Abstract: A lidar system includes a transmitter that encodes successive transmit pulses with different pulse characteristics and a receiver that detects the pulse characteristics of each received (scattered or reflected) pulse and that distinguishes between the received pulses based on the detected pulse characteristics. The lidar system thus resolves range ambiguities by encoding pulses of scan positions in the same or different scan periods to have different pulse characteristics, such as different pulse widths or different pulse envelope shapes. The receiver includes a pulse decoder configured to detect the relevant pulse characteristics of the received pulse and a resolver that determines if the pulse characteristics of the received pulse matches the pulse characteristics of the current scan position or that of a previous scan position.

Abstract: Examples described herein include methods, devices, and systems which may compensate input data for nonlinear power amplifier noise to generate compensated input data. In compensating the noise, during an uplink transmission time interval (TTI), a switch path is activated to provide amplified input data to a receiver stage including a recurrent neural network (RNN). The RNN may calculate an error representative of the noise based partly on the input signal to be transmitted and a feedback signal to generate filter coefficient data associated with the power amplifier noise. The feedback signal is provided, after processing through the receiver, to the RNN. During an uplink TTI, the amplified input data may also be transmitted as the RF wireless transmission via an RF antenna. During a downlink TTI, the switch path may be deactivated and the receiver stage may receive an additional RF wireless transmission to be processed in the receiver stage.

Abstract: Methods and apparatuses for performing predistortion on transmissions to antennas are disclosed. In some embodiments, a method includes obtaining a type and scan angle of a flat panel antenna of a satellite terminal; selecting, based on the type and the scan angle, predistortion to apply to a signal to be transmitted to the flat panel antenna; applying the predistortion to the signal; and transmitting the signal to the flat panel antenna of the satellite terminal.

Abstract: An electronic device may include signal transmission circuitry such as wireless circuitry having a signal source, a signal path, and an output node coupled to an output load. The signal source may transmit a signal to the output load over the signal path. The output load may have an impedance characterized by a first reflection coefficient. A signal coupler may be disposed on the signal path. A power detector coupled to a coupled node of the signal coupler may measure a voltage at the third node. A termination coupled to an isolated node of the signal coupler may include components that cause the termination to exhibit a second reflection coefficient. The second reflection coefficient may be selected to configure the voltage at the third node to track a power wave at the output load to within a constant that is invariant as the first reflection coefficient changes over time.

Abstract: A method for building a factual database of concepts and entities that are related to the concepts through a learning process. Training content (e.g., news articles, books) and a set of entities (e.g., Bill Clinton and Barack Obama) that are related to a concept (e.g., Presidents) is received. Groups of words that co-occur frequently in the textual content in conjunction with the entities are identified as templates. Templates may also be identified by analyzing parts-of-speech patterns of the templates. Entities that co-occur frequently in the textual content in conjunction with the templates are identified as additional related entities (e.g., Ronald Reagan and Richard Nixon). To eliminate erroneous results, the identified entities may be presented to a user who removes any false positives. The entities are then stored in association with the concept.

Abstract: Implementations can include a system to trace and identify target signals by cross-correlation to a signal pattern for a circuit, the system including a data processing system including memory and one or more processors to identify a target signal among a plurality of signals propagating through a circuit, detect one or more reference signals associated with an input to the target signal, the reference signals satisfying a threshold based on a depth associated with the target signal and the circuit, generate a cross-correlation object between the target signal and the reference signals based on a waveform of the target signal and corresponding waveforms of the reference signals, generate a metric corresponding to a cross-correlation between at least a portion of the target signal and at least a portion of the cross-correlation object, and modify, based on the metric, a control object of the circuit, the control object associated with the target signal.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a configuration indicating one or more directions for applying directional digital pre-distortion (DPD) to mitigate interference in a direction to another UE. The UE may transmit a communication to a wireless node based at least in part on applying the directional DPD according to the configuration. Numerous other aspects are described.

