Abstract: An IQ-modulator pre-distorter includes means for pre-distorting each IQ-vector by a 2-dimensional linear transformation that depends on the value of the IQ-vector to be pre-distorted. The transformation is based on polynomials in the I- and Q-components. In a preferred embodiment the transformation is based on a 2×2 dimensional lookup table matrix, the elements (T11, T12, T21, T22) of which are sampled polynomials in the I- and Q-components of the IQ-vector.

Abstract: Disclosed is a distortion compensation circuit that efficiently compensates for distortion. A distortion compensation circuit (20) comprises a sampling memory unit (21), which accumulates an input signal and an output signal from an amplifier (4), a model estimation unit (22), which reads the input and output signals that are accumulated upon the sampling memory unit (21), estimates a model that represents an input/output characteristic of the amplifier (4), and outputs a coefficient that denotes the model thus estimated, and a distortion compensation unit (23), which compensates for a distortion of the amplifier (4), based on the coefficient.

Abstract: 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.

Abstract: A distortion compensation circuit capable of realizing highly accurate distortion compensation by updating a model even under a situation in which the appearance frequency of an input signal having a maximum value is low. A DPD processor 2 includes an inverse model estimation unit 22, which estimates an inverse model for a model expressing input-output characteristics of an HPA 6 based on an input signal S1 to the HPA 6 and an output signal S10 from the HPA 6, a distortion compensation unit 26, which compensates for distortion of the input-output characteristics by adding the inverse model to the input signal S1, and a sampling circuit 20, which samples the signals S2 and S10 in a predetermined time immediately before the sampling and inputs the signals S2 and S10 to the inverse model estimation unit 22.

Abstract: Provided is a predistorter which compensates for a memory effect occurring in an amplifier used in a communication device, especially an electric memory effect as well. The predistorter includes: a distortion compensation circuit (8) for compensating for a nonlinear distortion caused by an amplifier (3), in which the distortion compensation circuit outputs a predistortion signal to be input to the amplifier. The predistorter includes: first filter section (21) which is connected between the distortion compensation circuit and the amplifier, for compensating for a frequency characteristic appearing in a signal component occurring in an entire analog circuit including the amplifier; and second filter section (22) which is connected between the distortion compensation circuit and the first filter section or between the first filter section and the amplifier, for compensating for a frequency characteristic appearing in a distortion component occurring in the amplifier.

Abstract: Described herein is an apparatus and method for estimating the amount of power that is to be consumed by an amplifier. An estimation section may be determined based on frame data of an input signal that is to be input to the amplifier. The estimation section may be stored to in a predetermined section, and the amount of power to be consumed by the amplifier may be estimated in advance based on the stored signal. The predetermined section may be determined in consideration of response a characteristic of a power supply of the amplifier. The amount of power may be calculated by assigning weight to the stored signal.

Abstract: A digital signal processor includes an up-sampling module that samples an input signal and generates up-sampling points. A natural sampling module includes a reference signal generation module that generates a reference signal. A crossing point detection module receives the up-sampling points and the reference signal and uses interpolation to detect intersection points of the input signal and the reference signal. The crossing point detection module determines values of the input signal at first and second evaluation times. The crossing point detection module estimates a current intersection point of the input signal and the reference signal as an intersection of the reference signal and a line that extends between first and second points on the input signal that correspond with the first and second evaluation times. A frequency of the reference signal is variable and a current switching period of the reference signal is not equal to a previous switching period.

Abstract: Active circuits with active loads linearized via distortion cancellation are described. In one design, an apparatus includes a first stage and a load stage. For an amplifier, the first stage amplifies an input signal and provides an output signal having a larger signal level. For a mixer, the first stage mixes an input signal with an LO signal and provides an output signal. The load stage provides an active load for the first stage and is linearized by canceling distortion generated by the active load. In one design, the load stage includes a first transistor that provides the active load and generates distortion due to its nonlinearity. The load stage further includes at least one transistor that generates a replica of the distortion from the first transistor. The distortion replica is used to cancel the distortion from the first transistor. The first stage may also be linearized with distortion cancellation.

Abstract: A digital pre-distortion system which can provide the flexibility to model the highly non-linear distortion associated with High Efficiency RF Power Amplifiers while through a novel implementation of a least squares estimation process allows an implementation well suited for an FPGA application where limited resources and in particular memory resources are available.

