble corresponding to the subcarrier are generated; a signal symbol is generated according to a data transmit mode; and a frame is generated by adding a second long preamble between the signal symbol and a data field for the purpose of estimating a channel of a subcarrier which is not used.05-17-2012
20120121039DIGITAL FAST CORDIC FOR ENVELOPE TRACKING GENERATION - Disclosed is a coordinate rotation digital computer (CORDIC) having a maximum value circuit that selects a larger of the first component or the second component. A minimum value circuit selects a minimum operand that is a smaller one of the first component or the second component. Also included are N rotator stages, each corresponding to a unique one of N predetermined vectors, each of the N rotator stages having a first multiply circuit to multiply the maximum operand by a cosine coefficient of a predetermined vector to output a first rotation component, a second multiply circuit for multiplying the minimum operand by a sine coefficient of the predetermined vector to output a second rotation component, and an adder circuit for adding the first rotation component to the second rotation component to output one of N results, and a maximum value circuit for outputting a maximum one of the N results.05-17-2012
20120121038Processing Method And Device For Simulating And Adding Noise To Digital Signals - The invention relates to a method of synthesizing the color-changing noise, which comprises the following steps: collecting target digital signals or target digital signal traces to be subject to the noise-adding processing; generating white noise signals or white noise signal traces; performing a convolution operation on the target digital signals and the white noise signals to generate color-changing noise signals or performing a convolution operation on the target digital signal traces and the white noise signal traces to generate color-changing noise signal traces. In addition, the invention also relates to a method and device for performing simulating and noise-adding processing using the color-changing noise.05-17-2012
20120121036METHOD AND APPARATUS FOR CLOCK SPUR SUPPRESSION IN DIRECT-RF MODULATORS - Methods and systems to reduce clock spurs produced by a direct-RF modular to acceptable levels using a digital predistortion compensation signal. The digital compensation signal may be used to generate a sine wave in the digital domain with adjustable phase and amplitude. The digital compensation signal may be added to a digital signal processor (DSP) section of an upconvertor, and may be combined with the undesired clock spur signal to reduce it or even cancel it out completely. In some implementations, the digital predistortion compensation signal may have a similar level of the clock spur such that when added to the clock spur, results in a clock spur having a reduced amplitude.05-17-2012
20120128098APPARATUS AND METHOD FOR DIGITAL PREDISTORTION OF NON-LINEAR AMPLIFIERS - A method used in a transmitting device comprising a non-linear amplifier and a digital predistortion (DPD) circuit. The method updates real and imaginary look-up tables used by the DPD. The method comprises: i) time-aligning a complex input signal, A, and a complex output signal, E. Signal A is a scan from 0 to a maximum value comprising N discrete points and signal E also comprises N discrete points. The method comprises: ii) performing an array division of A/E=(Y05-24-2012
20120128097METHODS AND APPARATUS FOR TRANSMITTING SIGNALS WITH SELECTIVE DELAY FOR COMPENSATION OF INTERSYMBOL INTERFERENCE AND SIMULTANEOUS SWITCHING OUTPUTS - Transmitter-based techniques are provided for compensation of intersymbol interference and/or simultaneous switching outputs, using selective pulse width modulation. One or more signals are transmitted by detecting whether one or more of said signals satisfy one or more predefined signal corruption conditions, wherein said predefined signal corruption conditions indicate that one or more of said signals are anticipated to exhibit one or more of intersymbol interference and simultaneous switching outputs; and selecting a delay for one or more of the signals based on the one or more predefined signal corruptions conditions. The predefined signal corruption conditions comprise, for example, (i) digital data encoded in the one or more signals maintaining a same binary value for two or more consecutive clock cycles (to indicate intersymbol interference); and (ii) a predefined minimum number of aggressor data edges in digital data encoded in the one or more signals, and a corresponding predefined number of victim data edges in the digital data encoded in the one or more signals, wherein the victim edges are moving in an opposite direction to the aggressor data edges (to indicate simultaneous switching outputs).05-24-2012
20110182381System and Method for Digital Communications with Unbalanced Codebooks - A system and method for digital communications with unbalanced codebooks is provided. A transmitter includes a channel encoder that generates an output codeword from an information vector provided by an information input, and a modulator/transmitter circuit coupled to the channel encoder. The modulator/transmitter circuit prepares the output codeword for transmission over a physical channel. The channel encoder encodes the information vector into an intermediate codeword using a first code and shapes the intermediate codeword into the output codeword having a desired distribution.07-28-2011
20120213312WIRELESS TRANSMITTING APPARATUS, WIRELESS TRANSMITTING METHOD, AND WIRELESS TRANSMITTING PROGRAM - An interference suppression signal suppresses a leakage power caused by a transmission information symbol outside a desired transmission band. In a wireless transmitting apparatus, an interference suppression signal waveform shaping unit performs waveform shaping to the interference suppression signal while the interference suppression signal is separated from the transmission information symbol.08-23-2012
20120163497CHANNEL ESTIMATION BASED ON LONG TRAINING SYMBOL WITH DOUBLED CYCLIC PREFIX - In at least some embodiments, a receiver includes channel estimation logic configured to a process a long training field symbol having a doubled cyclic prefix. The channel estimation logic is configured to vary an amount of the doubled cyclic prefix used for channel estimation. Further, in some embodiments, a wireless communication device includes logic to enable communications based on at least two long training field symbols having a doubled cyclic prefix as part of a synchronization header. Further, in some embodiments, a method includes receiving a long training field symbol having a synchronization header with a doubled cyclic prefix and varying an amount of the doubled cyclic prefix used for channel estimation.06-28-2012
20120250791Codebook Method for a Multiple Input Multiple Output Wireless System - A method for wireless encoding includes encoding wireless multiple input and multiple output signals in accordance with a codebook being one of a discrete codebook restricting elements of codebook entries to be within a predetermined finite set of complex numbers and a constant amplitude codebook including each entry in its codebook having equal column norm and equal row norm. In a preferred embodiment the digital codebook further includes restricting elements of a finite set in the discrete codebook to be in the form of k10-04-2012
20120250789GENERATING A MODULATED SIGNAL FOR A TRANSMITTER - A technique includes generating an angle modulated square wave signal and progressively filtering the angle modulated square wave signal in a transmitter using a plurality of low pass filters to produce a modulated sinusoidal signal to drive an antenna. The technique includes programming the transmitter to tune a corner frequency of the filtering to a frequency within a range of frequencies selectable using the programming, based on a carrier frequency associated with the modulated sinusoidal signal.10-04-2012
