Silicon Storage Technology, Inc.

Mediatek Corporation

Mediatek Singapore Pte. Ltd.

Rockwell Technologies, Inc.

Rockwell Scientific Licensing LLC

Sst Communications, Corp.

Charles Chien

Chih-Yuan Lin

Zhiwei A Xu

Qiang Zhou

Paul Cheng Po Liang

Balachander Narasimhan

Bao-Chi Peng

Heng-Yu Jian

Yi-Cheng Wu

Shan Jiang

Wen-Wei Yang

Cheng-Chou Zhan

David Hsueh-Chia Chien

Ming Lei

Sheng-Hong Yan

Chun-Ying Ma

Ahmad Gomaa

A method of sparse digital cancellation of receiver nonlinear distortion in carrier aggregation systems is proposed. A reference signal generator generates possible candidate reference signals to be included in a dictionary matrix D. A sparsity-based solution is then applied to dynamically select reference signals based on the RF transceiver configuration. Based on the auto-correlation and cross-correlation with an observed radio signal, a subset of reference signals is selected from the dictionary matrix to match the distortion signal. The number of selected reference signals is flexibly determined based on the design constraints on complexity and power consumption. A greedy sparse estimation approaches, e.g., Orthogonal Matching Pursuit (OMP) can be used for reference signal selection. The reference signal selection is dynamic and adapts itself for different channel responses through correlating the observed radio signal with the dictionary reference signals.

Digital cancellation of receiver nonlinear distortion in carrier aggregation systems

An electronic device for a wireless communication system is described. The electronic device comprises: a receiver configured to receive a modulated signal on a communication channel; and a processor, coupled to the receiver and configured to: process the received modulated signal; identify a communication channel characteristic based on the processed received modulated signal; select an equalizer having a first set of equalization coefficients based on the identified communication channel characteristic, wherein the first set of equalization coefficients is selected from a plurality of equalization coefficients, each of the plurality of equalization coefficients being associated with different communication channel characteristics; equalize the processed received modulated signal on the communication channel using the selected equalizer; and detect the equalized received modulated signal.

Electronic device with equalization, integrated circuit and methods therefor

A method suppresses transmission noise comprised in a plurality of downlink signals received by one of a first radio module or a second radio module comprised in a communications apparatus. The method receives a plurality of first signals and a plurality of second signals, wherein the first signals and the second signals are the downlink signals respectively received via different antennas of the one of the first radio module or the second radio module, or the first signals are the downlink signals received by the one of the first radio module or the second radio module and the second signals are a portion of the uplink signals provided by the other one of the first radio module and the second radio module, and processes the plurality of first signals and the plurality of second signals to cancel transmission noise comprised in the plurality of downlink signals.

Method for suppressing transmission noise comprised in received downlink signal and communications apparatus utilizing the same

A communications apparatus is disclosed. A first radio module provides a first wireless communications service and communicates with a first communications device in compliance with a first protocol. A second radio module provides a second wireless communications service and communicates with a second communications device in compliance with a second protocol. A transmission noise suppression device is operative to process downlink signals received by the first radio module to cancel transmission noise comprised in the downlink signals, where the transmission noise is generated when the second radio module is processing uplink signals to be transmitted.

A method of configuring at least one frequency dependent (FD), in-phase/quadrature (I/Q), imbalance compensation filter within a radio frequency (RF) module is described. The method includes applying an input signal to an input of the RF module, receiving a filtered I-path signal for the RF module and deriving at least one I-path filtering estimate value therefrom, receiving a filtered Q-path signal for the RF module and deriving at least one Q-path filtering estimate value therefrom, and configuring the at least one FD I/Q imbalance compensation filter based at least partly on at least one ratio between the derived I-path and Q-path filtering estimate values.

Method and apparatus for configuring a frequency dependent I/Q imbalance compensation filter

A local oscillator (LO) buffer circuit comprises first and second LO buffers arranged in a cross coupled configuration. The first LO buffer generates in-phase output signals in response to in-phase input signals, and quadrature output signals from the second LO buffer. The second LO buffer generates the quadrature output signals in response to quadrature input signals and the in-phase output signals. The LO buffers may include inductive loads. The LO buffers may include MOS transistors or bipolar junction transistors.

