Abstract: Subset based coherent fast frequency hopping (S-CFFH) is a novel FFH scheme, which enables efficient channel estimation for FFH signals. In this paper, we study the analytical bit error ratio (BER) of the S-CFFH/BPSK with maximum likelihood (ML) combining in the presence of multitone jamming (MTJ) and Rayleigh fading channels. Closed-form BER expressions are presented with perfect channel state information (CSI), and for special cases with imperfect CSI. The analytical results are validated by simulation. As compared with the maximum ratio combining (MRC), ML combining not only shows significant performance gain, but also greatly reduces the jammers’ efficiency. As compared with the noncoherent FFH/BFSK with ML combining, the S-CFFH/BPSK with ML combining shows significant gain with the increase of signal to jamming ratio.