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Power amplifier

Subclass of:

375 - Pulse or digital communications

375295000 - TRANSMITTERS

375296000 - Antinoise or distortion (includes predistortion)

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DocumentTitleDate
20130044836DEVICE AND METHOD FOR PRE-DISTORTING AND AMPLIFYING A SIGNAL BASED ON AN ERROR ATTRIBUTE - A method and a device. The device may include: a non-linear amplifying circuit for applying a non-linear gain function on an analog signal to provide an amplified signal; an input circuit, for clipping I-channel and Q-channel digital input signals, to provide clipped I-channel and Q-channel digital signals; a pre-distortion circuit, for pre-distorting the clipped I-channel and Q-channel digital signals such as to at least partially compensate for a non-linearity of the non-linear gain function, to provide pre-distorted I-channel and Q-channel digital signals; a mixed signal circuit for converting the pre-distorted I-channel and Q-channel digital signals to the analog signal; a reconstruction circuit for generating reconstructed I-channel and Q-channel signals; and a control circuit, arranged to: calculate an error attribute based on the clipped and the reconstructed I-channel and Q-channel digital signals and to affect a gain of at least one components of the device in response to the error attribute.02-21-2013
20090285331CONTROL OF POWER AMPLIFIERS IN DEVICES USING TRANSMIT BEAMFORMING - A radio transmitter and method controls efficiency of each of a plurality of power amplifiers that amplify a corresponding one of a plurality of radio frequency signals for a beamforming transmission by a corresponding one of a plurality of antennas. Each of the plurality of power amplifiers is controlled to operate with one or more operating parameters that optimize the efficiency for an output power level of corresponding ones of the radio frequency signals. Transmit weights for transmit signals are determined and updated on a per-packet basis.11-19-2009
20090074106MULTI-MODE AND MULTI-BAND TRANSMITTERS FOR WIRELESS COMMUNICATION - Transmitters supporting multiple modulation modes and/or multiple frequency bands are described. A transmitter may perform large signal polar modulation, small signal polar modulation, and/or quadrature modulation, which may support different modulation schemes and systems. Circuit blocks may be shared by the different modulation modes to reduce cost and power. For example, a single modulator and a single power amplifier may be used for small signal polar modulation and quadrature modulation. The transmitter may apply pre-distortion to improve performance, to allow a power amplifier to support multiple frequency bands, to allow the power amplifier to operate at higher output power levels, etc. Envelope and phase distortions due to non-linearity of the power amplifier may be characterized for different input levels and different bands and stored at the transmitter. Thereafter, envelope and phase signals may be pre-distorted based on the stored characterizations to compensate for non-linearity of the power amplifier.03-19-2009
20130077713SYSTEM AND METHOD FOR INCREASING BANDWIDTH FOR DIGITAL PREDISTORTION IN MULTI-CHANNEL WIDEBAND COMMUNICATION SYSTEMS - A digital predistortion linearization method is provided for increasing the instantaneous or operational bandwidth for RF power amplifiers employed in wideband communication systems. Embodiments of the present invention provide a method of increasing DPD linearization bandwidth using a feedback filter integrated into existing digital platforms for multi-channel wideband wireless transmitters. An embodiment of the present invention utilizes a DPD feedback signal in conjunction with a low power band-pass filter in the DPD feedback path.03-28-2013
20130034188Signal Transmitter Linearization - A linearizer for a non-linear transmitter includes a tap delay line that provides samples of an input signal at selected times. At least one Volterra tap is coupled to the tape delay line. The Volterra tap includes a lookup table representation of a polynomial. An adaptive controller is coupled to the Volterra tap for modifying values in the lookup table.02-07-2013
20090154596RF TRANSMITTER HAVING MULTIPLE CONSTANT TRANSMIT POWER LEVELS - A radio frequency transmitter includes a baseband transmit processing module, a mixing module, a power amplifier, a transmit power sense module, and a transmit power control module. The baseband transmit processing module is operably coupled to encode outbound data into outbound baseband signals in accordance with one of a plurality of encoding protocols. The mixing module is operably coupled to convert the outbound baseband signals into outbound radio frequency signals. The power amplifier is operably coupled to amplify the outbound RF signals prior to transmission to produce amplified outbound RF signals. The transmit power sense module is operably coupled to sense the amplified outbound RF signals to provide a transmit signal strength indication (TSSI). The transmit power control module is operably coupled to adjust gain of the baseband transmit processing module, the mixing module, and/or the power amplifier based on the TSSI and the particular encoding protocol used to produce the baseband signals.06-18-2009
20130083866DISTORTION COMPENSATOR AND DISTORTION COMPENSATION METHOD - A distortion compensator compensates for distortion of a signal caused by an amplifier. A storage section stores a plurality of compensation coefficients used for distortion compensation. A selection section selects a compensation coefficient corresponding to an index value indicative of a power level of the signal from among the plurality of compensation coefficients. The selection section determines whether or not the power level is higher than a threshold, and uses, based on a determination result, a first index value calculated without using a logarithmic operation or a second index value calculated by using a logarithmic operation.04-04-2013
20130058435HIGH EFFICIENCY TRANSMITTER - A transmitter includes: a decoder for transforming an IQ signal into a linear sum of two vectors which have non-negative coefficients, respectively, which form an angle of (π/4), and which are included in eight vectors representing directions indicated by eight angles of (−π/2), 0, (π/2), π, (−3π/4), (−π/4), (π/4), and (3π/4), respectively, and for outputting information upon magnitudes and angles of the two vectors; a phase generator for generating eight phase signals corresponding to phases of (−π/2), 0, (π/2), π, (−3π/4), (−π/4), (π/4), and (3π/4), respectively, and outputting the eight phase signals; and a selector for selecting two phase signals having phases equivalent to angles of the two vectors, from among the eight phase signals, and amplifying the two phase signals having been selected, based on the information upon the magnitudes and the angles, and outputting, as a plurality of amplification signals, the two phase signals having been amplified.03-07-2013
20120224654TRANSMITTER AND DISTORTION COMPENSATING METHOD - A transmitter, when the power changes at a certain timing, adjusts the gain for the transmission signal before the application of the distortion compensation process correspondingly to the amplitude of the transmission signal at the certain timing based on the average of the power of a transmission signal before application of the distortion compensation process, obtains a distortion compensation coefficient corresponding to the value of the power of the adjusted transmission signal from the LUT, applies the distortion compensation process to the transmission signal using the obtained distortion compensation coefficient, calculates an update for a distortion compensation coefficient corresponding to the obtained distortion compensation coefficient and stored in the LUT based on an error between the power of the transmission signal amplified by an amplifier and the power of the transmission signal before the application of the distortion compensation process, and updates the LUT using the calculated update.09-06-2012
20130064325LINEARIZATION FOR A SINGLE POWER AMPLIFIER IN A MULTI-BAND TRANSMITTER - A multi-band signal is generated by combining two or more input signals separated in frequency. The input signals are combined either before or after predistortion depending on the bandwidth of the multi-band signal. If the bandwidth of the multi-band signal is less than a predetermined bandwidth threshold, the input signals are combined and predistortion is applied to the combined signal to generate the multi-band signal. If the bandwidth of the multi-band signal is greater than the bandwidth threshold, the individual input signals are predistorted and subsequently combined to generate the multi-band signal.03-14-2013
20130163696APPARATUS FOR COMPENSATING FOR DISTORTION OF TRANSMITTER ARRAY IN RADIO COMMUNICATION SYSTEM AND METHOD FOR CONTROLLING THE SAME - Provided is a method in which a Digital Pre-Distorter (DPD) performs digital pre-distortion on a received In-phase (I) signal, a received Quadrature-phase (Q) signal, a feedback I signal, and a feedback Q signal; a mixer mixes a signal output from the DPD with a frequency signal output from an oscillator; each of n phase shifters phase-shifts a signal output from the mixer according to a preset beamforming pattern; each of n Power Amplifiers (PAs) amplifies a signal output from an associated phase shifter according to a gain, the PAs connected to the associated phase shifter on a one-to-one basis; each of n envelope detectors detects an envelope signal from a signal output from an associated PA, the envelope detector connected to the associated PA on a one-to-one basis; and a control unit determines whether the n PAs operate normally, using the envelope signals output from the n envelope detectors.06-27-2013