Abstract: Certain aspects of the present disclosure provide techniques for envelope tracking schemes for a node in a wireless communication network. One aspect provides a method for wireless communication by a transmitter device. The method generally includes: combining envelopes associated with subbands of an input signal to be amplified for transmission based on a combination function; amplifying, via an amplifier, the input signal to generate a transmission signal, the input signal being amplified based on a combined envelope signal, representing the combination of the envelopes, received at a supply input of the amplifier; and transmitting the transmission signal to a receiver device.

Abstract: A wireless transceiver. The transceiver includes: (i) a transmit signal path; (ii) a calibration path, comprising a conductor to connect a calibration tone into the transmit signal path; (iii) a receive signal path, comprising a first data signal path to process a first data and a second data signal path, different than the first data signal path, to process a second data; (iv) a first capacitive coupling to couple a response to the calibration tone from the transmit signal path to the first data signal path; and (v) a second capacitive coupling to couple a response to the calibration tone from the transmit signal path to the second data signal path.

Abstract: A embodiment method, for linearizing a transmission signal resulting from a quadrature amplitude modulation of an analog baseband signal and a radiofrequency amplification, comprises a demodulation of a feedback signal taken from the transmission signal, a comparison between the demodulated feedback signal and the baseband signal, a digital calculation of a predistortion control signal based on the comparison, and an analog predistortion of the analog baseband signal controlled by the predistortion control signal.

Abstract: Systems and methods for digital predistortion (DPD) are disclosed herein. In an example embodiment, a digital front-end circuit includes a DPD block, power amplifier, and transmitter. The DPD block is configured to receive an input signal and to provide a first output signal, and includes a nonlinear model that is configured to generate a nonlinear model output signal based upon the input signal. The DPD block additionally includes a first mixing module that is configured to generate a mixing module output signal based upon the input signal and the nonlinear model output signal. The DPD block further includes a summation block that is configured to generate the first output signal at least in part as a first sum of the nonlinear model output signal and the mixing module output signal, and the first mixing module includes a plurality of first finite impulse response (FIR) filters.

Abstract: Apparatus and methods provide predistortion for a phased array. Radio frequency (RF) sample signals from phased array elements are provided along return paths and are combined by a hardware RF combiner. Phase shifters are adjusted such that the RF sample signals are phase-aligned when combined. Adaptive adjustment of predistortion for the amplifiers of the phased array can be based on a signal derived from the combined RF sample signals.

Abstract: An integrated circuit operable to measure an impedance presented to a transmitter path of the integrated circuit and a method thereof are provided. The integrated circuit includes a directional coupler that has an input port, a through port, a coupled port, and an isolation port. The integrated circuit also includes a power amplifier coupled to the input port of the directional coupler, a power detector configured to measure output levels from the coupled port and the isolation port of the directional coupler, a reference signal generator coupled to the isolation port of the directional coupler, and a vector modulator configured to adjust a phase of a signal generated from the power amplifier.

Abstract: A method and/or process of interface bridging device for providing a C physical layer (“C-PHY”) input output interface via a field programmable gate arrays (“FPGA”) is disclosed. The process, in one aspect, is capable of coupling a first wire of data lane 0 to a first terminal of first IO serializer of FPGA for receiving first data from a D-PHY transmitter of a first device and coupling a second wire of the data lane 0 to a second terminal of the first IO serializer of FPGA for receiving second data from the D-PHY transmitter. Upon activating a first scalable low-voltage signal to generate a first value on P channel and a second value on N channel in response to the first data and the second data, a first signal on first wire of trio 0 for a C-PHY output is generated based on the first value on the P channel.

Abstract: Transceiver circuitry in an integrated circuit device includes a receive path including an analog front end for receiving analog signals from an analog transmission path and conditioning the analog signals, and an analog-to-digital converter configured to convert the conditioned analog signals into received digital signals for delivery to functional circuitry, and a transmit path including a digital front end configured to accept digital signals from the functional circuitry and to condition the accepted digital signals, and a digital-to-analog converter configured to convert the conditioned digital signals into analog signals for transmission onto the analog transmission path. At least one of the analog front end and the digital front end introduces distortion and outputs a distorted conditioned signal.

