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Quadrature amplitude modulation

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375 - Pulse or digital communications

375295000 - TRANSMITTERS

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DocumentTitleDate
20120163499APPARATUS, METHOD, AND SYSTEM FOR TRANSMITTING AND RECEIVING HIGH-SPEED DATA IN POINT-TO-POINT FIXED WIRELESS COMMUNICATION - Disclosed are an apparatus, method, and system for transmitting and receiving high-speed data in point-to-point (P2P) fixed wireless communication. In an apparatus for transmitting high-speed data in P2P fixed wireless communication, an amplitude zero autocorrelation waveform (CAZAC) sequence generator generates and outputs a CAZAC sequence. A frame generator generates a frame in which the CAZAC sequence is arranged as part of a preamble before a payload including actual data. A continuous wave (CW) generator generates and outputs a CW signal. A multiplexer receives the CW signal output by the CW generator, and arranges and outputs the CW signal in a position before a signal output by the frame generator.06-28-2012
20100150268Log Likelihood Ratio Arithmetic CircuitTransmission Apparatus, Log Likelihood Ratio Arithmetic Method, and Program - [Problems] To realize a log likelihood ratio calculation performed at a higher speed while the circuit size and the power consumption are reduced, regardless of the multilevel number of a modulation method.06-17-2010
20100040171SYSTEMS AND METHODS FOR COMMUNICATING USING ASK OR QAM WITH UNEVEN SYMBOL CONSTELLATION - Systems and methods of performing ASK or QAM modulation with uneven distance between symbols are provided. These are used to provide differing BER performances among bits sent from a transmitter to a receiver.02-18-2010
20090122912Method for Transmitting and Receiving Quadrature-Amplitude Modulation Signals, System for Implementing Thereof, Machine-Readable Medium, and Application of the Method for Synchronizing Reception of Amplitude Modulation Signals - The invention relates to signal transmitting engineering. The use of the inventive method in systems for transmitting and receiving quadrature amplitude-modulation signals (QAM) exhibiting a low carrier frequency synchronisation threshold makes it possible to decrease a demodulation threshold by means of said low carrier frequency synchronisation threshold. The result is attainable by supplementing a burst of M m-level sensitive QAM symbols by predetermined symbols, one part of which remains constant form one burst to another and the other part is periodically invertible in certain bursts, thereby the QAM signal components corresponding to the additional predetermined symbols (whose frequencies are known) are extracted on a receiving side. The inversion frequency is determined according to said components, thereby making it possible to eliminate the ambiguity of the receiving frequency synchronisation control and to approach the Shannon's threshold.05-14-2009
20080260067Bit Reliability Equalization by Modulation Switching for Harq - A method is disclosed for digital data transmission using higher order modulation schemes, wherein a plurality of bits is mapped to bit positions of a symbol and the transmission has different error probabilities for at least two out of said bit positions. A data bit is mapped to a bit position in a first modulation scheme and transmitted in a symbol on the mapped bit position of the first modulation scheme. When a request is received from a receiver, for retransmission of a data block containing this data bit, a decision is made about a re-transmission of said bit, based on a reliability of the bit position in the first transmission, and if it is decided to retransmit the bit, the data bit is mapped to a bit position of a second modulation scheme and retransmitted in a symbol on the mapped bit position of the second modulation scheme.10-23-2008
20100046668DIGITAL IF WIRELESS TRANSMITTER, RF MODULATOR, AND RF MODULATING METHOD - Provided are a digital IF wireless transmitter, an RF modulator, and an RF modulating method. A digital IF wireless transmitter includes an IF up-converting unit up-converting a baseband I signal and a baseband Q signal on the basis of a first IF, a first operating unit subtracting the first IF-up-converted I signal and the first IF-up-converted Q signal, a D/A converting unit analog converting an output signal of the first operating unit, an IF modulating unit separating the same first and second signals from the output signal of the D/A converting unit, and modulating the first and the second signals on the basis of a second IF, a high-pass filtering unit passing a single sideband of the modulated first signal, a miss-matching correcting unit correcting an error of the modulated second signal, a second operating unit subtracting an output signal of the high-pass filtering unit and an output signal of the miss-matching correcting unit, a feedback unit receiving a feedback signal output from the second operating unit, detecting an error of the feedback signal, and providing the detected error to the miss-matching correcting unit, and an RF up-converting unit up-converting the output signal of the second operating unit on the basis of an RF.02-25-2010
20130034189HIGH-DENSITY MULTI-CHANNEL QAM MODULATOR USING AN IDFT/IFFT AND POLYPHASE FILTER BANK - Methods and apparatuses are provided for increasing the frequency resolution of a multi-channel QAM modulator and using a novel IDFT/IFFT and polyphase filter bank architecture to provide a more computationally efficient and high density multi-channel QAM modulator. The implementations of the improved multi-channel QAM modulator modulate QAM symbol streams onto respective carrier signals where the frequency of each carrier signal is an integer multiple of a fraction of the input sample rate of the respective QAM symbol stream. The modulated carriers are then combined using a novel IDFT/IFFT and polyphase filter bank architecture.02-07-2013
20100322347NOVEL FRAME STRUCTURE FOR A QAM SYSTEM - A novel framing method for a variable net bit rate digital communications system that utilizes a set of different QAM constellations and punctured trellis code combinations, each combination designated as a mode. This frame structure has a variable integral number of QAM symbols per frame depending on the selected mode, but the number of bytes and Reed-Solomon packets per frame is constant. This is achieved even though the number of data bits per QAM symbol for some modes is fractional. Also the number of trellis coder puncture pattern cycles per frame is an integer for all modes. This arrangement simplifies the synchronization of receiver processing blocks such as the Viterbi decoder, de-randomizer, byte de-interleaver, and Reed-Solomon decoder.12-23-2010
20100040170SYSTEMS AND METHODS FOR COMMUNICATING USING ASK OR QAM WITH UNEVEN SYMBOL CONSTELLATION - Systems and methods of performing ASK or QAM modulation with uneven distance between symbols are provided. Different bit positions mapped to such symbols are assigned to different receivers, with the result that there are different BER performances among bits sent from a transmitter to the different receivers.02-18-2010
20110013726DIRECT MM-WAVE M-ARY QUADRATURE AMPLITUDE MODULATION (QAM) MODULATOR OPERATING IN SATURATED POWER MODE - In one embodiment, a circuit comprises a first pair of elements, a second pair of elements, a combiner, and a signal output. Each element in the first and second pair of elements comprises an amplitude-control input for receiving an amplitude-control bit, a phase-control input for receiving a phase-control bit, a signal input for receiving an input signal, a modulator for producing an output signal based on the amplitude-control bit, the phase-control bit, and the input signal, and an signal output for transmitting the output signal to the combiner. The combiner combines the two output signals from the first and second pair of elements to produce an output signal for the circuit to be transmitted by the signal output of the circuit.01-20-2011
20090232253Method and system for creating quadrature modulation signal constellations with arbitrary spectral efficiency - Methods, systems, transmitters, and receivers implement and use Quadrature Amplitude Modulation QAM2N modulation types and constellations, where N is a real number, e.g., 1.5; 1.33; 2.5; 3.5. The methods, systems, transmitters, and receivers use constellations with the number of points on the circle not equal to a power of two, sending QAM signals of zero power together with other QAM signals, and/or sending sequences of QAM signals of different types.09-17-2009
20090232252Method and Apparatus for Digital Encoding with Reduced Memory Requirement and Complexity - Systems and methods may be provided for supporting encoding of digital communications, including space time block encoding (STBC). Example systems and methods may include receiving at least one input bit, wherein the at least one input bit is associated with a mapping on a Gray-coded constellation map, storing the received at least one input bit in one or more memory locations, retrieving the at least one bit from the one or more memory locations, inverting a bit of the at least one bit to generate a conjugate of the at least one bit, and obtaining first coordinates of the conjugate according to the Gray-coded constellation map.09-17-2009
20120114075TRANSMISSION CIRCUIT - A transmission circuit (05-10-2012
20100086080QUASI-ORTHOGONAL SPACE-TIME BLOCK ENCODER, DECODER AND METHODS FOR SPACE-TIME ENCODING AND DECODING ORTHOGONAL FREQUENCY DIVISION MULTIPLEXED SIGNALS IN A MULTIPLE-INPUT MULTIPLE-OUTPUT SYSTEM - Embodiments of quasi-orthogonal space-time encoder, decoder and method for space-time encoding and decoding orthogonal frequency division multiplexed (OFDM) signals in a multiple-input multiple-output (MDMO) system are generally described herein. Other embodiments may be described and claimed. In some embodiments, a method of decoding received multicarrier signals comprises deriving objective functions from a received signal matrix, minimizing the objective functions to generate decoded hard bits, and solving a set of linear equations of the objective functions to generate decoded soft bits.04-08-2010
20120236967DATA MODULATION - A modulator includes a symbol mapper that is configured to map respective bits sets of a bit sequence corresponding to a burst and including data, training, tail, and guard bits into respective symbols to form a symbol sequence of data, training, tail, and guard symbols. A vector precoder is configured to apply a vector precoding transformation to the data and training symbols to form precoded symbols. These precoded symbols are combined with the tail and guard symbols in a symbol processor to form a sequence of transmit symbols. The record precoding conducted by the modulator of a transmitter enables improved link performance without the cost of increased processing complexity of the receiver algorithm.09-20-2012