20090010359APPARATUS AND METHOD FOR INTERFERENCE CANCELLATION IN MULTI-ANTENNA SYSTEM - An apparatus and a method for interference cancellation in a transmitting end of a multi-antenna system are provided. A precode is generated which maximizes a diversity gain of one or more receive antennas using channel information of the receive antennas to be serviced. Transmit powers of the receive antennas are updated by taking into account a power loss and a shaping loss according to a dirty paper coding. Transmit signals are precoded by updating the precode according to the updated transmit powers. The dirty paper coding is performed on the precoded transmit signals to be transmitted to the receive antennas.01-08-2009
20120236964SYSTEM AND METHOD FOR REDUCING BIT-ERROR-RATE IN ORTHOGONAL FREQUENCY-DIVISION MULTIPLEXING - System and method for reducing BER in OFDM based communication system. A cost function relating the power partition coefficients and the average power emitted by the linear power amplifier at the transmitter during quasistatic periods of the channel may be minimized, solved or estimated, based on the received channel partial CSI, and on knowledge of the linear power amplifier gain and linear dynamic range, to get power partition coefficients. The total available power may be divided among the subcarriers according to the resultant power partition coefficients. Additionally, the OFDM signal may amplified by a variable gain calculated based on the resultant power partition coefficients.09-20-2012
20120269293RF TRANSMITTER ARCHITECTURE, INTEGRATED CIRCUIT DEVICE, WIRELESS COMMUNICATION UNIT AND METHOD THEREFOR - A radio frequency (RF) transmitter architecture includes at least one digital signal processing module. The at least one digital signal processing module is configurable to operate in at least a first mode wherein the at least one digital signal processing module is arranged to receive a digital input signal, select, from a reduced set of digital power amplifier (DPA) control values, a plurality of DPA control values based at least partly on the received digital input signal, perform interpolation of the plurality of selected DPA control values to determine a DPA control value from a non-reduced set of DPA control values representative of the received digital input signal, and output to at least one DPA component the determined DPA control value representative of the received digital input signal.10-25-2012
20120269292RF TRANSMITTER, INTEGRATED CIRCUIT DEVICE, WIRELESS COMMUNICATION UNIT AND METHOD THEREFOR - A radio frequency (RF) transmitter including at least one digital signal processing module is described. The at least one digital signal processing module is arranged to receive a complex digital input signal, successively apply pre-distortion to the received complex digital input signal with a progressively finer granularity, simultaneously progressively increase a sampling rate of the received complex digital input signal, and output a first, in-phase digital control word and a second, quadrature, digital control word for controlling at least one digital power amplifier component to generate an RF signal representative of the received complex digital input signal.10-25-2012
20120269291RF TRANSMITTER, INTEGRATED CIRCUIT DEVICE, WIRELESS COMMUNICATION UNIT AND METHOD THEREFOR - A radio frequency (RF) transmitter has at least one digital signal processing module and at least one power amplifier module. The digital signal processing module includes at least one digital pre-distortion component arranged to receive at least one complex input signal, perform two-dimensional non-uniform mapping of the complex input signal to a first, in-phase, digital pre-distortion control word and a further, quadrature, digital pre-distortion control word, and output the in-phase and quadrature pre-distortion digital control words. The power amplifier module includes a first, in-phase, array of switch-mode power cells and at least one further, quadrature, array of switch-mode power cells. The two-dimensional non-uniform mapping has a pre-distortion profile at least partly based on an input/output relationship for the power amplifier module arranged to generate an analogue RF signal based at least partly on the in-phase and quadrature digital pre-distortion control words.10-25-2012
20120027125CODEBOOK, CODEBOOK CREATING METHOD, UPLINK TRANSMISSION METHOD AND EQUIPMENT BASED ON THE CODEBOOK - A codebook, a codebook creating method, and an uplink transmission method and equipment based on the codebook are provided. A new codebook is put forward in the method. The codebook includes one or any combination of the following elements:02-02-2012
20130163695APPARATUS AND METHOD FOR CALIBRATION OF TRANSMITTER IN COMMUNICATION DEVICE - A method and an apparatus for calibration of a transmitter not having a Surface Acoustic Wave (SAW) filter are provided. The apparatus includes a calibration unit for outputting a detuning signal by which a resonance frequency of a Radio Frequency (RF) circuit is detuned with respect to a transmit operating frequency, and an RF unit for changing the resonance frequency according to the detuning signal and for outputting an out-of-band noise and a transmit signal having a relatively lower power than that of a case where the resonance frequency and the transmit operating frequency are tuned to each other.06-27-2013
20120288030DISTORTION COMPENSATION DEVICE AND DISTORTION COMPENSATING METHOD - A distortion compensation device which reduces a distortion of an amplifier which is added to an output signal of the amplifier, the distortion compensation device including: a plurality of distortion compensation coefficient storage circuits which stores a plurality of distortion compensation coefficients and outputs the distortion compensation coefficients according to an amplitude of an input signal of the amplifier, a distortion compensating processing circuit which adds the distortion compensation coefficient output from each of the plurality of distortion compensation coefficient storage circuits to the input signal of the amplifier, and a distortion compensation coefficient updating circuit which performs weighting processing on the distortion compensation coefficient output from each of the plurality of distortion compensation coefficient storage circuits to reduce the distortion compensation coefficient and which calculates an update value of the distortion compensation coefficient by using the distortion compensation coefficient which is subjected to the weighting processing.11-15-2012
20130163694ARCHITECTURE OF A LOW BANDWIDTH PREDISTORTION SYSTEM FOR NON-LINEAR RF COMPONENTS - Systems and methods for compensating for non-linearity of a non-linear subsystem using predistortion are disclosed. In one embodiment, a system includes a non-linear subsystem and a predistorter configured to effect predistortion of an input signal of the non-linear subsystem such that the predistortion compensates for a non-linear characteristic of the non-linear subsystem. In addition, the system includes a narrowband filter that filters a feedback signal that is representative of an output signal of the non-linear subsystem to provide a filtered feedback signal, and an adaptor that adaptively configures the predistorter based on the filtered feedback signal and a reference signal that is representative of an input signal of the non-linear subsystem. By utilizing the filtered feedback signal, rather than the feedback signal, a complexity, and therefore, cost of the adaptor is substantially reduced.06-27-2013
20110280338TRANSMISSION APPARATUS AND METHOD OF CONTROLLING THE SAME - A transmission apparatus according to the present invention includes: a baseband signal generator; a local oscillator; a modulator that generates a modulation signal by multiplying a baseband signal by a carrier wave signal including a local oscillation frequency; a power amplifier that amplifies the modulation signal; a filter having a pass bandwidth that is narrower than a frequency bandwidth that can be set or emerge in the local oscillator and removes at least a part of unwanted component generated in association with the modulation signal that is amplified; and a frequency bandwidth inside/outside decision unit that decides that the local oscillation frequency is out of a predetermined bandwidth. The transmission apparatus controls one of the baseband signal generator and the local oscillator to reduce the modulation signal when it is decided by the frequency bandwidth inside/outside decision unit that the local oscillation frequency is out of the predetermined bandwidth.11-17-2011