Abstract: The present disclosure provides a method of linearization for a non-linear system, comprising: a group of steps comprising: inputting an input signal to the non-linear system; obtaining an output signal from the non-linear system in response to the input signal being input to the non-linear system; obtaining a desired signal for the non-linear system; comparing the output signal with the desired signal, to determine whether the input signal is a target signal for the non-linear system to achieve a desired performance; and in response to determining that the input signal is not the target signal for the non-linear system to achieve the desired performance, generating an updated signal in frequency domain by applying a coefficient to eliminate a difference between the output signal and the desired signal, for updating the input signal to the non-linear system. The present disclosure also provides a corresponding device, computer programs, and computer-readable storage.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a transceiver chain may receive, using a downconverter tuned by at least one local oscillator, transmit signals that are modulated using a modulation bandwidth and that span a total bandwidth greater than or equal to the modulation bandwidth. The at least one local oscillator may cover a first fraction of the total bandwidth. The transceiver chain may receive, using at least one analog-to-digital converter, input from the downconverter, and may output a first digital signal based at least in part on the input and sampling at the first fraction of the total bandwidth. The transceiver chain may determine an error associated with the transmit signals based at least in part on the first digital signal, and may perform digital pre-distortion on new signals based at least in part on the error. Numerous other aspects are described.

Abstract: Method of demodulation of M-CPFSK signal, includes receiving the M-CPFSK radio signal; moving it to zero frequency; sampling at no less than double a frequency of symbols; storing the samples with their amplitude and phase for at least L4 symbols; demodulating the sampled signal in three stages, wherein each stage includes iterating over symbol values within a block of symbols, of length is L1, L2 and then L3; in the first stage, N1 symbol sequences out of all possible symbol sequences are iterated over, at the second stage, N2 symbol sequences out of all possible symbol sequences are iterated over, and at the third stage, N3 symbol sequences out of all possible symbol sequences are iterated over, to obtain final symbol values; symbol values obtained at previous stage is used in a next stage to reduce a number of symbol sequences; and determining encoded bits based on final symbol values.

Abstract: Embodiments of this disclosure provide a system and method for wireless communication and wireless sensing in a low-cost common transceiver structure. In particular, the common transceiver structure may have a common digital-to-analog converter (DAC) configured to convert a digital wireless communication signal and a digital wireless sensing signal into an analog wireless communication signal and an analog wireless sensing signal, respectively. The common transceiver may also have a common transmitting antenna configured to transmit the analog wireless communication signal and the analog wireless sensing signal.

Abstract: A circuit for generating a radio frequency signal is provided. The circuit includes an amplifier configured to generate a radio frequency signal based on a baseband signal. Further, the circuit includes a power supply configured to generate a variable supply voltage based on a control signal indicating a desired supply voltage, and to supply the variable supply voltage to the amplifier. The circuit further includes an envelope tracking circuit configured to generate the control signal based on a bandwidth of the baseband signal, and to supply the control signal to the power supply.

Abstract: A method for calibrating one or more compensation values utilized by a compensation device of a transmitter includes: obtaining a plurality of output signals which were sequentially generated by the transmitter by processing a pair of input signals according to multiple pairs of compensation values as a plurality of feedback signals, where each feedback signal corresponds to one of the multiple pairs of compensation values, determining a plurality of coefficients of a cost function according to the multiple pairs of compensation values and the feedback signals in an operation of calibration; and determining a pair of calibrated compensation values according to the coefficients and providing the pair of calibrated compensation values to the compensation device.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive one or more indications of parameters associated with one or more downlink communications transmitted to one or more additional UEs. The UE may receive a downlink communication, including applying digital post distortion (DPoD) correction based at least in part on measurements of the one or more downlink communications transmitted to the one or more additional UEs and the one or more indications of the parameters. Numerous other aspects are described.

