Nanosemi, Inc.

Ppc Broadband, Inc.

Massachusetts Institute of Technology

University of Texas System

Maxlinear, Inc.

Osram Gesellschaft MIT Beschraenkter Haftung

Nanosemi Technologies

Yan Li

Alexandre Megretski

Helen Haeran Kim

Zohaib Mahmood

Kevin Chuang

Paul Bailey

Chad T Wells

Yanyu Huang

Erdogan Alkan

Vladimir Marko Stojanovic

Yu-Chen Wu

George Stone, Iv

Zhipeng Li

Yehuda Avniel

Mien-Chie Hung

Omer Tanovic

Dmitri Fomin

Yong Wen

Michael Beau

Thomas Schroeder

Hajir Roozbehani

Shijun Li

According to an aspect of an embodiment, a base station configured for beamforming estimation in a massive multiple input multiple output (mMIMO) radio access network (RAN) (mMIMO-RAN) may comprise a processing device and a transceiver. The processing device may be configured to obtain a channel estimate for a user equipment (UE). The processing device may be configured to compute a first power level adjustment for a downlink (DL) signal and a second power level adjustment for the DL signal. The second power level adjustment may be based on a power constraint. The transceiver may be configured to transmit the DL signal to the UE.

Beamforming estimation

A system for communicating wireless signals over a cable network includes a wireless over cable (WoC) amplifier configured to communicate wireless frequency band signals with a modem. The system may also include a WoC splitter configured to communicate the wireless frequency band signals with the WoC amplifier directly or via one or more cables, and a WoC adapter configured to receive the wireless frequency band signals from the WoC splitter via one or more cables and transmit the wireless frequency band signals wirelessly to one or more wireless communication devices.

Wireless over cable communication system

Disclosed are systems, devices, modules, methods, and other implementations, including a method for digital predistortion that includes receiving, by a digital predistorter, a first signal that depends on amplitude variations based on an input signal, u, with the variations of the first signal corresponding to time variations in non-linear characteristics of a transmit chain that includes a power amplifier. The method further includes receiving, by the digital predistorter, the input signal u, generating, by the digital predistorter, based at least in part on signals comprising the input signal u and the first signal, a digitally predistorted signal v to mitigate the non-linear behavior of the transmit chain, and providing the predistorted signal v to the transmit chain.

Linearization with level tracking

A system for communicating wireless signals over a cable network includes a wireless over cable (WoC) amplifier configured to communicate wireless frequency band signals with a modem. The system may also include a WoC splitter configured to communicate the wireless frequency band signals with the WoC amplifier directly or via one or more cables, and a WoC adapter configured to receive the wireless frequency band signals from the WoC splitter via one or more cables, and transmit the wireless frequency band signals wirelessly to one or more wireless communication devices.

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.

Passive intermodulation cancellation

An entry device includes an entry port, a filter connected to the entry port, a plurality of first output ports, and a plurality of second output ports. A first path extends from the entry port, through the filter, to the first output ports. The first path is configured to pass cable television (CATV) signals therethrough and to prevent at least a portion of multimedia over coax alliance (MoCA) signals from passing therethrough. A second path extends from the entry port, through the filter, to the second output ports. The second path is configured to prevent at least a portion of the CATV signals and at least a portion of the MoCA signals from passing therethrough. A third path extends from the first output ports, through the filter, to the second output ports. The third path is configured to pass the MoCA signals therethrough and to prevent at least a portion of the CATV signals from passing therethrough.

MoCA entry device

Disclosed are implementations, including a method for monitoring a performance of a transmitter in a radio with an adjustable digital predistortion system. The method includes determining a plurality of system characteristics, including determining one or more of, for example, data characterizing an input/output characteristic of a digital predistorter of the system, data characterizing a performance of a crest factor reduction process of the system, data characterizing a quality of a plurality of parameters associated with the digital predistorter, data characterizing an average time delay associated with the system, data characterizing an average gain associated with the system, and/or data characterizing a phase associated with the system. The method further includes comparing one or more of the plurality of system characteristics to respective one or more reference values, and controlling the adjustable digital predistortion system based on a result of the comparing.