20110200139MULTIPLE-INPUT MULTIPLE-OUTPUT SYSTEMS AND METHODS FOR WIRELESS COMMUNICATION THEREOF FOR REDUCING THE QUANTIZATION EFFECT OF PRECODING OPERATIONS UTILIZING A FINITE CODEBOOK - A method for reducing the quantization effect of precoding operations utilizing a finite codebook in multiple-input multiple-output (MIMO) or multiple-input single-output (MISO) systems from a transmitter to a receiver is provided. First, downlink channel state information is obtained at the receiver side. A set of indices of precoding matrices or a set of precoding matrices within the finite codebook are determined according to the obtained downlink channel state information at the receiver side. The selected indices of precoding matrices and a set of scalar coefficients are transmitted from the receiver to the transmitter. Thereafter, a refined precoding matrix is generated based on the set of indices of precoding matrices and the one or more scalar coefficients at the transmitter side. The refined precoding matrix is applied for transmission between the transmitter and the receiver.08-18-2011
20120250790FREQUENCY SELECTIVE IQ CORRECTION - In conventional radio frequency (RF) systems, transmitters will usually convert baseband signals to RF so as to be transmitted. As part of the conversion process, the transmitters will perform digital preditortion (DPD), which uses feedback from a power amplifier. However, there are usually mismatches between the in-phase (I) and quadrature (Q) paths within with feedback loop. Traditional IQ correction filters were ineffective at providing adequate compensation for these mismatches, but here a filter is provided that provides adequate out-of-band compensation by use of frequency selectivity.10-04-2012
20120076236METHOD AND APPARATUS FOR EFFICIENT FEEDBACK IN A WIRELESS COMMUNICATION SYSTEM SUPPORTING MULTIPLE ANTENNA - A method and apparatus for transmitting effective channel status information (CSI) in a wireless communication system supporting multiple carriers are disclosed. A method for transmitting CSI of DL transmission via uplink in a wireless communication system includes transmitting a rank indicator (RI) at a first subframe, and transmitting a first precoding matrix indicator (PMI), a second PMI, and a wideband (WB) channel quality indicator (CQI) at a second subframe. UE preferred precoding matrix is indicated by a combination of the first PMI and the second PMI. A subsampled codebook for each precoding codebook of ranks from Rank-1 to Rank-4 is applied to the first PMI and the second PMI, and a sum of the first PMI and the second PMI for each of Rank-1 to Rank-4 is comprised of 4 bits.03-29-2012
20120076235NONLINEAR COMPENSATING APPARATUS AND TRANSMITTER - The present invention provides nonlinear compensating apparatus and transmitter. The nonlinear compensating apparatus comprises: an information acquiring unit to acquire a symbol information sequence of the pulse information input by a transmitting side; a perturbation quantity calculating unit to calculate the weighted sum of the interaction of the pulses of several items at several different instants relative to the current instant, to obtain the perturbation quantity produced by the current instant nonlinear effect on a transmission link of a certain length; and an information compensating unit to compensate for the symbol information sequence of the pulses at the current instant acquired by the information acquiring unit by using the perturbation quantity obtained by the perturbation quantity calculating unit, so as to obtain the symbol information sequence compensated at the current instant to cause the transmitting side to transmit signals according to the compensated symbol information sequence. The apparatus corrects the symbol information sequence of the pulse signals input by a transmitting side, with the complexity of calculation being low, and the apparatus is applicable to single-polarization and dual-polarization multiplexing systems, and at the same time, compatible with any modulation format.03-29-2012
20120314806METHOD FOR TRANSMITTING A SIGNAL IN A DISTRIBUTED ANTENNA SYSTEM - The present invention relates to a method for configuring, for each of one or more ranks in the DAS (distributed antenna system), a codebook for a DAS, including pre-coding matrices for the DAS, wherein the matrices include information on at least one or more antennas used for communication with a specific terminal, from among the whole antenna of the base station which belongs to the DAS, and information on the ratio of electric power allocated to each of the antennas of the base station. The present invention also relates to a method for transmitting a signal which is pre-coded using the thus-configured pre-coding matrices for the DAS.12-13-2012
20100008445Method and system for generating reference signals in a wireless communication system - A method of generating reference signals is provided. The method includes precoding a reference signal to generate a plurality of precoded reference signals. For each precoded reference signal, a signal based on the precoded reference signal is transmitted from a corresponding physical antenna.01-14-2010
20090074105Correction of distortions in an emission chain - An emission chain is suitable for receiving an input signal and for providing a signal to be emitted. It comprises a processing pathway for the input signal which includes a digital signal decomposition according to N signal components, with N an integer greater than or equal to 2, said N signal components, on the one hand, being converted from a digital form into an analog form and, on the other hand, following respectively distinct physical pathways, said physical pathways inducing first respective delays on the N signal components. The input chain comprises a power amplifier.03-19-2009
20120224652Method and Terminal for Channel State Information Feedback - The present invention discloses a method and terminal for feeding back channel status information, including: when the channel status information is fed back on the physical uplink control channel, code words contained in the used codebook C09-06-2012
20120257690ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) - A method for improving noise performance in a Radio Frequency (RF) transmitter that makes use of Orthogonal Frequency Division Multiplexing (OFDM). The method • comprising the steps of: receiving a stream of digital data symbols in the form of symbol vectors, for RF transmission after multiplexing onto a subset of a set of sub-carriers according to OFDM and transforming each received symbol vector to the time domain; generating a first time domain cancellation vector from a basis vector that has the same dimensionality as the symbol vectors. In the frequency domain the basis vector has substantially zero value in each of the first subset of sub-carriers of the symbol vector and in the time domain the difference between a first element of the basis vector having the highest value and a second element of the basis vector having the next highest value is maximised. The method also comprises processing each symbol vector by subtracting the first cancellation vector from it to produce a modified symbol vector having reduced Peak-to-Average Power Ratio (PAPR) and then iteratively generating a new cancellation vector using the modified symbol vector, and producing a new symbol vector have reduced Peak-to-Average Power Ratio (PAPR). Other aspects include software for performing the method, an RF transmitter for transmitting OFDM with improved noise performance characteristics, and an OFDM signal with improved noise performance characteristics.10-11-2012
20120257691DYNAMIC DIGITAL COMMUNICATION SYSTEM CONTROL - Control of a digital communication system having a plurality of communication lines on which signals are transmitted and received is implemented using a variety of methods and systems. According to one embodiment of the present invention, a method is implemented where the signals are affected by interference during transmission and each of the communication lines has at least one transmitter and at least one receiver. A model is created of the interference characteristics due to the signals carried on the communication lines. Interference characteristics for a line are determined based on the model and actual signals carried on other communication lines different from the line for which the characteristics are being determined. Actual interference is compensated for on the communication line using the determined interference characteristics.10-11-2012
20120328048PEAK SUPPRESSING APPARATUS, PEAK SUPPRESSING METHOD AND WIRELESS COMMUNICATIONS APPARATUS - A peak suppressing apparatus includes a pre-emphasis section that performs a pre-emphasis process on a signal, which is to be wirelessly transmitted and a peak of which is to be suppressed, the pre-emphasis process emphasizing a given frequency range component of the signal, a clipping section that limits, to a given threshold value, the amplitude of a signal that has been subjected to the pre-emphasis process, a de-emphasis section that performs a de-emphasis process on a signal, whose amplitude has been limited, the de-emphasis process suppressing a given frequency range component of the signal, and a frequency converter that converts, to allow wireless transmission, the frequency of a signal that has been subjected to the de-emphasis process.12-27-2012
