Anti-jamming Frequency Hopping System Using Multiple Hopping Patterns

Abstract

This paper deals with the follower jamming (FJ) and partial-band jamming (PBJ) resistance for the frequency hopping (FH) communication system with low hopping rate over AWGN channel. To gain a comprehensive FJ and PBJ rejection capability, we propose a multi-pattern frequency hopping (MPFH) scheme. In MPFH, the data channel and complementary channel are hopped on separate frequency slots determined by their respective frequency patterns, which will lure the follower jammer out of aiming at the complementary channel, thus mitigating the effect of FJ. Besides, narrow-band receiver is employed to ensure its PBJ rejection capability. We further enhance the proposed scheme by employing convolutional coding and maximum-likelihood decoding. Its upper bounds on bit error rate (BER) are derived under FJ and PBJ, respectively. Effects of three FJ parameters (tracking success probability, jamming duration ratio and jamming bandwidth ratio) and one PBJ parameter (jamming bandwidth ratio) on BER performance of MPFH are investigated versus the conventional FH/BFSK and recently developed differential frequency hopping (DFH) system. Numerical and simulation results show that when under the worst-case FJ, the proposed MPFH performs as well as DFH, but outperforms the conventional FH/BFSK by more than 5 dB; on the other hand, when under worst-case PBJ, the MPFH has the similar BER performance as conventional FH/BFSK, but outperforms DFH by more than 5 dB. The proposed MPFH shows superior jamming rejection performance under both PBJ and FJ.