Concatenated Coded Modulation for Optical Communication Systems

We study the use of trellis-coded modulation (TCM) as an inner code in combination with outer block codes that use hard decision decoding. As outer codes we consider a byte-oriented Reed Solomon code and a block code that comprises two interleaved extended three-error correcting Bose Chaudhuri Hocquenghem codes of length 1020 each. Simulations show that a maximum net coding gain improvement 2.85dB and 1.13dB, respectively, can be achieved with the considerd TCM inner codes for an output bit error rate of 10 sup (-13).