20120328049METHOD AND DEVICE FOR SENDING BETWEEN A RADIO FREQUENCY CIRCUIT AND A BASEBAND CIRCUIT - A method of sending a data signal and a Downlink Uplink clock signal between a radio frequency circuit of a device and a baseband circuit of the device. The method comprises: determining whether at least one of the data signal and the clock signal is disturbing in that it has a harmonic within the radio frequency band. If it is determined that at least one of the data signal and the clock signal is disturbing, the method further comprises: scrambling the at least one disturbing signal to flatten the spectrum thereof for frequencies below the clock frequency F12-27-2012
20120082262ADAPTIVE CLIPPING OF SYMBOLS BASED ON SIGNAL QUALITY - Techniques are provided for crest factor reduction of a symbol to be transmitted by a communication device. The symbol may be an orthogonal frequency division multiplexed (OFDM) formatted symbol. In a communication device, samples of the symbol are clipped with a clipping level. A signal quality of the symbol is computed after it is clipped. A determination is made as to whether the signal quality satisfies a predetermined criterion. When the signal quality does not satisfy the predetermined criterion, the clipping level is adjusted. The clipping, computing, determining and adjusting operations are repeated until the signal quality satisfies the predetermined criterion. The symbol clipped by the clipping level determined to result in satisfying the predetermined criterion is output for supply to a transmitter in the communication device. Techniques for computing for error vector magnitude that are faster and less computationally intensive are provided, as well as a computation for distortion that can be used as a measure of error vector magnitude.04-05-2012
20120263256LINEARIZATION OF A TRANSMIT AMPLIFIER - An apparatus and method of linearization of a digitally-controlled pre-power amplifier (DPA) and RF power amplifier (PA) for performing predistortion calibration to compensate for nonlinearlities in the DPA and PA circuits. A predistortion look up table (LUT) stores measured distortion compensation data that is applied to the TX data before being input to the digital-to-frequency converter (DFC), DPA and PA. The on-chip receiver, which is normally inactive during the TX burst in a half-duplex operation, demodulates the RF PA output and uses the digital I/Q RX outputs to perform calibration of the TX pre-distortion tables. A sample of the RF output signal is provided to the receiver chain. While the PA (DPA) code is increasing (or decreasing), the amplitude and phase of the recovered I/Q samples are used to determine the instantaneous value of the AM/AM and AM/PM pre-distortion from which an update to the predistortion tables may be computed.10-18-2012
20120263255DATA PROCESSING SYSTEM AND DATA PROCESSING METHOD - The present invention provides a source node device and a destination node in a data processing system, a data processing system, and a decoding method. The source node device includes: an encoding unit, configured to conduct an encoding processing on collected original data according to a codebook including an encoded numerical value and a sending interval corresponding to the original data so as to encode the original data into encoded data having a corresponding encoded numerical value included in the codebook, and to determine a sending interval corresponding to the encoded data included in the codebook. According to the present invention, sending intervals of different encoded data are determined and distinguished based on sending intervals corresponding to the encoded data included in the codebook, which provides a better performance on channel load, channel access collisions, energy efficiency, consumed resources or lifetime of the data processing system.10-18-2012
20120230449WIRELESS SENDING APPARATUS, WIRELESS SENDING METHOD, STORAGE MEDIUM AND BASEBAND CIRCUIT - A wireless sending apparatus with a change judging means to judge whether changing an interference causing avoiding transmission means on the basis of predetermined change judging information, and to output the judgment as a change judgment result; a signal separating means to separate the sending signal into each the group on the basis of the change judgment result; a first interference causing avoiding transmission means to input the sending signal which is separated into each the group, and to reduce leak power by a time-domain process; a second interference causing avoiding transmission means to input the sending signal which is separated into each the group, and to reduce the leak power by a frequency-domain process; and a synthesizing means to synthesize the sending signals which the first interference causing avoiding transmission means and the second interference causing avoiding transmission means carry out the interference causing avoiding process.09-13-2012
20080298500SYSTEMS, APPARATUS, AND METHODS FOR PERFORMING DIGITAL PRE-DISTORTION WITH FEEDBACK SIGNAL ADJUSTMENT - In an embodiment, a digital pre-distortion apparatus processes an input signal to produce a pre-distorted signal, and processes the pre-distorted signal to produce a feedback signal. The apparatus also rotates an adjustment gain by a gain rotation angle to produce a rotated adjustment gain, where the gain rotation angle is based on a phase difference between the input signal and the feedback signal. The apparatus also applies the rotated adjustment gain to the feedback signal, which may result in rotation of the feedback signal into a target phase region.12-04-2008
20120321018DIGITAL PRE-DISTORATION PROCESSING METHOD AND APPARATUS - This invention discloses a for digital pre-distortion processing method and apparatus, the method including that: training signals are sent to at least one radio frequency front-end device as needed (12-20-2012
20110243273TRANSMITTING APPARATUS IN MULTIPLE INPUT MULTIPLE OUTPUT SYSTEM - Provided are a transmitting apparatus and a transmitting method in a multiple input multiple output system. A power allocation controller includes a block Tomlinson-Harashima precoder (BTHP) that precodes and outputs data to be transmitted to each user in a nonlinear scheme. The BTHP removes and outputs inference signals from data for each user based on the channel information that is fed back from the users. The data for each user output from the BTHP are allocated with power by the power allocation controller. The power allocation controller calculates power allocation parameters so that receiving minimum distances at receiving ends for each user that receive data through the MIMO antennas are the same, and allocates the calculated parameters to data for each user.10-06-2011
20100220810Transmitter Characterization for Digital Pre-Distortion Using Offset Preamble Subcarriers - Techniques are provided to pre-distort a signal that is transmitted by a transmitter of a wireless communication device, e.g., a device configured for wireless radio frequency communication. The transmitter of the device inherently introduces distortion to the baseband signal to be transmitted. In at least one frame of a baseband signal to be transmitted, at least one subcarrier in a preamble of the frame is shifted in frequency such that the at least one subcarrier is offset from a normal subcarrier frequency position. The at least one frame of the baseband signal is supplied to the transmitter that is configured to produce a transmit signal for transmission. The transmit signal at an output of the transmitter is sampled or detected and inter-modulation distortion in the transmit signal is determined at one or more frequencies as a result of shifting of the frequency of the at least one subcarrier in the preamble of the at least one frame. The baseband signal is pre-distorted based on the inter-modulation distortion prior to coupling to the transmitter for transmission.09-02-2010
20100220811APPARATUS - An apparatus configured to receive a first signal and a second signal from a further apparatus, determine a third signal dependent on at least a first part of the first signal and a first part of the second signal, and generate a parameter value dependent on the third signal.09-02-2010
