Performance bounds for multiple tone interference of frequency-hopped noncoherent MFSK systems

The performance degradation resulting from multitone interference of orthogonal, noncoherent frequency-hopped, M-ary frequency-shift keyed receivers (FH/MFSK) is investigated. The effect of thermal and other wideband noise is not neglected, and the multiple, equal power jamming tones are assumed to correspond to some or all of the possible FH M-ary orthogonal signalling tones. Furthermore the channel is modeled as a Ricean fading channel, and both the information signal and the interference signal are assumed to be affected by channel fading. Both band and independent multitone interference are considered. The performance is evaluated by obtaining a union bound on the probability of bit error, and receiver performance is compared with exact results for band multitone interference of a noncoherent FH/MFSK receiver under comparable circumstances. Except for the case of Rayleigh fading of the signal the union bound is very tight for those cases that can be compared with exact results. The advantages of the union bound approach are twofold. First, the union bound approach yields a solution that is far less computationally intensive than that obtained with the exact approach. Second, the union bound approach allows numerical results to be obtained for interference conditions that are not amenable to exact analysis, such as independent multitone interference of FH/MFSK