Joint Interference Suppression and Symbol Detection in Slow FH/MFSK Systems with an Antenna Array

The performance of frequency hopping (FH) systems with M-ary frequency shift keying (MFSK) modulation may be significantly degraded in the presence of a follower jammer. In this paper, we introduce a signal model that takes into consideration the effect of a follower jammer explicitly, and then propose a maximum likelihood (ML) based interference cancellation and detection scheme for slow FH/MFSK systems. Based on using a simple 2-element antenna array, the scheme attempts to eliminate the unknown interfering follower jamming signal, and performs ML detection in a single integrated operation. Furthermore, an approximate expression of symbol error rate (SER) of the ML-based detection scheme is also derived in BFSK signaling. Simulation results show that the proposed scheme is able to remove jamming and outperform beamformers in the presence of a follower partial-band jammer.