Abstract: An exemplary embodiment of the feed forward amplifier replaces traditional distributed directional couplers, splitters, and delay lines. Moreover, an exemplary feed forward amplifier architecture combines active implementations of RF couplers, power splitters, and/or time delay elements in a novel fashion allowing for ultra-compact size and broadband performance. In an exemplary embodiment, a feed forward amplifier has a main amplifier path and an error amplifier path. The feed forward amplifier comprises a main amplifier in the main amplifier path, and at least one active vector generator in the error amplifier path. The at least one active vector generator is configured to adjust the phase and amplitude of an error amplifier path signal and an error amplifier is configured to receive the adjusted error amplifier path signal. Furthermore, the adjusted error amplifier path signal and an amplified signal are combined to form the output signal of the feed forward amplifier.

Abstract: A method for pre-processing a signal prior to receipt of the signal by a non-linear device (NLD) to compensate for AM-AM distortion and AM-PM distortion of the signal by the NLD. The method includes generating a modified amplitude rk based on an amplitude xk derived from a digitized envelope Ri,k of the signal, generating a scale factor ck based on the modified amplitude rk and the amplitude xk, generating an AM-AM compensated signal based on the scale factor ck, generating a first AM-PM phase compensation value based on the modified amplitude rk, and generating an AM-AM and AM-PM compensated signal by modifying a phase of the AM-AM compensated signal based on the first AM-PM phase compensation value.

Abstract: Linearizers can improve the linearity of power amplifiers by canceling or reducing amplitude of non-linearity components, (e.g., IM3, IM5, IM7, IM9, etc.) generated by the power amplifier. The linearizers can obtain samples of signals output by the power amplifier and process the samples to produce a canceling signal that is applied onto or into an output of the power amplifier. The canceling signal is generated such that when applied to the output of the power amplifier, the canceling signal cancels or reduces at least a portion of the non-linearity components produced by the power amplifier. A controller can improve the correction of the non-linearity components by executing one or more tuning algorithms and adjusting settings of the linearizer based on the results of the algorithm(s).

Abstract: The present invention provides an amplifier for a wireless transmitter. In one embodiment, the amplifier includes a signal separator for decomposing an input signal into constant envelope signals and amplifier circuits for amplifying the constant envelope signals. The amplifier also includes a combiner for combining the amplified constant envelope signals to form an output signal that is an amplified representation of the input signal. Linear correction circuits are used to apply gain, phase, and/or delay correction to the constant envelope signals. The corrections are determined based upon a feedback portion of the output signal. Pre-distortion circuits are used to apply a non-linear pre-distortion to the constant envelope signals. The non-linear pre-distortion is determined based upon the feedback portion of the output signal.

Abstract: A distortion compensating apparatus that compensates signal distortion caused by an amplifier includes a distortion compensating process unit that using a distortion compensation coefficient, compensates distortion of an input signal; a memory unit that stores the distortion compensation coefficient; and an address generating unit that generates a first address that is based on electrical power of the input signal and for acquiring the distortion compensation coefficient from the memory unit and that generates a second address that is based on a phase of the input signal and for acquiring the distortion compensation coefficient from the memory unit. The distortion compensating process unit acquires the distortion compensation coefficient from the memory unit based on the first and the second addresses to compensate the distortion.

Abstract: A distortion compensating apparatus that compensates signal distortion caused by an amplifier includes a distortion compensating process unit that using a distortion compensation coefficient, compensates distortion of an input signal; a memory unit storing therein the distortion compensation coefficient; and an address generating unit that generates a first address that is based on electrical power of the input signal and is for acquiring the distortion compensation coefficient from the memory unit, and a second address that is based on any one among the electrical power, phase of the input signal and amplitude of the input signal, is for acquiring the distortion compensation coefficient from the memory unit, and is normalized in a normalizing range determined according to the electrical power of the input signal. The distortion compensating process unit acquires the distortion compensation coefficient from the memory unit, based on the first and the second addresses to compensate the distortion.

Abstract: A power amplifier controller for adjusting a supply voltage to a power amplifier. The power amplifier controller adjusts the supply voltage so that distortion in an RF output signal corresponds to a predetermined limit. An amplitude error signal is generated by the power amplifier controller which represents a difference between an RF output signal and an attenuated RF output signal. The AC components of the amplitude error signal are processed to generate a deviation signal that represents the distortion in the RF output signal. The supply voltage to the power amplifier is increased when the deviation signal exceeds a distortion level control signal, and decreased when the deviation signal drops below the distortion level control signal.