20120236965QUADRATURE COMMUNICATIONS DEVICE WITH POWER COMBINER AND RELATED METHODS - A communications device may include In-phase (I) power amplifiers configured to generate I amplified signals, Quadrature (Q) power amplifiers configured to generate Q amplified signals, an I controller coupled to the I power amplifiers and configured to selectively enable some of the I power amplifiers, and a Q controller coupled to the Q power amplifiers and configured to selectively enable some of the Q power amplifiers. The communications device may also include a power combiner configured to combine the I amplified signals and the Q amplified signals in a combined amplified signal, and an antenna coupled to the power combiner.09-20-2012
20120269294Modulation code set (MCS) and LDPC (Low Density Parity Check) coding within multiple user, multiple access, and/or MIMO wireless communications - Modulation code set (MCS) and LDPC (Low Density Parity Check) coding within multiple user, multiple access, and/or MIMO wireless communications. Selective operation in accordance with different operational modes is performed. Operation within a first mode may correspond to that which is in full compliance with a given protocol, standard, and/or recommended practice, while operation within a second mode may correspond to that which provides additional/augmented capability and/or functionality with respect to that protocol, standard, and/or recommended practice. Operational modes selectivity may be made between proprietary and non-proprietary modes of operation. All available modulation coding sets (MCSs) may be in employed by providing such multi-mode operation. When operating within one of the operational modes (e.g., proprietary), a signal is generated to include an integer number of data bits per orthogonal frequency division multiplexing (OFDM) symbol using any desired operation (e.g., floor, ceiling, rounding, etc.).10-25-2012
20110033011METHODS AND APPARATUSES RELATING TO MULTI-RESOLUTION TRANSMISSIONS WITH MIMO SCHEME - A method of providing a multi-resolution transmission with a MIMO scheme may include employing a selected modulation scheme to generate a first data stream including basic information and a second data stream including both enhanced information and the basic information, and employing a modulation and multiple input/multiple output (MIMO) scheme to generate data for transmission. The data for transmission may employ a combination of spatial multiplexing and transmit diversity techniques. A corresponding apparatus is also provided. Another method of providing selective recovery of received data at a mobile terminal may include receiving data at a mobile terminal including at least one antenna, receiving information indicative of a data reception condition at the mobile terminal, determining, between spatial multiplexing and transmit diversity mode options, a reception mode to be employed for decoding the data received based on the information indicative of the data reception condition. A corresponding apparatus is also provided.02-10-2011
20110280339METHOD AND DEVICE FOR MODULATING THE INFORMATION OF TFCI - A modulation method and device for modulating transfer format combination indicator TFCI information, the method including: dividing equally original TFCI information in a unit of 2 bits in a transmission time interval TTI; extending the resultant respective parts of the TFCI information after the division to correspond to identifiers of one or more designated energy points in a preset constellation; and mapping the respective extended parts of the TFCI information to the corresponding energy points for modulating.11-17-2011
20100142644Hierarchical Modulation - A method for modulating first and second bit streams in a communications network that supports at least one of a binary phase-shift keying (BPSK), a quadrature phase-shift keying (QPSK) or a quadrature amplitude modulation (QAM) constellation uses hierarchical modulation. A hierarchical modulation parameter that varies within the network is set. The first bit stream is modulated based on a first constellation of the hierarchical modulation and the hierarchical modulation parameter. The second bit stream is modulated based on a second constellation in the first constellation.06-10-2010
20080260068Method and System of Diversity Transmission of Data10-23-2008
20120236966MODULATION METHOD AND RADIO COMMUNICATION SYSTEM - An input digital signal is periodically and alternately subjected to first modulation and second modulation, being thereby converted into a pair of a baseband I signal and a baseband Q signal. The first modulation and the second modulation are different from each other. The pair of the baseband I signal and the baseband Q signal are outputted. The first modulation may be at least 8-signal-point modulation while the second modulation may be phase shift keying.09-20-2012
20110026639SPATIAL MAPPING OF AN OFDM SIGNAL TO REDUCE ATTENUATION FROM AN INDIVIDUAL TRANSMIT ANTENNA IN A MIMO TRANSMITTER - A method is provided for transmitting a digital signal. The method includes generating a plurality of spatial streams from a digital signal and transforming the spatial streams into a plurality of space-time streams. Each of the space-time streams are cycled in the frequency domain among each of a plurality of transmit antennas. The space-time streams are wirelessly transmitted from the plurality of transmit antennas.02-03-2011
20110299628APPARATUS FOR TRANSMITTING AND RECEIVING A SIGNAL AND METHOD OF TRANSMITTING AND RECEIVING A SIGNAL - The present invention relates to a method of transmitting and a method of receiving signals and corresponding apparatus. One aspect of the present invention relates to an efficient layer 1 (L1) processing method for a transmitter and a receiver using data slices.12-08-2011
20090323859Flexible, Reconfigurable, Power Efficient Transmitter and Method - A flexible, reconfigurable, power efficient transmitter device and method is provided. In one embodiment, the method includes receiving outbound data and determining a mode of operation. When operating in a first mode the method may include modulation mapping the outbound data according a modulation scheme to provide first modulation mapped digital data, converting the first modulation mapped digital data to an analog signal that comprises an intermediate frequency (IF) analog signal, upconverting the IF analog signal to produce a first modulated radio frequency (RF) signal based on a local oscillator signal, upconverting the first RF modulated signal to produce a first RF output signal, and outputting the first RF output signal via an isolator. In a second mode of operation method may include modulation mapping the outbound data according a modulation scheme to provide second modulation mapped digital data, converting the second modulation mapped digital data to a first digital baseband signal, conditioning the first digital baseband signal to provide a first analog baseband signal, modulating one or more carriers with the first analog baseband signal to produce a second modulated RF signal based on a local oscillator signal, upconverting the second RF modulated signal to produce a second RF output signal, and outputting the second RF output signal via the isolator. The digital baseband signal may comprise an in-phase (I) digital baseband signal and a quadrature (Q) baseband signal.12-31-2009
20090310706Transmitter and Receiver Using Pseudo-Orthogonal Code - A transmitter using pseudo-orthogonal code includes a serial-to-parallel converter for converting serial transmission data into 9-bit parallel data, and a pseudo-orthogonal code memory for receiving the parallel data from the serial-to-parallel converter and outputting 16-bit pseudo-orthogonal code by using the received data as addresses. The pseudo-orthogonal code memory has the relationship of the input address and output code, as expressed in the following equation:12-17-2009
20090310708Transmitter and Method for Transmitting Soft Pilot Symbols in a Digital Communication System - A transmitter, channel coder, and method for coding and transmitting a sequence of symbols in a digital communication system utilizing soft pilot symbols. In one embodiment, the transmitter transmits a set of soft pilot symbols with higher reliability than the remaining symbols in the sequence by modulating the soft pilot symbols with a lower order modulation such as BPSK or QPSK while modulating the remaining symbols with a higher order modulation such as 16 QAM or 64 QAM. The transmitter shares the modulation type and location (time/frequency/code) of the soft pilot symbols with a receiver. Unlike traditional fixed pilots, the soft pilots still carry some data. Additionally, the soft pilots are particularly helpful in establishing the amplitude reference essential in demodulating the higher order modulation symbols. In another embodiment, soft pilot symbols are inserted by low-level puncturing of channel encoded bits and replacing the punctured bits with known bit patterns.12-17-2009
20120189081TRANSMISSION CIRCUIT AND COMMUNICATION APPARATUS USING POLAR MODULATION METHOD - Provided is a transmission circuit which can adjust a difference between signal delay amounts in the amplitude path and the phase path with a low power consumption. An amplitude modulation section 07-26-2012
20090074108METHOD AND SYSTEM FOR ADJUSTING THE AMPLITUDE AND PHASE CHARACTERISTICS OF REAL AND IMAGINARY SIGNAL COMPONENTS OF COMPLEX SIGNALS PROCESSED BY AN ANALOG RADIO TRANSMITTER - A method and system for determining amplitude and phase compensation values used to adjust the amplitude and phase characteristics of real and imaginary signal components of complex signals processed by an analog radio transmitter. The compensation values may be determined in response to detecting a significant temperature change in the transmitter. Corresponding amplitude and phase adjustment signals having levels that correspond to the compensation values are provided to respective amplitude and phase imbalance compensation modules to adjust the amplitude and phase characteristics of at least one of the real and imaginary signal components.03-19-2009
