Maximum-likelihood diversity combining in partial-band noise interference channel

Maximum-likelihood diversity combining for an FFH/MFSK spread spectrum system on a partial-band noise (PBN) interference channel is investigated. The structure of maximum-likelihood diversity reception on a PBN channel with additive white Gaussian noise (AWGN) is derived. It is shown that signal-to-noise ratio and the noise variance at each hop have to be known to implement this optimum diversity combining. The performance of the maximum-likelihood combining can be used as a standard in judging the performance of other suboptimum, but more practical diversity combining schemes. The performance of the optimum combining scheme is evaluated. It is shown that the performance difference between some of the known diversity combining schemes, which do not require channel information to operate, and the optimum scheme is not small when the diversity order is low