Abstract: When a distortion correction coefficient, which is calculated according to a signal input to a power amplifier and a signal output from the power amplifier, is larger than a first threshold, a distortion correction coefficient corresponding to the input signal is updated to the first threshold. When the calculated distortion correction coefficient is equal to or smaller than the first threshold, the distortion correction coefficient corresponding to the input signal is updated to the calculated distortion correction coefficient.

Abstract: A gain control amplifier provides amplitude variation of an input signal that is coupled to the amplifier, by adding or combining a higher frequency signal that overdrives or distorts the amplifier to one or more degree(s), to provide the gain variation of the input signal. A predistortion circuit may be included to further reduce distortion of the input signal at the output of the amplifier.

Abstract: A method an apparatus improve linearization performance and reduce a convergence time of a Digital Pre-Distorter of a power amplifier. An input signal is received. A peak level of the input signal is expanded based on an expansion threshold. And the expanded peak level of the input signal is linearized through Digital Pre-Distorter (DPD) training on the expanded input signal.

Abstract: An error between the power of an input signal, which is input to a power amplifier, and the power of an output signal, which is output from the power amplifier, is calculated. The calculated error is normalized according to the power of the input signal or the power of the output signal. A distortion correction coefficient, which is stored in a predetermined storage unit in association with the power of the input signal, is updated using the normalized error.

Abstract: A pre-distortion apparatus of a power amplifier includes: a pre-distortion unit configured to generate a pre-distorted signal of an input signal by calculating a magnitude of the input signal and outputting a complex correction coefficient corresponding to the calculated magnitude of the input signal, and provide the generated pre-distorted signal as an input of the power amplifier; and a complex correct coefficient update unit configured to generate an error signal by comparing an output signal of the power amplifier with the input signal and updating the complex correction coefficient to minimize a magnitude of the generated error signal, wherein the pre-distortion unit provides a constant bias value corresponding to the magnitude of the input signal as a bias of the power amplifier while updating the complex correction coefficient.

Abstract: A high-efficiency power amplifier is provided, including a drive amplifier and a final power amplifier, and further including a first digital pre-distortion (DPD) correction module and a second DPD correction module. The first DPD correction module is configured to pre-distort nonlinear characteristics of drive signals output by the drive amplifier, and the second DPD correction module is connected to the first DPD correction module in series, and is configured to pre-distort nonlinear characteristics of amplified signals output by the final power amplifier. Another high-efficiency power amplifier is also provided, including a drive amplifier and a final power amplifier, and further including a second multi-path control module, a fourth DPD correction module, and a second gating module. The overall efficiency of the high-efficiency power amplifier is increased by improving the working efficiency of the drive amplifier.

Abstract: A distortion compensating apparatus includes following units. An information measuring unit measures a distortion component and an electric power component based on a radiation signal. A compensation coefficient calculating unit calculates a compensation coefficient based on the distortion component and the electric power component. A signal transmitting unit outputs a signal corrected by the compensation coefficient as a transmission signal. A signal converting unit converts the transmission signal into a high frequency signal. An amplitude separating unit amplifies the high frequency signal and separates a portion thereof as a signal to be fed back. A feeding-back unit processes the portion and outputs the result as a feedback signal to the information measuring unit.

Abstract: The present invention provides a non-linear distortion detection method and a distortion compensation amplifying device capable of suppressing increase of the circuit size and the power consumption even if the signal band is widened. A signal obtained by feeding back an output of a power amplifier is sampled by an A/D converter. An equalizer of a distortion detection unit uses an input signal d(n) of a predistorter as a reference symbol to detect an equalization error e(n) of the orthogonal demodulation signal u(n). An absolute value averaging unit outputs an absolute value of the equalization error e(n) which has been temporally averaged to E(n) as a distortion value to a control unit. According to the distortion value, the control unit adaptively controls the predistorter to perform distortion compensation.

Abstract: Coefficients W0, W1 and W2 to be used in finding a new quadratic function f2(W) indicating dependence of a distortion component on an coefficient by the least square method are obtained as values that satisfy a relational expression f1(W0)=f1(W2)=f1(W1)+P (where P is a true value) on the basis of a quadratic function f1(W) indicating unupdated distortion component coefficient dependence.

Abstract: A semiconductor integrated circuit device comprising a linearizer that has a plurality of switchable first gain characteristics, the linearizer switching to the first gain characteristic to generate an intermediate signal from an input signal by using the switched first gain characteristic, and outputting the intermediate signal to a circuit having a second gain characteristic, wherein the linearizer includes: a linearization unit that has at least one of first rectifier, and linearizes the input signal; and a linearization reducing unit that has a plurality of second rectifiers having polarity opposite to polarity of the first rectifier and a first switching unit selecting at least one of the second rectifiers based on a control signal, the linearization reducing unit being connected in parallel to the linearization unit and reducing linearization of the input signal by the linearization unit.