Abstract: A power voltage generator includes a charge pump and a regulator. The charge pump generates a charge pumping voltage. The charge pumping voltage has a headroom margin which is automatically set. The charge pumping voltage is varied based on a target voltage. The regulator generates a power voltage based on the charge pumping voltage.

Abstract: A first UE may transmit, to a second subset of one or more second UEs, one or more pilot signals associated with DPD training. The first UE may receive, from a third subset of the one or more second UEs, one or more feedback messages associated with DPD training. The one or more feedback messages may be based on the one or more pilot signals. Each second UE in the third subset of the one or more second UEs may correspond to one of the one or more feedback messages. The second UE may calculate one or more DPD parameters based on the one or more feedback messages. The second UE may transmit a first signal based on the calculated one or more DPD parameters.

Abstract: The electronic device with power-off partition includes a signal transmitting module, two repeater modules, and a working module. Each of the repeater modules includes a first power domain, a second power domain, and a transceiver circuit. A transmission path between the first power domain and the second power domain is maintained at a logic state when the second power domain is in power off mode. The transceiver circuit of one of the two repeater modules encodes a standby signal obtained from the signal transmitting module and transmits an encoded standby signal. The transceiver circuit of the other of the repeater modules decodes the encoded standby signal and transmits a decoded standby signal. The working module transmits, according to the decoded standby signal, a power-off signal to the transceiver circuits of the two repeater modules, so that the second power domains enter the power-off mode in response to the power-off signal.

Abstract: A received signal is enhanced by removing distortion components of a concurrently transmitted signal. A received signal is acquired in a receive frequency band concurrently with transmission of a transmit signal in a transmit frequency band. The received signal includes an intermodulation distortion component of the transmit signal. A representation of the transmit signal is processed using a non-linear predictor to output a distortion signal representing predicted distortion components in the received signal. The received signal is enhanced using the distortion signal by removing the predicted distortion components from the received signal corresponding to the distortion signal.

Abstract: Provided is a distortion compensation device performing distortion compensation on a signal to be amplified by an amplifier, of which an internal state affecting a distortion characteristic varies, using a distortion compensation model, wherein the distortion compensation model includes a plurality of calculation models having respective distortion compensation characteristic for the amplifier in different internal states, and a combiner combining the plurality of calculation models at a combination ratio corresponding to the internal state that varies.

Abstract: A digital modulator according to the present disclosure includes a polar converter that generates a phase signal and an amplitude signal from a baseband signal, an RF phase signal generator that generates an RF phase signal on the basis of the phase signal, a rectangulating unit that generates a rectangular RF phase signal by converting the RF phase signal into a rectangular shape, a time interleaver that time interleaves the amplitude signal and outputs first and second time interleaved signals, a ?? modulator that ?? modulates the first and second time interleaved signals on the basis of the rectangular RF phase signal and outputs first and second ?? modulated signals, and a selector that selects and outputs one of the first and second ?? modulated signals on the basis of the rectangular RF phase signal.

Abstract: A user equipment for wireless communications includes a memory configured to store a peak reduction tone (PRT) table and a processor configured to retrieve a plurality of PRT sequences from the PRT table. The plurality of PRT sequences includes a first PRT sequence based upon a first data rate and a second PRT sequence based upon a second data rate. The second data rate is larger than the first data rate, and the second PRT sequence is a subset of the first PRT sequence. The user equipment also includes a power amplifier operable to transmit data with the first PRT sequence according to the first data rate or with the second PRT sequence according to the second data rate.

Abstract: A method is provided. The method includes estimating adjacent channel leakage ratios respectively corresponding based on a test output signal output from a power amplifier according to a test input signal corresponding to a plurality of frequencies; selecting a test delay value corresponding to a largest value among the estimated adjacent channel leakage ratios; and providing a supply voltage to the power amplifier based on an envelope signal delayed according to the selected test delay value. For each of the plurality of test delay values, a corresponding adjacent channel leakage ratio is estimated based on a ratio of a magnitude of a component included in the test output signal and a magnitude of an inter-modulated component.