20090097591APPARATUS AND METHOD FOR ENVELOPE TRACKING POWER AMPLIFICATION IN WIRELESS COMMUNICATION SYSTEM - An apparatus and a method for Envelope Tracking (ET) power amplification in a wireless communication system are provided. The apparatus includes a baseband signal controller for outputting an envelope signal in an envelope signal path and outputting a constant signal in a baseband signal path when measuring a time delay of the envelope signal path, and for outputting a constant signal in the envelope signal path and outputting a baseband signal in the baseband signal path when measuring a time delay of the baseband signal path, a time delay difference measurer for measuring a time delay of each path by calculating a correlation coefficient between the envelope signal path and the baseband signal path and a signal time controller for setting a time delay in a corresponding path using the time delay difference of each path and aligning times.04-16-2009
20100034315REVERSE LINK POWER CONTROL FOR AN OFDMA SYSTEM - Techniques for performing power control of multiple channels sent using multiple radio technologies are described. The transmit power of a reference channel, sent using a first radio technology (e.g., CDMA), is adjusted to achieve a target level of performance (e.g., a target erasure rate) for the reference channel. The transmit power of a data channel, sent using a second radio technology (e.g., OFDMA), is adjusted based on the transmit power of the reference channel. In one power control scheme, a reference power spectral density (PSD) level is determined based on the transmit power of the reference channel. A transmit PSD delta for the data channel is adjusted based on interference estimates. A transmit PSD of the data channel is determined based on the reference PSD level and the transmit PSD delta. The transmit power of the data channel is then set to achieve the transmit PSD for the data channel.02-11-2010
20110261903WIRELESS COMMUNICATION UNIT, INTEGRATED CIRCUIT AND METHOD OF POWER CONTROL OF A POWER AMPLIFIER THEREFOR - A wireless communication unit comprises a transmitter having a forward path comprising a power amplifier, PA, and a feedback path operably coupled to the power amplifier, wherein the feedback path comprises a coupler arranged to feed back a portion of a signal to be transmitted and a controller logic module arranged to control a power control value of the power amplifier, such that the forward path and feedback path form a closed loop power control. The controller logic module is arranged to determine a gain variation in the transmitter and provide attenuation to a transmit signal passing therethrough on a transmit slot by transmit slot basis and instruct a power backoff where necessary.10-27-2011
20080310549Transmission controlling method in wireless communications system and receiver for use in the same system - The present invention relates to a transmission controlling method in a wireless communications system and a receiver for use in the same system. The invention aims at realizing power control (or transmit rate control) more effective than previous techniques by means of utilizing a certain relationship between an error rate and an evaluation amount relating to the estimation amount. Thus, a certain relationship is defined between the evaluation amount relating to a reception condition and an error rate on the receiver, and on the basis of this certain relationship, transmit power of the transmitter is controlled.12-18-2008
20090285329TRANSMISSION POWER CONTROL METHOD AND TRANSMISSION APPARATUS - Even when there is limit placed upon transmission power control time, the transmission power control method enables accurate control transmission power. The transmission power control method includes: a first measuring step of measuring, in a symbol interval before a symbol interval where mode of the power amplifier changes, output power of the power amplifier before mode changes; a first setting step of setting target power of the power amplifier after mode changes based on a measurement result obtained in the first measuring step and a transmission power control signal; a second measuring step of measuring, in the symbol interval where mode of the power amplifier changes, output power of the power amplifier after mode changes, the output power being controlled using the target power set in the first setting step; and a second step of setting corrected target power based on a measurement result obtained in the second measuring step.11-19-2009
20090207939System and Method for Burst Mode Amplifier - Embodiments related to burst mode amplifying are described and depicted.08-20-2009
20090245419METHOD AND APPARATUS FOR IMPROVING POWER AMPLIFIER EFFICIENCY IN WIRELESS COMMUNICATION SYSTEMS HAVING HIGH PEAK TO AVERAGE POWER RATIOS - A power management system and method for a wireless communication device generates an average desired transmit power signal based on at least one of a received signal strength indicator signal and a power control instruction signal from a base station. A power supply level adjustment signal is generated based on the data parameters of an outgoing data stream and at least one environmental information signal. A combination of the power supply level adjustment signal and the average desired transmit power or a gain control signal and an altered version of the power supply level adjustment signal is used to generate a variable power supply signal that is provided to an output amplifier block for sufficiently generating outgoing wireless device radio signals while reducing power loss in the output amplifier block.10-01-2009
20120106676Transmitter Linearized In Response To Signal Magnitude Derivative Parameter and Method Therefor - A transmitter (05-03-2012
20090296855TRANSMISSION CIRCUIT FOR BIAS CONTROL OF POWER AMPLIFIER - Provided is a transmission circuit that is capable of switching a bias circuit without allowing a power amplifier to enter a non-bias state. A first bias circuit 12-03-2009
20110200142Up-Converted and Amplified Transmission Signal Using Log-Antilog - According to one exemplary embodiment, a method for producing an up-converted and amplified transmission signal comprises performing a logarithmic transformation of an input transmission signal to form a logarithmically transformed transmission signal, adding the logarithmically transformed transmission signal to a logarithmic local oscillator signal to form a sum signal, and performing an antilogarithmic transformation of the sum signal to produce the up-converted and amplified transmission signal. In one embodiment, a log-antilog circuit for producing an up-converted and an amplified transmission signal comprises a transmission log block configured to receive an input transmission signal and to provide a logarithmically transformed transmission signal as a transmission log block output, and an antilog block coupled to the transmission log block. The antilog block is configured to receive a sum signal of the transmission log block output and a logarithmic local oscillator signal.08-18-2011
20080285681Systems and Methods of RF Power Transmission, Modulation, and Amplification - Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.11-20-2008
20130216000METHOD AND APPARATUS FOR CONTROLLING A TRANSMIT POWER - An apparatus and a method are described which determine a maximum power reduction metric based on a comparison between a magnitude of at least one data channel and a magnitude of at least one control channel. A transmit power, for example of a user equipment, is controlled based on the determined maximum power reduction metric.08-22-2013
20080240288DIFFERENTIAL TRANSMISSION CIRCUIT, DISK ARRAY APPARATUS, AND OUTPUT SIGNAL SETTING METHOD - To provide a signal transmitting/receiving apparatus etc. where a cable length can be measured by using a general-purpose cable, without using an interface. A differential transmission circuit by the present invention includes a signal output circuit sending a high-speed differential signal and a pulse wave; a signal input circuit including a terminating resistor; a bias controller controlling a bias voltage on a transmission path; a terminating resistance controller disconnecting the terminating resistor on sensing a bias voltage and connecting it on sensing no bias voltage, by a bias sensing circuit; a sensing input circuit sensing a pulse wave reflected at the signal input circuit; and an output setting controller setting an electric characteristic of a signal outputted from the signal output circuit by a propagation time from sending the pulse wave by the signal output circuit to receiving the reflected pulse wave by the sensing input circuit.10-02-2008
20090161793Processing transmission signals in radio transmitter - A method, apparatus, and computer program is presented for use in a radio transmitter using a polar transmitter structure in which a transmission signal is separated into an amplitude component and a phase component. The transmission signal includes transmission symbols distributed to a number of transmission resource blocks allocated to the radio transmitter for transmission. The amplitude component of the transmission signal is low-pass filtered in a low-pass filter configured by filtering parameters selected according to the number of transmission resource blocks allocated to the radio transmitter. Then, the low-pass filtered amplitude component is used in power supply of a power amplifier configured to power-amplify a phase component of the transmission signal.06-25-2009