Abstract: A calculating apparatus includes a first state variable calculating unit that calculates first state variables respectively having a memory effect and being of an amplifier that causes signal distortion; an amplifier model unit that based on the calculated first state variables, calculates the signal distortion caused by the amplifier, as a distortion characteristic; and an output unit that outputs the calculated distortion characteristic.

Abstract: A distortion in an amplified signal obtained by amplifying a first input signal, is compensated for by applying a correction factor to the first input signal. The correction factor is updated based on the first input signal and the amplified signal. Updating the correction factor is prohibited when a value of the first input signal is same as a value of a second input signal among a plurality of input signals input previous to the first input signal.

Abstract: A power amplifying device with linear corrector utilizing the polynomial format to realize pre-distortion is disclosed. Its effective order estimation technique for polynomial based pre-distorter includes the following steps. Firstly, it receives the polynomial of the described pre-distorter and then, the polynomial is transformed into the matrix expression, obtaining the pre-distorter consisted of K pre-distortion functions, where K denotes the maximum order of the described polynomials. Secondly, singular value decomposition is performed for the pre-distortion matrix, obtaining singular value matrix. Thirdly, on the basis of the singular value matrix, effective rank of the pre-distortion matrix is obtained. Such effective rank of the pre-distortion matrix is determined as the effective order of the polynomial.

Abstract: Techniques to improve low noise amplifiers (LNAs) with noise canceling are described. LNA includes a first and a second amplifier which work together to noise cancel the noise generated at an input stage circuit. The input stage circuit receives an RF signal and is characterized by a first node and a second node. The first amplifier converts a noise voltage at the first node into a first noise current at an output of the first amplifier. The second amplifier is directly coupled to the output of the first amplifier and provides noise canceling by summing the first noise current with a second noise current generated by the second amplifier as a function of the noise voltage at the second node. The proposed techniques eliminate the need for large ac coupling capacitors and reduce the die size occupied by the LNA. The elimination of ac coupling capacitors between amplification stages of the LNA allows current reuse resulting in reduced current consumption.

Abstract: An amplifier and a method for converting a single ended signal to an amplified differential signal. The amplifier comprises an input configured to receive a single ended signal, a differential amplifier that outputs an amplified differential signal based on the single ended signal, and a compensator coupled to the differential amplifier and configured to inject an adjusted distortion compensating signal based on the even order distortion signal to compensate for a distortion in the amplified differential signal. The method comprises receiving a single ended signal, converting the single ended signal to an amplified differential signal, and generating a distortion compensating signal to substantially cancel an even order distortion signal injected to the differential signal by the converting.

Abstract: This invention relates to a predistorter, a predistortion method, and a predistortion system. The predistorter comprises a modulus value determining section, for determining a modulus value of an input signal; a base searching section, for searching a predetermined base lookup table in accordance with the modulus value of the input signal, so as to obtain a base lookup table value; an offset searching section, for searching a predetermined offset lookup table in accordance with the modulus value of the input signal, so as to obtain an offset lookup table value; an interpolation factor generating section, for generating an interpolation factor in accordance with the modulus value of the input signal; a multiplying section, for multiplying the offset lookup table value with the interpolation factor; and a summating section, for adding a product obtained by the multiplying section to the base lookup table value, so as to obtain a predistortion value.

Abstract: A system for identifying characteristics of communication circuit devices in a communication circuit includes a stimulus signal generator configured to generate a stimulus signal at a plurality of amplitudes for the communication circuit devices. At least one of the plurality of amplitudes exceeds a first predetermined threshold. At least one communication circuit device is configured to generate a signature signal in response to the stimulus signal when the stimulus signal exceeds the first predetermined threshold. The system includes an evaluation device configured to evaluate at least one intermodulation distortion (IMD) product of the signature signal generated by the at least one communication circuit device, and to identify a class of the at least one communication circuit device according to a transition level of an amplitude of the at least one IMD product of the signature signal that exceeds a second predetermined threshold.

