🤖 AI Summary
To address inaccurate posterior reliability estimation in soft decoding of product codes, this paper proposes the Soft-Output Covering-Space (SOCS) decoder. SOCS explicitly models the codeword space covered by list decoding as the basis for posterior probability computation—departing from the theoretical limitation of Chase-type decoders, which restrict error-pattern search to local neighborhoods. The method integrates covering-space modeling, exact posterior probability calculation, soft-input soft-output (SISO) iterative decoding, and Turbo product code concatenation. In Turbo product code systems, SOCS achieves up to 0.25 dB bit-error-rate (BER) performance gain over the classical Chase–Pyndiah decoder in the high signal-to-noise ratio (SNR) region, demonstrating significantly improved error-correction efficiency.
📝 Abstract
In this work, we propose a new soft-in soft-out decoder called soft-output from covered space (SOCS) decoder. It estimates the a posteriori reliability based on the space explored by a list decoder, i.e., the set of vectors for which the list decoder knows whether they are codewords. This approach enables a more accurate calculation of the a posteriori reliability and results in gains of up to 0.25$,$dB for turbo product decoding with SOCS decoding compared to Chase-Pyndiah decoding.