Error performance analysis of a concatenated coding scheme with64/256-QAM trellis coded modulation for the north American cable modemstandard

摘要

Concatenated coding schemes with Reed-Solomon (RS) coding in theouter stage and trellis coded modulation (TCM) in the inner stage areanalyzed. The TCM decoder incorporates a Viterbi decoder compliant withITU-T Recommendation J.83, Annex B (north American digital videotransmission specifications for multimedia cable network system (MCNS)).The module is suitable as the inner stage for a concatenated decodingscheme. A triple-error-correcting extended RS (128,122,7) code is usedin the outer stage. Union bounds on the bit error performance ofconcatenated coding schemes, over 64- and 256-QAM signal constellationsover AWGN channels are derived and verified by computer simulations. Theeffects of quantization of input symbols and of trace-back depth in theViterbi decoder are simulated as well