Entries |
Document | Title | Date |
20080207148 | Voice, data and RF integrated circuit with multiple modulation modes and methods for use therewith - A voice data and RF integrated circuit (IC) includes a driver that generates an RF signal to a power amplifier module from an up-converted signal. A modulation controller provides a first modulation signal to the driver for modulating the up-converted signal when a modulation control signal has a first value and provides a second modulation signal to the power amplifier module for modulating the RF signal when the modulation control signal has a second value. | 08-28-2008 |
20080220732 | Method for Stabilising Time Position of an Ultrabandwidth Signal and a Live Object Monitoring Locator for Carrying Out Said Method - The invention relates to search and rescue service and can be used for debris active sounding. Said invention makes it possible to improve interference protection related to a temperature, the operator hands motion and trembling effecting the locator operation. The inventive method consists in forming an ultrabandwidth signal (UBW) according to a reference signal, in emitting the thus formed UBW signal to space, in receiving the UBW signal, in processing the UBW signal by correlating it with a reference UBW signal, wherein while processing the received UBW signal, the reference UBW signal is delayed for a time during which the initial position of a check point on a middle section between the maximum and minimum voltage of the correlated signal is set, in periodically monitoring the position of said check point and in modifying the space emission delay of the formed UBW signal when the check point position shifts from the initial position thereof, thereby resetting the check point position. | 09-11-2008 |
20080233902 | METHOD AND APPARATUS FOR COMMUNICATING PRECODING OR BEAMFORMING INFORMATION TO USERS IN MIMO WIRELESS COMMUNICATION SYSTEMS - Methods and apparatus for communicating precoding or beamforming information to users are disclosed. A feedback signal including a reported preceding matrix index (PMI) is received and a determination made as to the state of the feedback. Precoding rules associated with the determined state are then used to select a precoding matrix. The state information is transmitted to a wireless transmit receive unit (WTRU), which uses the state information and the precoding rules associated therewith to select the precoding matrix used to precoded a received precoded data signal. | 09-25-2008 |
20080268794 | Linearization in a transmission chain - A transmission chain comprises a power amplifier adapted for receiving as input a signal to be amplified S | 10-30-2008 |
20080268795 | PREDISTORTION CIRCUIT FOR A TRANSMIT SYSTEM - Systems and methods related to amplifier systems which use a predistortion subsystem to compensate for expected distortions in the system output signal. A signal processing subsystem receives an input signal and decomposes the input signal into multiple components. Each signal component is received by a predistortion subsystem which applies a predistortion modification to the component. The predistortion modification may be a phase modification, a magnitude modification, or a combination of both and is applied by adjusting the phase of the fragment. The predistorted component is then separately processed by the signal processing subsystem. The processing may take the form of phase modulation and amplification. The phase modulated and amplified components are then recombined to arrive at an amplitude and phase modulated and amplified output signal. The predistortion modification is applied to the components to compensate for distortions introduced in the signal by the signal processing subsystem. | 10-30-2008 |
20080287076 | Compact Wide Dynamic Range Transmitter For Point To Point Radio - A radio frequency transmitter comprising a modem which receives one or more input data signals and an adaptive predistortion signal and provides a baseband in-phase signal and a baseband quadrature signal. The transmitter may comprise a power amplifier module which receives the in-phase and quadrature phase signals and provides a radio frequency output signal. A predistortion module receives the radio frequency signal, downconverts the radio frequency signal to an intermediate frequency signal, and downconverts the intermediate frequency signal to a baseband feedback signal. The transmitter samples the feedback signal and provides an adaptive predistortion signal to the modem. | 11-20-2008 |
20080299920 | Transmission Device - In a transmission device including an RF power amplifier with less number of terminals for monitoring an input/output signal of the RF power amplifier, there are provided with an input signal detector detecting the input signal; an output signal detector detecting the output signal; a first power amplifier switch switching ON or OFF the power amplifier; a monitor terminal; and an RF switch selecting an input signal or output signal of the power amplifier to be transmitted to the monitor terminal, in association with the first power amplifier switch being switched ON or OFF. | 12-04-2008 |
20090029658 | ULTRA-WIDEBAND RANGING METHOD AND SYSTEM USING NARROWBAND INTERFERENCE SUPRESSION WAVEFORM - Disclosed herein is an Ultra-WideBand (UWB) ranging method using a narrowband interference suppression waveform. A transmission signal is transmitted to a target object. The transmission signal, reflected from the target object, is received. A template signal is generated by combining the narrowband interference suppression waveform and a channel estimation signal together. A correlation output signal is generated by convoluting the template signal and the received signal. A distance is calculated using a time delay when the correlation output signal has the maximum value thereof. The narrowband interference suppression waveform is any one of two waveforms that are expressed by the following Equation: | 01-29-2009 |
20090054016 | Apparatus and Method for Adaptive Cartesian Transmitter Linearization and Wireless Transmitter Employing the Same - A Cartesian transmitter and a method of linearizing a Cartesian transmitter. In one embodiment, the transmitter includes: (1) a transmit chain configured to receive an input signal having in-phase and quadrature components and having a predistorter configured to employ at least one compensation lookup table to carry out in-phase and quadrature compensation predistortion with respect to the input signal, a combiner configured to combine outputs of the predistorter and a nonlinear element configured to process an output of the combiner, (2) a receiver coupled to the transmit chain and (3) predistortion compensation circuitry associated with the receiver and configured to update the at least one compensation lookup table based on the input signal and a signal from the receiver. | 02-26-2009 |
20090088093 | Signal predistortion in radio transmitter - A transmission signal to be transmitted from a radio transmitter is predistorted in order to compensate for the signal distortion caused by a power amplifier. The predistortion parameters for at least one of envelope and phase predistortion are selected according to the bandwidth of the transmission signal. Then, the transmission signal is predistorted with the selected predistortion parameters, and the predistorted transmission signal is power-amplified in the power amplifier for transmission | 04-02-2009 |
20090104882 | RADIO TRANSMISSION APPARATUS - A radio transmission apparatus does not update the distortion compensation coefficient for a certain period, which is shorter than the transmission period, after the transmission period start timing. Instead, update operation of the distortion compensation coefficient is carried out after the lapse of a certain period from the start timing. Further, in order to shorten the convergence time of the distortion compensation coefficient, the radio transmission apparatus performs interpolation processing of the distortion compensation coefficient. The distortion compensation coefficient is given to a two-dimensional coordinate (address): one is the power level of an input transmission signal and the other is the difference of power between the input transmission signal and a feedback signal. The distortion compensation coefficient at a predetermined coordinate is updated to an interpolated value, which is obtained through interpolation calculation using the distortion compensation coefficient at a coordinate adjacent to the predetermined coordinate. | 04-23-2009 |
20090111399 | ADAPTIVE PRE-DISTORTION WITH INTERFERENCE DETECTION AND MITIGATION - Embodiments include methods, apparatus, and electronic systems adapted to perform adaptive pre-distortion. Embodiments include combining an input sample with a gain value to generate a pre-distorted data sample, where the gain value is a function of at least one gain entry stored within a gain lookup table. An amplified analog signal is generated from the pre-distorted data sample, and a feedback sample is also generated, which corresponds to an antenna output signal. The antenna output signal includes the amplified analog signal. A difference indicator is generated to reflect a difference between the input sample and the feedback sample, and at least one updated gain value is generated based on a comparison between the difference indicator and at least one previous difference indicator. At least one gain entry within the gain lookup table is updated with the at least one updated gain value. | 04-30-2009 |
20090221245 | Method and system for estimating and compensating non-linear distortion in a transmitter using calibration - Aspects of a method and system for estimating and compensating for non-linear distortion in a transmitter using calibration are presented. Aspects of the system may include one more circuits that may enable estimation, within a single IC device, of distortion in output signals generated by a transmitter circuit. The circuitry may enable compensation of the estimated distortion by predistorting subsequent input signals. The transmitter circuit may generate subsequent output signals based on the predistorted subsequent input signals. | 09-03-2009 |