20090086849Method and apparatus of improved circular buffer rate matching for turbo-coded MIMO-OFDM wireless systems - Methods and apparatus for determining the starting points of redundancy version transmissions in a circular rate matching operation. At least one block of information bits to be transmitted are encoded to generate a plurality of coded bits, which are then segmented into a plurality of sub-blocks of coded bits. Each of the sub-blocks of coded bits is interleaved by using a certain interleaver. The interleaved coded bits of the plurality of sub-blocks are collected and filled into a circular buffer having a plurality of redundancy versions in the circular buffer, with each redundancy version corresponding to a starting bit index in the circular buffer. For each transmission, a subset of bits are selected from the circular buffer by selecting a redundancy version from among the plurality of redundancy version. The selected subset of bits are modulated by using a certain modulation scheme, and are transmitted via at least one antenna. The redundancy versions of the circular being determined such that in at least one pair of redundancy versions, the number of bits between the starting point of a first redundancy version and the starting point of a second redundancy version is not divisible by at least one modulation order.04-02-2009
20090279641Delay Detection Circuit, Distortion Compensation Circuit, And Communication Apparatus - A delay detection circuit, including: a conversion circuit which converts time-domain signal into frequency-domain signal or which converts frequency-domain signal into time-domain signal, wherein the conversion circuit is used in a signal processing circuit which performs signal processing by quadrature modulation for a transmission signal, and the conversion circuit outputs a delay amount of a first signal with respect to the transmission signal.11-12-2009
20090257526METHODS AND APPARATUS FOR CONDITIONING COMMUNICATIONS SIGNALS BASED ON DETECTION OF HIGH-FREQUENCY EVENTS IN POLAR DOMAIN - Methods and apparatus for conditioning communications signals based on detection of high-frequency in the polar domain. High-frequency events detected in a phase-difference component of a complex baseband signal in the polar domain are detected and used as a basis for performing hole-blowing on the complex baseband signal in the quadrature domain and/or nonlinear filtering either or both the magnitude and phase-difference components in the polar domain. Alternatively, high-frequency events detected in the phase-difference signal that correlate in time with low-magnitude events detected in a magnitude component of the complex baseband signal are used as a basis for performing hole-blowing on the complex baseband signal in the quadrature domain and/or nonlinear filtering either or both the magnitude and phase-difference components in the polar domain.10-15-2009
20090202018SYNCHRONIZATION TECHNIQUES FOR POLAR TRANSMITTERS - Various techniques involving polar modulation are disclosed. For instance, an apparatus may include a storage medium and a calibration module. The storage medium stores multiple adjustment settings. Each of these adjustment settings corresponds to an operating condition. The calibration module selects one of the stored adjustment settings that corresponds to a current operating condition. With the selected adjustment setting, the calibration module reduces a polar modulation timing misalignment. The current operating condition may include one or more operational parameter values. Examples of such parameter values include output power level, signal frequency, and/or temperature.08-13-2009
20090262862SIGNAL TRANSMITTING APPARATUS FOR OFDM SYSTEM AND PARAMETER ADJUSTING METHOD THEREOF - A signal transmitting apparatus for orthogonal frequency division multiplexing (OFDM) system comprises a compandor, a predistortor, a power amplifier and a feedback module. The compandor is configured to compress and expand a transmitted signal. The predistortor is configured to perform a predistortion operation on output signals of the compandor. The power amplifier is configured to amplify output signals of the predistortor. The feedback module is configured to adjust parameters of the compandor and the predistortor based on a feedback signal.10-22-2009
20100278283APPARATUS AND ASSOCIATED METHODS TO PERFORM SPACE-FREQUENCY INTERLEAVING IN A MULTICARRIER WIRELESS COMMUNICATION CHANNEL - An apparatus and associated methods for performing space-frequency interleaving in a multicarrier wireless communication system is generally described.11-04-2010
20090310707TRANSMITTER AND METHOD FOR TRANSMITTING SOFT PILOT SYMBOLS IN A DIGITAL COMMUNICATION SYSTEM - A transmitter, channel coder, and method for coding and transmitting a sequence of symbols in a digital communication system utilizing soft pilot symbols. In one embodiment, the transmitter transmits a set of soft pilot symbols with higher reliability than the remaining symbols in the sequence by modulating the soft pilot symbols with a lower order modulation such as BPSK or QPSK while modulating the remaining symbols with a higher order modulation such as 16 QAM or 64 QAM. The transmitter shares the modulation type and location (time/frequency/code) of the soft pilot symbols with a receiver. Unlike traditional fixed pilots, the soft pilots still carry some data. Additionally, the soft pilots are particularly helpful in establishing the amplitude reference essential in demodulating the higher order modulation symbols. In another embodiment, soft pilot symbols are inserted by low-level puncturing of channel encoded bits and replacing the punctured bits with known bit patterns.12-17-2009
20090103650METHOD FOR DIGITAL WIRELESS COMMUNICATIONS - In a multivalue modulation type with one pilot symbol inserted for every 3 or more symbols, signal points of each one symbol immediately before and after a pilot symbol are modulated using a modulation type different from that for pilot symbols. In this way, it is possible to suppress deterioration of the accuracy in estimating the reference phase and amount of frequency offset by pilot symbols and improve the bit error rate characteristic in the signal to noise ratio in quasi-coherent detection with symbols whose symbol synchronization is not completely established.04-23-2009
20100111225Forward Error Correction Coding For AM 9kHz and 10kHz In-Band On-Channel Digital Audio Broadcasting Systems - A method of broadcasting an AM compatible digital audio broadcasting signal includes: producing an analog modulated carrier signal centrally positioned in a radio channel, wherein the analog modulated carrier signal is modulated by an analog signal, producing a plurality of digitally modulated subcarrier signals in the radio channel, wherein the digitally modulated subcarrier signals are modulated using complementary pattern-mapped trellis code modulation (CPTCM) including a code mapped to overlapping partitions including an upper main partition, a lower main partition, an upper backup partition and a lower backup partition, and a non-overlapping tertiary partition, and transmitting the analog modulated carrier signal and the plurality of digitally modulated subcarrier signals. Transmitters that broadcast the signal and receivers that receive the signal, and the reception method are also included.05-06-2010
20080279307Very High Data Rate Communications System - A method of communicating data in which the data is transmitted using a star 8-Quadrature Amplitude Modulation scheme. In one embodiment of the invention, the data is encoded with a systematic trellis code in which the systematic bit corresponds to the amplitude of the transmitted signal. In another embodiment of the invention, the data is encoded using a Reed-Solomon coding without convolutional coding nor trellis coding.11-13-2008
20080240289PILOT SIGNAL TRANSMISSION TECHNIQUE AND DIGITAL COMMUNICATION SYSTEM USING SAME - In a digital communication system such as a mobile radio system, fading distortion is compensated with a raised precision. In a transmitter, pilot signals are regularly inserted in the information signals. The amplitude of the pilot signals are set larger than the maximum possible amplitude of the information signals. The modulation scheme of the pilot signals may be different from that of the information signals. In a receiver, the fading distortion of each of the pilot signals is determined. The fading distortions of the information signals are estimated by interpolation using the determined fading distortion of the pilot signal, and then compensated. The frequency band of each information signal is preferably limited with a roll-off filter with a roll-off coefficient ranging from 0.1 to 0.4.10-02-2008
20090135950MAXIMIZING DATA RATE BY ADJUSTING CODES AND CODE RATES - The present invention provides for making code rate adjustments and modulation type adjustments in a pseudonoise (PN) encoded CDMA system. Coding rate adjustments may be made by changing the number of information bits per symbol, or Forward Error Code (FEC) coding rate. A forward error correction (FEC) block size is maintained at a constant amount. Therefore, as the number of information bits per symbol are increased, an integer multiple of bits per epoch is always maintained. The scheme permits for a greater flexibility and selection of effective data rates providing information bit rates ranging from, for example, approximately 50 kilobits per second to over 5 mega bits per second (Mbps) in one preferred embodiment.05-28-2009
20090185638RADIO TRANSMISSION DEVICE AND RADIO TRANSMISSION METHOD - Provided are a radio transmission device and a radio transmission method capable of improving downlink and uplink throughput even when performing dynamic symbol allocation. In the device and the method, BS and MS share a table correlating a basic TF as a combination of parameters such as TB size used for transmitting only user data, an allocation RB quantity, a modulation method, and an encoding ratio, with a derived TF having user data of different TB size by combining L1/L2 control information. Even when multiplexing L1/L2 control information, Index corresponding to the basic TF is reported from BS to MS.07-23-2009
20090052576DATA TRANSMISSIONS IN A MOBILE COMMUNICATION SYSTEM EMPLOYING DIVERSITY AND CONSTELLATION REARRANGEMENT OF A 16 QAM SCHEME - The invention relates to methods for transmitting and receiving a data bit stream in a communication system using 16-QAM constellations. Further, an apparatus for performing the methods is provided. To improve the bit-error rate performance of the communication using the 16-QAM constellations the invention suggests the use 16-QAM constellations with specially selected mapping rules together with a special constellation rearrangement for creating different versions of the 16-QAM constellations. Further, the data stream is transmitted according to a diversity scheme employing different versions of the 16-QAM constellations obtained adhering the mapping rules and rearrangement rules defined by the invention.02-26-2009