Abstract: A digital filter circuit is described. The digital filter circuit includes at least one signal input and at least one finite impulse response (FIR) filter associated with the at least one signal input. The at least one signal input is configured to receive an input signal, wherein the input signal includes a product of at least two input signal samples. The at least one FIR filter is established as a short-length FIR filter. Further, a signal processing method is described.

Abstract: A radio transmitter circuit (10) for transmitting signals within an uplink or sidelink frequency band of a cellular communications system is disclosed. It comprises a signal-generation circuit (20) configured to generate a transmission signal to be transmitted, and a radio front-end circuit (30), connected to the signal-generation circuit (20) at an input of the radio front-end circuit (30), for receiving the transmission signal, and configured to be connected to an antenna (40) at an output of the radio front-end circuit and to transmit the transmission signal to a remote node via said antenna (40). The signal-generation circuit (20) is configured to select a distortion function (D1, D2) based on a location of an allocated radio frequency resource, within said uplink or sidelink frequency band, for the transmission signal. Furthermore, the signal-generation circuit (20) is configured to generate an intermediate transmission signal, based on information to be transmitted in the transmission signal.

Abstract: A radio frequency transmitter includes an upconverter that outputs in-phase (I) and quadrature (Q) signals, a digital timing offset circuit, first and second digital-to-analog converters (DACs), an analog timing offset removal circuit, first and second pulse shapers, and an adder. The digital timing offset circuit introduces a time offset between the I and Q signals. The first and second DACs output analog I and Q signals, respectively, and have first and second clock signals, respectively. The first and second clock signals have the same frequency and are offset relative to each other by the time offset. The analog timing offset removal circuit removes the time offset between the analog I and Q signals. The first and second pulse shapers receive the analog I and Q signals, respectively, and output pulse-shaped I and Q signals. The adder receives the pulse-shaped I and Q signals and outputs an intermediate frequency signal.

Abstract: An electronic device includes a network monitor configured to acquire network environment information related to a radio frequency (RF) transmission signal; a transceiver configured to generate an envelope signal of the RF transmission signal; a transmission (Tx) module including a power amplifier for receiving the RF transmission signal from the transceiver and amplifying the RF transmission signal; and an envelope tracking (ET) modulator configured to receive the envelope signal from the transceiver and to provide a bias of a power amplifier to correspond to the envelope signal, wherein the ET modulator determines a magnitude of the bias of the power amplifier based on the network environment information acquired by the network monitor.

Abstract: A digital isolator module with pulse carrier modulation is provided, comprising an isolation barrier, operable to develop an isolated output signal in response to an input signal, a transmitter circuit adapted to receive a data input signal and coupled to the isolation barrier, and a receiver circuit coupled to the isolation barrier to receive the isolated output signal and generate a data output signal. The transmitter circuit is adapted to be operable to generate a transmitter output signal in response to the data input signal, and the transmitter output signal comprises different number of pulse carrier respectively responsive to a rising edge and a falling edge of the data input signal. By employing the proposed pulse carrier modulation of the present invention, it has been verified to reduce channel numbers, IC power consumption and electromagnetic interferences. In addition, jitter disturbances can be avoided and solved effectively.

Abstract: Certain aspects of the present disclosure provide techniques for training a digital pre-distorter (DPD) using real-time over-the-air transmissions and receptions by a user equipment (UE). A method for training the DPD generally includes transmitting a signal, generated by a transmitter front end, via a first port; sampling the signal, received over the air, at a second port; performing signal processing cleaning (e.g., synchronization, linear over-the-air channel estimation and equalization); calculating coefficients for a DPD; and configuring the DPD with the coefficients, for use in digitally pre-distorting sub sequent transmissions.