20090258613 | Systems, Methods and Devices for Dual Closed Loop Modulation Controller for Nonlinear RF Amplifier - In accordance with various exemplary embodiments of the present invention, systems, methods and devices are configured to facilitate RF envelope amplitude control. For example, a RF envelope amplitude control system comprises: a RF amplifier, wherein the RF amplifier is associated with a feedback device that is configured to create a first feedback signal representing the power in an RF output signal; a transmit waveform generator configured to generate a reference waveform signal; an adaptive table waveform generator configured to compare the reference waveform signal and the first feedback signal and to create a second feedback signal based on that comparison; and a loop filter configured to combine the reference waveform signal, the first feedback signal, and the second feedback signal to form an amplifier control signal, wherein the amplifier control signal is provided to the RF amplifier to adjust the RF output signal to conform to a specified RF envelope. | 10-15-2009 |
20090264089 | MULTI-BAND LOOKUP TABLE TYPE PREDISTORTER - A lookup table type predistorter for reading out distortion compensation data by using a difference signal between a power amplifier input signal and an output signal as a reference signal; wherein N input side variable band signal extractors extract transmitting signals in N frequency bands from the input signal, N output side variable band signal extractors extract signals in N frequency bands from the output of power amplifier, and N difference detectors detect differences between N frequency band signals respectively detected at the input side and the output side as N reference signals, which are used to read out N compensation data from N lookup tables, the N compensation data are added to the transmitting signals in N frequency bands, and N results of addition are combined to produce an output of the predistorter. | 10-22-2009 |
20090286494 | Iterative tree search-based precoding technique for multiuser mimo communication system - An iterative tree search-based preceding method for a multi-user Multi-Input Multi-Output (MIMO) communication system includes determining a reference value of a cumulative branch metric of a candidate symbol, eliminating candidates having values that exceed the determined reference value of the cumulative branch metric of the candidate symbol, and registering values, which do not exceed the determined reference value of the cumulative branch metric of the candidate symbol, as entries, and selecting the least value from the values registered as the entries. Thereby, the method has low complexity and similar performance compared to an existing Sphere Encoding (SE) technique. | 11-19-2009 |
20090291649 | In-phase and quadrature-phase signal amplitude and phase calibration - In-phase (I) and quadrature-phase (Q) signals are corrected for both amplitude and phase imbalances by passing the I and Q signals successively through a first amplitude correction stage, a sum-difference stage, and a second amplitude correction stage. The first amplitude correction stage balances the signal levels of the I and Q signals. The sum-difference stage produce a sum of the input I and Q signals, and a difference of the input I and Q signals, resulting in ideal quadrature in the outputs produced. The second amplitude correction stage corrects the amplitude differences from the sum-difference stage. Circuit configurations are used that minimize errors produced by the signal processing stages. | 11-26-2009 |
20090291650 | ADAPTIVE PREDISTORTER COUPLED TO A NONLINEAR ELEMENT - In one embodiment, a circuit comprises an adaptive predistorter and a nonlinear element coupled to an output of the predistorter. The predistorter is operative to predistort an input signal according to predistortion control parameters at a given sampling rate. The circuit further comprises an identification unit and a translation unit. The identification unit identifies nonlinearity parameters representing the nonlinearity of the nonlinear element by sampling the output of the nonlinear element at an identification sampling rate lower than twice a bandwidth at the output of the nonlinear element. The translation unit translates the identified nonlinearity parameters into the predistortion control parameters. Other systems and methods are disclosed. | 11-26-2009 |
20100022208 | APPARATUS AND METHOD FOR CALIBRATION OF GAIN AND/OR PHASE IMBALANCE AND/OR DC OFFSET IN A COMMUNICATION SYSTEM - An example of a radio frequency (RF) transmitter system for communication may include a transmit pre-distortion module configured to provide a second transmit calibration signal during a transmit calibration mode based on a first transmit calibration signal and one or more transmit calibration adjustment signals. The one or more transmit calibration adjustment signals may include an offset parameter associated with DC offset and an imbalance parameter associated with at least one of gain and phase imbalances. The system may include a transmit channel frequency converter coupled to the transmit pre-distortion module. The transmit channel frequency converter may be configured to provide a fourth transmit calibration signal during the transmit calibration mode based on a third transmit calibration signal and a transmit reference signal. | 01-28-2010 |
20100041352 | RADIO TRANSMITTER FRONT-END WITH AMPLITUDE AND PHASE CORRECTION AND METHODS FOR USE THEREWITH - A radio transmitter front-end for use in a voice data and RF integrated circuit (IC) includes a phase correction module that produces a phase adjusted signal in response to a phase modulated signal and at least one phase correction signal. An amplitude correction module produces an amplitude adjusted signal in response to an amplitude modulating signal and an amplitude correction signal. An amplifier amplifies the phase adjusted signal and amplitude modulates the phase adjusted signal, based on the amplitude adjusted signal, to produce a polar coordinate transmit signal. A correction generation module generates the at least one phase correction signal and the amplitude correction signal, based on the polar coordinate transmit signal and the phase adjusted signal. | 02-18-2010 |
20100048149 | Techniques for Adaptive Predistortion Direct Current Offset Correction in a Transmitter - A technique for performing adaptive predistortion in a transmitter includes receiving, at a first input of an error signal unit, a delayed version of a baseband input signal. The technique also includes receiving, at a second input of the error signal unit, a power amplifier feedback signal from an output of a power amplifier. An input error signal that corresponds to a difference between the delayed version of the baseband input signal and the power amplifier feedback signal is then provided at an output of the error signal unit. The input error signal is then received at an input of a signal conditioner. An adjusted error signal that has a lower direct current offset than the input error signal is provided at an output of the signal conditioner. | 02-25-2010 |
20100048150 | APPARATUS AND METHOD FOR FEEDFORWARD-TYPE PHASE NOISE ELIMINATION IN PORTABLE TERMINAL - The present invention relates to an apparatus and method for feedforward-type phase noise elimination in a portable terminal, which detect and eliminate phase-reversed phase noise by subtracting a GSM transmission signal, passed through the power amplifier of a GSM transmission device, from a GSM transmission signal, extracted from an upstream stage of the power amplifier, so that phase noise signals attributable to high-power transmission signals. | 02-25-2010 |
20100056082 | COMMUNICATION SYSTEM WITH FREQUENCY-ADAPTIVE PREDISTORTER DESIGN - A communication system comprises a predistorter for distorting an input signal according to at least one parameter to generate a distorted signal, an amplifier for amplifying the distorted signal according to an input-output characteristic to generate an output signal, and a frequency-domain adaptive calibration module for adaptively adjusting the parameter of the predistorter according to a frequency characteristic of the output signal. Because the calibration is performed in the frequency domain, there is no need to precisely estimate the group delay formed by the feedback path. The system complexity is therefore reduced without loss of performance. | 03-04-2010 |
20100062733 | DISTORTION CORRECTION CONTROL APPARATUS AND DISTORTION CORRECTION CONTROL METHOD - A distortion correction control apparatus is for compensating for a burst distortion of a transmission amplifier caused by a burst of an input signal of a transmission target. The apparatus includes a generation unit that generates a distortion correction coefficient having reverse characteristics to the foregoing burst distortion; a unit that multiplies the distortion correction coefficient output from the generation unit by the input signal or adds the distortion correction coefficient output from the generation 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 and a branch signal fed back as an output signal of the transmission amplifier, parameters of functions used for adaptively generating the distortion correction coefficient, and that inputs the updated parameters to the generation unit. | 03-11-2010 |
20100069023 | METHOD AND APPARATUS FOR PREDISTORTING A WAVEFORM FOR INPUT TO AN AMPLIFIER - A method of predistorting a waveform for input to an amplifier includes receiving information associated with the waveform, the information comprising a modulation configuration of the waveform. The method further includes predicting a chain model for the waveform based on the modulation configuration. In addition, the method includes predistorting the waveform for input to the amplifier, based on the chain model, an ideal waveform, and target output power. An apparatus is also provided for predistorting a waveform for input to an amplifier. | 03-18-2010 |
20100081399 | PRECODING FOR MULTIPLE ANNTENNAS - A wireless network ( | 04-01-2010 |
20100105342 | ELECTRONIC DEVICE WITH A DISTORTION CORRECTION CIRCUIT FOR A POWER AMPLIFIER, AND ASSOCIATED METHODS - An electronic device includes a radio frequency (RF) modulator, a power amplifier, and a distortion correction circuit coupled between the RF modulator and the power amplifier. The distortion correction circuit includes a variable gain amplifier coupled between the RF modulator and the power amplifier, and an amplitude correction control loop. The amplitude correction control loop includes a first logarithmic converter having an input coupled to the REF modulator, a second logarithmic converter having an input coupled to an output of the power amplifier, and a difference circuit coupled to outputs of the first and second logarithmic converters for controlling the gain of the variable gain amplifier for correcting distortion in an output signal from the power amplifier. | 04-29-2010 |