20130216001INTERLEAVING METHOD AND DEINTERLEAVING METHOD - An interleaving method performed by a transmitter for a communication system with quasi-cyclic low-density parity-check codes, spatial multiplexing, and T transmit antennas is used for applying permutation to N cyclic blocks of a codeword in order to map bits of the permutated cyclic blocks onto T constellation words constituting multiple spatial-multiplexing blocks from the codeword. Each cyclic block consists of Q bits.08-22-2013
20110142167TRANSMITTING APPARATUS WITH BIT ARRANGEMENT METHOD - A transmitting apparatus, that includes a means for generating bit sequences to adjust an occupation rate occupied with predetermined bits included in a first data block, which is obtained by encoding first data in a first encoding process, to be equal or closer to an occupation rate occupied with predetermined bits included in a second data block, which is obtained by encoding second data in a second encoding process, in regard to first bit positions of the bit sequences generated using bits included in the first and second data blocks and a modulator for performing multi-level modulation for transmission based on the generated bit sequences.06-16-2011
20090202019RF POLAR TRANSMITTER AND INTEGRATED CIRCUIT WITH PROGRAMMABLE FILTER MODULE AND METHODS FOR USE THEREWITH - A radio frequency (RF) transmitter includes a transmitter processing module that generates a processed signal and a modulating signal based on outbound data. An up-conversion module up-converts the processed signal to generate an up-converted signal. A programmable filter module generates a first plurality of delayed signals from the up-converted signal and that generates a filtered up-converted signal by combining the up-converted signal and the first plurality of delayed signals, wherein a delayed signal of the first plurality of delayed signals is scaled based on one of a first plurality of coefficients, wherein the first plurality of coefficients are selected based on a control signal. A polar amplifier amplifies and amplitude modulates the filtered up-converted signal based on the modulating signal to generate a transmit signal. A processing module generates the control signal to attenuate at least one RF spur of the up-converted signal.08-13-2009
20130121442METHOD AND APPARATUS FOR MAPPING QUADRATURE AMPLITUDE MODULATION SYMBOL - A method and an apparatus for mapping a quadrature amplitude modulation (QAM) symbol. The QAM symbol mapping apparatus includes a frequency checker, which checks frequencies of sub-carriers in an orthogonal frequency division multiplexing (OFDM) symbol; and a data categorizer, which maps data coded for error correction and uncoded data to the sub-carriers based on the checked frequencies, wherein the data categorizer maps a combination of the coded data and the uncoded data with respect to sub-carriers having frequencies lower than a reference frequency.05-16-2013
20090245420Quarter Duty Cycle Pulse Generator for Interleaved Switching Mixer - An integrated transmit circuit includes a voltage controlled oscillator (10-01-2009
20080260069APPARATUS AND METHOD FOR DIGITAL WIRELESS COMMUNICATION - In a multivalue modulation type with one pilot symbol inserted for every 3 or more symbols, signal points of each one symbol immediately before and after a pilot symbol are modulated using a modulation type different from that for pilot symbols. In this way, it is possible to suppress deterioration of the accuracy in estimating the reference phase and amount of frequency offset by pilot symbols and improve the bit error rate characteristic in the signal to noise ratio in quasi-coherent detection with symbols whose symbol synchronization is not completely established.10-23-2008
20100226459Apparatus and Method for I/Q Modulation - An apparatus and method for I/Q modulation are provided. According to the apparatus and method, the symbol error probability performance of a conventional I/Q modulation method can be improved by a maximum of 3dB, and when the same symbol error rate (SER) as that of the conventional method is obtained, the power consumption can be reduced to half that required by the conventional method. The apparatus includes: an oscillator generating a sine wave signal; an IQ sine wave signal generation unit adjusting the phase of the sine wave signal based on I channel data and Q channel data, thereby generating an I channel sine wave signal and a Q channel sine wave signal such that a signal obtained by mixing a first signal and a second signal satisfies the condition that the mixed signal has a phase on a signal constellation diagram corresponding to the I and Q channel data, in which the first signal is obtained by applying the I channel data to the I channel sine wave signal and the second signal obtained by applying the Q channel data to the Q channel sine wave signal; and a transmission signal generation unit generating a transmission signal corresponding to the I and Q channel data, by respectively applying the I channel data and the Q channel data to the I channel sine wave signal and the Q channel sine wave signal.09-09-2010
20100254488APPARATUS AND METHOD FOR COMMUNICATION USING NEAR GOLAY SEQUENCE - A communication system and method using a Golay sequence, are provided. In the communication method, 210-07-2010
20100128816METHOD AND APPARATUS FOR MINIMIZING CO-CHANNEL INTERFERENCE BY SCRAMBLING - An approach is provided for minimizing co-channel interference in a communication system is disclosed. Non-header portions of frames, which are transmitted over the communication system, are scrambled according to respective different scrambling sequences. The above arrangement is particularly suited to a digital satellite broadcast and interactive system.05-27-2010
20120140852WIRELESS COMMUNICATION APPARATUS - A transmitter circuit includes a first synthesizer section, and a second synthesizer section which consumes less current than the first synthesizer section. The transmitter circuit performs switching such that the first synthesizer section is operated and the second synthesizer section is powered off in polar modulation, and the second synthesizer section is operated and the first synthesizer section is powered off in quadrature modulation, thereby reducing consumed power. While the first synthesizer section is operating, calibration for an oscillation frequency is performed, and when the operation is stopped, a calibration value is stored. When an operation of the first synthesizer section is restarted, the stored calibration value is corrected by using temperature change, thereby enhancing calibration accuracy and preventing degradation in quality of a transmission signal.06-07-2012
20090316828APPARATUS, AND ASSOCIATED METHOD OF PHASE-OFFSET MODULATION, FOR SPACE-TIME CODED WIRELESS COMMUNICATION SYSTEMS - An apparatus, and an associated methodology, for facilitating communication of data in a wireless communication systems. Binary data are modulated to form modulated symbols on parallel paths. The symbols formed on one of the parallel paths are phase-offset by a phase rotator to form phase-offset symbols. The parallel paths of symbols provide the symbols, both the phase-offset symbols and the symbols that are not phase-offset, to an Alamouti encoder. As a result, the dynamic range of the transmitted RF signals is reduced due to the introduction of the phase offset between the symbols of the parallel paths applied to the Alamouti encoder.12-24-2009
20090110113Wireless Communication Systems, Apparatus and Method for Encoding and Decoding a Plurality of Information Bits - Wireless transmitted system and apparatus and method for encoding a plurality of information bits to a plurality of transmitted signals thereof, and wireless received system and apparatus and method for decoding a received signal to a plurality of information bits thereof are provided. The wireless transmitted system encodes a plurality of information bits to a plurality of transmitted signals by two logic operation modules, an interleaving module, and a combination module. The wireless received system decodes a received signal to a plurality of information bits by a division module, two probability generation modules, two status calculation modules, a signal generation module and a combination module.04-30-2009
20110235751DATA TRANSMISSION DEVICE AND METHOD THEREOF, AND DATA RECEPTION DEVICE AND METHOD THEREOF - The present invention discloses a data transmission device and method thereof, and a data reception device and method thereof. The data transmission method in the present invention includes the following steps: encoding information data to obtain mother codes; generating transmission data including the mother codes and repetition codes from the mother codes, wherein parts of the mother codes with low reliability are selected to be repetition codes according to the modulation type of the mother codes; modulating the transmission data; transmitting the modulated data.09-29-2011
20100278282TRANSMITTING APPARATUS WITH BIT ARRANGEMENT METHOD - A method of transmitting data including controlling generation of bit sequences to adjust an occupation rate occupied with predetermined bits included in a first data block, which is obtained by encoding first data, to be closer to an occupation rate occupied with predetermined bits included in a second data block, which is obtained by encoding second data. With regard to first bit positions of the predetermined bits, the first bit positions being distinguished from second bit positions based on an error tolerance resulting from a correspondence to a signal point on a phase plane. Wherein a sum of a number of the predetermined bits included in the first data block and the predetermined bits included in the second data block is less than a total number of the first bit positions. Also including performing multi-level modulation for transmission based on the generated bit sequences.11-04-2010
20090067543Method and Apparatus for Multi-Rate Control in a Multi-Channel Communication System - An apparatus for data processing in a multi-channel communication system is provided. The apparatus includes an encoder configured to encode a number of bits for transmission via channels in the multi-channel communication system into coded bits and split the coded bits into a number of first sets of bits at a first ratio, a number of first rate units coupled to the encoder, each of the first rate units being configured to adjust one set of the first sets of bits in size at at least one rate, and a controller configured to assign the first ratio to the encoder and the at least one rate to each of the first rate units based on conditions of the channels.03-12-2009