20120321017TRANSMISSION BEAMFORMING METHOD AND APPARATUS IN AN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING-BASED MIMO WIRELESS SYSTEM - The present invention relates to a transmission beamforming method and apparatus in an orthogonal frequency division multiplexing (OFDM)-based MIMO wireless system. In particular, the present invention relates to a transmission beamforming method in an OFDM-based MIMO wireless system and an apparatus therefor, wherein the transmission beamforming method comprises: estimating a channel from a received pilot signal and obtaining time for the estimating channel and 2D channel correlation information of a frequency band; obtaining estimated channel information based on the channel correlation information; obtaining differential information that represents a difference between the current channel and the estimated channel and quantizing the differential information; and generating a transmission beam weight by using a predefined code book from the quantized differential information. The present invention may also provide a method and apparatus for reducing the channel quantization error and feedback load by employing the OFDM-based MIMO in a wireless communication system using a transmission beamforming scheme, wherein a receiver estimates current channel information by using time and 2D channel correlation information of a frequency based on the previous channel information, compares the estimated current channel information with an actual channel and then feeds back the differential channel information, i.e., the difference between the estimated channel and the actual channel, to a transmitter.12-20-2012
20100202563METHOD AND PRE-CORRECTOR FOR CORRECTING SIGNALS IN RADIO FREQUENCY LINKS - A method and pre-corrector for correcting signals in radio frequency links are provided. The method comprises: obtaining, in a time division order, a set of pre-distortion vectors for the respective radio frequency links by using one and the same set of pre-distortion vector obtaining means based on difference in arrival time of cyclic delay frames in the respective radio frequency links of a multiple input multiple output (MIMO) system; and correcting a subsequent signal in the respective radio frequency links by using the set of pre-distortion vectors corresponding to that radio frequency link. With the present invention, it is only required to scan a frame header once to generate an error vector table for the input signal across the entire dynamic range of power. The device can be reused by utilizing the cyclic delay frame structure, so as to achieve high linearity of a radio frequency header.08-12-2010
20130010892Methods and Systems for Low-power and Pin-efficient Communications with Superposition Signaling Codes - A communication system uses a bus to transmit information, by receiving signals and mapping them to a second set of signals representing codewords of a superposition signaling code, and transmitting the second set of signals. The superposition signaling code can comprise more than one layer. The pin-efficiency can be larger than 1. The system may encode bits into a codeword of a superposition signaling code that is defined by two basis vectors of predetermined size and then have two encoders for permutation modulation codes defined by the basis vectors. The bits of information are divided into a first part representing a predetermined number of bits and a second part representing a predetermined number of bits, with the parts provided to the respective encoding circuits and their outputs combined by a superposition.01-10-2013
20130010896Method And System For Selecting Pre-Coding Matrix In Closed Loop Multi-Input Multi-Output System - A method and a system for selecting a pre-coding matrix in a closed loop MIMO system are provided. The method includes: traversing all pre-coding matrices and respectively calculating a CINR corresponding to each pre-coding matrix; and obtaining an MCS according to a CINR corresponding to a pre-coding matrix, calculating a spectral efficiency corresponding to the MCS, and selecting a pre-coding matrix with a largest spectral efficiency. According to the method and system provided by the present disclosure, an appropriate pre-coding matrix can be selected. By using the appropriate pre-coding matrix in the closed loop MIMO system, the channel quality, the throughput of a closed loop multiplexing system in the scenario that the channel changes slowly, and the gain can be improved. Besides, the method of the present disclosure can avoid calculation of the BER formula on the premise of a large number of assumptions, and reduce the computation complexity.01-10-2013
20130010893X-MIMO Systems with Multi-Transmitters and Multi-Receivers - A method and apparatus for transmitting and receiving a wireless transmission of a plurality of data streams in a wireless communication system having a plurality of nodes is disclosed. Each node has multiple antennas. The method involves receiving first and second data streams from respective first and second nodes at a receiver node, causing the receiver node to generate a receive filter for decoding each of the received data streams, and causing the receiver node to transmit receive filter information for each of the first and second data streams, the receive filter information facilitating precoding of the first and second data streams for simultaneous transmission within a common frequency band to the receiver node.01-10-2013
20100150267PRECODING WITH REDUCED FEEDBACK FOR COORDINATED MULTIPOINT TRANSMISSION ON THE DOWNLINK - Techniques for reducing the number of bits needed to specify the best precoding vector for each mobile station in a wireless communication network that employs multi-point transmission are disclosed. An exemplary method begins with the estimation of path loss between a mobile station and each of a plurality of geographically separated transmitter sites, each transmitter site having at least one transmitter antenna. Based on the estimated path losses, one of a plurality of pre-determined subsets (codebooks) of a pre-determined set of antenna precoding vectors is selected. A group index identifying the selected subset is then transmitted to the mobile station. Subsequently, a vector index is received from the mobile station, the vector index corresponding to a precoding vector in the selected subset, and data is transmitted to the mobile station, using the precoding vector applied to the transmitter antennas at the plurality of transmitter sites.06-17-2010
20100150266METHOD AND APPARATUS FOR CODEBOOK-BASED FEEDBACK IN A CLOSED LOOP WIRELESS COMMUNICATION SYSTEM - A method and apparatus are provided for feedback for closed-loop transmitting with multiple transmit antenna elements and multiple receive antenna elements. A base station includes a codebook containing sets of weightings for the multiple transmit antenna elements, with each set of weightings identified by an index and the codebook known to the base station and a served mobile station (MS). The base station pre-codes pilot signals using a precoding matrix, preferably a unitary matrix, to produce pre-coded pilot signals, which precoding matrix may or may not be known to the MS and which precoding matrix may or may not be included in the codebook. The base station then transmits the pre-coded pilot signals to the MS via the multiple transmit antenna elements and, in response, receives an index to a set of weightings in the codebook for use in a subsequent transmission of a data stream.06-17-2010
20100150264Precoder Design for Different Channel Lengths - Apparatus and methods construct parameters for a unit associated with a precoder to a channel. Embodiments include forming a plurality of values for precoder constructions, where the values may be obtained from applying a transmission quality criterion to each precoder construction for varying channels lengths. Each precoder construction may be built for a predetermined channel length with a different channel length for each precoder construction. A subset of the precoder constructions operate substantially over the entire distance range covered by the varying channels lengths.06-17-2010