Abstract: Aspects of the subject disclosure may include, a non-linear energy detector that obtains baseband information from a mixed signal that corresponds to an information component of a received radio frequency (RF) signal, wherein the mixed signal comprises a local oscillator signal combined, without multiplication, with the received RF signal, wherein the received RF signal comprises a carrier wave component operating at a carrier frequency within a millimeter wave spectrum, wherein the non-linear energy detector is associated with a non-linear current-voltage (I-V) characteristic curve, and wherein the baseband information is obtained by applying the mixed signal to the non-linear I-V characteristic curve. Other embodiments are disclosed.

Abstract: A power management circuit operable to adjust voltage within a defined interval(s) is provided. The power management circuit is configured to generate a time-variant voltage for amplifying an analog signal based on a target voltage. In embodiments disclosed herein, the power management circuit can be configured to generate a lower initial target voltage at a start of the defined interval(s), such as during a cyclic prefix (CP) of an orthogonal frequency division multiplexing (OFDM) symbol, and dynamically adjust the initial target voltage, if necessary, within the defined interval(s) based on a time-variant power envelope of the analog signal. By generating the lower target voltage, in contrast to a conventional method of generating a maximum target voltage, at the start of the defined interval(s), it is possible to reduce energy waste and help improve efficiency in a power amplifier configured to amplify the analog signal based on the time-variant voltage.

Abstract: Various examples are directed to systems and methods for operating a plurality of power amplifiers. A predistortion circuit may pre-distort an input signal according to a predistortion configuration to generate a pre-distorted signal for the plurality of power amplifiers. An adaption circuit may receive a first feedback signal from a first power amplifier of the plurality of power amplifiers and generate predistortion correlation data describing a correlation between parameters of a model describing the plurality of power amplifiers. The adaption circuit may receive a first feedback signal from a second power amplifier of the plurality of power amplifiers and update the predistortion correlation data to generate updated predistortion correlation data using the first feedback signal from the second power amplifier. The adaption circuit may also generate the predistortion configuration using the updated predistortion correlation data.

Abstract: A method comprises obtaining a transmission signal to be power-amplified in a power amplifier (361) prior to transmission; separating the transmission signal into two or more polyphase components of the transmission signal; feeding one or more polyphase components of the transmission signal comprised in the two or more polyphase components to each of two or more parallel predistortion circuits (320,321,322); selecting a dedicated predistortion model and dedicated predistortion coefficients for each of the two or more parallel predistortion circuits (320,321,322); performing non-linear memory-based modeling on the transmission signal according to the selected dedicated predistortion models and coefficients using the one or more polyphase components; and combining output signals of the two or more parallel predistortion circuits (320,321,322) to form a predistorted transmission signal (y[n]) to be applied to the power amplifier (361).

Abstract: The present invention is a computationally-efficient compensator for removing nonlinear distortion. The compensator operates in a digital post-compensation configuration for linearization of devices or systems such as analog-to-digital converters and RF receiver electronics. The compensator also operates in a digital pre-compensation configuration for linearization of devices or systems such as digital-to-analog converters, RF power amplifiers, and RF transmitter electronics. The adaptive Volterra compensator effectively removes nonlinear distortion in these systems by implementing an adaptive background algorithm to periodically update actual filter coefficients to maintain optimal performance in operating conditions varying over time (e.g., temperature, frequency, signal level, and drift); or both. The xadaptive background algorithm calculates the optimal nonlinear filter coefficients to reduce nonlinear distortion.

Abstract: Systems and methods are disclosed herein that provide low-complexity Digital Predistortion (DPD) for a transceiver system that uses an Advanced Antenna System (AAS) to provide analog or hybrid beamforming.

Abstract: A system and method for digital receiver linearization is provided. An input digital signal is accepted with a plurality of spectral components. The input digital signal may be either a radio frequency (RF) digital signal or a baseband digital signal. Nonlinear distortion is created in response to the input digital signal. As the result of a corrected input digital signal, a primary baseband signal is created with real (I) and imaginary quadrature (Q) components. In response to the nonlinear distortion, auxiliary baseband signals are created with real (IAUX) and imaginary quadrature (QAUX) components. The primary baseband signal is compared to the auxiliary baseband signals to supply complex amplitude correction coefficients. The complex amplitude correction coefficients are used to modify the nonlinear distortion, and the modified nonlinear distortion is subtracted from the input digital signal to supply the corrected input digital signal.