20090067542Method and Device for Communicating Incremental Broadcast Information - This invention relates to a system, terminals, and a method of communicating broadcast information where broadcast information comprising at least two parts is transmitted to at least one communications terminal. The transmission comprises transmitting the broadcast information during at least a first time instance, and where the transmission further comprises transmitting incremental broadcast information during a time instance being different than the first time instance. In this way, by sending the broadcast information in increments, i.e. incrementally, it is ensured that terminals capable of it (due to better capabilities like higher information rate, greater bandwidth, etc. and/or due to better location like near the base station, having favorable propagation conditions, having line-of-sight to the base station, etc.) will receive the broadcast information more quickly and thereby faster can resume a “sleep” state (unless they are required to act in an active way upon the received broadcast information) without being limited by less complex or capable terminal or terminals under worst case conditions, as would otherwise be the case if the sending of broadcast information was designed to accommodate the worst or worse case situations. This saves power for the more capable and/or favorable placed terminals since the transceiver will be active for a shorter amount of time to receive the same amount of broadcast information.03-12-2009
20110026638POSITIVE COEFFICIENT WEIGHTED QUADRATURE MODULATION METHOD AND APPARATUS - A differential positive coefficient weighted quadrature modulator is actuated responsive to quadrature clock signals and positive digital modulation signals input to the modulator. The modulator includes an I-channel positive coefficient weighted modulator (PCWM) and a Q-channel PCWM. The I-channel PCWM has differential output nodes configured to output a differential I-channel signal responsive to the state of first and second positive digital modulation signals and first and second complimentary quadrature clock signals input to the I-channel PCWM. The Q-channel PCWM has differential output nodes configured to output a differential Q-channel signal responsive to the state of third and fourth positive digital modulation signals and third and fourth complimentary quadrature clock signals input to the Q-channel PCWM. The positive digital modulation signals input to the I-channel and Q-channel PCWMs have positive amplitude and the I-channel and Q-channel PCWMs conduct at approximately half clock cycle or less of the corresponding quadrature clock signals.02-03-2011
20090034653METHOD AND SYSTEM FOR POLAR MODULATION WITH DISCONTINUOUS PHASE - Aspects of a method and system for polar modulation with discontinuous phase are provided. In this regard, in-phase and quadrature-phase components may be generated from a modulated baseband signal, and the signal components may be utilized to generate a signal representative of the amplitude of the baseband signal. Furthermore, the signal components may be pulse shaped and the pulse-shaped components may be divided by the signal representative of the amplitude of the baseband signal. The resulting signals may be up-converted to RF, summed, and amplified, where the amplification may be controlled via a quantized representation of the signal representative of the amplitude of the baseband signal. In this regard, one or more bias points, and/or one or more binary weighted current sources coupled to one or more power amplifiers may be controlled. The pulse-shaping may comprise passing the signal components through a raised cosine filter.02-05-2009
20110129032Systems and Methods for Dual-Carrier Modulation Encoding and Decoding - Systems and methods for dual-carrier modulation (DCM) encoding and decoding for communication systems. Some embodiments comprise a DCM encoder for applying a pre-transmission function to at least one 16-QAM input symbol and mapping resulting transformed symbols onto at least one larger constellation prior to transmission. Some embodiments joint decode, by a DCM decoder, a predetermined number of received data elements and compute a set of log-likelihood ratio (LLR) values for at least eight bits from a resulting at least one transformed symbol.06-02-2011
20110090988APPARATUS AND METHODS FOR QAM MODULATION USING DUAL POLAR MODULATION - Apparatus and methods for QAM modulation are disclosed using dual polar modulation. QAM modulation of a signal is accomplished by translating a QAM signal into two phasors having the same or constant amplitude and then phase shifting one of the phasor by 180 degrees for a differential load. The phasors are then polar modulated such that, when differentially combined in the load through summation or superposition, a QAM modulated symbol results. The use of constant amplitude phasors when power amplified for transmission of QAM modulated signals allows amplifiers to be operated in a saturation mode with greater efficiency than conventional amplifiers used in QAM modulation, which operate in a less efficient linear mode to effect amplitude modulation. Additionally, differential combining of the phasors affords relaxation of the turns of a transformer used in amplifying the phasors.04-21-2011
20100322348CONSTELLATION DETECTION IN A MULTI-MODE QAM COMMUNICATIONS SYSTEM - Systems and methods for determining an unknown QPSK or QAM constellation from a set of possible received constellations are described. One method utilizes a histogram of the power of the signal after inter-symbol-interference has been minimized with a modified constant modulus algorithm equalizer. The constellation may be determined before carrier frequency and phase has been fully recovered. An unknown QPSK or QAM constellation may be identified before or after equalization using disclosed methods for analyzing an output power histogram.12-23-2010
20090323858Dual Carrier Modulation - A coding unit for determining two different types of modulation to be applied to two carrier signals such that each modulated carrier signal represents a data symbol in accordance with a group of modulation points, each modulation point representing a modulation of the first type and a modulation of the second type that can be applied to one of the carrier signals, the coding unit being arranged to associate the data symbol with a first one of the modulation points by applying a first mapping function to that data symbol and associate the data symbol with a second one of the modulation points by applying a second mapping function to that data symbol, the first and second mapping functions being such that they each map two different data symbols to a respective common modulation point; and determine the modulation of the first and second types to be applied to the first carrier signal to be the modulation of the first and second types represented by the first modulation point and the modulation of the first and second types to be applied to the second carrier signal to be the modulation of the first and second types represented by the second modulation point.12-31-2009
20090245421SCRAMBLING AND MODULATION TO CONSTRAIN THE CONSTELLATION SIZE OF ACK/NAK TRANSMISSION ON THE DATA CHANNEL - Aspects describe maximizing a Euclidean distance for an ACK transmission as a function of the number of bits in a HARQ-ACK and a modulation order. Encoding includes placing escape sequences in the HARQ-ACK, wherein the number of escape sequences is based on the number of bits and the modulation order. Multiple encoded ACK blocks are combined to obtain a vector sequence that is multiplexed with the encoded data and interleaved, such as on a “time-first” manner. Scrambling is performed as a function of the size and the modulation order. For a 1-bit ACK, the scrambling is performed to achieve any two corners in any constellation for transmission for the ACK. For a 2-bit ACK, the scrambling is performed to achieve any four corners in any constellation for transmission for the ACK.10-01-2009
20090022241WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD - A wireless communication apparatus capable of suppressing the reduction in the error correction ability in the wireless communication apparatus at the receiving end even when the propagation path environment is bad and hence the reception quality of received signals is low. This apparatus comprises a turbo encoding part (01-22-2009
20100284490METHOD FOR TRANSMITTING SIGNALS USING HARQ SCHEME TO GUARANTEE CONSTELLATION REARRANGEMENT GAIN - A method for transmitting signals using a hybrid automatic repeat request (HARQ) scheme to guarantee a constellation rearrangement gain having a predetermined level or more is provided. Predetermined code blocks are encoded, sub-block interleaving is performed with respect to the encoded code blocks, and the sub-block interleaved code blocks are transmitted according to redundancy version (RV) start locations of the sub-block interleaved code blocks. The RVs are set such that the order of bit streams modulated by an M-QAM (M>4) scheme is changed upon a retransmission. In addition, the RVs are set such that the RV start locations applied to code blocks having different sizes are different.11-11-2010
20100246716METHODS AND APPARATUS FOR REDUCING HIGH-FREQUENCY EVENTS IN POLAR DOMAIN SIGNALS - Methods and apparatus for reducing high-frequency events in polar domain signals. An exemplary method includes first generating an unmodified rectangular-coordinate signal having in-phase (I) and quadrature phase (Q) components that are modulated according to a predetermined modulation scheme. Next a first sample of the unmodified rectangular-coordinate signal is modified based on how close the first sample is to the origin in the complex signal plane and how fast a signal trajectory between the first sample and a subsequent sample changes. Finally, the modified rectangular-coordinate signal is converted to a polar domain signal having amplitude and phase components. By modifying the first sample in this manner, either or both the amplitude and phase components have reduced high-frequency content compared to a polar domain signal that would be generated without the first sample having been first modified.09-30-2010
20110261904Techniques for Data Transmission using High-Order Modulation - Techniques for data transmission using high-order modulation are provided. According to one aspect, parameters of a transmission link are determined, and a multilevel coding scheme and a high-order modulation signal constellation are selected on the basis of the determined parameters. An information indicating the selected multilevel coding scheme and high-order modulation signal constellation and data symbols encoded according to the selected multilevel coding scheme and high-order modulation signal constellation are transmitted. In other aspects, QPSK data symbols are embedded between M-QAM data symbols or M-PSK data symbols with M>4. The QPSK data symbols may be used to improve the efficiency of the decoding process.10-27-2011
