Preliminary results on performance evaluation of concatenated coding schemes over Rayleigh fading ionospheric channels

The behaviour of a concatenated coding scheme using TCM on the 8-DPSK signal set as inner codes and RS outer codes is investigated over a slow Rayleigh fading and AWGN channel. It is shown that TCM schemes alone can not provide a satisfactory performance but concatenated systems can give acceptable performance using burst error-correcting outer codes in parallel with interleaving techniques with a loss of 1/8-1/4 bits/sec/Hz. The resulting systems seem to be powerful tools that can effectively operate on heavily distorted HF ionospheric links.