分组M元扩频Pattern时延差编码水声通信

Grouping M-ary spread spectrum with Pattern time delay shift coding used in underwater acoustic communication

针对水声通信中通信速率和频带利用率不高的问题,提出将M元扩频技术与Pattern时延差编码相结合,将多进制扩频码作为Pattern波形进行时延差信息调制,在接收端利用拷贝相关器解出信息,提高了系统的通信速率和抗干扰能力;在此基础上又提出了分组扩频的概念,对发送端扩频码进行有效分组,利用其良好的正交性,将各组挑选出的扩频码并行传输,进一步改善系统的通信速率和频带利用率.在信道水池内进行了通信实验,在2.5 kHz带宽内,M元扩频PDS系统通信速率为91 bit/s,分组M元扩频PDS系统可达302bit/s,误码率为1×10-4,实验结果验证了该系统的可行性和鲁棒性.

There are the low ratio of band utilization and the low information rate in the underwater acoustic（UWA） channel.The scheme for M-ary spread spectrum combined with Pattern time delay shift（PDS） coding is proposed.Spread spectrum（SS） code was chosen as pattern wave for time delay coding and information bits were decoded by copy correlator in the receiver.Thus system＇s information rate and anti-jamming capability were improved.The novel concept of grouping spread spectrum was put forward.SS codes were divided into several groups effectively and the candidate codes from each group were transmitted in parallel for the superior relativity.The information rate and ratio of band utilization were improved further.The communication experiment was implemented in the UWA Channel Laboratory.M-ary SS system information rate is 91 bit/s in 2.5 kHz band.But in the same band Grouping M-ary SS system is up to 302 bit/s and bit error rate is 1×10^-4.The feasibility and robustness of the system were validated through the experienmental results,which is helpful to the Middle/Long range UWA communication.