20100130145 | AMPLIFICATION SYSTEM FOR INTERFERENCE SUPPRESSION IN WIRELESS COMMUNICATIONS - An amplification system including a high gain amplifier, filter module and low gain amplifier. The high gain amplifier for receiving an input RF signal and processing the input RF signal to produce a first amplified signal while the high gain amplifier is operating near its saturation point. The filter module having at least one band pass filter to receive the first amplified signal and process the first amplified signal to remove unwanted characteristics of the first amplified signal to produce a processed first amplified signal. The low gain amplifier receiving the processed first amplified signal and processing the processed first amplified signal to produce a second amplified signal that has an increase in signal strength over the processed first amplified signal while the low gain amplifier is operating near its saturation point. | 05-27-2010 |
20100159855 | TECHNIQUES FOR PRE-DISTORTING TRANSMITTED SIGNALS FOR A TRANSMITTER DEVICE - Techniques for sending and receiving signals include pre-distorting signals before transmission across a communication path. The signals are pre-distorted as a function of a distortion on the communication path. In one embodiments, transmitter a broadcasts to receiver b and there is also a transmitter b broadcasting to receiver a. This return channel enables both transmitters a and b to have a priori information regarding the transmission medium and path the signal takes. In this way, the nature of the distortion or interference is known to the transmitter, therefore, it pre-distorts the transmitted signal to compensate for the receiver exceeding its capabilities in recovering signal. | 06-24-2010 |
20100159856 | Distortion compensator, distortion compensation method, and transmitter - A distortion compensator for reducing a level of a distortion component included in an output analog signal of an amplifier, includes: an A/D converter to convert the output analog signal of the amplifier into a digital output signal; a comparator to generate a distortion characteristic of the amplifier based on a digital input signal and the digital output signal; a rate controller to control a sampling rate of the A/D converter based on the digital input signal and the digital output signal; a predistorter to multiply the digital input signal and a compensation value for compensating the amplifier, the compensation value being calculated based on the digital input signal and the distortion characteristic of the amplifier; and a D/A converter to convert multiplication result of the predistorter into an analog input signal to input the analog input signal to the amplifier. | 06-24-2010 |
20100233974 | Feedback Compensation Detector For A Direct Conversion Transmitter - A feedback compensation detector for a direct conversion transmitter includes a baseband processor, a direct up-converter, an antenna, and an impairment detection and compensation feedback circuit. The baseband processor generates an in-phase (I) baseband signal and a quadrature-phase (Q) baseband signal. The direct up-converter is coupled to the baseband processor, and combines the I and Q baseband signals with an RF carrier signal to generate an RF output signal. The antenna is coupled to the direct up-converter, and transmits the RF output signal. The impairment detection and compensation feedback circuit is coupled to the RF output signal and the I and Q baseband signals. The impairment detection and compensation feedback circuit down-converts the RF output signal to generate an intermediate frequency (IF) signal, measures at least one signal impairment in the IF signal, and pre-distorts the I and Q baseband signals to compensate for the measured signal impairment. | 09-16-2010 |
20100240329 | AMPLIFYING DEVICE AND TRANSMITTER APPARATUS - An amplifying device includes an amplifier including a first amplifying element with a drain voltage thereof being controlled, and a second amplifying element, the amplifier amplifying a transmission signal with the first and second amplifying elements, synthesizing the transmission signals amplified by the first and second amplifying elements, and outputting the synthesized transmission signal; a distortion compensator part which performs distortion compensation on the input signal in accordance with a compensation coefficient derived from a difference between a input signal and a feedback signal generated from a portion of a signal output from the amplifier; and a controller part which controls the drain voltage of the first amplifying element in response to a result of a comparison between a power level of the input signal prior to the distortion compensation operation by the distortion compensator part and a threshold value. | 09-23-2010 |
20100248658 | METHOD AND SYSTEM OF ADAPTIVE PREDISTORTION OF A WIRELESS TRANSMITTER - A method of adaptive predistortion of a power amplifier, characterised in that the method comprises the steps of: storing values of a plurality of corresponding first and second coefficients; selecting one of the stored first coefficients; processing a first signal with the first coefficient to produce an input signal for the power amplifier; amplifying the input signal in the power amplifier to produce an output signal; calculating an error value from the output signal and a previously selected first coefficient; selecting a stored second coefficient corresponding with the previously selected first coefficient; updating the previously selected first coefficient with a value calculated from the error value and the second coefficient; updating the second coefficient; and replacing the previously selected first coefficient and corresponding second coefficient with the updated first and second coefficients respectively. | 09-30-2010 |
20100297966 | Measuring and Correcting Errors in a Transmit Chain with an IQ Up-Converter and IQ Down-Converter - A transmit chain comprises a transmit path with a quadrature up-converter which up-converts quadrature signal components to RF. An observation path samples a portion of the RF signal and a quadrature down-converter down-converts the RF signal to baseband quadrature signal components. A local oscillator signal source provides the up-converter and the down-converter with a local oscillator signal and is operable in two states. In a second of the states the local oscillator signal is applied to the up-converter and the down-converter and a phase shift is made to the signal applied to up-converter or the down-converter compared to the first of the states. A processor monitors properties of the down-converted signal while the local oscillator signal source is operating in the first state and the second state. The processor calculates a correction to apply to the baseband observation signal to correct for errors introduced by the observation path. The processor also calculates a correction to apply to the input signal to correct for errors introduced in the transmit path. | 11-25-2010 |
20100304694 | WIRELESS COMMUNICATION APPARATUS - A wireless communication apparatus configured to amplify a transmission signal at an amplifier and transmit the amplified transmission signal, the wireless communication apparatus includes a memory configured to store a distortion compensation coefficient for compensating a distortion characteristic of the amplifier, and an electrical-power measuring unit configured to measure electrical power of the transmission signal. The wireless communication apparatus includes a gain control unit configured to calculate a gain adjustment value for correcting the distortion compensation coefficient stored in the memory based on a power value measured by the electrical-power measuring unit, and a distortion-compensation processing unit configured to perform distortion compensation on the transmission signal based on the distortion compensation coefficient stored in the memory and the gain adjustment value. | 12-02-2010 |
20100311360 | TRANSMITTER, METHOD FOR LOWERING SIGNAL DISTORTION, AND METHOD FOR GENERATING PREDISTORTION PARAMETERS UTILIZED TO LOWER SIGNAL DISTORTION - A transmitter includes a predistortion calculation unit, a transmitting circuit, a receiving circuit, an adjusting unit and a parameter generating and storing unit. The predistortion calculation unit is utilized for pre-distorting an input signal to generate a predistorted input signal according to a specific predistortion parameter. The transmitting circuit is utilized for processing the predistorted input signal to generate an output signal. The receiving circuit is utilized for receiving the output signal to generate a received signal. The adjusting unit is utilized for adjusting the received signal to generate an adjusted signal, where the adjusted signal is substantially equal to the input signal. The parameter generating and storing unit is utilized for generating the specific predistortion parameter, and updating at least one stored predistortion parameter according to the input signal and the adjusted signal. | 12-09-2010 |
20100311361 | SIGNAL 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. | 12-09-2010 |
20100323641 | METHOD AND APPARATUS FOR USING PRE-DISTORTION AND FEEDBACK TO MITIGATE NONLINEARITY OF CIRCUITS - Techniques for mitigating nonlinearity of circuits with both pre-distortion and feedback are described. An apparatus may include at least one circuit (e.g., an upconverter, a power amplifier, etc.), a pre-distortion circuit, and a feedback circuit. The circuit(s) may generate an output signal having distortion components due to their nonlinearity. The pre-distortion circuit may receive an input signal and generate a pre-distorted signal based on at least one coefficient determined by the nonlinearity of the circuit(s). The pre-distortion circuit may adaptively determine the coefficient(s) based on the input signal and an error signal. The feedback circuit may generate the error signal based on the input signal and the output signal and may filter the error signal to obtain a filtered error signal. The circuit(s) may process the pre-distorted signal and the filtered error signal to generate the output signal, which may have attenuated distortion components due to pre-distortion and feedback. | 12-23-2010 |
20110034136 | CANCELLATION OF OSCILLATOR REMODULATION - A wireless transmitter ( | 02-10-2011 |
20110045787 | Calibration-Less Transmit Beamforming - A calibration-less transmit beamforming apparatus and method are provided. In a wireless communication device that comprises a plurality of antennas, a gain block is provided in the front-end module associated with each antenna and the same gain block is used during transmit and receive operations. As a result, the transmit phase offset and receive phase offset for each antenna are made to be equal, thereby achieving conditions for transmit beamforming without the need for complex antenna calibration algorithms and hardware. | 02-24-2011 |