Abstract: A millimeter wave (MMW) circuitry includes a phase modulation circuitry, a plurality of amplifier multiplier chain circuitries and a power combiner circuitry. The phase modulation circuitry is configured to receive input data and a plurality of divided input signals and to provide as output a plurality of phase modulation circuitry output signals. Each phase modulation circuitry output signal corresponds to a respective divided input signal. At least one phase modulation circuitry output signal has a nonzero phase relative to the divided input signals that is related to the input data. Each amplifier multiplier chain circuitry is configured to amplify and frequency multiply and phase multiply the respective phase modulation circuitry output signal to yield a respective power combiner input signal. The power combiner circuitry is configured to sum a plurality of power combiner input signals to yield an output signal. A modulation of the output signal is related to the input data.

Abstract: Example embodiments relate to machine learning based digital pre-distortion for power amplifiers. A device may amplify a signal with a power amplifier and transmit the signal. The signal may be received by an internal feedback receiver of the device. The device may further comprise a first machine learning model configured to emulate an external feedback receiver and to generate an emulated feedback signal based on the internal feedback signal. The device may further comprise a second machine learning model configured to determine digital pre-distortion parameters for the power amplifier based on the emulated feedback signal. Apparatuses, methods, and computer programs are disclosed.

Abstract: A wireless communication apparatus includes: a processor that performs distortion compensation on a complex number transmission signal by using a distortion compensation coefficient; a power amplifier that amplifies the transmission signal subjected to distortion compensation by the processor; and a feedback path that feeds back a signal output from the power amplifier to supply a real number feedback signal to the processor. The processor executes a process including: estimating a complex number feedback signal by performing linear computation on the complex number transmission signal and the real number feedback signal; and updating the distortion compensation coefficient by using the estimated complex number feedback signal.

Abstract: Methods and devices for processing of RF signals according to different gain modes are presented. According to one aspect, an active amplification mode is provided by switchable active paths coupled to respective input RF signals and a passive attenuation mode is provided by switchable passive paths coupled to the respective RF signals. According to another aspect, a common switchable feedback path coupled to the switchable active paths is used to provide an active attenuation mode. Coupling of the common switchable feedback path to the switchable active path is provided by switches of the switchable passive paths, including for coupling both ends of the common switchable feedback path or just one end.

Abstract: A radio frequency transmitter includes N transmit channels, where each transmit channel includes one nonlinear module, a primary correction circuit, coupled to each of N nonlinear modules that correspond to the N transmit channels, and configured to provide a primary correction signal for the N nonlinear modules, and N secondary correction circuits, where the N secondary correction circuits are coupled to the N nonlinear modules respectively, and each secondary correction circuit is configured to provide a secondary correction signal for a nonlinear module coupled to the secondary correction circuit.

Abstract: Systems, methods, and devices detect variations in load impedances of wireless communications devices. Methods include determining a first distortion measurement of a transceiver based on a first comparison of a digital loopback path and a radio frequency (RF) loopback path, and determining a second distortion measurement of the transceiver based on a second comparison of the digital loopback path and the RF loopback path. Methods also include implementing, using a processor, a third comparison of the first distortion measurement and the second distortion measurement, and determining if there is a change in a load of the transceiver based on the third comparison.

Abstract: A transceiver in a wireless communication system is provided. The transceiver includes a first circuit configured to convert a digital signal having a third bandwidth, a second circuit configured to separate the analog signal into a first analog signal corresponding to the first band and a second analog signal corresponding to the second band, up-convert the first analog signal and the second analog signal to generate a first radio frequency (RF) signal in the first band and a second RF signal in the second band, and output an RF signal having the third bandwidth, and a third circuit configured to separate the RF signal into the first RF signal and the second RF signal, adjust a phase of the first RF signal for beamforming in the first band, and adjust a phase of the second RF signal for beamforming in the second band.