SYSTEMS AND METHODS FOR IMPLEMENTING SOFT-DECISION REED-SOLOMON DECODING TO IMPROVE CABLE MODEM AND CABLE GATEWAY PERFORMANCE

摘要

A system and method are provided for implementing a soft Reed-Solomon (RS) decoding scheme, technique or algorithm to improve physical layer performance in cable modems and cable gateways. The algorithm is implemented in a forward error correction (FEC) module connected to a QAM demodulator. The RS decoding scheme is implemented without significantly complicating hardware or processing overhead. The soft Reed-Solomon (RS) decoding scheme extracts candidate RS symbols and their Log Likelihood Ratios (LLRs) from QAM symbols. The set of highest probable candidate blocks are then chosen and these are decoded using a variant of the Chase algorithm until a valid codeword is detected at the decoder output.