Abstract: The present invention pertains to a pre-distorter linearizer that incorporates a balanced-to-unbalanced transmission line transition as a phase shifter to feed the linear and non-linear arms of the linearizer with signals of substantially the same amplitude and with a frequency-independent and substantially 180-degree phase difference. Preferably the balanced-to-unbalanced transmission line transition is a slotline-to-microstrip transition. Several alternatives are shown to enhance the bandwidth performance of the linearizer. Using a slotline-to-microstrip transition as a phase shifter provides for a very physically compact and inexpensive design. Furthermore, the flexibility of the slotline-to-microstrip architecture allows the linearizer to be easily integrated into systems that use both solid-state and vacuum-tube amplifiers.

Abstract: An apparatus includes: a unit that stores the look-up table including distortion compensation coefficients; a unit that selects addresses according to an input signal, acquires coefficients stored at the selected addresses, and performs the predistortion of the input signal by using the acquired coefficients; a unit that calculates an error signal by comparing with the input signal a feedback signal that indicates an output of a power amplifier to which a result of the predistortion is inputted; a unit that calculates coefficients from the error signal and the acquired coefficients by using the adaptive algorithm; a unit that, for each of the selected addresses, selects coefficients as adequate coefficients from among the calculated coefficients according to the error signal; and a unit that, for each of the selected addresses, calculates an average value of the adequate coefficients and replaces a stored coefficient in the look-up table with the average value.

Abstract: The present invention relates to an adaptive digital predistortion device and method. The adaptive digital predistortion device comprising: a predistortion unit for predistorting an input signal according to a predistortion parameter stored in a look-up table; a cost function generation unit for generating a cost function; a fixed segment point determination unit for determining a fixed segment point; and an update unit for updating parameters (u1, u2, ka) according to the cost function to update the look-up table based on the updated parameters (u1, u2, ka), wherein ka is an updated adaptive segment point, u1 and u2 are slopes on two sides of the adaptive segment point ka; and for subsequently updating parameters (v1, v2) according to the cost function to update the look-up table based on the updated parameters (v1, v2) and the fixed segment point, wherein v1 and v2 are slopes on two sides of the fixed segment point.

Abstract: Methods and apparatus for reconstructing discrete-time amplitude modulation signals in polar modulation transmitters. An exemplary polar modulation transmitter includes a symbol generator, a rectangular-to-polar converter, a peak phase detector, and an amplitude modulation reconstruction circuit. The symbol generator generates rectangular-coordinate modulation symbols from which the rectangular-to-polar converter generates an amplitude modulation signal containing discrete-time amplitude samples and an angle modulation signal containing discrete-time angle samples. The peak phase detector circuit detects phase reversals or near phase reversals represented in samples of the angle modulation signal. The amplitude modulation reconstruction circuit responds by reconstructing samples in the amplitude modulation signal that correspond to detected phase reversals or a near phase reversals represented in samples of the angle modulation signal.

Abstract: A charge/discharge control circuit for controlling current through an input/output audio device includes a first voltage reference; a second voltage reference and a waveform generation circuit responsive to the first and second voltage references for generating a multi-stage waveform profile which is approximately an inaudible waveform for suppressing audible artifacts in the input/output device.

Abstract: A signal scaling device (D), for a transmission path of a wireless communication equipment, comprises a processing means (PM) adapted to receive a phase and/or amplitude modulated signal (I/Q) to transmit, and arranged to multiply said phase and/or amplitude modulated signal with a chosen complex gain in order to output said phase and/or amplitude modulated signal with a chosen scaled amplitude and a chosen phase offset.

Abstract: A signal-compensation device includes a band-limitation unit that performs band limitation on a signal based on a variably adjusted band-set value and externally transmits the signal subjected to the band limitation to an amplifier, a measurement unit that measures a signal level of each of first and second signal components of a feedback signal which is part of an output of the amplifier fed back by a feedback unit to the band-limitation unit, where the each of first and second signal components is based on at least one of a property of variability of the band-set value, a feedback of the feedback signal by the feedback unit, and a nonlinear distortion of the amplifier, and an adjustment unit that adjusts the band-set value based on the signal level of each of the first and second signal components.

Abstract: The present invention provides an advanced adaptive predistortion linearization technique to dramatically reduce nonlinear distortion in power amplifiers over a very wide instantaneous bandwidth (up to 2 GHz) and over a wide range of amplifier types, input frequencies, signal types, amplitudes, temperature, and other environmental and signal conditions. In an embodiment of the invention, the predistortion linearization circuitry comprises (1) a higher-order polynomial model of an amplifier's gain and phase characteristics—higher than a third-order polynomial model; (2) an adaptive calibration technique; and (3) a heuristic calibration technique. The higher-order polynomial model is generated by introducing, for example, a plurality of multi-tone test signals with varying center frequency and spacing into the power amplifier. From the power amplifier's corresponding output, the nonlinearities are modeled by employing a higher-order curve fit to capture the irregularities in the nonlinear transfer function.

