水声信道下差分跳频信号检测的优化算法

A modified detection algorithm for underwater acoustic differential frequency hopping signals

为克服水声多途干扰影响,提出将差分跳频技术应用于水声通信,通过分析水声多途信道下差分跳频信号的特征,利用频率转移函数的隐含信息和水声信道的多途特征,优化了频率序列检测的Vitervi硬判决算法,并详细给出了算法流程.在含有加性高斯白噪声的多途信道下进行了仿真.结果表明,采用优化算法的系统性能得到显著提高,在频率检测差错率为10×10-3时,获得了近2.5 dB的增益,表明差分跳频体制能有效克服多途干扰,适用于水声通信.

Differential frequency hopping（DFH） was applied to underwater acoustic communications to overcome multi-path interference.After analyzing the characteristic of DFH signals,which had passed through underwater acoustic channels,a modified Viterbi hard-decision algorithm was proposed.It used the hidden information of the G function（frequency transfer function） and characteristics of the multi-path,and a detailed flow chart was worked out.The simulation results showed that the performance of a DFH system with the modified algorithm is better in a multi-path channel with additive white Gaussian noise（AWGN）.2.5 dB gain could result when the code error ratio is 10×10-3.These results proved that underwater acoustic DFH communication is feasible.