20110059705 | ROBUST LINEAR PRECODER DESIGNS FOR MULTI-CELL DOWNLINK TRANSMISSION - Methods and systems for optimizing the utilities of receiver devices in a wireless communication network are disclosed. Precoder design formulations that maximize a minimum worst-case rate or a worst-case sum rate are described for both full base station cooperation and limited base station cooperation scenarios. In addition, optimal equalizers are also selected to optimize the worst-case sum rate. | 03-10-2011 |
20110070846 | RADIO FREQUENCY-BASED COMMUNICATION TERMINAL HAVING TWO EXCHANGEABLE TRANSMITTING PATHS - A radio frequency (RF)-based communication terminal includes a first switching chip, a second switching chip, a comparison module, a low noise amplifier (LNA), a first filter, a power amplifier (PA), a second filter, and a control module. The comparison module compares the power of a radio signal Rx received from a base station with a pre-stored signal and to output a control signal according to the comparison result. The control module controls conductive modes of the first and the second switching chips according to the control signal. In the first conductive mode, a radio signal Tx is sent out from the PA and the second filter. In the second conductive mode, the radio signal Tx is exchanged to send out from the LNA and first filter. | 03-24-2011 |
20110098011 | MULTIMODE POWER AMPLIFIER WITH PREDISTORTION - A device may include an envelope detector to generate an envelope signal from the input signal, a drain bias controller to adjust a drain bias of the amplifier based on the envelope signal, a gate bias controller to adjust a gate bias of the amplifier based on the envelope signal, a predistortion controller to predistort the input signal based on the envelope signal, based on the adjusted drain bias, and based on the adjusted gate bias, and to output the predistorted signal, and an amplifier to receive the predistorted signal and to generate an amplified output signal from the predistorted signal. The device may be selectable to operate in a linear mode or a nonlinear mode. The nonlinear mode may be selected by applying a large gate offset bias. | 04-28-2011 |
20110143697 | SEPARATE I AND Q BASEBAND PREDISTORTION IN DIRECT CONVERSION TRANSMITTERS - In-Phase (I) and Quadrature (Q) signals passing from a modem into a direct conversion transmitter are predistorted separately from, and independently of, one another. The I signal is predistorted to compensate for nonlinearities in the baseband I path circuitry between the modem and the upconverter. The Q signal is predistorted to compensate for nonlinearities in the baseband Q path circuitry between the modem and the upconverter. By employing the separate I and Q path baseband predistortion method, 4FMOD power in the upconverted and amplified signal as supplied to the transmitter antenna is reduced or eliminated. In one example, the transmitter employs single sideband modulation in the 777-787 MHz Verizon Band | 06-16-2011 |
20110195678 | System and Method for Transceivers in a Wireless Network - In accordance with an embodiment, a method of operating a multi-output wireless transmitter includes determining a precoded data stream based on input data, where the determining includes determining a signal to interference plus noise ratio (SINR) of a plurality of receivers, determining a channel gain to each of the plurality of receivers, and maximizing a sum of utility functions, wherein each utility function is proportional to the SINR of each of the plurality of receivers at low SINR values and asymptotically approaches a constant value at high SINR values. The precoded data stream is transmitted on the multi-output wireless transmitter. | 08-11-2011 |
20110312290 | Method and System for Closed Loop Pre-Distortion for PSK/QAM Modulation Using Feedback from Distant End of a Link - A method of signal distortion correction in a telecommunications channel, the method comprising modeling predicted signal distortion of an electromagnetic (EM) signal using one or more non-linearity model parameters of a signal distortion model, calculating and transferring one or more coefficients of the one or more non-linearity model parameters to a signal transmit location, pre-distorting the signal using an inverse function based on the one or more non-linearity model parameters, and transmitting the pre-distorted signal over the telecommunications channel containing a non-linear amplifier to a remote receiving device. | 12-22-2011 |
20120028591 | APPARATUS AND METHOD FOR LOW VOLTAGE RADIO TRANSMISSION - Apparatus and methods are disclosed related to low-voltage radio transmitters with high spectral purity. One such apparatus includes a baseband path with a predistortion stage, a programmable filter, and an upconverter core. In an embodiment, the programmable filter is placed between the predistortion stage and the upconverter core. In an embodiment, the programmable filter is configured by a controller to reject out-of-band noise introduced at the predistortion stage or earlier. | 02-02-2012 |
20120064847 | Systems and Methods for Spurious Emission Cancellation - In accordance with some embodiments of the present disclosure, a method may include digitally pre-distorting a digital baseband signal with an opposite phase of a C-IM3 distortion term such that the pre-distortion and C-IM3 distortion cancel each other out in a transmitter. The method may also include digitally conditioning the pre-distorted digital signal in order to provide a flat amplitude response of a composite filter comprising a baseband filter and a digital half-band filter of the transmitter, and to provide a linear phase response for the composite filter. | 03-15-2012 |
20120064848 | Low Sample Rate Peak Power Reduction - Peak power reduction in transmit chains of radiocommunication devices is performed using a low sample rate. Filtering and, optionally, interpolation of a signal being processed for peak power reduction can be performed only in an error signal path or in both an error signal path and a primary signal path. | 03-15-2012 |
20120077449 | RADIO FREQUENCY POWER AMPLIFIER - The present invention offers a radio frequency module having a radio frequency power amplifier and a directional coupler integrated in a multi-layer board, and in particular, a small, inexpensive, and high-performance radio frequency module, and a small and inexpensive wireless device equipped with the radio frequency module. The radio frequency module includes: a multi-layer board; a radio frequency power amplifier formed on top of the multi-layer board; a directional coupler having two layers vertically arranged in the multi-layer board; an internal ground pattern provided between the radio frequency power amplifier and the directional coupler; and thermal vias used for the radio frequency power amplifier and provided (i) between the internal ground pattern and a rear surface ground pattern and (ii) between the directional coupler and a bias line which is (i) provided in the same layer as the directional coupler and (ii) used for the radio frequency power amplifier. | 03-29-2012 |
20120083229 | RADIO TRANSMITTER AND METHOD FOR TRANSMISSION OF COMBINED SIGNAL - A radio transmitter is disclosed which comprises at least two transmit paths. A combiner is connected to the at least two transmit paths for combining modified transmit signals on the at least two transmit paths to form a combined signal. The radio transmitter further comprises a; power amplifier for receiving and power amplifying the combined signal resulting in an amplified combined signal, at least one feedback path for sampling the amplified combined signal and at least two predistortion elements connected to the at least one feedback path and adapted to produce at least two individual predistortion functions for modification of the transmit signals in the at least two frequency bands to produce the modified transmit signals on the at least two transmit paths, resulting in a corrected amplified combined signal. A method for the transmission of a combined signal, wherein the combined signal comprises signals from different frequency bands, is also disclosed. | 04-05-2012 |
20120135695 | HIGH EFFICIENCY LINEARIZATION POWER AMPLIFIER FOR WIRELESS COMMUNICATION - A predistortion system for linearizing the output of a power amplifier includes a first signal representative of an RF modulated signal and a feedback signal representative of nonlinear characteristics of a power amplifier. The system also includes a predistortion controller, comprising at least one lookup table, adapted to receive the first signal and the feedback signal and to generate a correction factor for correcting the nonlinear characteristics of the power amplifier and combining logic which combines the RF modulated signal with a signal corresponding to the correction factor and supplies it to the power amplifier to linearize the output of the power amplifier. | 05-31-2012 |
20120142289 | Circuit Arrangement and Method for Setting an Analog Output Signal - A circuit arrangement includes a signal processing unit and a regulation unit. The signal processing unit processes an input signal to form an analog output signal. The regulation unit is coupled to the signal processing unit in order to produce a digital regulation signal as a function of the analog output signal for regulation of the analog output signal. | 06-07-2012 |
20120149316 | RADIO FREQUENCY POWER AMPLIFIER WITH LINEARIZING PREDISTORTER - A power amplifier circuit includes an amplifier MOSFET and a predistorter MOSFET. The predistorter MOSFET source and drain are connected together, and the predistorter MOSFET is connected between the gate of the amplifier MOSFET and a second bias voltage signal. This biasing of the predistorter MOSFET causes it to provide a nonlinear capacitance at the gate of the amplifier MOSFET. The combined non-linear capacitances of the amplifier MOSFET and predistorter MOSFET provide predistortion that promotes cancellation of the distortion or nonlinearity contributed by the amplifier MOSFET alone. | 06-14-2012 |
20120178389 | SYSTEMS, METHODS AND DEVICES FOR DUAL CLOSED LOOP MODULATION CONTROLLER FOR NONLINEAR RF AMPLIFIER - In accordance with various exemplary embodiments of the present invention, systems, methods and devices are configured to facilitate RF envelope amplitude control. For example, a RF envelope amplitude control system comprises: a RF amplifier, wherein the RF amplifier is associated with a feedback device that is configured to create a first feedback signal representing the power in an RF output signal; a transmit waveform generator configured to generate a reference waveform signal; an adaptive table waveform generator configured to compare the reference waveform signal and the first feedback signal and to create a second feedback signal based on that comparison; and a loop filter configured to combine the reference waveform signal, the first feedback signal, and the second feedback signal to form an amplifier control signal, wherein the amplifier control signal is provided to the RF amplifier to adjust the RF output signal to conform to a specified RF envelope. | 07-12-2012 |
