中文摘要：

提出了一种基于非相干平方律能量检测及逐符号译码的短波差分跳频系统方案，并在加性白高斯噪声（AWGN）信道与频率非选择性瑞利慢衰落信道条件下，开展了比特误码率（BER）性能的理论分析与数值仿真．数值仿真结果表明，差分跳频相邻两跳频率之间的相关性使其系统获得了一定的误跳纠正能力；对于可用频率数为4、每跳传输1比特的差分跳频系统，在AWGN信道条件下，当信噪比约为13．6dB时，则BER可达10^-5，而在瑞利衰落信道下，当信噪比约为33dB时，则BER可达10^-3．逐符号译码是一种实用的差分跳频译码算法．

英文摘要：

A bit error rate （BER） analysis is presented {or the symbol-by-symbol decoding shortwave differential frequency hopping （DFH） system over an additive white Gaussian noise （AWGN） channel and a frequency-nonselective slowly Rayleigh fading channel. The noncoherent square-law energy detector is used in the DFH receiver. Numerical and simulation results show that the inherent dependence of adjacent transmitted frequencies provides missed-hop-correction capability for DFH system. For a system with 4 available frequencies and 1 bit per hop, the BER is 10^-5 when the signal-to-noise （SNR） is approximately 13. 6 dB over AWGN channels, while it is 10^-3 when SNR is approximately 33 dB over Rayleigh fading channels. Symbol-by symbol decoding is a practical decoding algorithm for DFH systems.