Nonparametric diversity combining for fast frequency hopping

The inherent diversity in fast frequency hopped (FH) spread spectrum communications systems can provide some protection against interference. With M-ary frequency shift keyed (MFSK) signalling and a diversity L, there are L/spl times/M samples from which to make a decision on the symbol transmitted. Many diversity combining techniques have been developed for processing these values. Several nonparametric methods are introduced which process the ranks of the received values to produce a decision metric. They are shown to be robust to severe noise and multitone interference. A performance comparison is made between these nonparametric methods and more traditional methods. Results are given which show that these new methods provide excellent performance in MT interference and partial band jamming.