Abstract :
A method is presented for determining the effective number of neighbours for staged decoding of block coded modulation, for both coded 8-PSK and 16-QAM. The results are compared with ML decoding for 8-PSK, and it is shown that if the second row code has Hamming distance greater than 2, the number of neighbours is greater in staged decoding by a large factor, and causes a degradation in coding gain approaching 1 dB.