20090052575System and Method for Power Control in a Wireless Transmitter - A system and method for power control in a wireless transmitter. A power control loop includes a feed forward unit coupled to a data source, the feed forward unit processes a signal for transmission, a feedback unit coupled to the feed forward unit, the feedback unit generates a feedback signal representative of an output power level of the signal transmitted by the feed forward unit, a closed loop power control unit coupled to the feedback unit and to the feed forward unit, the closed loop power control unit generates an additive correction signal based on an error signal computed from the feedback signal and data provided by the data source, and a ramp path power control unit coupled to the data source, the ramp path power control unit generates a multiplicative correction signal based on an additive correction signal and data provided by the data source.02-26-2009
20110222630COMMUNICATION DEVICE AND POWER CORRECTION METHOD - A communication device that compensates a distortion of a transmission signal, amplifies the compensated transmission signal by an amplifier, and outputs the signal. The device includes a storage unit that stores a transmission characteristic of a transmission power of the communication device, a correcting unit that calculates a power value at a set transmission frequency by referring to the storage unit and that corrects a feedback signal of the transmission signal amplifier by the amplifier based on the calculated power value and a maximum transmission power defined by the communication device, and a calculating unit that calculates a distortion compensation coefficient based on the transmission signal and the feedback signal corrected.09-15-2011
20090252255PREDISTORTION METHODS AND APPARATUS FOR POLAR MODULATION TRANSMITTERS - Methods and apparatus for predistorting signals in a polar modulation transmitter. An exemplary method includes predistorting an envelope component signal in an amplitude path of a polar modulation transmitter according to a set of AM/AM predistortion coefficients, and predistorting a phase component signal in a phase path of the polar modulation transmitter according to a set of AM/PM predistortion coefficients. The AM/AM and AM/PM predistortion coefficients are stored in a memory in the form of a look up table (LUT). The envelope component signal is scaled and/or offset, before predistortion is applied, by an amount dependent upon which average power level of a plurality of average power levels the power amplifier of the polar modulation transmitter is configured to operate. Scaling and/or offsetting the envelope component signal prior to applying predistortion affords the ability to share the AM/AM and AM/PM predistortion coefficients of the predistortion LUT over the plurality of average power levels.10-08-2009
20090245417TRANSMITTER CHAIN TIMING AND TRANSMIT POWER CONTROL - In a communications system, transmitter power gain can be changed between symbols. A power gain change of a first part of a transmit chain is initiated a first time, whereas a power gain change of a second part of the transmit chain is initiated at a second time, such that the resulting power gain changes of the first and second parts both occur substantially within an inter-symbol time in a desired relationship to one another. In one example, the power gain change of the first part is initiated before the beginning of the inter-symbol time to account for expected serial bus latency between initiation and execution of the power gain change of the first part. The power gain change of the second part is initiated during the inter-symbol time such that overall power does not exceed an amount (for example, a maximum permitted under a communication standard).10-01-2009
20100239048METHOD AND APPARATUS FOR IMPROVING THROUGHPUT AND ERROR PERFORMANCE OF RATELESS CODING SYSTEMS - A method and system are described for adaptively adjusting data communication of a rateless coding system, including adaptively estimating a symbol coding length, determining a symbol threshold, determining if the adaptively estimated symbol coding length is less than the symbol threshold, adjusting a transmission power level based on the second determining act and adaptively adjusting a modulation scheme based on the second determining act. Also described are a method and system for decoding communication of a rateless coding system, including receiving encoded symbols, determining if a length of the received encoded symbols is greater than a threshold number of encoded symbols and decoding the received encoded symbols if the length of the received encoded symbols is greater than the threshold number of encoded symbols.09-23-2010
20090074107METHOD AND APPARATUS FOR OPTIMIZING TRANSMITTER POWER EFFICIENCY - A peak to average power ratio signal is generated from a first mapping function that selects the peak to average power ratio signal that corresponds to the data rate or data format of the signal to be transmitted. The selected peak to average power ratio signal is summed with a desired average transmit power signal. The resulting summation signal is input to a second effectively continuously valued mapping function comprising a table that has a plurality of power amplifier control signal values each with a corresponding peak transmit power. Each peak transmit power signal value results in a power amplifier control signal value that achieves the best possible transmitter power efficiency while still meeting out of band spurious emissions and waveform quality requirements. The summation signal value maps to one of the power amplifier control signal value that is then used to adjust a parameter such as bias of the power amplifier.03-19-2009
20090323857CONFIGURABLE SUB-BAND FILTERING TO REDUCE PEAK-TO-AVERAGE POWER RATIO OF OFDM SIGNALS OR THE LIKE - Briefly, in accordance with one or more embodiments, a reduction in peak-to-average power ratio (PAPR) in an OFDM signal may be achieved by clipping the OFDM signal, extracting the clipping noise, filtering the clipping noise, and then constructing the clipped OFDM signal with the filtered clipping noise.12-31-2009
20090202017Distortion Control Device and Method - This invention includes a waveform analyzing means (08-13-2009
20100303170METHOD AND APPARATUS FOR PRE-PROCESSING DATA TO BE TRANSMITTED IN MULTIPLE-INPUT COMMUNICATION SYSTEM - A method for pre-processing data to be transmitted in a multiple-input communication system comprises the following steps: generating a beamforming matrix and a pre-coding matrix; combining the beamforming matrix and the pre-coding matrix to generate a weight matrix; and pre-processing the data by using the generated weight matrix. There are also provided a transmitter, a base station, and a communication system using the method.12-02-2010
20100322346TRANSMITTER ARCHITECTURES - Techniques for generating a transmit (TX) signal with improved characteristics in the presence of interference such as noise and distortion. In one aspect, the TX output signal is used to generate a reconstructed signal having the characteristics of the interference, and the reconstructed signal is subtracted from the baseband TX signal. The reconstructed signal may be generated by high-pass filtering the TX output signal at baseband. Alternatively, the reconstructed signal may be generated from a reference signal Ref derived from the baseband TX signal.12-23-2010
20110007841RF TRANSMITTER AND METHOD OF OPERATION - A linear RF transmitter (01-13-2011
20090067541Digital linear amplification with nonlinear components (LINC) transmitter - Embodiments of the invention may provide for a digital LINC (linear amplification with nonlinear components) transmitter. The digital LINC transmitter may include a signal component separator, at least one digital delay modulator, a frequency synthesizer, at least one power amplifier, a power combiner, an antenna, and a mismatch compensator. Additionally, systems and methods may be provided for compensating for phase and amplitude mismatches between two signal paths.03-12-2009
20110085619SYSTEM AND METHOD FOR SYNCHRONIZATION, POWER CONTROL, CALIBRATION, AND MODULATION IN COMMUNICATION TRANSMITTERS - A system is provided for processing a communication signal including a baseband amplitude component and a baseband phase component. The system includes an amplitude predictor configured for closed-loop pre-distortion of a baseband amplitude component, an amplitude lookup table configured for open-loop pre-distortion of the baseband amplitude component, and an amplitude interpolator configured to build up the amplitude lookup table during a closed-loop calibration period. The system also includes a phase predictor configured for closed-loop pre-distortion of a baseband phase component, a phase lookup table configured for open-loop pre-distortion of the baseband phase component, and a phase interpolator configured to build up the phase lookup table during a closed-loop calibration period.04-14-2011
20090213961METHOD AND APPARATUS FOR CONTROLLING TRANSMISSION POWER IN A COMMUNICATION SYSTEM - In a communication system, a mobile terminal compares a first modulation/Forward Error Correction (FEC) rate level, which is a modulation/FEC rate level used in a previously transmitted signal, with a second modulation/FEC rate level, which is a modulation/FEC rate level to be used in a currently transmitted signal. If the second modulation/FEC rate level is higher than the first modulation/FEC rate level, the mobile terminal determines the transmission power using a normalized Carrier to Noise ratio (C/N) corresponding to the second modulation/FEC rate level on an ascending normalized C/N table, while if the second modulation/FEC rate level is lower than the first modulation/FEC rate level, the mobile terminal determines the transmission power using a normalized C/N corresponding to the second modulation/FEC rate level on a descending normalized C/N table.08-27-2009
