Pragmatic trellis coded modulation: a hardware implementation using 24-sector 8-PSK

The authors present the construction and test results of a system which implements pragmatic trellis coded modulation (TCM) for rate 2/3 encoded 8-PSK (phase shift keying). Pragmatic TCM is described. This system associates each sector of a quantized phase receiver (F. Carden et al., 1988) with a pair of weights to be used as soft decision inputs of the Viterbi decoder. This system approaches 3 dB of coding gain at bit error rates of 10/sup -5/ and less.<>