短波差分跳频系统抗部分频带干扰性能分析

对接收端采用非相干平方律能量检测器及维特比译码器的短波差分跳频通信系统,在无衰落信道和频率非选择性慢衰落信道下抗部分频带干扰的性能进行了理论分析.若信道存在衰落,则假设每跳所经历的衰落过程是相互独立的,且服从瑞利分布.部分频带干扰被模拟为加性高斯噪声,分析中考虑了背景热噪声.结果表明:差分跳频相邻两跳频率之间的相关性为系统提供了良好的抗部分频带干扰的能力.若忽略背景热噪声,则当信干比为20dB时,在无衰落信道下最坏情况比特误码率可达10-5,而在频率非选择性瑞利慢衰落信道下最坏情况比特误码率可达10-3.

Performance analysis of shortwave differential frequency hopping systems with partial-band jamming

This paper presents an error probability analysis for the shortwave differential frequency hopping (DFH) system over a nonfading channel and a frequency-nonselective slowly fading channel with partial-band jamming. The noncoherent square-law energy detector and the viterbi decoder are used in the DFH receiver. If fading exists in the channel, each transmitted hop is assumed to fade independently according to a Rayleigh process. The partial-band jamming is modeled as additive Gaussian noise. Background thermal noise is considered in the analysis. Numerical results show that the inherent dependence of adjacent transmitted frequencies provides good partial-band jamming rejection capability for the DFH system. If background thermal noise is neglected and the signal-to-jamming ratio (SJR) is 20dB, the worst-case bit error rate can reach 10-5 over a nonfading channel, while it can reach 10-3 over a frequency-nonselective slowly Rayleigh fading channel.