The Royal Institution for the Advancement of Learning / Mcgill University

Saied Hemati

Shie Mannor

Warren Jeffrey Gross

Francois Leduc-Primeau

Ali Naderi

Low-Density Parity-Check (LDPC) codes offer error correction at rates approaching the link channel capacity and reliable and efficient information transfer over bandwidth or return-channel constrained links with data-corrupting noise present. LDPC codes also offer error correction performance approaching channel capacity exponentially fast in terms of the code length, linear processing complexity, and parallelism that scales with the code length. They also offer challenges relating to the decoding complexity of the binary error-correction codes themselves and error floors limiting achievable bit-error rates. A new Relaxed Half-Stochastic (RHS) decoding algorithm is presented that reduces decoding complexity for high decoding throughput applications. The RHS algorithm uses an approach based on stochastic decoding algorithms but differs significantly from the conventional approaches of LDPC decoder implementation. The RHS algorithm also leads to a randomized decoding technique called redecoding that addresses the error floor limitation.

Method and system for decoding

Low-Density Parity-Check (LDPC) codes offer error correction at rates approaching the link channel capacity and reliable and efficient information transfer over bandwidth or return-channel constrained links with data-corrupting noise present. They also offer performance approaching channel capacity exponentially fast in terms of the code length, linear processing complexity, and parallelism that scales with code length. They also offer challenges relating to decoding complexity and error floors limiting achievable bit-error rates. Accordingly encoders with reduced complexity, reduced power consumption and improved performance are disclosed with various improvements including simplifying communications linking multiple processing nodes by passing messages where pulse widths are modulated with the corresponding message magnitude, delaying a check operation in dependence upon variable node states, running the decoder multiple times with different random number generator seeds for a constant channel value set, and employing a second decoder with a randomizing component when the attempt with the first decoder fails.

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Montreal, Canada

Saied Hemati