Performance of fast frequency-hopped self-normalized BFSK receivers over Ricean fading channels with multitone interference

Abstract

This thesis is an investigation of the performance of noncoherent self-normalized fast frequency-hopped binary frequency shift keying (FFH/BFSK) receivers under conditions of non-negligible thermal noise, band multitone interference and Ricean fading where both the information signal and interference tones are affected by channel fading. Since finding closed form expressions for the most general case of Ricean fading proved difficult, performance was evaluated for special cases of fading. The analysis assumed fixed jamming power and considered two general jamming strategies: jamming a fixed number of frequency-hop slots, and jamming a variable number depending on signal energy per hop. It was found that the degree of fading of the jamming tones had little effect on system performance. It was also found that the most effective jamming strategy depended on the degree of fading of the information signal and on the signal-to-thermal noise power ratio per hop. In general, two- fold diversity yields improved performance with respect to no diversity. When the information signal is Rayleigh faded and the signal power is greater than about 1% of total jamming power, higher diversities perform better than lower diversities. When the signal is Ricean faded, the effect of higher diversities depends on the signal power per hop-to-thermal noise power ratio, the degree of signal fading and on the ratio of signal power-to-total jamming power.