20100014609DISTORTION CORRECTION CONTROL APPARATUS AND DISTORTION CORRECTION CONTROL METHOD - A distortion correction control apparatus is for compensating for a burst distortion in a transmission amplifier caused by a burst of an input signal of a transmission target. The apparatus includes a holding unit that stores a distortion correction coefficient having reverse characteristics to the burst distortion; a unit that multiplies the distortion correction coefficient read out from the holding unit by the input signal or adds the distortion correction coefficient read out from the holding unit to the input signal, upon reception of burst information notifying of switching between presence and absence of the input signal; and an update unit that updates, based on the input signal, the distortion correction coefficient of the last time, and a signal fed back as an output signal of the transmission amplifier, the distortion correction coefficient by an adaptive algorithm, and that inputs the updated distortion correction coefficient to the holding unit.01-21-2010
20120243637Power Amplification Based on Phase Angle Controlled Frequency Reference Signal and Amplitude Control Signal - Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.09-27-2012
20120201330METHOD AND SYSTEM FOR TRANSMITTING SIGNALS WITH REDUCED SPURIOUS EMISSIONS - An RF power amplifier architecture minimizes spurious emissions by breaking the transmitted signal into narrow spectrum sub-bands, amplifying each separately, and then combining the signals for transmission purposes.08-09-2012
20090207940Predistortion Calibration In A Transceiver Assembly - Systems and methods are provided for calibrating a digital predistorter in an integrated transceiver circuit. A digital transmitter path provides a signal from a digital input. The transmitter path includes a digital predistorter that predistorts the digital input to mitigate nonlinearities associated with a power amplifier. The integrated transceiver circuit further includes a receiver path associated with the digital transmitter path. A coupling element provides the signal from the transmitter path to the receiver path. A signal evaluator determines values for at least one parameter associated with the digital predistorter based on the signal.08-20-2009
20090022240Low power distributed transmitter - A low power distributed transmitter includes a signal generator, signal partitioning module, signal processing module, a plurality of amplifiers, and a transmitting module. The signal generator is operably coupled to generate a signal to represent base-band data in accordance with a particular transmission protocol. The signal partitioning module is operably coupled to partition the signal into a plurality of signal partitions based on a peak-to-average ratio of the signal. The signal processing module processes the plurality of signal partitions to in accordance with the particular transmission protocol to produce processed signals. Each of the amplifiers amplifies a corresponding one of the processed signal partitions to produce amplified signal partitioned. The transmitting module transmits, via an antenna or a plurality of antennas, the amplified signal partitions as a composite amplified signal.01-22-2009
20110255636DISTORTION COMPENSATION CIRCUIT, TRANSMITTING APPARATUS AND DISTORTION COMPENSATING METHOD - A distortion compensation circuit for compensating for the distortion characteristics of an amplifier, includes a distortion compensating coefficient calculating element and a distortion compensating operation element. The distortion compensating coefficient calculating element calculates a distortion compensating coefficient to be used for compensation of the distortion characteristics by comparing an input signal with the output signal amplified by the amplifier. The distortion compensating operation element performs a distortion compensating operation on the input signal, using a variably set bit format and the distortion compensating coefficient calculated by the distortion compensating coefficient calculating element.10-20-2011
20080205548METHOD AND SYSTEM FOR A SOFTWARE DEFINED POWER AMPLIFIER FOR MULTI-BAND, MULTI-STANDARD APPLICATIONS - Methods and systems for a software defined power amplifier for multi-band, multi-standard applications are disclosed and may comprise configuring a single programmable output stage of a multi-band, multi-standard transmitter to handle transmission of a signal according to multiple wireless communication protocols and frequency ranges. The output stage may be configured by coupling a power amplifier (PA) within the programmable output stage to a switch or a duplexer, which may be coupled to one or more of multiple antennas, each of which may handle signals in a different frequency range. Each antenna may be impedance matched with the power amplifier using transformers, and may be coupled by activating at least one integrated transistor. The PA may be biased to operate in one of a plurality of classes of operation comprising Class A, AB, C and F associated with the wireless communication protocols, which may comprise EDGE, GSM, WCDMA and wireless LAN.08-28-2008
20100119008PROGRAMMABLE WIDE BAND DIGITAL RECEIVER/TRANSMITTER - A receiver uses a wideband intermediate frequency (IF) in the analog domain and performs low IF down-conversion in the digital domain, using low-power, high-speed, high resolution analog-to-digital converters. The receiver can be integrated into an integrated circuit as one of several receivers. Such an integrated circuit may include multiple transmitters using adaptive non-linear modeling pre-distortion. The non-linear modeling may include memory. Imbalance in intermediate frequency in-phase and quadrature signals may be corrected in the digital domains. DC offsets in the intermediate signal may be corrected in both analog and digital domains. In one instance, the receiver provides a feedback receiver for the adaptive pre-distorter in a transmitter on the integrated circuit.05-13-2010
20100158155SYSTEM AND METHOD FOR TRAINING PRE-INVERSE OF NONLINEAR SYSTEM - A circuit for use with an amplification circuit having a predistortion datapath portion, a power amplifier portion and a gain portion. The predistortion datapath portion can output a predistorted signal based on the input signal. The power amplifier portion can output an amplified signal based on the predistorted signal. The gain portion can output a gain output signal based on the amplified signal. The circuit comprises a digital predistortion adaptation portion and a combiner. The digital predistortion adaptation portion can output a predistortion adaptation portion output signal. The combiner can output an error signal. The predistortion adaptation portion output signal is based on the input signal, the gain output signal and the error signal. The error signal is based on the difference between the predistorted signal and the predistortion adaptation portion output signal.06-24-2010
20100020900DIGITAL PRE-DISTORTION TECHNIQUE USING NONLINEAR FILTERS - A method and computer program product for operating a linearizer for a circuit, including generating a set of coefficients via a characterizer; predistorting a signal input to the circuit responsive to the coefficients and generating a linearized output in response thereto; filtering the signal through a linear digital filter having linear digital filter taps, each tap other than a first tap being successively delayed by one delay unit; generating powers of the signal; inputting the generated powers of the signal through tapped delay lines, each line having nonlinear digital filter taps, each tap other than a first tap being successively delayed by one delay unit; applying the coefficients to the linear and nonlinear digital filter taps; summing each of the nonlinear digital filter taps corresponding to a certain number of delay units; and adding the sum of each of the delay units to a particular linear digital filter tap.01-28-2010
20100020899METHOD AND APPARATUS FOR IMPROVING DIGITAL PREDISTORTION CORRECTION WITH AMPLIFIER DEVICE BIASING - A method, apparatus, and electronic device for using digital predistortion are disclosed. A transmitter 01-28-2010
20110216851ROBUST TRANSMIT/FEEDBACK ALIGNMENT - Performing digital predistortion (DPD) for widely spaced narrowband signals, such as the signal used in multi-carrier GSM, can be very difficult. Here, a system is provided the performs DPD for widely spaced narrowband signals. In particular, this system uses a polynomial curve for values of a cross-correlation function (above a predetermined threshold) to determine a delay estimate, which allows for a more robust and accurate system.09-08-2011
20100177848TRANSMITTER WITH REDUCED SPECTRAL REGROWTH AND ASSOCIATED METHODS - A transmitter includes a monitoring circuit for monitoring phase transitions of in-phase and quadrature components of an input phase modulated signal. A filter is downstream from the monitoring circuit for generating a filtered phase modulated signal within an allocated bandwidth. A transmit gain controller is downstream from the filter for adjusting an amplitude of the filtered phase modulated signal based on a dynamic reference envelope control signal. A control circuit cooperates with the monitoring circuit and the transmit gain controller for generating the dynamic reference envelope control signal so that phase transitions are suppressed in the filtered phase modulated signal and so that the filtered phase modulated signal remains within the allocated bandwidth.07-15-2010
