Tuesday, April 1, 1997
Block coded modulation (BCM) is the alternative coded modulation scheme to trellis coded modulation (TCM). Yamaguchi demonstrated that a significant coding gain can be obtained at moderate SNR in an 8-PSK based BCMIM system with length-256 BCH codes. This large coding gain suggests that introducing interblock memory is an efficient way to combat the problem of nearest neighbors in a BCM system. However, we will show that the advantage of introducing interblock memory to a BCM system is to increase the rate with a fixed distance advantage, or increase the distance advantage with a fixed rate; both will increase the asymptotic gain of the coded system and a better performance at moderate SNR is resulted. In this talk, Upper and lower bounds on the best gain in terms of additional information bits will be given and several BCMIM systems with the highest rates for given distance advantages will be given to demonstrate how the bounds can be applied.
Not available at this time