20110158347METHOD AND TRANSMITTER FOR ITERATIVELY MODIFYING BEAMFORMING VECTOR - The present invention provides data transmission capacity that is optimized in a communication environment by iteratively modifying a beamforming vector by linearly coupling selfish beamforming with unselfish beamforming using feedback information. The transmitter for modifying the beamforming vector iteratively includes: a feedback receiving module that receives feedback information from a receiver: and a vector determination module that determines an initial beamforming vector by coupling a first vector for the selfish beamforming with a second vector for the unselfish beamforming at the time of initial beamforming, and corrects a coupling ratio of the first vector and the second vector of the beamforming vector with reference to the received feedback information whenever the beamforming is modified.06-30-2011
20110158346DUAL-LOOP TRANSMIT NOISE CANCELLATION - A transmitter circuit is described. The transmitter circuit includes a first local oscillator that generates a first frequency equal to a duplex frequency. The transmitter circuit also includes a second local oscillator that generates a second frequency equal to a receive frequency. The transmitter circuit further includes a first mixer that combines the first frequency with a first input signal. The transmitter circuit also includes a first feedback loop. The first feedback loop includes a second mixer that combines the second frequency with a transmit signal and a first filter and a first adder that combines an output of the first mixer with an output of the first filter. The transmitter circuit also includes a third local oscillator that generates a third frequency equal to the receive frequency. The transmitter circuit further includes a third mixer that combines the third frequency with an output of the first adder.06-30-2011
20130022148METHODS AND APPARATUS FOR SIGNAL CONDITIONING FOR POLAR TRANSMITTERS - Methods, systems, devices, and apparatuses for signal condition of polar transmitters are discussed this patent application. According to one embodiment, a frequency limiting mechanism for a polar transmitter can perform minimal distortion frequency limiting to comply with the polar transmitter requirements while meeting emissions specifications. Embodiments of the present invention may be utilized as features or components of wireless communication devices to enable minimal distortion to information carrying signals and to meet emissions specifications. Other aspects, embodiments, and features are claimed and discussed above.01-24-2013
20080247487Dynamic crest factor reduction system - A system and method for performing digital crest factor reduction. In one embodiment, the method is devised to suppress the signal amplitude to maintain a low signal peak to average ratio (PAR), while maintaining a desirable Error Vector Magnitude (EVM). This technique may be designed to operate in highly dynamic signal conditions.10-09-2008
20080232509Interference Suppression in Bit-Serial Data Streams - Described is an apparatus for suppressing spurious spectral lines in a frame based bit-serial data stream, in which frames include payload data and frame markers. The apparatus includes means (09-25-2008
20130142281SIDEBAND MITIGATION COMMUNICATION SYSTEMS AND METHODS FOR INCREASING COMMUNICATION SPEEDS, SPECTRAL EFFICIENCY AND ENABLING OTHER BENEFITS - Common wave and sideband mitigation communication systems and methods are provided that can be used with both wireless and wired communication links. The systems and methods provided can enable faster data rates, greater immunity to noise, increased bandwidth/spectrum efficiency and/or other benefits. Applications include but are not limited to: cell phones, smartphones (e.g., iPhone, BlackBerry, etc.), wireless Internet, local area networks (e.g., WiFi type applications), wide area networks (e.g., WiMAX type applications), personal digital assistants, computers, Internet service providers and communications satellites.06-06-2013
20130170580EMPHASIS CIRCUIT AND TRANSMITTER - An emphasis circuit includes: an applying circuit to add an emphasis signal to an input differential signal; a feedback path to feed back a differential output of the applying unit; a comparing circuit to compare a direct current component level of a positive phase signal and of a negative phase signal of the differential signal; a direct current component level controlling circuit to control a direct current component level of at least one of the positive phase signal and the negative phase signal; a delay unit circuit to add a delay to at least one of the fed-backed differential signal to generate the emphasis signal and inputs the emphasis signal into the applying unit; and a dummy load coupled to a positive phase signal output or a negative phase signal output of the applying unit.07-04-2013
20130177103APPARATUS AND METHOD FOR DETERMINING AN EFFECTIVE CHANNEL AND FEEDBACK INFORMATION - The present invention provides a method and apparatus for determining an effective channel and feedback information. The method for determining an effective channel comprises: selecting more than one basic column vectors for determining a precoding matrix; calculating products of channel row vectors and the basic column vectors; and determining the effective channel or a Hermitian matrix of the effective channel by using the products. It can be seen from above that with the calculation of products of channel row vectors and more than one basic column vectors determining a precoding matrix and determination of an effective channel or Hermitian matrixes of the effective channel by using the products, the equipment is enabled to lower the amount of calculation and the complexity of calculation, lower the power consumption of the equipment and reduce the circuit size needed in performing corresponding processing in determining an effective channel or Hermitian matrixes of the effective channel and in determining channel feedback information.07-11-2013
20130177104ORTHOGONAL MULTI-RATE MODULATION DEVICE AND METHOD - An orthogonal multi-rate modulation method for modulating a symbol vector made up of a plurality of data symbols is disclosed. The orthogonal multi-rate modulation method includes the following steps: firstly, a precoding matrix, in which the column vectors are mutually orthogonal, is provided. Then, a product of the symbol vector and the precoding matrix is made to generate a precoded vector. Finally, the precoded vector is filtered by a Nyquist Analog Filter, so as to output a complex baseband waveform.07-11-2013
20130177105METHOD AND SYSTEM FOR ESTIMATING AND COMPENSATING NON-LINEAR DISTORTION IN A TRANSMITTER USING CALIBRATION - Aspects of a method and system for estimating and compensating for non-linear distortion in a transmitter using calibration are presented. Aspects of the system may include one more circuits that may enable estimation, within a single IC device, of distortion in output signals generated by a transmitter circuit. The circuitry may enable compensation of the estimated distortion by predistorting subsequent input signals. The transmitter circuit may generate subsequent output signals based on the predistorted subsequent input signals.07-11-2013
20110274209CODEBOOK BASED PRECODING METHODS - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied.11-10-2011
20110274208Feedback Generator For Codebook With Nested Structure - A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.11-10-2011
20110274207Enhancing MIMO Transmission - A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.11-10-2011
20080219377Transmitter crosstalk cancellation in multi-standard wireless transceivers - A method of suppressing interference from a transmitter operating to a first standard to a local receiver operating to a second standard is provided. Such interference being increasingly common as a result of the deployment of multiple wireless transceivers within electronic devices supporting multiple international standards, such as WiFi and WiMAX. Advantageously, the invention presents a means of actively cancelling interference both from transmitters operating within the same frequency range as defined by the standard as well as those operating in different frequency ranges. The active cancellation accordingly allows improved performance for systems with very low received signal powers, such as GPS, in addition to wireless data communications standards. An exemplary embodiment providing active cancellation through delaying a portion of the transmitted signal and adjusting both the amplitude and phase by means of polar modulation prior to summing this signal with the detected signal to provide a receive signal within which the transmit signal is nulled.09-11-2008