Monitoring systems and methods for radios implemented with digital predistortion

A pre-distorter that both accurately compensates for the non-linearities of a radio frequency transmit chain, and that imposes as few computation requirements in terms of arithmetic operations, uses a diverse set of real-valued signals that are derived from separate band signals that make up the input signal. The derived real signals are passed through configurable non-linear transformations, which may be adapted during operation, and which may be efficiently implemented using lookup tables. The outputs of the non-linear transformations serve as gain terms for a set of complex signals, which are functions of the input, and which are summed to compute the pre-distorted signal. A small set of the complex signals and derived real signals may be selected for a particular system to match the classes of non-linearities exhibited by the system, thereby providing further computational savings, and reducing complexity of adapting the pre-distortion through adapting of the non-linear transformations.

Multi-band digital compensator for a non-linear system

Disclosed are implementations, including a method for digital predistortion of multiband signals that includes receiving an input signal comprising multiple signal portions in different frequency bands, the input signal configured to be processed by a transmit chain, of a power amplification system, comprising at least a power amplifier that produces output with non-linear distortions, with the non-linear distortions of the transmit chain being represented using a set of basis functions derived according to a single-band model of the non-linear distortions. The method further includes performing digital predistortion on signal components derived from the multiple signal portions of the input signal using a reduced set of the basis functions that excludes at least some basis functions for at least some cross-terms resulting from a full expansion of the single-band model applied to the multiple signal portions, to produce a digital predistorted signal provided to the transmit chain.

Multi-band linearization system

Disclosed are methods, systems, devices, apparatus, media, design structures, and other implementations, including a method for digital predistortion of multiband signals that includes receiving a plurality of input signals respectively associated with multiple radio frequency (RF) bands, with the plurality of input signals occupying an input frequency span corresponding to a difference between a maximum frequency in a highest of the multiple RF bands and a minimum frequency in a lowest of the multiple RF bands. The method further includes frequency shifting at least one signal from the plurality of input signals to produce condensed shifted signals, each corresponding to a respective one of the plurality of input signals, occupying a condensed frequency span smaller than the input frequency span, and processing the condensed shifted signals, including applying digital predistortion to the condensed shifted signals.

Multiband digital predistorter

Disclosed are crest factor reduction (CFR) implementations that include a method comprising getting communication system data representative of characteristics of a communication system comprising one or more radio transmission bands, and optimizing, based at least in part on the input communication system data, a plurality of updateable parameters that determine respective pulse shapes for one or more pulses as well as other certain algorithm execution parameters for use in the CFR system. Optimizing the plurality of updateable parameters includes iteratively updating the plurality of updateable parameters based on iterative evaluation of a plurality of performance parameters. The method further includes providing the optimized plurality of updateable parameters to configure the crest reduction system for use in processing signals for radio transmission using a pulse subtraction approach applied to one or more signals communicated through the communication system.

Crest factor reduction

Disclosed are implementations, including a method comprising selecting a location of a selection buffer (that stores observed output samples produced by a signal chain) according to a pseudo-random buffer selection process, and accessing at least one observed output sample generated in response to corresponding input samples (to the system) and/or intermediary samples (outputs of a digital compensator) produced by a compensator of the system. The method further includes computing an approximation of a sub-gradient value computed according to a stochastic gradient process to derive a sub-gradient of an error function representing a relationship between the observed output sample, and the input and/or intermediary samples, computing updated values for the compensator coefficients based on current values of the coefficients and the approximation of the sub-gradient value, and replacing, at a time instance determined independently of the buffer selection process, content of part or all of the selection buffer.

Buffer management for adaptive digital predistortion

Disclosed are digital predistortion implementations, including a method that includes obtaining a first set of digital predistortion (DPD) non-linear functions for controlling operation of a digital predistorter of a wireless device operating on a received at least one input signal directed to a power amplification system comprising a transmit chain with at least one power amplifier that produces output with non-linear distortions. The method further includes determining an expanded set of DPD non-linear functions comprising the first set of DPD non-linear functions and additional one or more sets of DPD non-linear functions derived based on the first set of DPD non-linear functions and on operating condition parameters associated with operation of the wireless device, and configuring the digital predistorter with DPD coefficients determined for the expanded set of the DPD non-linear functions based on observed samples of the transmit chain responsive to the at least one input signal.

Growing community of inventors

Lexington, MA, United States of America

Yan Li