20090285330LOOP DELAY AND GAIN CONTROL METHODS IN CLOSED-LOOP TRANSMITTERS AND WIRELESS DEVICES - Embodiments include transmitters, wireless devices, and methods for performing loop delay and gain control. In a transmitter, a gain application element receives and combines digital input samples and a digital gain signal to generate gain-compensated digital samples. A power amplifier receives and amplifies an analog version of the gain-compensated digital samples to generate an antenna output signal. A feedback path generates an analog feedback signal from the antenna output signal, to produce a sequence of digital feedback samples from the analog feedback signal, and generates the digital gain signal from the sequence of digital feedback samples and a loop gain estimate. A loop delay and gain calculator calculates a loop delay estimate from the gain-compensated digital samples and the sequence of digital feedback samples, and calculates the loop gain estimate using the loop delay estimate, the gain-compensated digital samples, and the sequence of digital feedback samples.11-19-2009
20120147993METHOD AND SYSTEM FOR BASEBAND PREDISTORTION LINEARIZATION IN MULTI-CHANNEL WIDEBAND COMMUNICATION SYSTEMS - In some embodiments, a method of reducing adjacent channel power ratio and compensating memory effects of multi-channel wideband communication systems using multiplexing modulation techniques is provided. The method includes generating an address from samples of a baseband input signal of a communication system. The method also includes retrieving from a memoryless lookup table an entry in accordance with the address. The method further includes pre-equalizing the baseband input signal, the pre-equalization depending on one or more magnitudes of the input signal. The method still further includes multiplying the pre-equalized baseband input signal and the lookup table entry.06-14-2012
20080260066Dynamic 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.10-23-2008
20120002752PREDISTORTION OF COMPLEX MODULATED WAVEFORM - Exemplary embodiments of the invention include a transmitter system configured to predistort an input signal to generate a target output signal. An exemplary transmitter system includes a forward path including a predistortion device coupled with an amplifier, the forward path configured for predistorting an input signal to the predistortion device in response to a phase error compensation signal and an amplitude error compensation signal in order to generate a desired output signal for the output signal of the amplifier, and a feedback path including a processor configured for generating the phase error compensation signal and the amplitude error compensation signal based on a comparison of the input signal with phase and amplitude information of the output signal of the amplifier, wherein the phase and amplitude information of the amplifier are transmitted to the processor on a single path of the feedback path. Other methods and apparatuses are also presented herein.01-05-2012
20120008717CONVERSION SYSTEM - The invention relates to frequency conversion systems, in particular for use as up-converters or down-converters in radiofrequency (RF) receivers or transmitters, exemplary embodiments including a radiofrequency receiver (01-12-2012
20120057654SELECTIVE PEAK POWER REDUCTION - The present invention provides a technique for reducing the peak power of a combined signal that has a first signal of a first modulation type and a second signal of a second modulation type. Based on the combined signal, peak reduction distortion is determined. The peak reduction distortion is configured such that, if applied to the entirety of the combined signal, excessive peaks throughout the combined signal would be reduced. However, instead of applying the entirety of the peak reduction distortion, a selected portion of the peak reduction distortion is applied to a corresponding portion of the combined signal to reduce the peak power of the combined signal.03-08-2012
20120063544METHOD AND DEVICE FOR PRE-DISTORTING AN EXCITER AND PREDISTORTION EXCITER - A method for pre-distorting an exciter includes obtaining a characteristic curve of a radio frequency (RF) amplifier, obtaining a first relationship between a gain amplitude correction value and an input power and a second relationship between a gain phase correction value and the input power based on the characteristic curve, obtaining a transmission gain for use in a scan from a magnetic resonance pre-scan, and obtaining the gain amplitude correction value and the gain phase correction value of an input of the exciter based on the input of the exciter, the transmission gain, the first relationship, and the second relationship. An input of the exciter is pre-distorted using the gain amplitude correction value and the gain phase correction value.03-15-2012
20130170581QUADRATURE DIGITAL-IF TRANSMITTER WITHOUT INTER-STAGE SAW FILTER AND DEVICES USING SAME - An RF transmitter comprises a digital-to-IF circuit block configured to receive a digital in-phase baseband signal and a digital quadrature baseband signal and to up-convert the digital in-phase and quadrature baseband signals to a digital in-phase IF signal and to a digital quadrature IF signal. The wireless RF transmitter further comprises an IF-to-RF circuit block configured to convert the digital in-phase and quadrature IF signals to analog signals and to up-convert the analog in-phase and quadrature IF signals to an RF output signal. The digital-to-IF circuit block comprises pre-compensation circuitry configured to reduce analog impairments associated with the IF-to-RF circuit block.07-04-2013
20120155572High efficiency, remotely reconfigurable remote radio head unit system and method for wireless communications - A remote radio head unit (RRU) system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier inside the RRU. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by a wideband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, embodiments of the present invention can compensate for the nonlinearities as well as memory effects of the power amplifier systems and also improve performance, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers, multi-frequency bands and multi-channels. As a result, the remote radio head system is particularly suitable for wireless transmission systems, such as base-stations, repeaters, and indoor signal coverage systems.06-21-2012
20110103512METHOD AND SYSTEM FOR MINIMIZING POWER CONSUMPTION IN A COMMUNICATION SYSTEM - A method for processing signals in a communication system includes delaying a baseband signal based on at least one calibration signal, and amplifying the delayed baseband signal. The at least one calibration signal may be generated based on an amount of intermodulation distortion associated with the amplified delayed baseband signal. A bias voltage of an amplifier used for the amplifying may be adjusted, where the adjusting is in proportion to an envelope of the baseband signal. A number of samples used for the delaying may be calculated, by minimizing the amount of the intermodulation distortion at an output of the amplifier. The envelope may be measured by evaluating a plurality of I and Q samples of the baseband signal. A supply and/or bias voltage for the amplifier may be generated by using a switching regulator. The bias voltage may control a gain of the amplifier.05-05-2011
20120128099Method and Frequency Agile Pre-distorted Transmitter Using Programmable Digital Up and Down Conversion - Pre-distorted transmitters operable over a wide range of frequencies including a plurality of predetermined frequency bands are provided. The transmitters include a programmable digital up-converter and a programmable digital down-converter, an ADC, a DAC, a power amplifier and at least one analog filter arranged along a transmit signal path and a feedback signal path.05-24-2012
20120314807RADIO COMMUNICATION DEVICE - A radio communication device includes an amplification unit configured to amplify a transmission signal, an antenna transmitting an amplification signal amplified by the amplification unit, a detection unit configured to detect a reflection signal that is the amplification signal reflected from a side of the antenna, and a correction processing unit configured to correct the transmission signal, wherein the correction processing unit is configured to correct the transmission signal based on the reflection signal when installation of a filter through which the amplification signal passes is recognized.12-13-2012
20120163498SAMPLING CIRCUIT, COMMUNICATION DEVICE, DISTORTION CORRECTION CIRCUIT, SIGNAL SAMPLING METHOD, AND PROGRAM - A sampling circuit samples a transmission signal containing a particular transmission signal transmitted in a regular and intermittent transmission pattern. The sampling circuit includes a sampling processing unit that performs a sampling process that samples the transmission signal; a determination unit that determines whether the sampling process has been successfully or unsuccessfully performed; and a sampling control unit that sets up sampling acquisition intervals for the sampling processing unit in which the intervals differ depending on whether the sampling process is successfully or unsuccessfully, the sampling processing unit performing the sampling process based on the sampling acquisition interval that has been set up by the sampling control unit.06-28-2012
