LDPC Decoding Over Nonbinary Queue-Based Burst Noise Channels

Abstract

Iterative decoding based on the sum-product algorithm (SPA) is examined for sending low-density parity check (LDPC) codes over a discrete nonbinary queue-based Markovian burst noise channel. This channel model is adopted due to its analytical tractability and its recently demonstrated capability in accurately representing correlated flat Rayleigh fading channels under antipodal signaling and either hard or soft output quantization. SPA equations are derived in closed form for this model in terms of its parameters. It is then numerically observed that potentially large coding gains can be realized with respect to the Shannon limit by exploiting channel memory as opposed to ignoring it via interleaving. Finally, the LDPC decoding performance under both matched and mismatched decoding regimes is evaluated. It is shown that the Markovian model provides noticeable gains over channel interleaving and that it can effectively capture the underlying fading channel behavior when decoding LDPC codes.