20120208477 | SYSTEMS AND METHODS FOR A RADIO FREQUENCY TRANSMITTER WITH IMPROVED LINEARITY AND POWER OUT UTILIZING PRE-DISTORTION AND A GAN (GALLIUM NITRIDE) POWER AMPLIFIER DEVICE - Various embodiments provide for systems and methods for increased linear output power of a transmitter. An exemplary wireless communications system for transmitting an input signal comprises a predistorter module, a GaN power amplifier, a coupler, and an antenna. The predistorter module is configured to detect existing distortion by comparing the input signal to a feedback signal and generate a correction signal. The predistorter may adaptively adjust its operation to minimize the existing distortion due to GaN power amplifier nonlinear characteristics. The result is that the GaN power amplifier may send a power signal of improved linearity to the antenna. The coupler is configured to sample the amplified signal from the GaN power amplifier to generate the feedback signal. The antenna is configured to transmit the amplified signal. | 08-16-2012 |
20120252382 | PREDISTORTION CALIBRATION AND BUILT IN SELF TESTING OF A RADIO FREQUENCY POWER AMPLIFIER USING SUBHARMONIC MIXING - A novel and useful apparatus for and method of predistortion calibration and built-in self testing (BIST) of a nonlinear digitally-controlled radio frequency (RF) power amplifier (DPA) using subharmonic mixing. The RF power amplifier output is temporarily coupled into the frequency reference (FREF) input and the phase error samples generated in the phase locked loop (PLL) are then observed and analyzed. The digital predistortion and BIST mechanisms process the phase error samples to calibrate and test the DPA in the transmitter of the Digital RF Processor (DRP). The invention enables the characterization of nonlinearities, the configuration of internal predistortion, as well as the testing of the transmitter's analog/RF circuitry, thereby eliminating commonly employed RF performance testing using high-cost test equipment and associated extended test times. | 10-04-2012 |
20120295561 | COMPACT WIDE DYNAMIC RANGE TRANSMITTER FOR POINT TO POINT RADIO - A radio frequency transmitter comprising a modem which receives one or more input data signals and an adaptive predistortion signal and provides a baseband in-phase signal and a baseband quadrature signal. The transmitter may comprise a power amplifier module which receives the in-phase and quadrature phase signals and provides a radio frequency output signal. A predistortion module receives the radio frequency signal, downconverts the radio frequency signal to an intermediate frequency signal, and downconverts the intermediate frequency signal to a baseband feedback signal. The transmitter samples the feedback signal and provides an adaptive predistortion signal to the modem. | 11-22-2012 |
20130005283 | Multi-Dimensional Volterra Series Transmitter Linearization - A radio transmission system comprising a plurality of Volterra Engine (VE) linearizers; a power amplifier (PA) coupled to the YE linearizers; a feedback circuitry coupled to the VE linearizers and the PA; and at least one adaptive controller coupled to the feedback circuitry, wherein each VE linearizer is coupled to at least another VE linearizer in series, in parallel, or both, and is configured to compensate for at least one distortion aspect of an output signal from the PA. | 01-03-2013 |
20130005284 | Circuit and Method for Interference Reduction - A radio frequency transmitter comprises an amplifier, an antenna port, an isolator adapted to isolate an output of the amplifier from an interfering signal of the antenna port, a linearization loop and a transmission line comprising a first part (coupling a signal source to an input of the amplifier), a second part (coupling the output of the amplifier to an input of the isolator) and a third part (coupling an output of the isolator to the antenna port). The linearization loop is adapted to reduce non-linearity of the isolator and comprises a first directional coupler coupled to the third part of the transmission line, a loop impedance, and at least one further linearization loop element adapted to adjust a linearization signal and to feed the adjusted linearization signal to the transmission line. The radio frequency transmitter also comprises an interference reducing circuit adapted to reduce an influence of the interfering signal on the linearization loop. The circuit comprises a variable gain and phase shifter, and second and third directional couplers. The variable gain and phase shifter is coupled to the third part of the transmission line via the second directional coupler, which extracts a compensation signal from the transmission line, and is adapted to adjust amplitude and phase of the compensation signal based on the amplitude and phase of the interfering signal passing through the loop impedance. The third directional coupler couples the variable gain and phase shifter to the loop feed line and feeds the adjusted compensation signal thereto. | 01-03-2013 |
20130072139 | APPARATUS AND METHOD FOR PROCESSING REDUCED BANDWIDTH ENVELOPE TRACKING AND DIGITAL PRE-DISTORTION - An apparatus and a method for processing reduced bandwidth Envelope Tracking (ET) and Digital Pre-Distortion (DPD) are provided. The apparatus includes a Crest Factor Reduction (CFR) unit, a resealing Digital Pre-Distortion (DPD) unit, an envelope converter, a Supply Modulator (SM), and a Power Amplifier (PA). The CFR unit suppresses an increase of a side lobe occurring when a Peak to Average Power Ratio (PAPR) decreases with respect to a signal generated in a baseband according to a standard and passes through a transmit (Tx) filter. The resealing DPD unit receives an original envelope amplitude and a reduced bandwidth envelope amplitude of an In-phase/Quadrature-phase (I/Q) signal output from the CFR unit to perform a pre-distortion process. The envelope converter converts an envelope signal to a reduced bandwidth envelope signal based on the I/Q signal output from the CFR unit. | 03-21-2013 |
20130095776 | CANCELLATION OF SPECTRAL IMAGES IN COMMUNICATION DEVICES - Digital-to-analog conversion in a communication device typically results in superimposed spectral images in the frequency spectrum of the analog waveform. These superimposed spectral images can distort the analog waveform and potentially violate the spectral mask and the constraints on out-of-band emissions set by the FCC. The communication device can be configured to implement a spectral image cancellation unit with feed-forward architecture to minimize the spectral images in the frequency spectrum of the analog waveform. The spectral image cancellation unit can generate a spectral image error signal comprising the spectral images at one or more spectral image frequencies. The spectral image cancellation unit can then subtract the spectral image error signal from the analog waveform to reduce spectral image components of the analog waveform and to yield an output signal for transmission. | 04-18-2013 |
20130109334 | TRANSMITTER FRONT END WITH PROGRAMMABLE NOTCH FILTER AND METHODS FOR USE THEREWITH | 05-02-2013 |
20130122834 | BROADBAND AMPLIFIER SYSTEM USING A 3dB QUADRATURE COMBINER TO DYNAMICALLY MODULATE LOAD IMPEDANCE - Systems and methods are provided for modulating a radio frequency (RF) carrier signal with a baseband input signal and amplifying the modulated RF carrier signal to provide an amplified RF signal. A quadrature combiner is configured to provide the amplified RF signal at an associated output port. A main amplifier is configured to receive a first modulated RF signal and provide a main output to one of a through port and a coupled port of the quadrature combiner. An auxiliary amplifier is configured to receive a second modulated RF signal and provide an auxiliary output to an isolation port of the quadrature combiner. | 05-16-2013 |
20130165060 | ARCHITECTURE OF NONLINEAR RF FILTER-BASED TRANSMITTER - Systems and methods for compensating for a non-linear characteristic of a non-linear filter in a transmit chain of a transmitter using predistortion are disclosed. In one embodiment, a transmitter includes a power amplifier configured to amplify a radio frequency input signal to provide an amplified radio frequency signal, a non-linear filter configured to filter the amplified radio frequency signal to provide an output signal of the transmitter, and a predistorter configured effect predistortion of the amplified radio frequency signal, where the predistortion compensates for a non-linear characteristic of the non-linear filter. In this manner, the output signal is as if the non-linear filter were a linear, or substantially liner, filter. The predistortion applied by the predistorter may be fixed or adaptive. | 06-27-2013 |
20130183915 | METHOD AND SYSTEM FOR GENERATING ODD ORDER PREDISTORTIONS FOR A POWER AMPLIFIER RECEIVING CONCURRENT DUAL BAND INPUTS - A method and system for pre-distorting a dual band signal to compensate for distortion of a non-linear power amplifier in a radio transmitter are disclosed. In one embodiment, a first and second signal of the dual band signal are up-sampled at a sampling rate that is based at least in part on the bandwidth of at least one of the first and second signals and based at least in part on an intermediate frequency by which the first and second signal are tuned before pre-distortion of the tuned signals. | 07-18-2013 |
20130231069 | Envelope Tracking Power Amplifier System with Delay Calibration - An envelope tracking power amplifier system time-aligns a supply voltage to an input signal to a power amplifier. The power supply operates in a static mode for low amplitude input signals and operates in a dynamic mode for high amplitude input signals. In the static mode, the power supply produces a substantially constant supply voltage independent of the amplitude of the input signal. In the dynamic mode the power supply produces a dynamically varying envelope tracking supply voltage based on the amplitude of the input signal. A first delay is determined based on portions of the input and output signals captured during static operation of the power supply and a second delay is determined based on portions of the input and output signals captured during dynamic operation. A delay mismatch is estimated based on a difference between the first and second delays. | 09-05-2013 |