Cross coupled high frequency buffer

A phase lock loop (PLL) includes a calibration loop for calibrating a tank circuit for capacitance variation through process variations of manufacturing an integrated circuit including the PLL. A capacitance profile for setting the frequency of the PLL at a process comer is stored. At power up, or after an idle time, a calibration is performed at two frequencies. The capacitances of operating the phase lock loop at the two frequencies are determined and stored. During a frequency change, the capacitance of operating the PLL is determined from the capacitance profile and stored capacitances. The capacitance of the PLL is presumed to change linearly with frequency and the two stored capacitances are used to determine a difference capacitance at the selected frequency by linear interpolating between the two stored capacitances, which is added to the capacitance in the capacitance profile at the selected frequency to generate an operating capacitance.

Method and system for calibration of a tank circuit in a phase lock loop

A transceiver includes a switching unit configurable for isolating an input of a receiver from an output of a transmitter during a local calibration mode. A known signal present at the output at a first power level during the calibration mode will also be present at the input at a second power level lower than the first power level and will be converted by the quadrature demodulator. A compensation factor is estimated for compensating the receiver section for imbalances in the in-phase and quadrature phase signals resulting from conversion of the known signal. Remote calibration is implemented using a method for remotely compensating for I-Q imbalance wherein a data packet having a known signal is transmitted to a receiver for conversion by a quadrature demodulator and compensation factors are estimated for compensating for imbalances in the in-phase and quadrature phase signals resulting from conversion of the known signal.

Compensation of I-Q imbalance in digital transceivers

A receiver, system and method for providing symbol timing recovery that allows for inexpensive and low-complexity synchronization for communication systems. A receiver receives a signal including digital data in the form of packets that is transmitted from a transmitter. The receiver uses information contained in each of the packets to align a phase of the receiver clock with a phase of the transmitter clock. The receiver further controls a sampling device such that the in-phase (I) and quadrature (Q) components are sampled at an optimum sample rate and at an optimum instance of time without requiring a numerically controlled oscillator or voltage controlled oscillator.

Low complexity synchronization for wireless transmission

A system or method for calibrating an RF transmitter includes inputting a test tone to the RF transmitter. LO leakage calibration is performed on an output of the RF transmitter with the test tone inputted thereto, in order to determine a minimum LO leakage. Thereafter, sideband image calibration is performed on the output of the RF transmitter with the test tone inputted thereto, in order to determine a minimum sideband image. Operational values for the RF transmitter are stored in memory based on the detected minimum LO leakage and the detected minimum sideband image, to be used during a normal operation mode of the RF transmitter.

LO leakage and sideband image calibration system and method

A calibration system for an RF system that includes an RF receiver capable of operating in a normal mode and in a calibration mode. The calibration system includes a phase delay unit provided on at least one of an I channel output and a Q channel output of the RF receiver. The system further includes a phase detector configured to detect a phase difference between the I channel output of the RF receiver and the Q channel output of the RF receiver. The system also includes a calibration control unit configured to provide a digital calibration control signal to the RF receiver based on the phase difference as provided by the phase detector.

RF receiver mismatch calibration system and method

An apparatus and method for concealing errors in digital data. An interpolator estimates a value of a sample of digital data from other samples of the digital data. The interpolator has an input for inputting the digital data and an output for outputting the estimated value of the sample of the digital data. A holding unit has an input for selectively receiving the sample of the digital data only when the sample is error free, and an output for outputting the error free sample. The input of the holding unit may be in parallel with the input of the interpolator. A selector selects between outputting the estimated value of the sample of the received digital data from an output of the interpolator and outputting the error free sample of the received digital data from an output of a holding unit based on at least one error indicator.

Low complexity error concealment for wireless transmission

The invention monitors a communication channel and estimates its characteristics from time to time, thus providing a dynamic estimate of channel characteristics. Based on the channel characteristics, a control processor calculates a preferred configuration of digital (and optionally, analog) signal processing to best manage the available energy for the present channel characteristics. The selected configuration is then down-loaded into communication modules stored in extra memory during runtime. The communication modules preferably include a one or more of: a reconfigurable forward error correcting codec (with adjustable code lengths and a plurality of code choices); a reconfigurable interleaver with adjustable depth; a decision feedback equalizer (DFE) with a reconfigurable number of taps; maximum likelihood sequence estimator with an adjustable number of states; a frequency hopping coder with an adjustable number of hops or hop rate; and a direct-sequence (or direct sequence spread spectrum) codec with an adjustable number of chips per bit.

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Newbury Park, CA, United States of America

Charles Chien