20120076237Close-loop power amplifier pre-distortion correction - Attenuation is provided at the output of a power amplifier that provides transmitted signals or packets. The attenuation particularly provides separation of linear and non linear behavior of the signals. A reference packet is transmitted during attenuation. A normal packet is delivered without attenuation. Feedback from the reference packet can be extracted using the normal packet to calculate a loop-back response that is extracted and sent to a power amplifier pre-distortion correction algorithm.03-29-2012
20120177143COMPOSITE AMPLIFIER, TRANSMITTER, AND COMPOSITE AMPLIFIER CONTROL METHOD - A signal distributor sequentially outputs N input signals respectively corresponding to N rows of a matrix of which each has N element signals in which a predetermined matrix is obtained by dividing the matrix by a predetermined value. A coupler adds the amplified N element signals for each the input signal. A solver computes feedback signals Y* for the individual amplifiers by using an addition result Y of the outputs for each the input signal and the inverse matrix L07-12-2012
20100272214RADIOFREQUENCY TRANSMISSION SYSTEM - The invention relates to a radiofrequency transmission system comprising: means of producing a complex digital signal quantised on N bits; means of transforming the complex digital signal into two complex digital signals with an identical and constant envelope that are phase-shifted with respect to one another; a digital processing pathway associated with each of the two complex digital signals with a constant envelope and comprising at least some filtering means of the sigma-delta type for quantising on M bits signals travelling in the processing pathway, M being less than N; digital-to-analogue conversion means for converting the outputs of the digital processing pathways into analogue signals; means of selectively filtering (of the bandpass type) the analogue signals in a predetermined transmission frequency band; means of amplifying the filtered analogue signals; and means of recombining the amplified analogue signals.10-28-2010
20120224653COMPOSITE POWER AMPLIFIER, TRANSMITTER, AND COMPOSITE-POWER-AMPLIFIER CONTROL METHOD - C-HPA separates an input signal into separated signals, and amplifies and combines the separated signals. The C-HPA includes a plurality of signal splitters, a delay discrepancy estimator, and a delay discrepancy adjuster. Each of the signal splitters splits each of the separated signals into a signal in which a time component of the separated signal is put ahead a predetermined time and a signal in which the time component is delayed the predetermined time, and outputs split signals. The delay discrepancy estimator uses the input signal, the split signals output from each of the signal splitters and the combined output signal to estimate delay discrepancy between the separated signals. The delay discrepancy adjuster uses the estimated delay discrepancy to adjust the delay discrepancy between the separated signals.09-06-2012
20120328050CENTRALIZED ADAPTOR ARCHITECTURE FOR POWER AMPLIFIER LINEARIZATIONS IN ADVANCED WIRELESS COMMUNICATION SYSTEMS - Embodiments of a centralized predistortion system and corresponding adaptive predistortion processes are disclosed. In general, a central node includes one or more centralized predistortion components that enable predistortion for one or more remote transmit chains in order to compensate for non-linearity of power amplifiers in the one or more remote transmit chains. For instance, in one embodiment, the central node is a hub base station and the one or more remote transmit chains are included in one or more transmitters at one or more satellite base stations.12-27-2012
20120263257SIGNAL AMPLIFYING APPARATUS, WIRELESS TRANSMITTING APPARATUS, AND SIGNAL AMPLIFYING METHOD - A signal amplifying apparatus, a wireless transmitting apparatus, and a signal amplifying method are provided. The signal amplifying apparatus modulates an envelope signal using a multi-bit quantizer, thereby increasing coding efficiency and tracking optimal supply voltage with respect to envelope variation due to the use of the multi-bit quantizer.10-18-2012
20080298501Method and apparatus for distortion correction of RF amplifiers - A method of reducing distortion in the output of an amplifier is provided. The method comprises subtractively combining an error signals with the appropriate phase shift with input signals to be amplified. The error signal being generated by subtractively combining a fed-forward portion of the input signal with a portion of the fed-back amplified output signal, and signal processing applied to it between its generation and application to correcting the input signal in the baseband domain. The error therefore being down-converted, filtered, and up-converted in the feedback path. The filtered baseband error signal components providing inputs to a controller which adjusts active elements of the amplification and feedback path in order to minimize the distortion within the output of the amplifier.12-04-2008
20120087441METHOD AND APPARATUS FOR OPTIMIZING TRANSMITTER POWER EFFICIENCY - A peak to average power ratio signal is generated from a first mapping function that selects the peak to average power ratio signal that corresponds to the data rate or data format of the signal to be transmitted. The selected peak to average power ratio signal is summed with a desired average transmit power signal. The resulting summation signal is input to a second effectively continuously valued mapping function comprising a table that has a plurality of power amplifier control signal values each with a corresponding peak transmit power. Each peak transmit power signal value results in a power amplifier control signal value that achieves the best possible transmitter power efficiency while still meeting out of band spurious emissions and waveform quality requirements. The summation signal value maps to one of the power amplifier control signal value that is then used to adjust a parameter such as bias of the power amplifier.04-12-2012
20100215120Low-Power Polar Transmitter - Apparatus and methods for providing transmit signals in polar transmitters are described. A modulation signal may be provided from a VCO to low noise and low power signal paths and selectively combined based on a desired output power level. CMOS and CML divider circuits may be used to implement the low noise and low power signal paths respectively, and logic may be provided to select desired signals from the low noise and low power signal stages based on the desired output power level.08-26-2010
20080253477Iq-Modulator Pre-Distortion - An IQ-modulator pre-distorter includes an iteratively updated digital filter (gQ10-16-2008
20090245418TRANSMITTER USING CARTESIAN LOOP - A transmitter includes a signal generator to generate a digital baseband signal corresponding to a signal to be transmitted, a digital-analog converter to convert the digital baseband signal into an analog baseband signal by operating in accordance with a clock signal, a subtracter to subtract a feedback baseband signal from the analog baseband signal to generate a residual signal, a loop filter to filter the residual signal by amplifying a low-frequency component and suppressing a high-frequency component, a modulator to modulate the filtered signal by multiplying the filtered signal, a power amplifier to amplify the modulated signal, a high frequency filter to filter the amplified modulated signal to obtain a transmit RF signal, the high frequency filter having a passband width narrower than a frequency of the clock signal, and a demodulator to demodulate a feedback RF signal which is divided from the transmit RF signal.10-01-2009
20080225981SYSTEM AND METHOD FOR SYNCHRONIZATION, POWER CONTROL, CALIBRATION, AND MODULATION IN COMMUNICATION TRANSMITTERS - A system is provided for processing a communication signal including a baseband amplitude component and a baseband phase component. The system includes an amplitude predictor configured for closed-loop pre-distortion of a baseband amplitude component, an amplitude lookup table configured for open-loop pre-distortion of the baseband amplitude component, and an amplitude interpolator configured to build up the amplitude lookup table during a closed-loop calibration period. The system also includes a phase predictor configured for closed-loop pre-distortion of a baseband phase component, a phase lookup table configured for open-loop pre-distortion of the baseband phase component, and a phase interpolator configured to build up the phase lookup table during a closed-loop calibration period.09-18-2008
20130170582Interpolation of Filter Coefficients - The frequency response of a digital filter, such as a pre-emphasis filter in a signal transmitter having a phase-locked loop, is adjusted using interpolation of the filter coefficients, enabling sets of filter coefficients to be pre-computed or generated as needed in the transmitter. The phase error behavior of the digital filter can be significantly improved.07-04-2013
