Systems and methods for sparse code multiple access

Abstract

Coding gains can be achieved by encoding binary data directly to multi-dimensional codewords, which circumvents QAM symbol mapping employed by conventional CDMA encoding techniques. Further, multiple access can be achieved by assigning different codebooks to different multiplexed layers. Moreover, sparse codewords can be used to reduce baseband processing complexity on the receiver-side of the network, as sparse codewords can be detected within multiplexed codewords in accordance with message passing algorithms (MPAs).

Description

[0001] The invention claims U.S. Provisional Application No. 61 / 727,486, filed November 16, 2012, entitled "Systems and Methods for Sparse Code Multiple Access," and 2012 Priority to U.S. Application No. 13 / 730,355, filed December 28, 1999, entitled "Systems and Methods for Sparse Code Multiple Access," Both applications are incorporated herein by reference as if reproduced in full. technical field [0002] The present invention relates to the field of communications and, in particular embodiments, to systems and methods for sparse code multiple access. Background technique [0003] Code Division Multiple Access (CDMA) is a multiple access technique in which data symbols are spread over orthogonal or near-orthogonal code sequences. Traditional CDMA encoding is a two-step process in which binary codes are mapped to quadrature amplitude modulation (QAM) symbols before applying a spreading sequence. Although conventional CDMA coding can provide relatively high coding rates, n...

AI Technical Summary

Problems solved by technology

Although conventional CDMA coding can provide relatively high coding rates, new technologies / mechanisms for achieving higher coding rates are required to meet the growing demands of next-generation wireless networks

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