20130094610Digital Multi-band Predistortion Linearizer with Nonlinear Subsampling Algorithm in the Feedback Loop - A concurrent multi-band linearized transmitter (CMLT) has a concurrent digital multi-band predistortion block (CDMPB) and a concurrent multi-band transmitter (CMT) connected to the CDMPB. The CDMPB can have a plurality of digital baseband signal predistorter blocks (DBSPBs), an analyzing and modeling (A&M) stage, and a signal observation feedback loop. Each DBSPB can have a plurality of inputs, each corresponding to a single frequency band of the multi-band input signal, and its output corresponding to a single frequency band; each output connect corresponding to an input of the CMLT. The A&M stage can have a plurality of outputs connected to and updating the parameters of the DBSPBs, and a plurality of inputs connected to either both outputs of the signal observation loop or the output of the subsampling loop and to outputs of the DBSPBs. The A&M stage can perform signals' time alignment, reconstruction of signals and compute parameters of DBSPBs.04-18-2013
20130114762RECURSIVE DIGITAL PRE-DISTORTION (DPD) - Recursive digital pre-distortion (DPD) techniques are provided. Digital pre-distortion is performed by applying a signal to a recursive system to generate a state vector; providing the state vector as a feedback value to the recursive non-linear system; and applying the state vector to a second function to generate an output signal, wherein at least one of the recursive system and the second function comprise a non-linear function. The recursive non-linear system can be initialized to a known initial value. The recursive system is defined by a system of non-linear differential equations.05-09-2013
20130114763TRANSMITTING DEVICE AND A METHOD OF COMMUNICATING THEREWITH, AND RECEIVING DEVICE AND A METHOD OF COMMUNICATING THEREWITH - An embodiment of the present invention relates to a wireless communication system, and more specifically relates to a wireless communication system using multi-input and multi-output (MIMO) antennas in all transmission and reception terminals.05-09-2013
20130114761MULTI-STAGE CREST FACTOR REDUCTION (CFR) FOR MULTI-CHANNEL MULTI-STANDARD RADIO - Multi-stage crest factor reduction (CFR) techniques are provided for multi-channel multi-standard radio (MSR). A multi-stage crest factor reduction method comprises applying one or more data samples associated with at least one channel of a first technology type to a first individual crest factor reduction block; applying one or more data samples associated with at least one channel of a second technology type to a second individual crest factor reduction block; aggregating outputs of the first and second individual crest factor reduction blocks to generate an aggregated output; and applying the aggregated output to a composite crest factor reduction block. The individual crest factor reduction blocks can be implemented using a sampling rate appropriate for the corresponding technology type. The composite crest factor reduction block operates at a higher sampling rate than the individual crest factor reduction blocks.05-09-2013
20130101066SYSTEMS AND METHODS FOR DIGITAL PROCESSING BASED ON ACTIVE SIGNAL CHANNELS OF A COMMUNICATION SYSTEM - A communication system includes digital signals that carry data and correspond to channels of a composite signal to be transmitted across a communication channel. Active channels are detected and used to configure digital processing. In one embodiment, active channels are detected, where a particular active channel corresponds to the presence of a particular one of the digital signals. Active channel detection may be used to configure pre-distortion of a composite signal to be transmitted to compensate for distortion in a digital-to-analog converter. Likewise, active channel detection may be used to optimize the configuration of an up-converter. In one embodiment, a programmable device is configured based on detected active channels into a plurality of different configurations.04-25-2013
20110268227POWER LEVEL SETTINGS FOR TRANSMISSION LINES - A method, wherein the following steps are iteratively repeated: providing each of a plurality of signals at a respective one of a plurality of transmission links; transmitting each of the plurality of signals over the respective one of the plurality of transmission links; and measuring signal-to-noise ratios of the plurality of signals transmitted over the plurality of transmission links, wherein an input power level of each of the plurality of signals is set such that the signal-to-noise ratios of the plurality of signals converge when measured after their transmission over the plurality of transmission links.11-03-2011
20130129017EDGE WINDOWING OF OFDM BASED SYSTEMS - Various methods and systems are provided for edge windowing of orthogonal frequency division multiplexing (OFDM) systems. In one example, among others, a method includes obtaining an edge windowing portion by reducing a cyclic prefix size for a quantity of edge subcarriers in an OFDM symbol and reducing side lobes by applying a windowing function to the edge subcarriers. In another example, a device includes a separator capable of dividing subcarriers of an OFDM symbol into first and second subcarrier groups, a first CP adder capable of obtaining a windowing portion by adjusting a cyclic prefix size of the first subcarrier group, and a first windower capable of reducing side lobes by applying a windowing function to the first subcarrier group. In another example, a method includes determining a RMS delay spread of a mobile station and scheduling a subcarrier based at least in part upon the RMS delay spread.05-23-2013
20130129018METHOD AND APPARATUS FOR TRANSCEIVING A PRECODED SIGNAL IN A MULTIPLE ANTENNA SUPPORTED WIRELESS COMMUNICATION SYSTEM - The present invention relates to a method for transmitting a signal from a transmitter to a receiver through N number of transmitting antennas (where N≧2), comprising: selecting a first and a second matrix from a first and a second codebook related to a first and a second precoding matrix indicator (PMI), respectively, and determining a precoding matrix on the basis of the first and second matrix; performing precoding by using the determined precoding matrix for L number of layers (where 1≦L≦N) to which a signal to be transmitted to the receiver is mapped; and transmitting the precoded signal to the receiver through the N number of transmitting antennas. Here, the first codebook includes one or more diagonal matrices having an N×N size, non-zero elements in the diagonal matrix has a predetermined phase value, and the second codebook includes one or more matrices having an N×L size.05-23-2013
20080205546OFDM PRE-EQUALIZING - For example in case of an OFDM multicarrier transmission system the transmission characteristics of subcarriers of a multicarrier transmission system using a plurality of antenna elements (08-28-2008
20110211656METHOD AND SYSTEM FOR A DELTA QUANTIZER FOR MIMO PRE-CODERS WITH FINITE RATE CHANNEL STATE INFORMATION FEEDBACK - A delta quantizer for MIMO pre-coders with finite rate channel state information feedback may comprise partly quantizing a change in channel state information in a MIMO pre-coding system onto at least a first and a second codebook, each of which comprises one or more unitary matrices, using a cost function; and generating the at least first and second codebook based on at least the channel state information. The channel state information may be a matrix V and the cost function may be defined by the following relationship:09-01-2011
20080198945REDUCED EMI DEVICE AND METHOD THEREOF - A method and system are disclosed for spreading the power associated with digital signals being transmitted to reduce electromagnetic interference (EMI) emissions by receiving, via a first transmission line, a first power spread signal representative a first digital signal modified using a first power spreading digital noise signal, modifying the power spread signal using a second power spreading digital noise signal substantially similar to the first power spreading digital noise signal to generate a second digital signal substantially similar to the first digital signal, modifying the second digital signal using a third power spreading digital noise signal to generate a second power spread signal and providing the second power spread signal for output to a second transmission line.08-21-2008
