Kevin S Chuang, Age 39Belmont, MA

D412440, Aug 3, 1999

Nov 28, 1995

D/047296

Kevin Chuang - Commerce CA

0901

D 9503

2021015, May 20, 2021

Nov 25, 2020

17/104529

- Waltham MA, US
Zohaib Mahmood - Westwood MA, US
Yan Li - Lexington MA, US
Kevin Chuang - Cambridge MA, US
Helen H. Kim - Sudbury MA, US
Yu-Chen Wu - Bedford MA, US

H04B 1/04
H03F 1/02
H03F 1/32
H03F 3/189
H03F 3/24

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.

2021002, Jan 21, 2021

Jul 14, 2020

16/928145

- Hanover NH, US
Kevin Shun-Chieh Chuang - Cambridge MA, US

H04B 7/08
H04B 7/0456

Receive diversity combining uses signals received at multiple antennas and combine them to obtain a higher overall signal to noise ratio. Multi-level ranking is employed to determine the weight assigned to each channel and, once the channels are weighted the weighted signals are added together. In a two-level example the first level ranks the signals according to fidelity of the signal. This is done by calculating cross correlation coefficients, where highest coefficient indicates best fidelity. The second level ranks the channels according to peak to average power ratio. The lowest value indicates the best channel. The two rankings are combined to generate the weight coefficient for each channel prior to combining the signals from all the channels.

2020039, Dec 17, 2020

Aug 28, 2020

17/005944

- Waltham MA, US
Kevin Chuang - Cambridge MA, US
Yan Li - Lexington MA, US
Zohaib Mahmood - Westwood MA, US
Helen H. Kim - Sudbury MA, US

H04B 1/04
G06F 16/22
G06F 16/23

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.

2020039, Dec 17, 2020

Aug 28, 2020

17/005999

- Waltham MA, US
Kevin Chuang - Cambridge MA, US
Yan Li - Lexington MA, US
Zohaib Mahmood - Westwood MA, US
Helen H. Kim - Sudbury MA, US

H04B 1/04
G06F 16/22
G06F 16/23

Disclosed are implementations for digital predistortion of signals provided to a radio frequency (RF) transmission path configured to transmit radio signals in a plurality of subbands within a spectral range, including a method that includes configuring a digital predistorter for predistorting signals comprising arbitrary spectral content within the spectral range. The configuring includes acquiring data samples representing operation of the RF transmission path to transmit radio signals in different subbands, each sample including a digital input signal representing spectral content concentrated in a respective subband, and updating parameters of the digital predistorter according to the acquired data samples to mitigate non-linear characteristics of the RF transmission path. The method further includes receiving a further input signal representing spectral content in a particular subband within the spectral range, and using the configured predistorter to process the further input signal to yield a predistorted signal for providing to the RF transmission path.

2020036, Nov 19, 2020

May 4, 2020

16/865715

- Waltham MA, US
Kevin Chuang - Cambridge MA, US
Yan Li - Lexington MA, US
Zohaib Mahmood - Westwood MA, US
Helen H. Kim - Sudbury MA, US

H03F 1/32
H03F 3/193
H03F 3/21

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.

2020020, Jun 25, 2020

Jun 8, 2018

16/620725

- Waltham MA, US
Alexandre Megretski - Concord MA, US
Kevin Chuang - Cambridge MA, US
Zohaib Mahmood - Westwood MA, US
Yan Li - Lexington MA, US
Helen H. Kim - Sudbury MA, US
George Stone - Hollis NH, US

H04L 27/26
H04L 25/03

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.

2020016, May 28, 2020

Oct 18, 2019

16/656686

- Waltham MA, US
Kevin Chuang - Cambridge MA, US
Yan Li - Lexington MA, US
Zohaib Mahmood - Westwood MA, US
Helen H. Kim - Sudbury MA, US

H03F 1/32
H03F 3/193
H03F 3/21

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.