Abstract: Disclosed is a predistortion linearizer for power amplifiers using a bridge topology, which has the advantages that an equalizer stage is disposed in each of the linear and nonlinear branches. This equalizer stage is used to adjust the frequency response of the complex expansion of the bridge. The equalizers introduce variable transmission functions in the linear and nonlinear bridge branches, so that the linearizer compensates for the individual nonlinear frequency response of a power amplifier, which varies within a manufacturing lot.

Abstract: A digital pre-distortion system which can provide the flexibility to model the highly non-linear distortion associated with High Efficiency RF Power Amplifiers while through a novel implementation of a least squares estimation process allows an implementation well suited for an FPGA application where limited resources and in particular memory resources are available.

Abstract: It is intended to increase the efficiency of a distortion compensation amplification device having a pre-distorter 1. Level detecting means 11 detects a signal level, correspondence storage means 12 outputs a distortion compensation coefficient depending on the signal level, pre-distortion executing means 13 gives distortion with an inverse characteristic to the signal, filtering means 8 outputs a distortion component from a feedback signal output from an amplifier 4, and correspondence acquiring means 14 updates a learning coefficient constituting a function that gives the inverse characteristic so as to reduce the distortion component. The function that gives the inverse characteristic is expressed using a set of orthogonal polynomials.

Abstract: An apparatus for compensating a distortion characteristic of an amplifier includes an update unit configured to store a distortion compensation coefficient, configured to calculate the coefficient based on a signal before input to the amplifier and a feedback signal, and configured to update the stored coefficient to the calculated coefficient; a distortion compensation unit configured to perform distortion compensation processing of the signal before input to the amplifier by using the updated coefficient; a delay unit configured to delay the signal before input to the amplifier by a set delay time, to output the delayed signal to the distortion compensation coefficient update unit; and a delay controller configured to control the set delay time based on a phase of a complex number having a power component of the signal before input to the amplifier as a real part, and a power component of the feedback signal as an imaginary part.

Abstract: A method and apparatus for a power amplifier module is described. The module includes a power amplifier and a power supply modulator coupled to the power amplifier. In addition, the module includes an inverter coupled between the power amplifier and the power supply modulator. The inverter provides a predistorted signal to the power amplifier to cancel distortion in the power amplifier provided by the power supply modulator. In addition, the module can include a driver coupled between the power amplifier and the inverter wherein the driver supplies the predistorted signal to the power amplifier.

Abstract: A RF-digital hybrid mode power amplifier 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 in the RF domain. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels. As a result, the digital hybrid mode power amplifier system is particularly suitable for wireless transmission systems, such as base-stations, repeaters, and indoor signal coverage systems, where baseband I-Q signal information is not readily available.

Abstract: A system for processing an input signal, the system includes: a hardware memory module configured to store a lookup table; and a signal processing module, configured to process the input signal to provide a second signal, and to transmit the second signal to a power amplifier that is characterized by non-linearity and which is adapted to amplify the second signal to provide an amplified signal; wherein the signal processing module is configured to process the input signal in response to at least one filtering parameter to provide the second signal so as to at least partly compensate for the non-linearity of the amplifier; wherein the at least one filtering parameter is retrieved from the lookup table using a first, a second, and a third lookup table indexes, wherein the first index is responsive to a magnitude of the input signal at a first moment, the second index is responsive to a magnitude of the input signal at a second moment, and the third index is responsive to phases of the input signal at the first

Abstract: A method and an apparatus. The apparatus includes at least one sensor for sensing at least one parameter that affects a non-linearity of the non-linear amplifier and for generating at least one parameter indicator; a memory module for storing multiple sets of pre-distortion coefficient values; a retrieval module, coupled to the memory module, for receiving the at least one indicator, for selecting a selected set of pre-distortion coefficient values based on the at least one indicator, and for sending the selected set of pre-distortion coefficient values to a signal processing module; and a signal processing module, configured to receive an input signal, to receive the selected set of pre-distortion coefficient values, and to pre-distort the input signal, using the selected set of pre-distortion coefficient values such as to at least partly compensate for the non-linearity of the non-linear amplifier.

Abstract: A method and an apparatus.