20110228879Method and Device for Transmission of Signals in a GSM System - Methods and devices for transmitting a burst of signals in a cellular radio system supporting data transmission using EGPRS/EGPRS2 are provided. The transmission involves providing additional symbols in the EGPRS/EGPRS2 burst thereby forming a long burst and pulse shaping the long burst to form a long baseband signal whose duration exceeds the duration of one EGPRS/EGPRS2 time slot. The long baseband signal is then shortened to a shortened burst having the duration of an EGPRS/EGPRS2 time slot wherein the shortened burst fulfills the same spectrum mask requirement as the EGPRS/EGPRS2 burst, which can be transmitted.09-22-2011
20130148759Weighting Matrix Selection Based on Information Aquired from Remote Station - The present disclosure provides for an improved application of signal strength weightings in an SDMA sectored cellular network. The improved signal strength weightings application is conducted through the improved selection of weightings from a new codebook subset or by the selection of weightings from a larger codebook subset. In a further embodiment, an antenna beam index or bit map can be used to select the best beam(s) in an SDMA sectored cellular network. In another embodiment, a field or factor in an uplink or downlink transmission packet can designate which directional transmission beam is best suited for the transmission or when the directional transmission beam should be activated.06-13-2013
20080317166METHODS FOR PROPAGATING A NON SINUSOIDAL SIGNAL WITHOUT DISTORTION IN DISPERSIVE LOSSY MEDIA - Systems and methods are described for transmitting a waveform having a controllable attenuation and propagation velocity. An exemplary method comprises: generating an exponential waveform, the exponential waveform (a) being characterized by the equation V12-25-2008
20100284489DIGITAL DIFFERENTIAL SIGNAL TRANSMITTER FOR LOW SUPPLY VOLTAGE - A digital differential signal transmitter circuit for a low supply voltage. A phase correction circuit for correcting digital signals transmitted through two signal paths in such a way as to have a phase relationship of differential signals and duty cycle correction circuits for correcting the digital signals in such a way as to maintain signal integrity in spite of changes in process, supply voltage and temperature are installed on the two signal paths so that the distortion of digital differential signals is compensated for. Power consumption at a final output section of the transmitter circuit is reduced. Impedances of the transmitter circuit and transmission lines are matched so that the transmitter circuit can operate insensitively with respect to operation circumstances.11-11-2010
20120275543SELECTIVE PEAK POWER REDUCTION - A communication system comprising signal processing circuitry and up-conversion circuitry. The signal processing circuitry is configured to: i) generate a first signal of a first modulation type and a second signal of a second modulation type; ii) combine the first and second signals to form a combined input signal; iii) generate peak reduction distortion based on the combined input signal; iv) select a portion of the peak reduction distortion that corresponds to a first frequency band; and v) apply the selected portion of the peak reduction distortion in the first frequency band of the combined input signal to provide a combined output signal. The up-conversion circuitry up-converts the combined output signal to an RF signal for transmission.11-01-2012
20130156129Method and Faculty to Measure and Compensate DCO Frequency Distortions using a DPLL - One embodiment of the present invention relates to a communication system having a digital to analog converter, a first input, a summation component, a compensation filter, and a compensation unit. The converter is configured to receive a first signal. The first input is configured to receive a phase modulation signal. The compensation filter generates a filtered frequency deviation signal to mitigate frequency distortions, such as those from a digital controlled oscillator. The compensation unit includes one or more inputs and is configured to generate a correction signal according to the filtered frequency deviation signal and the first signal. The correction signal at least partially accounts for estimated distortions of the phase modulation signal from the amplitude modulation path and mitigates frequency induced distortions. The summation component is configured to receive the phase modulation signal and the correction signal and to generate a corrected phase modulation signal as a result.06-20-2013
20130182792RADIO FREQUENCY DIGITAL FILTER GROUP DELAY MISMATCH REDUCTION - A radio frequency (RF) front end having group delay mismatch reduction is provided. One embodiment provides a first feed forward path and a second feed forward path. The second feed forward path is electrically in parallel with the first feed forward. The second feed forward path has a first signal path and a second signal path. The first and second signal paths are arranged to be electrically in parallel. The first signal path has a digital filter. The second signal path has a tunable analog filter. The tunable analog filter operates to reduce a delay associated with the second feed forward path as compared with a delay associated with the first feed forward path.07-18-2013
20130182793METHOD, APPARATUS AND SYSTEM FOR CALIBRATING CHANNEL - A method for calibrating a channel which includes: performing slide-window correlation on a delayed downlink service signal of a current transmit channel and a feedback signal of the transmit channel, and performing sampling to obtain a group of correlation values of the transmit channel in a sliding window; determining a peak amplitude value among amplitude values of the group of correlation values in the sliding window, and amplitude values at two points that are left adjacent and right adjacent to a point corresponding to the peak amplitude value; performing an interpolation operation on the peak amplitude value and the amplitude values at the two points that are left adjacent and right adjacent to the point to obtain an amplitude value, a delay and a phase at an actual peak point in the group of correlation values of the transmit channel in the sliding window; and calibrating the transmit channel.07-18-2013
20130188751Precoding Technique - A technique for precoding a signal to be transmitted over a physical channel (07-25-2013
20130188750METHOD AND APPARATUS FOR DETERMINING PRECODING MATRIX, WIRELESS COMMUNICATION SYSTEM - A method and apparatus for determining a precoding matrix and a wireless communication system. In data retransmission, when the retransmission rank is less than an initial transmission rank, the transmitting end selects a matrix having a maximum similarity with an initial transmission precoding matrix in spatial direction according to the retransmission rank. In multiple data retransmissions, precoding matrixes for the retransmissions are different from each other and may have a minimum similarity in the spatial direction, but have a maximum similarity with the initial transmission precoding matrix in the spatial direction. Or, the similarity between each retransmission precoding matrix and the initial transmission precoding matrix in the spatial direction progressively decreases. When precoding matrixes (or identity matrixes) are required for the initial transmission, precoding matrixes having the minimum similarity with each other in the spatial direction are selected according to the retransmission rank, and then orderly used in multiple retransmissions.07-25-2013
20130188749POLAR TRANSMITTER HAVING DIGITAL PROCESSING BLOCK USED FOR ADJUSTING FREQUENCY MODULATING SIGNAL FOR FREQUENCY DEVIATION OF FREQUENCY MODULATED CLOCK AND RELATED METHOD THEREOF - A polar transmitter includes a frequency modulating path, a clock divider and a digital processing block. The frequency modulating path is arranged for generating a frequency modulated clock in response to a frequency modulating signal. The clock divider is coupled to the frequency modulated clock, and arranged for generating a down-divided clock. The digital processing block is coupled to the down-divided clock, and arranged for generating the frequency modulating signal, wherein the frequency modulating signal is adjusted for frequency deviation of the frequency modulated clock. A method for polar transmission includes: generating a frequency modulated clock in response to a frequency modulating signal; dividing a frequency of said frequency modulated clock to generate a down-divided clock; and generating said frequency modulating signal according to said down-divided clock, wherein said frequency modulating signal is adjusted for frequency deviation of said frequency modulated clock.07-25-2013
