Performance of coherent fast frequency-hopped spread-spectrum receivers with partial-band noise jamming and AWGN

Abstract

Performance analyses of coherent fast frequency-hopped spread-spectrum (FHSS) systems with the presence of partial-band noise jamming (PBNJ) and additive white gaussian noise (AWGN) are presented. Bit-error-rate expressions for the coherent maximum-likelihood (ML), linear-combination (LC), and hard-decision majority-vote (HDMV) receivers with binary phase-shift-keying are derived and validated by simulation results. Among the three proposed receivers, the coherent ML receiver gives the best performance under the worst-case PBNJ condition, followed by the coherent HDMV receiver and the coherent LC receiver. The BER results of the coherent ML receiver improve as the diversity level increases, although the incremental improvement in performance will diminish eventually when the diversity level is sufficiently large. The coherent LC receiver is incapable of providing diversity improvement under the worst-case PBNJ condition. For the coherent HDMV receiver it has been shown that there is an optimum diversity level under the worst-case PBNJ condition. The locus of the optimum diversity level for the coherent HDMV receiver is also presented, which allows one to obtain the optimum diversity level for the coherent HDMV receiver under different levels of signal-to-jamming ratio. It has been shown that the three coherent receivers significantly outperform the various existing noncoherent diversity-combining receivers under the worst-case PBNJ and AWGN conditions.