20120147994SIGNAL PROCESSING DEVICE AND METHOD, RADIOFREQUENCY TRANSMISSION SYSTEM INCLUDING SUCH A DEVICE - A device for processing a signal carrying information to be transmitted using a radiofrequency signal, for transformation of the signal into two signals of identical amplitude phase-shifted respectively relative to the information-carrying signal according to two variable and opposing phase shifts. The device includes a mechanism transforming the information-carrying signal. The device transforms the information-carrying signal into two signals of constant amplitude and of variable phase shifts according to values of the information-carrying signal, for as long as the amplitude of the information-carrying signal is greater than a predetermined value, and transforms the information-carrying signal into two signals of variable amplitude according to the values of the information-carrying signal, when the amplitude of the information-carrying signal is less than the predetermined value.06-14-2012
20080219379QUADRATURE IMBALANCE MITIGATION USING UNBIASED TRAINING SEQUENCES - A system and method are provided for transmitting an unbiased communications training sequence. The method generates an unbiased training sequence in a quadrature modulation transmitter. The unbiased training sequence represents a uniform accumulated power evenly distributed in the complex plane. As a result, training information in the time domain is sent via an in-phase (I) modulation path having an accumulated power. Training information in the time domain is sent via a quadrature (Q) modulation path having an accumulated power equal to the I modulation path power. Also provided are system and method for calculating an unbiased channel estimate from a received unbiased training sequence.09-11-2008
20080219378LOW POWER WIRELESS COMMUNICATION SYSTEM - A transmitter, a receiver, and a transceiver for use in a wireless communication system are disclosed. In one embodiment, the radio frequency (RF) transmitter comprises a first parallel-to-serial converter to convert first parallel data corresponding to a I quadrature baseband signal component into a first set of serial data bits, a second parallel-to-serial converter to convert second parallel data corresponding to a Q quadrature baseband signal component into a second set of serial data bits, and one or more stages having a first NOR gate coupled to a first transistor and a second NOR gate coupled to a second transistor. The first XOR gate has a pair of inputs coupled to the first set of serial data bits and a first clock (e.g., an I clock) that corresponds to the I quadrature baseband signal component, and has a first output coupled to drive the first transistor, while the second XOR gate has a pair of inputs coupled to the second set of serial data bits and a second clock (e.g., the Q clock) that corresponds to the Q quadrature baseband signal component, and has a second output coupled to drive the second transistor. The first and second outputs are summed at a node to obtain a single-side band (SSB) RF output.09-11-2008
20100166111METHOD AND APPARATUS FOR PERFORMING HARQ IN WIRELESS COMMUNICATION SYSTEM - A method and an apparatus for performing hybrid automatic repeat request (HARQ) using constellation rearrangement and a circular buffer in a wireless communication system is provided. An encoded information bit is stored into a circular buffer. A transport block in selected from the circular buffer. A bit set comprising n bits of the transport block is mapped to a data symbol on a constellation for 207-01-2010
20110051844Programmable Hybrid Transmit Baseband Module - A programmable hybrid transmit baseband module includes a wireless protocol conversion module, a set of modules, and a mode select module. The wireless protocol conversion module is operable to convert outbound data into a complex signal having an in-phase (I) signal component and a quadrature (Q) signal component. The set of modules is operable to generate an offset adjusted normalized I signal component, an offset adjusted normalized Q signal component, and corrected amplitude modulation data, wherein each of the normalized I and Q signal components includes phase modulation data. The mode selection module is operable to output the I and Q signal components when the programmable hybrid transmit baseband module is in a first mode; and output the offset adjusted normalized I and Q signal components and the corrected amplitude modulation data when the programmable hybrid transmit baseband module is in a second mode.03-03-2011
20110188603Compact pulse shaping for QM-MSK and PAM/QAM transmission - Compact pulse shape partial response (CPS PR) signaling is developed for trellis based signals like QM-MSK, and for PAM/QAM type signals to improve the performance to bandwidth tradeoff. Compact pulse shaped signals are partial response signals that employ a very short pulse shaping filter and use Viterbi decoding to optimally detect the CPS signal in presence of its inherent inter-symbol interference. The CPS filters considered herein have much shorter impulse response than the well-known raised cosine (RC) filter. There is no need to equalize the received signal to eliminate ISI or to allow a fixed amount of ISI between received signal samples as sampled at the symbol rate as is common in partial response maximum likelihood (PRML) systems. Numerical results indicate that CPS QM-MSK and CPS QAM provides between several dB of gain, depending on constellation size, over PR-CPM and RC QAM, when compared at a given value of bandwidth, i.e., B08-04-2011
20100027714System and method for power saving coding in integer cycle or impulse type modulation transmissions - A system and method for substantially reducing average transmit power by omitting the transmission of a majority of pulses by using a modified run length coding to reduce signal power. By lowering the average power, an opportunity is presented to either decrease the total power drawn by the transmitter (battery life) or raise the peak power of all symbols (Eb/No), thereby increasing range of a RF transmission system.02-04-2010
20080292018VSB MODULATION APPARATUS AND METHOD FOR GENERATING A VSB-MODULATED WAVE - A vestigial sideband (VSB) modulation apparatus includes a signal processing unit which extracts an I-axis data signal component and a Q-axis data signal component from a baseband signal with symbol data superimposed thereon, a band-limiting filter which frequency-shifts the I-axis data signal component and the Q-axis data signal component, extracted by the signal processing unit, by only a specific frequency smaller than a rate of the symbol data and limits a passband width by a frequency width smaller than the rate of the symbol data, and a quadrature modulating unit which obtains a VSB modulation signal by quadrature-modulating the I-axis data signal component and the Q-axis data signal component output from the band-limiting filter.11-27-2008
20110116574Trellis coded modulation with periodically-reduced signal constellations - An family of improved trellis coded signaling schemes is provided that by vary the signal constellation to a smaller constellation periodically according to a pre-selected pattern. A set of specific embodiments involving periodically-reduced 4-PAM/2-PAM trellis coded schemes are disclosed that change their signal constellations periodically from 4-PAM to 2-PAM during selected intervals to improve performance. Similar periodically QAM and higher-dimensional coding schemes are also disclosed. Simplified receiver and decoder structures to decode the periodically-reduced trellis codes are also presented. The present invention allows embodiments to be produced that reduce coding complexity, reduce decoding complexity, and simplify symbol timing recovery and equalization. The cost is a moderate increase in the path memory length of the decoder.05-19-2011
20110305300APPARATUS FOR TRANSMITTING AND RECEIVING A SIGNAL AND METHOD OF TRANSMITTING AND RECEIVING A SIGNAL - The present invention relates to a method of transmitting and receiving signals and a corresponding apparatus. One aspect of the present invention relates to a method of extracting PLP from data slices.12-15-2011
20080285682CALIBRATION APPARATUS AND METHOD FOR QUADRATURE MODULATION SYSTEM - A calibration apparatus for a quadrature modulation system with a quadrature modulation compensator and a logarithmic envelop detector, wherein a parameter update of the quadrature modulation compensator is derived by utilizing a transformed offset value and a transformed gain value of the logarithmic envelop detector as intermediate parameters, and the transformed offset and the transformed gain parameters are used in a training sequence of the quadrature modulation compensator.11-20-2008
20080212713METHOD AND APPARATUS FOR GENERATING TRAINING SEQUENCE CODE IN A COMMUNICATION SYSTEM - A method and apparatus for generating a TSC in a communication system are provided, in which a pair of sequences A and B having auto-correlation and cross-correlation properties are generated and the TSC is generated by inserting guard sequences Z each having z zero symbols in the most significant bits of the sequences A and B.09-04-2008
20120045021TRANSMISSION METHOD AND APPARATUS FOR MULTI-ANTENNA RETRANSMISSION - A transmission method for multi-antenna retransmission is provided, comprising steps of: generating the bits to be transmitted by respective antennas; mapping the bits to be transmitted by the respective antennas into symbols; and multiplying by a constant the vector constituted by the mapped symbols transmitted by multiple antennas, wherein the resulting vector is orthogonal to the matrix constituted by the symbols previously transmitted by multiple antennas, and transmitting the orthogonal symbols. According to the method of the present invention, the remapped symbols transmitted by the respective antennas and the symbols previously transmitted by the respective antennas constitute a matrix that has an orthogonal property. The orthogonal property can be used to effectively detect signals. In addition, the method has a reception algorithm with low complexity and brings about significant performance gains over conventional methods.02-23-2012
20120045020DIGITAL RF TRANSMITTER OPTIMIZED FOR LINEAR QUANTIZED IQ UP CONVERSION - The digital RF transmitter includes a decoder for receiving the in phase (I) and quadrature (Q) digital baseband signals, a phase generator for generating eight waveforms at a carrier frequency where each phase is a multiple of 45 degrees, a first set of main amplifiers of fixed output power, a second set of auxiliary amplifiers of fixed output power such that the ratio of the voltage amplitudes at the outputs of the second set of auxiliary amplifiers to the voltage amplitudes at the outputs of the first set of main amplifiers is fixed at sqrt(2)−1, and a set of multiplexers for selecting one of the eight carrier waveforms, or an off signal, to transmit to each of the first set of main amplifiers and the second set of auxiliary amplifiers based on both the in phase (I) digital baseband signal and the quadrature (Q) digital baseband signal.02-23-2012