20120020434TRANSMISSION USING COMMON AND DEDICATED PILOTS - A method, system, base station and wireless terminal are provided for transmission of a set of mixed pilots that includes both common and dedicated pilots. The method includes selecting a number D of dedicated pilots having regard to performance of the communication link, D≧0, selecting a first pre-coder for pre-coding D dedicated pilots based on some criteria, performing a first pre-coding of the D dedicated pilots with the first pre-coder to produce a set of pre-coded dedicated pilots, performing a second pre-coding of the set of pre-coded dedicated pilots and a set of common pilots to produce a set of mixed pilots, and transmitting data from the transmitter on the communication link with the set of mixed pilots.01-26-2012
20120020433FEEDBACK FOR SUPPORTING SU-MIMO AND MU-MIMO OPERATION IN WIRELESS COMMUNICATION - A method, an apparatus, and a computer program product for wireless communication are provided in which a precoding matrix is determined from a set of precoding matrices with a first throughput based on a reference signal. In addition, a subset of precoding matrices is determined from the set of precoding matrices with a second throughput greater than a fraction of the first throughput based on the reference signal. Furthermore, a precoding matrix is selected from the subset of precoding matrices based on a metric.01-26-2012
20120020432METHOD FOR ESTIMATING MIMO CHANNEL USING LOOSELY SYNCHRONOUS CODES, AND APPARATUS USING THE SAME - Disclosed are a method and apparatus for estimating a Multiple Input Multiple. Output (MIMO) channel. A signal transmission method for estimating the MIMO channel via 2N transmission antennas (N is greater than or equal to “1”) includes generating a code having a predetermined Interference Free Window (IFW), and transmitting the code via two transmission antennas.01-26-2012
20130195218METHODS AND APPARATUS FOR THE INTELLIGENT SCRAMBLING OF CONTROL SYMBOLS - Methods and apparatus for the scrambling of control symbols. In one embodiment, the control symbols are associated with an HDMI interface, and the methods and apparatus are configured to scramble the symbols to as to mitigate the effects of electromagnetic interference (EMI) created by the transmission of otherwise unscrambled sequences of symbols which may contain significant “clock pattern” or other undesirable artifact.08-01-2013
20130195217PRECODING FOR WIRELESS SIGNALS - A system for determining precoding for a wireless signal may include a derivation module and a selection module. The derivation module may be configured to determine precoding information for a composite channel. The composite channel may represent characterizations of multiple wireless paths established between multiple receiving antennas and multiple transmitting antennas. The transmitting antennas may be distributed among multiple transmission points. The selection module may further be configured to select a codeword for each transmission point from a subset of predefined codewords based on the precoding information. The codeword for each transmission point may be used to manipulate data signals sent over the wireless paths established between the receiving antennas and the transmitting antennas of the respective transmission point.08-01-2013
20120045018COMMUNICATION APPARATUS, COMMUNICATION METHOD AND BASE STATION - The present invention relates to communication apparatus, communication method and base station. The communication apparatus has a plurality of antennas and is capable of using a Multi-Input Multi-Output (MIMO) technique, comprising: a MIMO mode determining unit configured to determine a MIMO mode to be adopted; a precoding matrix information determining unit configured to determine precoding matrixes according to the determined MIMO mode; a transmitting unit configured to transmit information related to the precoding matrix, wherein, in case the MIMO mode to be adopted is a single-cell multi-user MIMO mode, the precoding matrix information determining unit determines a precoding matrix to be used by a service base station in a cell where the communication apparatus locates to communicate with the communication apparatus, and determines a precoding matrix to be used by the service base station to communicate with other communication apparatus in the cell which is grouped with the communication apparatus.02-23-2012
20120300878DYNAMIC DIGITAL PRE-DISTORTION SYSTEM - A Dynamic Digital Pre-Distortion (DDPD) system is disclosed to rapidly correct power amplifier (PA) non-linearity and memory effects. To perform pre-distortion, a DDPD engine predistorts an input signal in order to cancel PA nonlinearities as the signal is amplified by the PA. The DDPD engine is implemented as a composite of one linear filter and N−1 high order term linear filters. The bank of linear filters have programmable complex coefficients. To compute the coefficients, samples from the transmit path and a feedback path are captured, and covariance matrices A and B are computed using optimized hardware. After the covariance matrices are computed, Gaussian elimination processing may be employed to compute the coefficients. Mathematical and hardware optimizations may be employed to simplify and reduce the number of multiplication operands and other operations, which can enable the DDPD system to fit within a single chip.11-29-2012
20120093260METHOD AND DEVICE FOR TRANSMITTING SIGNAL - Embodiments of the present invention disclose a method and a device for transmitting a signal, and relate to the field of communications. The technical solutions provided by the embodiments of the present invention are: the method for transmitting a signal, including: determining a peak clipping threshold of a signal according to f(MCS), where MCS represents a modulation and coding scheme (MCS) of the signal, and f(MCS) is a corresponding relationship between the MCS and noise at a receiving end; performing peak clipping on the signal by using the peak clipping threshold to obtain a peak-clipped signal; and transmitting the peak-clipped signal. According to the embodiments of the present invention, different peak clipping thresholds may be selected according to different MCSs, and thus, the reliability of data transmission is improved.04-19-2012
20120093259METHOD AND APPARATUS FOR TRANSMITTING CONTENT, METHOD AND APPARATUS FOR RECEIVING CONTENT, AND CONTENT SERVICE SYSTEM - A method and an apparatus for transmitting contents, a method and an apparatus for receiving contents, and a content service system are provided. The method for transmitting contents includes converting first contents including distortion part contents in which at least an area of a specific part of source contents is subjected to distortion processing into a transmittable type through a transmission network to generate a first transmission signal; converting any one the source part contents that are the part contents corresponding to the part of the source contents and differential information between the source part contents and the distortion part contents into a transmittable type through the transmission network to generate the second transmission signal; and transmitting part information indicating the first transmission signal, the second transmission signal, and the part through the transmission network.04-19-2012
20130208826REDUCTION OF SMALL SPURS IN TRANSMITTERS - An apparatus for reducing spurs is described. The apparatus includes a coarse digital to analog converter (DAC). The apparatus also includes a correction term generator. The correction term generator generates a correction term. The correction term has an amplitude within a dynamic range of the coarse digital to analog converter (DAC). The apparatus also includes a baseband filter. The correction term is selected such that the baseband filter reduces the correction term to an amplitude approximating that of a spur in a transmit signal. The correction term is used to reduce a spur.08-15-2013

Patent applications in class Antinoise or distortion (includes predistortion)

Patent applications in all subclasses Antinoise or distortion (includes predistortion)