Nonbinary decoding of structured LDPC codes
Daniele Capirone, Giacomo Como, Fabio Fagnani, Federica Garin · 2008
A class of serial turbo codes admitting low-density parity-check (LDPC) representation is considered. Their parity matrix has a random and a structured part. Thanks to their turbo structure, these codes are linear-time encodable, while they can be decoded as LDPC codes. An ensemble analysis for the error floor region, on the line of classical results for serial turbo codes, suggests a design parameter. Simulation results using usual LDPC message-passing show poor performance and no dependence on such parameter. A different block-wise decoding algorithm is proposed, which considerably improves performance. With this new decoding scheme, simulations confirm the theoretical design parameters in the medium-high SNR region.