Reed-Solomon coded QAM modulation on a Rayleigh fading channel

The authors propose the design of a coded transmission system for the terrestrial urban radio channel, with a 4 bit-spectral efficiency. They evaluated the performances of a Reed-Solomon coded 64-QAM modulation on a Rayleigh fading channel. Three decoding algorithms are considered: a hard decision and an erasure Berlekamp-Massey decoding algorithm and a soft decision maximum likelihood decoding algorithm. By computing the cutoff rate they found that when the spectral efficiency is not close to 6, the gain of soft decision decoding over erasure decoding and the gain of erasure decoding over hard decision decoding are not so large. However, this gain must increase when the spectral efficiency becomes closer to 6 bits