Zte Canada Inc.

Research in Motion Corporation

Blackberry Corporation

Yiwen Liu

Sean Bartholomew Simmons

Dayong Chen

Method and apparatus of obtaining better detection performance by improving matrix condition for an M&#xd7;N over-determined MIMO system are disclosed. The condition of a matrix to be inverted for solving various detection problems is improved by reordering equations of the original MIMO system, resulting in a reordered channel matrix and reordered received signal vector so that the top N&#xd7;N sub-matrix has the largest determinant among all N&#xd7;N sub-matrices of the reordered channel matrix. The disclosed method may be used to obtain a more accurate estimate of the transmit data bits.

Detection of spatially multiplexed signals for over-determined MIMO systems

A method includes estimating spatial signatures of the signal and interference data streams, forming a composite channel matrix comprising all or a subset of estimated spatial signatures, performing QR decomposition (QRD) of channel matrix with different spatial orderings, selecting the stream with the largest post-detection signal-to-interference-plus-noise ratio (SINR) based on the elements of the R matrices from different QRD processes, pre-processing received signal using the Q matrix corresponding to the spatial ordering with the largest SINR, demodulating the strongest stream using single-stream sliced maximum likelihood (SSS-ML) method, cancelling the strongest stream and demodulating the remaining weaker streams using low-complexity MMSE method.

Single-stream sliced maximum likelihood aided successive interference cancellation

Techniques to adaptively apply interference rejection combining (IRC) for signal demodulation, include estimating an impairment covariance matrix, computing an interference correlation metric based on the determinant of the estimated impairment covariance matrix, selecting an interference correlation threshold, comparing the interference correlation metric with the threshold to determine if IRC should be used for demodulation, estimating a desired signal covariance matrix, computing a desired signal correlation metric based on the determinant of the desired signal covariance matrix, selecting desired signal correlation threshold, comparing the desired signal correlation metric with the desired signal correlation threshold to select one of the supported detection algorithms, filtering the received signal and associated channel matrix, and passing the whitened signal and channel matrix to the selected detection algorithm to generate estimates of code bits, if IRC is enabled. If IRC is disabled, no whitening is applied to the received signal and channel matrix.

Adaptive MIMO signal demodulation using determinant of covariance matrix

A method and system are described herein that a employ a lost frame concealment technique for processing data frames received during transmission over a communications channel. The lost frame concealment technique involves determining whether a current data frame is a bad frame, performing source decoding on the current data frame with one or more parameters that are limited by a first set of one or more values if the current data frame is a bad frame, and performing source decoding on the current data frame with one or more parameters that are not limited if the current data frame is a good frame.

Device and method for improved lost frame concealment

A system and method for coding and decoding an information signal sent through a communication system. The system includes: an encoder for encoding the information signal without adding additional information and for sending an encoded information signal; and a soft bit decoder including a-priori information related to the communication system for receiving the encoded information signal and decoding the encoded information signal using the a-priori information.

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Waterloo, Canada

Yiwen Liu