20120002753Method for Encoding Data Symbols with Implicitly Embedded Pilot Symbols in Resource Blocks for Wireless Networks - A set of data symbols is selected from a set of modulation constellation, and a sample-mean of the set of data symbols is determined. Each data symbol is first shifted by the sample-mean to obtain a shifted data symbol, and then the shifted symbol is multiplied by a first constant to obtain a scaled data symbol. A second constant is added to the scaled data symbol to obtain a mapped data symbol. The sample-mean is multiplied by a third constant to obtain a sample-mean mapped symbol. The set of mapped data symbols and the sample-mean mapped symbol are then transmitted as a resource block.01-05-2012
20120008718Wireless Precoding Methods - Various wireless precoding systems and methods are presented. In some embodiments, a wireless transmitter comprises an antenna precoding block, a transform block, and multiple transmit antennas. The antenna precoding block receives frequency coefficients from multiple data streams and distributes the frequency coefficients across multiple transmit signals in accordance with frequency-dependent matrices. The transform block transforms the precoded frequency coefficients into multiple time domain transmit signals to be transmitted by the multiple antennas. The frequency coefficients from multiple data streams may be partitioned into tone groups, and all the frequency coefficients from a given tone group may be redistributed in accordance with a single matrix for that tone group. In some implementations, the frequency coefficients within a tone group for a given data stream may also be precoded. In some alternative embodiments, tone group precoding may be employed in a single channel system.01-12-2012
20120027126APPARATUS AND METHOD FOR CONSTELLATION REARRANGEMENT IN BROADBAND WIRELESS ACCESS SYSTEM - An apparatus and a method for operating a transmitter supporting constellation rearrangement for 256-Quadrature Amplitude Modulation (QAM) in a broadband wireless access system are provided. The method include generating complex symbols according to a first version of a constellation mapping rule, transmitting an initial transmit packet comprising the complex symbols, and when retransmitting the initial transmit packet, generating complex symbols according to a second first version of a constellation mapping rule.02-02-2012
20120063545Method and System for Enhancing Efficiency by Modulating Power Amplifier Gain - Aspects of a method and system for enhancing efficiency by modulating power amplifier (PA) gain are presented. Aspects of the system may comprise a PA gain modulator that enables modification of an amplitude of a digital baseband signal. A baseband processor may enable computation of a first gain value based on the modification. The baseband processor may enable computation of a second gain value based on the first gain value. A PA may enable generation of an RF output signal based on the modified digital baseband signal and the second gain value.03-15-2012
20120163500TRANSMITTER APPARATUS - Provided is a transmitter apparatus including: a signal conversion section for, in polar modulation, converting input data into an amplitude-component signal and a phase-component signal, and in quadrature modulation, converting input data into an in-phase component signal and a quadrature component signal; a carrier wave generation section for outputting a carrier wave; a mixer section for, in quadrature modulation, generating a quadrature modulation signal; a regulator for, in polar modulation, outputting a supply voltage control signal; and a power amplifier for, in polar modulation, amplifying the supply voltage control signal and superimposing the resultant signal onto the carrier wave, thereby generating a transmission signal, wherein in polar modulation, the carrier wave generation section outputs the carrier wave modulated with respect to phase component, and in quadrature modulation, the carrier wave generation section outputs the carrier wave that is yet to be modulated.06-28-2012
20110182382DIGITAL AMPLITUDE MODULATION - A transmitter using quadrature modulation includes a rectangular to polar converter for converting data symbols into a polar form, where each polar symbol has a magnitude signal and an angle signal. Digital phase modulation circuitry includes an all digital PLL circuit for generating a phase modulated RF carrier signal responsive to the angle signal frequency control word (FCW) and a carrier frequency FCW. A digitally controlled amplifier for amplifying the phase modulated signal is controlled by a digital amplitude control circuitry for controlling the gain of the digitally controlled amplifier responsive to the magnitude signal.07-28-2011
20080267316Method for Using a Symbol Mapper Using a Symbol Mapping Scheme to Generate Modulation Symbols According to a Different Symbol Mapping Scheme and a Method for Generating a Symbol Mapping Scheme - The invention relates to method and apparatus for generating modulation symbols according to a second symbol mapping scheme by a symbol mapping unit being adapted to generate symbols according to a first symbol mapping scheme, wherein the first and second symbol mapping schemes define different mappings of data words of a stream to modulation symbols of a modulation scheme according to the respective symbol mapping scheme. Further, the invention relates to a method and apparatus for generating a mapping of data words to modulation symbols of a square 16 QAM constellation, the modulation symbols being representable by an inphase component and quadrature component. One aspect of the invention is the introduction of a bit sequence transformer unit transforming the data words to be mapped to modulation symbols prior to mapping thereby changing the Hamming distance properties of the mapping. Another aspect of the invention is the generation of a new AICO (Antipodal Inverted COnstellation) mapping scheme.10-30-2008
20110038438APPARATUS AND METHOD FOR TRANSPORTING/RECEIVING DATA IN A CDMA MOBILE COMMUNICATION SYSTEM - A data transportation/reception apparatus and method in a mobile communication system. The data transportation apparatus and method divides transport data bits into bits having higher priority and bits having lower priority, maps the bits having higher priority to bit positions having higher reliability, and maps the bits having lower priority to bit positions having lower reliability. The data reception apparatus and method demodulates received modulated symbols, divides the demodulated coded bits into two coded bit groups according to priority, deinterleaving the coded bit groups using different deinterleavers, and decodes the deinterleaved coded bits.02-17-2011
20130010897Low Density Parity Check (LDPC) Encoded Higher Order Modulation - A method and apparatus is disclosed to map a sequence of data to Quadrature Amplitude Modulation (QAM) constellation symbols. The method and apparatus encodes only a portion of the sequence of data and leaves a remaining portion of the sequence of data unencoded. The encoded portion of the sequence of data and the remaining unencoded portion of the sequence of data are then mapped into modulation symbols of the QAM constellation. The encoded portion of the sequence of data selects subsets of the QAM constellation, and the remaining unencoded portion of the sequence of data determines a specific modulation symbol within each subset of the QAM constellation.01-10-2013
20100150269SIGNAL MODULATING DEVICE, SIGNAL TRANSMITTING METHOD, AND CODE GENERATING METHOD - The present invention relates to a signal modulation device, a transmission method, and a code generation method. The signal modulation device includes a code storage unit including a plurality of n-bit members and storing a code with a number n or n−1 of different bits between two neighboring members, and a mapper for mapping data on symbols according to the code.06-17-2010
20080317168Integer Spreading Rotation Matrices for Qam Constellations and Its Application to Decode-Remodulate-Forward Cooperative Communication Strategy - Diversity techniques are commonly used in wireless communications to combat multi-path fading. Recent interests in ultra-wideband technology focus on multi-band OFDM systems that can explore the high diversity due to the independent frequency bands. To achieve full diversity with high data rate, a system (12-25-2008
20130016796SIGNAL MODULATOR AND SIGNAL MODULATING METHODAANM Sun; Chih-HaoAACI New Taipei CityAACO TWAAGP Sun; Chih-Hao New Taipei City TWAANM Yu; Chi-YaoAACI Hsinchu CountyAACO TWAAGP Yu; Chi-Yao Hsinchu County TW - A signal modulator includes: a modulating circuit; a first signal trace block arranged to conduct a first in-phase oscillating signal to the modulating circuit, and conduct a first quadrature-phase oscillating signal to the modulating circuit; and a second signal trace block arranged to conduct a second in-phase oscillating signal to the modulating circuit, and conduct a second quadrature-phase oscillating signal to the modulating circuit, and a phase difference caused by the first signal trace block substantially equals a phase difference caused by the second signal trace block.01-17-2013
20110158349RADIO TRANSMISSION DEVICE AND MODULATION METHOD - A radio transmission device includes a modulation unit that maps a transmission bit sequence to a symbol corresponding to any one signal point by using a constellation in which a plurality of congruent equilateral triangles having a signal point as an apex are formed in each of four quadrants of an IQ plane representing an in-phase component and a quadrature component of a signal, two arbitrary neighboring equilateral triangles share one side, and signal points closest to an original point in the four quadrants form two neighboring equilateral triangles that share one side. The radio transmission device also includes a transmission unit that transmits the symbol obtained by mapping performed by the modulation unit.06-30-2011
