Low Density Parity Check Codes over GF(q)

Matthew C. Davey and David J. C. MacKay

Gallager's low density binary parity check codes have been shown to have near Shannon limit performance when decoded using a probabilistic decoding algorithm. We report the empirical results of error-correction using the analogous codes over GF(q) for q>2, with Binary Symmetric channels and Binary Gaussian Channels. We find a significant improvement over the performance of the binary codes, including a rate 1/4 code with bit error probability 1e-5 at Signal to Noise Ratio 0.2dB.

Status: Published in IEEE Communications Letters, Vol 2, No. 6, June 1998.

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