20130309985 | TRANSMISSION MODULE - A multiband transmission module includes a power amplifier and a multiband isolator. An output end of the power amplifier is connected to a single input terminal of the multiband isolator. The multiband isolator includes a low-frequency individual isolator and a high-frequency individual isolator. Input ends of the individual isolators are connected to the single input terminal of the multiband isolator. Output ends of the individual isolators are respectively connected to a low-frequency output terminal and a high-frequency output terminal of the multiband isolator. | 11-21-2013 |
20130344827 | Compensation of a Transmitter Distortion - There is described a method for compensating the phase and gain distortions of a transmitter analog front end affected by a leakage of a local oscillator. The method comprises generating a single complex tone signal in a digital front end, wherein the generation comprises compensating the signal gain and phase with gain and phase offsets. The method comprises feeding the compensated signal into the transmitter analog front end. The method comprises feeding a corresponding output signal of the transmitter analog front end into a nonlinear component, thereby generating an inter-modulation between the complex tone signal and at least one tone signal due to the local oscillator leakage. The method comprises feeding the output of the nonlinear component into a measurement receiver analog front end. The method comprises filtering the output of the measurement receiver analog front end with a band pass filter in order to isolate the inter-modulation, which is indicative of the distortions introduced by the transmitter analog front end. The method comprises measuring the power of the filtered signal. The method comprises updating the gain and phase offsets according to the measured power, by reducing said measured power. The disclosure also relates, in particular, to a digital front end, to an analog system, to a telecommunication device, to a computer program, and to a storage medium. | 12-26-2013 |
20130344828 | ENVELOPE POWER SUPPLY CALIBRATION OF A MULTI-MODE RADIO FREQUENCY POWER AMPLIFIER - The present disclosure relates to envelope power supply calibration of a multi-mode RF power amplifier (PA) to ensure adequate headroom when operating using one of multiple communications modes. The communications modes may include multiple modulation modes, a half-duplex mode, a full-duplex mode, or any combination thereof. As such, each communications mode may have specific peak-to-average power and linearity requirements for the multi-mode RF PA. As a result, each communications mode may have corresponding envelope power supply headroom requirements. The calibration may include determining a saturation operating constraint based on calibration data obtained during saturated operation of the multi-mode RF PA. During operation of the multi-mode RF PA, the envelope power supply may be restricted to provide a minimum allowable magnitude based on an RF signal level of the multi-mode RF PA, the communications mode, and the saturation operating constraint to provide adequate headroom. | 12-26-2013 |
20140051373 | METHOD FOR SIMULTANEOUS TRANSMITTER OPERATION - A method and system mitigates receiver desensitization caused by a reverse inter-modulation distortion (IMD) signal generated by a power amplifier associated with one of at least two concurrently operating transmitters. A power amplifier controller (PAC) determines whether at least one power amplifier operating in a first operating state generates a reverse IMD signal that can substantially interfere with at least one receive channel due to a concurrent operation of at least two concurrently operating transmitters. In response to determining that at least one power amplifier generates the reverse IMD signal when in the first operating state, the PAC initiates a second operating state of the power amplifier to increase the linearity of the at least one power amplifier in order to reduce the reverse IMD signal. The PAC initiates the second operating state by adjusting parameters of the power amplifier. | 02-20-2014 |
20140065989 | SYSTEM AND METHOD TO IMPLEMENT A RADIO TRANSMITTER WITH DIGITAL PREDISTORTION HAVING REDUCED NOISE - A system and method provide for a radio transmitter with digital predistortion. The radio transmitter includes a high output power narrowband upconverter and a low output power wideband upconverter. In a stage of the radio transmitter, digital predistortion is applied to transmit data by setting digital coefficients by a digital predistortion algorithm, resulting in a predistortion signal. A predistortion signal is separated into a narrowband component and a wideband component, where the narrowband component corresponds to a desired traffic signal and the wideband component corresponds to a digital predistortion signal reflecting separated digital predistortion correction products. The narrowband upconverter provides a transmission path for a desired traffic signal or transmit data (the narrowband component of the digital predistortion signal), while the wideband upconverter provides a transmission path for the wideband component representing digital predistortion correction products. | 03-06-2014 |
20140073272 | METHOD AND APPARATUS FOR CALIBRATING AN ENVELOPE TRACKING SYSTEM - A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit, applying a training signal having an envelope that varies with time to an input of the RF transmitter module, receiving at least an indication of instantaneous output signal values for the power amplifier module in response to the training signal, calculating instantaneous gain values based at least partly on the received output power values, and adjusting a mapping function between an instantaneous envelope of a waveform signal to be amplified by the power amplifier module and the power amplifier module supply voltage to achieve a constant power amplifier module gain. | 03-13-2014 |
20140073273 | METHOD AND APPARATUS FOR CALIBRATING AN ENVELOPE TRACKING SYSTEM - A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit: applying training signal having time-variant envelope to input of the RF transmitter module; receiving indication of instantaneous output signal value(s) for the power amplifier module in response to the training signal; and adjusting timing alignment between envelope tracking path of the envelope tracking system and transmit path of the RF transmitter module to align envelope tracking power amplifier module supply voltage to instantaneous envelope(s) of a waveform signal to be amplified by the power amplifier module, based at least partly on the received indication of the instantaneous output signal value(s) for the power amplifier module in response to the training signal. | 03-13-2014 |
20140073274 | METHOD AND SYSTEM FOR GENERATING ODD ORDER PREDISTORTIONS FOR A POWER AMPLIFIER RECEIVING CONCURRENT DUAL BAND INPUTS - A method and system for pre-distorting a dual band signal to compensate for distortion of a non-linear power amplifier in a radio transmitter are disclosed. In one embodiment, a first and second signal of the dual band signal are up-sampled at a sampling rate that is based at least in part on the bandwidth of at least one of the first and second signals and based at least in part on an intermediate frequency by which the first and second signal are tuned before pre-distortion of the tuned signals. | 03-13-2014 |
20140099906 | REDUCING EFFECTS OF RF MIXER-BASED ARTIFACT USING PRE-DISTORTION OF AN ENVELOPE POWER SUPPLY SIGNAL - A radio frequency (RF) power amplifier (PA) and an envelope tracking power supply are disclosed. The RF PA receives and amplifies an RF input signal to provide an RF transmit signal using an envelope power supply signal, which at least partially envelope tracks the RF transmit signal, such that the RF input signal has an RF mixer-based artifact. The envelope tracking power supply provides the envelope power supply signal, which includes mixer-based artifact pre-distortion to at least partially remove effects of the RF mixer-based artifact from the RF transmit signal. | 04-10-2014 |
20140106691 | AAS Transmitter Distortion Improvement - The invention provides a method for processing signals in a radio transmission apparatus ( | 04-17-2014 |
20140155006 | TRANSMITTER, SIGNAL GENERATION DEVICE, CALIBRATION METHOD, AND SIGNAL GENERATION METHOD - It is intended to provide a transmitter capable of correcting signal distortion with high accuracy. Provided are a test signal generator; a frequency characteristics corrector for correcting an amplitude characteristic and a phase characteristic of a test signal; a modulator; an envelope detector; a frequency characteristics calculator for calculating frequency characteristics of an envelope signal; and a coefficients calculator for calculating, on the basis of the frequency characteristics, correction coefficients to be used for correcting the amplitude characteristic and the phase characteristic of the test signal. The test signal generator generates a test signal in which signal loci in each of at least two pairs of quadrants of first to fourth quadrants of the IQ plane are not symmetrical with each other. | 06-05-2014 |
20140162576 | Envelope Detector and Method for Detecting an Envelope of a Signal to be Amplified by a Power Amplifier - An envelope detector includes an input receiving a digital input signal indicative of a magnitude of a signal to be amplified by a power amplifier. A circuit is provided for generating an analog envelope signal based on the digital input signal. The envelope detector includes an output for outputting the analog envelope signal. | 06-12-2014 |
20140179248 | HIGH EFFICIENCY LINEARIZATION POWER AMPLIFIER FOR WIRELESS COMMUNICATION - A predistortion system for linearizing the output of a power amplifier includes a first signal representative of an RF modulated signal and a feedback signal representative of nonlinear characteristics of a power amplifier. The system also includes a predistortion controller, comprising at least one lookup table, adapted to receive the first signal and the feedback signal and to generate a correction factor for correcting the nonlinear characteristics of the power amplifier and combining logic which combines the RF modulated signal with a signal corresponding to the correction factor and supplies it to the power amplifier to linearize the output of the power amplifier. | 06-26-2014 |