20110158348Dynamic tone grouping and encoding for multi-carrier quadrature amplitude modulation in OFDM - A method of dynamic tone grouping (DTG) used by a transmitter in a wireless OFDM system is proposed. First, a sequence of coded and interleaved bits is de-multiplexed into a number of bit-streams. Each bit-stream is mapped into a sequence of QAM symbols, which are grouped into non-overlapping sets of QAM symbols. Unitary transformation is then applied on the QAM symbols to produce groups of complex signals. Finally, the complex signals are dynamically mapped to subcarrier groups based on tone mapping information to improve link performance. The tone mapping information is derived from information associated with each OFDM subcarrier, such as channel state information (CSI). The OFDM subcarriers are grouped into subcarrier groups according to the tone mapping information such that the channel quality of each subcarrier group is balanced. In addition, the tone mapping information is efficiently encoded and transmitted to/from a corresponding receiver.06-30-2011
20130022151COMMUNICATIONS TRANSMITTER HAVING HIGH-EFFICIENCY COMBINATION MODULATOR - A communications transmitter includes a combination modulator and a baseband processor configured to generate amplitude, angle, in-phase and quadrature signals. The combination modulator is configured to modulate in the quadrature domain or the polar domain, depending on an output power level of the transmitter and/or the type of modulation scheme being used. When configured to modulate in the quadrature domain, the baseband processor is configured to generate time-varying in-phase and quadrature modulating signals and time-invariant amplitude and angle signals for the combination modulator. When configured to modulate in the polar domain, the baseband processor is configured to generate time-varying amplitude and angle modulating signals and time-invariant in-phase and quadrature signals for the combination modulator. In another embodiment of the invention, the communications transmitter is configurable to operate in three different operational modes: linear, envelope tracking and switch modes. Which operational mode the communications transmitter is configured to transmit depends on the type of modulation scheme being used and/or the transmitter output power level.01-24-2013
20130022150COMMUNICATIONS TRANSMITTER HAVING HIGH-EFFICIENCY COMBINATION MODULATOR - A communications transmitter includes a combination modulator and a baseband processor configured to generate amplitude, angle, in-phase and quadrature signals. The combination modulator is configured to modulate in the quadrature domain or the polar domain, depending on an output power level of the transmitter and/or the type of modulation scheme being used. When configured to modulate in the quadrature domain, the baseband processor is configured to generate time-varying in-phase and quadrature modulating signals and time-invariant amplitude and angle signals for the combination modulator. When configured to modulate in the polar domain, the baseband processor is configured to generate time-varying amplitude and angle modulating signals and time-invariant in-phase and quadrature signals for the combination modulator. In another embodiment of the invention, the communications transmitter is configurable to operate in three different operational modes: linear, envelope tracking and switch modes. Which operational mode the communications transmitter is configured to transmit depends on the type of modulation scheme being used and/or the transmitter output power level.01-24-2013
20130022149COMMUNICATIONS TRANSMITTER HAVING HIGH-EFFICIENCY COMBINATION MODULATOR - A communications transmitter includes a combination modulator and a baseband processor configured to generate amplitude, angle, in-phase and quadrature signals. The combination modulator is configured to modulate in the quadrature domain or the polar domain, depending on an output power level of the transmitter and/or the type of modulation scheme being used. When configured to modulate in the quadrature domain, the baseband processor is configured to generate time-varying in-phase and quadrature modulating signals and time-invariant amplitude and angle signals for the combination modulator. When configured to modulate in the polar domain, the baseband processor is configured to generate time-varying amplitude and angle modulating signals and time-invariant in-phase and quadrature signals for the combination modulator. In another embodiment of the invention, the communications transmitter is configurable to operate in three different operational modes: linear, envelope tracking and switch modes. Which operational mode the communications transmitter is configured to transmit depends on the type of modulation scheme being used and/or the transmitter output power level.01-24-2013
20080232510Bit-Operated Rearrangement Diversity for Aico Mapping - Transmit diversity system in which constellation rearrangement is used. Both diversity signals contain the same data and both are 16-QAM, but the location of the data bits within the constellation is different. This averages the effect of the different levels of reliability of the different constellation points. A method for modifying a quadruple of data bits in a data transmission system using Quadrature. Amplitude Modulation with 16 different modulation states, 16-QAM, using an Antipodal Inverted Constellation AICO) mapping, swapping bits selecting contiguous symbol regions with bits selecting non-contiguous symbol regions. Depending on the particular pre-defined mapping and on the particular permutation of bits, inversion of selected bits may be performed in addition. The quadruples thus obtained are mapped to modulation symbols according to a pre-defined AICO mapping. In the corresponding method for receiving the symbols, likelihood values are swapped and modified in a way which is complementary to the permutation and inversion of bits, before they are combined with likelihood values from other symbols representing the same bits. Method ensures that there is a one to one correspondence between Hamming distance and Euclidian distance for the combined received data. In other words it ensures that, once combined, all 4 bit data words which differ by the same number of bits (Hamming distance) are the same distance apart in the constellation (Euclidian distance).09-25-2008
20130121443QUADRATURE MODULATOR BALANCING SYSTEM - A method of balancing a quadrature modulator includes exciting an in-phase input of the quadrature module and sweeping a phase of an injection signal through a range of degrees, and determining a plurality of in-phase DC components. The method further includes exciting a quadrature input of the quadrature module and sweeping a phase of the injection signal through the range of degrees, and determining a plurality of quadrature DC components. An in-phase sinusoidal equivalent of the plurality of in-phase DC components and a quadrature sinusoidal equivalent of the plurality of quadrature DC components may be determined. At least one correction factor that balances the quadrature modulator may be determined based on a comparison between the in-phase sinusoidal equivalent and the quadrature sinusoidal equivalent.05-16-2013
20130142282RADIO COMMUNICATION APPARATUS AND RADIO COMMUNICATION METHOD - Provided is a wireless communication apparatus wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. In the wireless communication apparatus (06-06-2013
20100290561APPARATUS FOR TRANSMITTING AND RECEIVING A SIGNAL AND METHOD FOR TRANSMITTING AND RECEIVING A SIGNAL - A method for transmitting and receiving a signal and an apparatus for transmitting and receiving a signal are disclosed. The method includes receiving the signal from a first frequency band in a signal frame including at least one frequency band, demodulating the received signal by an orthogonal frequency division multiplexing (OFDM) method and parsing the signal frame, acquiring a symbol stream of a service stream from the at least one frequency band included in the parsed signal frame, demapping symbols included in the symbol stream and outputting the demapped symbols to sub streams, multiplexing the output sub streams and outputting one bit stream, and deinterleaving and error-correction-decoding the output bit stream.11-18-2010
20100316164Methods and Apparatus for Reducing Average-to-Minimum Power Ratio in Communications Signals - A baseband circuit for a communications transmitter includes a baseband modulator, a pulse-shaping filter, and an AMPR reduction circuit. The baseband modulator is configured to generate a sequence of symbols formatted in accordance with a non-constant envelope modulation scheme. The pulse-shaping filter is configured to band-limit the sequence of samples to provide a sequence of samples. The AMPR reduction circuit is configured to analyze and modify one or more samples in the sequence of samples, if a sample in the sequence of samples that has been previously analyzed by the AMPR reduction circuit is determined to have a magnitude less than a predetermined low-magnitude threshold.12-16-2010
20110317788COMMUNICATION APPARATUS, DATA COMMUNICATION METHOD, AND STORAGE MEDIUM STORING DATA COMMUNICATION PROGRAM - A communication apparatus for executing half-duplex data communication conforming to V.34 recommendation including, a modulation-demodulation device modulating and demodulating data; a control device determining that the communication procedure shift to a recovery procedure by receiving an INFO12-29-2011
20120020435Constellation Mapping Method - The present invention provides a constellation mapping method, and the method includes: flipping a plurality of bits in each modulation symbol unit to be mapped in part of or all of modulation symbol units to be mapped of a bit sequence to be mapped; and mapping each flipped modulation symbol unit to be mapped as a modulation symbol in a constellation. By means of the present invention, the phenomenon that consecutive bits have the same reliability can be effectively avoided by changing unevenness of reliability distribution of the consecutive bits, and at the same time, the link performance can be improved.01-26-2012
20130208828TRANSMITTING APPARATUS AND TRANSMITTING METHOD - A duplicating section duplicates a hit sequence to be input, and a 16 QAM section modulates a bit sequence of a duplicating source to form a symbol, a 16 QAM section modulates the duplicated bit sequence to form a symbol, an S/P section parallel converts the symbol sequence input in series, an S/P section parallel converts the symbol sequence input in series, and an IFFT section provides IFFT processing to the input symbol sequence. Since each of multiple same bits duplicated by the duplicating section is included in a different symbol, each of the multiple same bits is allocated to each of multiple subcarriers each having a different frequency by IFFT processing. As a result, a multicarrier signal including the multiple same bits each having a different frequency is generated.08-15-2013

Patent applications in class Quadrature amplitude modulation