International Business Machines Corporation

Greater Shine Limited

Zeku Technology (shanghai) Corp., Ltd.

Other

4d Connect, Inc.

Jian Gu

Bin Liu

Su-Lin Low

Tianan Tim Ma

Hausting Hong

Hong Kui Yang

Jianping Pan

Hang Zhou

Chengzhi Li

Prasanna Desai

Yuanye Wang

Chun-I Lee

Jianzhou Li

Xiaoshu Qian

Chenxi Wang

Anna Gontar

A method performed by a receiver of a wireless communications system to reduce the latency of channel estimation. The method includes receiving a data signal and a sequence of reference signals communicated over a wireless communication channel. In response to determining that the data signal is time critical or that a threshold reliability of the channel estimation is not required, the receiver estimates a channel condition of the wireless communication channel based on a portion of the sequence of reference signals. The receiver performs demodulation and decoding of the data signal prior to processing the entirety of the sequence of reference signals. The demodulation and decoding are adapted based on the estimated channel condition of the wireless communication channel.

Channel estimation optimizations in wireless communication systems

An apparatus and method for downlink data transmission and decoding are disclosed. In the method, a physical layer code block or a physical layer code block group is decoded. A medium access control (MAC) sub-packet corresponding to the decoded physical layer code block or the physical code block group is decoded without waiting for any subsequent physical layer code blocks to be decoded. The decoded MAC sub-packet is passed up a protocol stack.

Downlink protocol alignment and decoding

A method includes: receiving, at a first layer of a protocol stack, multiple code blocks from a base station, the multiple code blocks is a portion of a transport block and is associated with an error rate; transmitting, to a second layer of the protocol stack, the multiple code blocks; and determining, at the second layer and based on the error rate, whether to (1) store the multiple code blocks in memory or (2) process the multiple code blocks. A method for saving power in a physical (PHY) layer-to-medium access (MAC) layer interface and a network device, and a system are also provided.

Power saving techniques for layer-to-layer interface

Introduced here is at least one technique to better estimate interference at a receiver. The technique includes receiving a plurality of reference signals, which each have information indicative of noise. Thus, the technique further includes, for each reference signal, determining a noise estimation and determining a distance metric and log-likelihood ratio (LLR) of the noise estimation. Once the distance metric and LLR of each reference signal is determined, the receiver can determine a final LLR based on the distance metric and LLR of each reference signal. In this manner, a final LLR is determined. This technique can be applied by any device operating on MIMO technology.

Multiple-input and multiple-output (MIMO) detection in wireless communications

According to one aspect of the present disclosure, a baseband chip may be configured to receive a data stream associated with a channel. The baseband chip may be configured to select a first anchor point from the first constellation points of the first transmission layer. The baseband chip may be configured to select a first subset of constellation points from the first constellation points and the second constellation points. The baseband chip may be configured to perform a first iteration of a recursive tree search. The baseband chip may be configured to determine a first path metric based at least in part on the first iteration of the recursive tree search operation. The baseband chip may be configured to select a second anchor point from the second constellation points of the second transmission layer. The second anchor point may be associated with a second iteration of the recursive tree search.

Apparatus and method of recursive tree search based multiple-input multiple-output detection

The present invention is a method and apparatus to remove the adverse effects due to the imbalance between in-phase (I) and quadrature (Q) channels for I-Q demodulators and modulators in multi-carrier systems. A first balancer generates a first balancing signal from a first signal of a first index corresponding to a first frequency. A first combiner combines the first balancing signal and a second signal of a second index corresponding to a second frequency. The second frequency is symmetrical to the first frequency with respect to a center frequency in a multi-carrier composite signal. The first combiner generates a first balanced signal corresponding to the second frequency.

Method and apparatus to remove effects of I-Q imbalances of quadrature modulators and demodulators in a multi-carrier system

A method for removing effects of gain and phase mismatch in amplification branches of a linear amplification using nonlinear components (LINC) system. The method includes receiving an input signal, calculating a relative phase and gain difference in the amplification branches, and generating phasing components. The input signal is then controllably separated into a plurality of branch signals of different but constant envelope. The mismatch between branches may cause each branch signal to have a different envelop. The phases of the branch signals are then appropriately adjusted in a certain amount of corresponding phasing components, such that when the branch signals are recombined, the combined signal substantially replicates the input signal.

Removing effects of gain and phase mismatch in a linear amplification with nonlinear components (LINC) system

A method and a system for configuring and initializing an equalizer. The equalizer equalizes a signal received over a propagation channel. The received signal includes symbols, a synchronizing signal and is formed by one or more rays including a dominant ray. The method comprising the following: (a) generating a multi-path intensity profile of the propagation channel from the received signal; (b) determining an arrival time of the dominant ray and a propagation channel response corresponding to the arrival time based on the multi-path intensity profile; (c) decimating the received signal synchronously with the arrival time of the dominant ray to provide signal samples to the equalizer; (d) configuring the equalizer based on the multi-path intensity profile to deactivate some of the coefficients of the equalizer; and (e) initializing active coefficients of the equalizer based on the propagation channel response.

Fast converging equalizer for a demodulator

A method and an apparatus for detecting a frequency correction burst embedded in a signal which includes ordered samples. The method comprises the following: (a) correlating K sequences of the ordered samples with a predetermined waveform to produce K correlation outputs, each of the K correlation outputs corresponding to one of the K sequences, having a magnitude and being associated with an order index, K being an integer, the predetermined waveform corresponding to the frequency correction burst; (b) storing the K correlation outputs in a buffer according to the order indices; and (c) estimating a parameter based on the K correlation outputs, the parameter indicating detection of the frequency correction burst. The estimated parameter includes a frequency error and an ending time of a frequency correction burst. A quality metric associated with each frequency error is also computed.

Frequency correction burst detection

The present invention is a method and an apparatus for demodulating a signal received over a propagation channel. The received signal includes a synchronizing signal and is formed by one or more rays including a dominant ray. The method comprises the following: (a) generating a multi-path intensity profile of the propagation channel from the received signal; (b) determining an arrival time of the dominant ray and a propagation channel response corresponding to the arrival time based on the multi-path intensity profile; (c) decimating the received signal synchronously with the arrival time of the dominant ray to provide signal samples to an equalizer; (d) configuring the equalizer based on the multi-path intensity profile to deactivate some of the coefficients of the equalizer; (e) initializing the active coefficients of the equalizer based on the propagation channel response; (f) updating the active coefficients of the equalizer; and (g) equalizing the received signal using the equalizer to produce a filtered signal.

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San Diego, CA, United States of America

Jian Gu