Quantization of signals and metrics in the decoding of 8-PSK TCM

The performance of rate 2/3 8-PSK Trellis Coded Modulation was investigated as a function of the numerical resolution of the metrics and signal vectors used in decoding by the Viterbi algorithm. It was found that a 16 state Ungerboeck code using 5 bit I and Q with 7 bit metrics achieved roughly the same performance as pragmatic TCM. The findings were applied to the digital logic design of a TCM decoder.<
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