20140220913 | Distortion Correction Based Feedforward Control Systems and Methods For Radio Frequency Power Sources - A distortion module includes a first module, at least one module and a correction module. The first module is configured to (i) receive radio frequency signals from radio frequency sensors of a power amplifier, and (ii) generate a distortion signal indicating distortion values for the radio frequency signals. The radio frequency signals are indicative of radio frequency power out of the power amplifier and received by a transmission line. At least one module is configured to estimate a phase of the distortion signal. The phase of the distortion signal is indicative of a phase of the transmission line. The correction module is configured to generate a distortion correction signal based on the phase to correct at least one of the distortion values of the radio frequency signals. | 08-07-2014 |
20140308908 | APPARATUS AND METHOD FOR SIGNAL PREDISTORTION - Apparatus and a method for predistortion of a radio-frequency signal are described. At least one predistortion unit is described that is arranged to receive an analog baseband signal before amplification and to generate an analog predistortion signal based on said analog baseband signal. At least one mixer unit is also described and may be electrically coupled to the at least one predistortion unit. In this case, the at least one mixer unit is arranged to receive the analog baseband signal before amplification and the analog predistortion signal and to generate a weighted combination of said signals. | 10-16-2014 |
20140342680 | SIGNAL AMPLIFYING APPARATUS, TRANSMITTER, AND SIGNAL AMPLIFYING METHOD - A transmission signal amplifying apparatus has an OFDM subcarrier division unit, a transmission side analog unit, a digital distortion compensation unit, and a main signal combiner. The OFDM subcarrier division unit divides a signal whose frequency bands are continuous, and outputs a plurality of subcarrier aggregations obtained by the division in a state in which the frequency bands are adjacent to each other. The transmission side analog unit amplifies signals of a plurality of systems having the respective output subcarrier aggregations for the respective signals of the respective systems, while maintaining the above-described state. The digital distortion compensation unit compensates distortions of the amplified signals of the plurality of systems. The main signal combiner combines the signals of the plurality of systems whose distortions have been compensated, and outputs as an RF signal. | 11-20-2014 |
20140357204 | Signal Processing - Apparatus, methods and methods of manufacture are provided for the processing of a current mode signal. A first signal processing stage comprising at least one output terminal is configured to produce a current mode output signal. A mutual inductance stage is arranged to inductively couple the at least one output terminal of the first signal processing stage to at least one input terminal of a second signal processing stage, wherein an input signal is generated at the at least one input terminal of the second signal processing stage on the basis of the current mode output signal produced at the at least one output terminal of the first signal processing stage. | 12-04-2014 |
20150017933 | TRANSMITTER AND METHOD WITH RF POWER AMPLIFIER HAVING CONTROL LOOP STABILIZED BIAS - A transmitter ( | 01-15-2015 |
20150017934 | AMPLIFYING DEVICE, TRANSMITTING DEVICE - An amplifying device of an embodiment includes: a first amplifier amplifying a first component of an input signal; a first output circuit having an input connected to an output of the first amplifier and converting impedance seen from an output of the first output circuit to make the converted impedance seen from the first amplifier; a second amplifier amplifying a second component of the input signal with a bias deeper than that of the first amplifier; a second output circuit having an input connected to an output of the second amplifier, having a longer electrical length than that of the first output circuit part, and converting impedance seen from an output of the second output circuit to make the converted impedance seen from the second amplifier; and a combiner combining the first component amplified by the first amplifier and the second component amplified by the second amplifier. | 01-15-2015 |
20150024699 | Convergence Estimation for Iterative Predistortion Factor Determination for Predistortion in Power Amplifiers - To estimate complex factors for use in predistortion of a power amplifier, a complex factor is selected a set of complex factors a computation interval. A solution value is estimated for the selected complex factor during the computation interval by an iterative computation that constrains the estimated solution value towards a final solution value over an arbitrary number of iterations that is not bounded by the duration of the computation interval. A cumulative error in the estimated solution value is computed at each iteration over consecutive computation intervals. From the cumulative error, it is determined whether a convergence criterion is met and, if so, the estimating is terminated. The termination occurs independently of the solution value estimated for any one of the complex factors in the set. | 01-22-2015 |
20150031317 | APPARATUS AND METHODS FOR PROVIDING A POWER AMPLIFIER WITH INTERFERENCE CANCELLATION - Methods and apparatus are provided for amplifying an input signal. An electronic circuit system comprises a first circuit comprising a power amplifier, configured to receive a first branch of an input signal, and generate a first amplified signal based on the input signal of the first branch; a second circuit, configured to receive a second branch of the input signal, generate a cancellation signal based on the input signal of the second branch, and combine the first amplified signal and the cancellation signal to generate a second amplified signal. The second circuit comprises an interference re-construction module, which is configured to model an inverse characteristic of residual distortion and interference of the first circuit via a predefined re-construction function, and generate an anti-phased interference signal based on the input signal of the second branch and the predefined re-construction function. The cancellation signal is generated from the anti-phased interference signal. | 01-29-2015 |
20150031318 | TRANSMITTER AND METHOD WITH RF POWER AMPLIFIER HAVING PREDISTORTED BIAS - A transmitter ( | 01-29-2015 |
20150072631 | AMPLIFIER AND AMPLIFICATION METHOD - [Problem] To provide an amplifier and an amplification method in which degradation in the quality of the output signal is reduced. [Solution] This amplifier is characterized in having: an amplification unit; a power supply modulator for determining the modulation voltage applied to the amplification unit according to an input signal inputted into the amplification unit; a first predistorter for modeling the characteristics of the amplification unit and performing distortion compensation with respect to the amplification unit; a first controller for controlling the parameters of the first predistorter on the basis of an input signal inputted into the first predistorter and an output signal from the amplification unit; a second predistorter for modulating an input signal inputted into the power supply modulator; and a second controller for controlling the second predistorter on the basis of the input signal inputted into the power supply modulator and a signal from which the RF component of the drain voltage of an FET of the amplification unit has been removed; the amplifier performing a correction such that the signal from which the RF component of the drain voltage of the FET has been removed is linear. | 03-12-2015 |
20150087250 | RADIO FREQUENCY COMMUNICATION SYSTEM AND NOISE ISOLATION METHOD APPLIED THERETO - A radio frequency communication system and a noise isolation method applied to the radio frequency communication system are provided. The radio frequency communication system includes an antenna, an amplifier and a noise isolating unit. The amplifier is electrically connected to the antenna to amplify a common-mode signal transmitted by the antenna and outputs an amplified common-mode signal. The noise isolating unit is electrically connected to the amplifier to isolate the amplified common-mode signal. The noise isolating unit includes a first transformer and a second transformer. The noise isolating unit isolates the common-mode signal and transmits the differential-mode signal, which can effectively reduce the noise and improve a signal to noise ratio without affecting the original signal. | 03-26-2015 |
20150099478 | FREQUENCY AGILE FILTER USING A DIGITAL FILTER AND BANDSTOP FILTERING - A method of providing frequency dependent signal attenuation. An RF input signal is split into a first signal portion and a second signal portion. Discrete time filtering, a negative group delay and bandstop filtering are applied to the first signal portion to provide a filtered signal portion. The second signal portion is applied to a component, and a component output signal portion is received from the component. The component output signal portion is combined with the filtered signal portion to provide an RF output signal having frequency dependent attenuation. | 04-09-2015 |
20150126141 | Adaptive ISO-Gain Pre-Distortion for an RF Power Amplifier Operating in Envelope Tracking - The output of a Radio Frequency (RF) Power Amplifier (PA) is sampled and down-converted, and the amplitude envelope of the baseband feedback signal is extracted. This is compared to the envelope of a transmission signal, and the envelope tracking modulation of the RF PA supply voltage V | 05-07-2015 |
20150147986 | POWER AMPLIFIER WITH SELF ALIGNED PEAKING STAGE - RF PA circuitry includes an amplifier stage, gain compensation circuitry, and an adder. The amplifier stage is configured to receive and amplify an RF input signal to provide an RF output signal. The gain compensation circuitry is coupled in parallel with the amplifier stage and configured to receive the RF input signal and provide a gain compensation signal, wherein the gain compensation signal is configured to linearize at least a portion of the gain response of the amplifier stage or the RF PA circuitry in general. The adder is coupled between an output of the amplifier stage and the gain compensation stage and is configured to receive and add the RF output signal and the gain compensation signal to provide a linearized RF output signal. | 05-28-2015 |
