第 41 卷 第 6 期 电 子 科 技 大 学 学 报 2012年11月 by more than 8 dB compared with conventional linear combining receiver and nonlinear product combining receiver at dB signal-to-noise ratio and the desired 104 SER under worst-case PBNJ. Key words frequency hopping; jamming; differential frequency hopping; noise-normalization combining; partial-band noise jamming; Rayleigh fading