20130177106MULTIPLE FUNCTIONAL EQUIVALENCE DIGITAL COMMUNICATIONS INTERFACE - A multiple functional equivalence digital communications interface and a group of functional circuits are disclosed. The multiple functional equivalence digital communications interface presents a functional equivalence of each of a group of digital communications interfaces to a digital communications bus. Each functional equivalence of the group of digital communications interfaces is associated with a corresponding one of the group of functional circuits.07-11-2013
20110274210TIME ALIGNMENT ALGORITHM FOR TRANSMITTERS WITH EER/ET AMPLIFIERS AND OTHERS - An apparatus and method for aligning input and feedback signals in a transmission circuit are provided. The method includes capturing an input signal and a feedback signal, determining a first time delay between the input signal and the feedback signal, determining a second time delay between the input signal and the feedback signal, the determination of the second time delay having a higher resolution than the determination of the first time delay, and applying the first time delay and the second time delay to temporally align the input signal with the feedback signal. Use of the present invention provides an improved resolution of time alignment while reducing the overall complexity and cost of the transmission circuit.11-10-2011
20130094612MULTI-BAND WIDE BAND POWER AMPLIFIER DIGITAL PREDISTORTION SYSTEM - A high performance and cost effective method of RF-digital hybrid mode power amplifier systems with high linearity and high efficiency for multi-frequency band wideband communication system applications is disclosed. The present disclosure enables a power amplifier system to be field reconfigurable and support multiple operating frequency bands on the same PA system over a very wide bandwidth. In addition, the present invention supports multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels.04-18-2013
20130094611DIGITALLY-CONTROLLED POWER AMPLIFIER WITH BANDPASS FILTERING/TRANSIENT WAVEFORM CONTROL AND RELATED DIGITALLY-CONTROLLED POWER AMPLIFIER CELL - A digitally-controlled power amplifier (DPA) with bandpass filtering includes a radio-frequency (RF) clock input, an amplitude control word (ACW) input, and a plurality of DPA cells. The RF clock input is arranged for receiving an RF clock. The ACW input is arranged for receiving a digital ACW signal. The DPA cells are coupled to the RF clock and the digital ACW signal, wherein at least one of the DPA cells is gradually turned on and off in response to at least one bit of the digital ACW signal.04-18-2013
20130129019RF Power Transmission, Modulation, and Amplification, Including Direct Cartesian 2-Branch Embodiments - Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.05-23-2013
20080205547METHOD AND SYSTEM FOR SOFTWARE DEFINED POWER AMPLIFIER FOR MULTI-BAND APPLICATIONS - Methods and systems for software definition of a power amplifier for multi-band applications are disclosed and may comprise configuring a single programmable output stage of a transmitter to transmit a signal via one of a plurality of selectively coupled antennas, wherein each antenna handles signals in a different frequency band. A power amplifier within the single programmable output stage may be tuned to a frequency within a range of frequencies handled by the selectively coupled antenna. The tuning may be accomplished by programmably adjusting at least one inductance and capacitance. The antennas may be impedance matched to the power amplifier using transformers and may be activated by at least one integrated transistor. The power amplifier may be biased in a class of operation, which may include Class A, AB, C and F, and may be biased utilizing a digitally-controlled current source and a digitally-controlled voltage source.08-28-2008
20130148760TRANSFORMER POWER COMBINER WITH FILTER RESPONSE - A method for generating an amplified radio frequency (RF) signal is provided. In-phase (I) and quadrature (Q) signals are received and interleaved so as to generate a time-interleaved signal. Delayed time-interleaved signals are then generated from the time interleaved signal, and each of the delayed time-interleaved signals is amplified so as to generate a plurality of amplified signals. The amplified signals are then combined with a transformer, where the delayed time-interleaved signals are arranged to generate a filter response with the transformer.06-13-2013
20120275545DISTORTION COMPENSATION APPARATUS AND DISTORTION COMPENSATION METHOD - A distortion compensation apparatus for performing distortion compensation processing by applying the inverse properties of distortion properties of said power amplifier to a transmission signal to be input to a power amplifier, includes a plurality of distortion compensation coefficient storage units configured to store a plurality of distortion compensation coefficients used for said distortion compensation processing, an offset correction processing unit configured to subject said distortion compensation coefficient stored in each of said plurality of distortion compensation coefficient storage units to offset correction processing, and to generate distortion compensation coefficients in the case that said offset correction processing has not been performed, corresponding to said plurality of distortion compensation coefficient storage units, in a pseudo manner and a distortion compensation processing unit configured to subject said transmission signal to said distortion compensation processing based on said distortion compensation coefficients generated in a pseudo manner.11-01-2012
20120275544ENVELOPE EXTRACTION WITH REDUCED BANDWIDTH FOR POWER MODULATION - A system according to one embodiment includes a digital data modulator configured to generate encoded symbols; an envelope detector configured to receive the encoded symbols and to estimate transmission power information associated with the encoded symbols; a peak detector configured to receive the transmission power information, detect a peak transmission power from two or more sequential data points of the received transmission power information, and to generate a power regulation signal representative of the detected peak transmission power; and a digital to analog converter (DAC) configured to receive the power regulation signal and to provide a reference voltage to a power supply associated with an RF amplifier.11-01-2012
20120281786Compensating for a Radio Frequency Amplifier - An analog radio frequency input and an analog feedback from an output of a radio frequency amplifier are digitized and down-converted. Pre-distortion coefficients are calculated based on the down-converted input and down-converted feedback and the down-converted input is filtered using the pre-distortion coefficients. The filter output is then up-converted to a carrier frequency and converted to analog to be provided to the radio frequency amplifier.11-08-2012
20130182794ANTENNA DEVICE AND METHOD IN A MIMO SYSTEM - The invention relates to the technical field of radio communications, and in particular to an antenna device for a radio base station, and a method of operating an antenna device in a Multiple-Input Multiple-Output system. Embodiments of the invention disclose a secondary precoder (07-18-2013
20130195220POWER AMPLIFIER DIGITAL PREDISTORTION SYSTEM FOR CONCURRENT DUAL BAND INPUTS - A method and system for pre-distorting dual band signals to compensate for distortion of a non-linear power amplifier in a radio transmitter are disclosed. According to one embodiment, a first signal in a first frequency band and a second signal in a second frequency band are pre-distorted according to first and second pre-distortion function, respectively, the first and second pre-distortion functions being the dual of one another.08-01-2013
20130195221SIGNAL PROCESSING SYSTEM AND SIGNAL PROCESSING METHOD - A signal processing system is provided. The signal processing system includes: a peak-to-average ratio (PAPR) reducer that reduces a peak-to-average ratio (PAPR) of an input signal x(n), a clipping noise processing system that generates an equivalent clipping noise signal ε*08-01-2013
20130195219MOBILE WIRELESS COMMUNICATIONS DEVICE WITH SELECTIVE POWER AMPLIFIER CONTROL AND RELATED METHODS - A mobile wireless communications device may include a processor, a modulator coupled downstream from the processor, a power amplifier coupled downstream from the modulator and having a control voltage input, an antenna coupled downstream from the power amplifier, and a feedback path coupled between the antenna and the processor. The processor may be coupled to the control voltage input of the power amplifier, and may be configured to determine an adjacent channel leakage value based upon the feedback path and to selectively set a control voltage for the power amplifier based upon the adjacent channel leakage value.08-01-2013
20130208827METHOD AND APPARATUS TO USE AUXILIARY RECEIVER TO COMPENSATE MULTIPLE TRANSMITTERS BASED UPON ONE OF THE TRANSMITTERS - A communications device includes a plurality of wireless transmitters operable at different respective frequencies and each configured to generate respective IQ signals having an initial IQ imbalance. An auxiliary receiver is coupled to a given wireless transmitter. In addition, a controller is configured to apply predistortion to the each wireless transmitter of the plurality thereof based upon the initial IQ imbalance generated by the given wireless transmitter to reduce the initial IQ imbalance in each wireless transmitter.08-15-2013

Patent applications in class Power amplifier