Error probabilities of fast frequency-hopped FSK with ratio-statistic combining in a fading channel with partial-band interference

An error probability analysis is performed for a fast frequency-hopped, noncoherent binary frequency-shift keying (FSK) receiver using ratio-statistic combining. The channel is assumed to be a frequency nonselective, slowly fading Rician channel with partial-band interference. Both envelope and quadratic detectors are analyzed. The bit error probability is examined for different levels of diversity, severity of fading, fraction of bandwidth jammed, levels of jamming power, and thermal noise. For Gaussian and Rician channels, the ratio-statistic circuit provides complete immunity to partial-band interference provided sufficient diversity is used. For Rayleigh channels, partial-band interference has very little effect on overall performance, and the ratio-statistic receiver offers little improvement over a comparable conventional demodulator