Abstract: Noise-normalization combining (NNC) differential frequency hopping (DFH) receiver is proposed to improve the performance of DFH system in rejecting partial-band noise jamming (PBNJ).(SER) performance of this receiver using sequence detection over Rayleigh fading channel is analyzed with consideration of background thermal noise. The anti-PBNJ performances of linear, product and noise-normalization combining DFH receiver are compared. Numerical and simulation results show that the worst-case PBNJ against NNC receiver is full-band jamming. The jamming margin of NNC receiver is improved by more than 8 dB compared with conventional linear combining receiver and nonlinear product combining receiver at 21.4 dB signal-to-noise ratio and the desired 10-4 SER under worst-case PBNJ.