20150295545 | DISTORTION COMPENSATION APPARATUS AND WIRELESS COMMUNICATION EQUIPMENT - A distortion compensation apparatus that compensates for distortion of an amplifier is provided. The distortion compensation apparatus includes: a distortion compensation processing section that performs a predistortion process for a signal provided to the amplifier, based on an amplifier model of the amplifier, and outputs a compensated signal; an estimation section that estimates the amplifier model; and a filter. The estimation section estimates the amplifier model, based on the compensated signal and a monitor signal obtained by monitoring an output of the amplifier. The monitor band of the monitor signal provided to the estimation section is narrower than a frequency band of the compensated signal. The filter is provided so as to eliminate an influence of a signal component outside the monitor band among signal components of the compensated signal, on the estimation of the amplifier model by the estimation section. | 10-15-2015 |
20150326271 | Signal Acquisition in a Multimode Environment - A transmitter comprises a symbol mapper operable to map a frame of bits to a frame of symbols, where the symbols correspond to a determined modulation scheme, and circuitry operable to convert the frame of symbols to a physical layer signal and transmit the physical layer signal onto a communication medium. The circuitry is operable to process the physical layer signal such that a first portion of the physical layer signal is a first type of signal (e.g., a linear signal and/or non-ISC signal) and a second portion of the physical layer signal is a second type of signal (e.g., nonlinear signal and/or ISC signal). The first portion of the physical layer signal may comprise a header, a preamble, and/or a payload of the frame. The second portion of the physical layer signal may comprise a header, a preamble, and/or a payload of the frame. | 11-12-2015 |
20150333706 | RADIO FREQUENCY POWER AMPLIFIER CIRCUIT - An RF power amplifier circuit has an input terminal for receiving an input signal having an input power, and an output terminal for outputting an output signal. The RF power amplifier circuit comprises three amplifier stages and an input power splitter for providing respective power fraction signals to respective inputs of each amplifier stage. The input power splitter comprises a first input transmission line arranged between a first node and a second node, a second input transmission line arranged between a third node and a fourth node, and an electrical reactive element having a first terminal electrically connected to both the first and the second nodes, and a second terminal electrically coupled to a third one of the respective three inputs. | 11-19-2015 |
20150365114 | Power Amplifier Pre-Distortion Signal Generator Using an Analog Baseband Envelope Feedback Loop - Presented are methods and apparatuses for maintaining a substantially constant gain and reducing gain compression (AM-AM distortion) of a power amplifier based on a pre-distortion signal generated from an analog, baseband envelope feedback loop. | 12-17-2015 |
20160036399 | LIMITING DRIVER FOR SWITCH-MODE POWER AMPLIFIER - A switch-mode RFPA driver includes first and second field-effect transistors (FETs) arranged in a totem-pole-like configuration. The switch-mode RFPA driver operates to generate a switch-mode RFPA drive signal having a generally square-wave-like waveform from an input RF signal having a generally sinusoidal-like waveform. According to one embodiment of the invention, to maximize high-frequency operation and avoid distorting the switch-mode RFPA drive signal, the switch-mode RFPA driver is designed so that its output can be connected directly to the input of the switch-mode RFPA to be driven, i.e., without using or requiring the use of an AC coupling capacitor. The first and second FETs of the switch-mode RFPA driver are designed and configured to limit and control the upper and lower magnitude levels of the switch-mode RFPA drive signal to levels suitable for switching the switch-mode RFPA directly, obviating any need for DC biasing at the input of the switch-mode RFPA. | 02-04-2016 |
20160043754 | SINGLE TONE RF SIGNAL GENERATOR - A single tone RF signal generator and a method of generating a single tone RF signal. The single tone RF signal generator includes an output and a power amplifier that has an input. The power amplifier is operable to receive an RF signal including a first harmonic corresponding to a single tone signal to be produced by the signal generator. The power amplifier is also operable to amplify the RF signal. The power amplifier is further operable to provide the amplified RF signal to the output of the signal generator. The single tone RF signal generator further includes a feedback circuit connected between the output of the signal generator and the input of the power amplifier. The feedback circuit is configured to add one or more predistortion harmonics to the RF signal received by the power amplifier for cancelling harmonics in the amplified RF signal provided by the power amplifier. | 02-11-2016 |
20160065137 | REDUCED BANDWIDTH ENVELOPE TRACKING - Envelope power supply circuitry includes an envelope power converter circuitry and envelope tracking circuitry. The envelope power converter circuitry receives an envelope power converter control signal from the envelope tracking circuitry and a supply voltage and provides an envelope power supply signal for an amplifier based thereon. In a first mode of operation, the envelope power converter control signal is provided such that the envelope power supply signal causes the gain of the amplifier to remain substantially constant over a range of input power provided to the amplifier. In a second mode of operation, the envelope power converter control signal is provided such that the envelope power supply signal remains substantially constant for values within the range of input power below a predetermined threshold, and such that the envelope power supply signal causes the gain of the amplifier to remain substantially constant for other values. | 03-03-2016 |
20160065251 | SELECTING A PRECODING CONFIGURATION BASED ON SELF-JAMMING METRICS - A method for wireless communication by a wireless communication device is described. The wireless communication device determines that an aggressor radio in the wireless communication device is causing (or can potentially cause) self-jamming to a victim radio in the wireless communication device. A precoding configuration is selected based on one or more link throughput metrics and one or more self-jamming metrics. The precoding configuration is applied to transmissions of the aggressor radio. | 03-03-2016 |
20160080010 | WIRELESS COMMUNICATION APPARATUS, COMMUNICATION CONTROL METHOD, AND COMPUTER-READABLE RECORDING MEDIUM - A wireless communication apparatus includes an amplifying unit that amplifies an input signal that includes signals with different frequencies of a first frequency and the second frequency; a measuring unit that measures a level of inter modulation distortion generated in a signal obtained by the input signal being amplified by the amplifying unit; a determining unit that determines whether the level of the inter modulation distortion measured by the measuring unit is equal to or greater than a regulation value that is previously stored; and a control unit that decreases, when a result of the determination obtained by the determining unit indicates that the level of the inter modulation distortion is equal to or greater than the regulation value, a level of a signal input to the amplifying unit. | 03-17-2016 |
20160080013 | ADAPTIVE ISO-GAIN PRE-DISTORTION FOR AN RF POWER AMPLIFIER OPERATING IN ENVELOPE TRACKING - The output of a Radio Frequency (RF) Power Amplifier (PA) is sampled and down-converted, and the amplitude envelope of the baseband feedback signal is extracted. This is compared to the envelope of a transmission signal, and the envelope tracking modulation of the RF PA supply voltage is adaptively pre-distorted to achieve a constant ISO-Gain (and phase) in the RF PA. In particular, a nonlinear function is interpolated from a finite number gain values calculated from the feedback and transmission signals. This nonlinear function is then used to pre-distort the transmission signal envelope, resulting in a constant gain at the RF PA over a wide range of supply voltage values. Since the gains are calculated from a feedback signal, the pre-distortion may be recalculated at event triggers, such as an RF frequency change. | 03-17-2016 |
20160094253 | RELAXED DIGITIZATION SYSTEM LINEARIZATION - An approach to linearization relaxes the requirements on the digitization of the analog output signal while maintaining the benefits of a high sampling rate of the output signal. The digitization approach extracts sufficient information to characterize the output signal over a wide bandwidth without necessarily determining sufficient information to fully represent the output signal, for example, without sampling the output signal at the Nyquist sampling rate with a sufficient precision to accurately represent the signal. | 03-31-2016 |
20160094254 | SHARED INTEGRATED DC-DC SUPPLY REGULATOR - The systems and processes described herein can reduce the footprint of the internal devices of a wireless device by combining the DC-DC supply regulator with a FEM. Further, the device footprint can be further reduced by sharing the integrated DC-DC supply regulator among multiple FEMs reducing or eliminating the use of a separate DC-DC supply regulator for each FEM of a wireless device. Moreover, in certain embodiments, by integrating the DC-DC supply regulator into a 2G FEM, power efficiency can be improved for some wireless devices. For example, the DC-DC supply regulator may be used to supply power to a PA used for high-band 2G transmission functions. Using the DC-DC supply regulator can improve power efficiency compared to systems that supply the power for the high-band 2G PA directly from the power supply (e.g., the battery). | 03-31-2016 |
20160197584 | POWER AMPLIFIER AND TRANSMISSION APPARATUS | 07-07-2016 |
20160380671 | METHODS AND SYSTEMS FOR CREATING A SUPPLEMENTAL COMMUNICATION SIGNAL - A wireless access point or other transmitter can be configured to inject a supplemental signal into a data modulated carrier signal. In some examples, a transmitter system includes an antenna, a primary modulator, and a supplemental modulator. The primary modulator receives a baseband data signal and a carrier signal and outputting to the antenna a data modulated carrier signal according to a communications protocol. The supplemental modulator injects a supplemental signal into the data modulated carrier signal by distorting the data modulated carrier signal within an error bound of the communications protocol. A corresponding receiving system includes an antenna and a supplemental signal detector for detecting the supplemental signal by detecting the distortion within the data modulated carrier signal. | 12-29-2016 |
20170237455 | Analog Predistorter Core Module and Analog Predistorter System | 08-17-2017 |