单载波高速相干水声通信技术研究

Abstract

对单输入单输出系统(SISO)和单输入多输出系统(SIMO)单载波高速相干水声通信中时域判决反馈结合二阶数字锁相环路均衡技术进行了研究.采用低信噪比下鲁棒的稀疏水声信道估计算法(dAMP)估计信道,利用信道估计结果设计均衡器前馈、反馈阶数和均衡器初值,提高了系统鲁棒性.在厦门港进行了10kM距离高速水声通信实验,结果表明:在厦门港10kM距离,接收信噪比均值约为6db的环境下,4kbIT/S通信数据误码率均小于2%,传输图片清晰.结合多通道处理,误码率可降低到10-4数量级以下,提高了系统鲁棒性.

The research on time domain decision feedback of SISO and SIMO in the high speed coherent underwater communications combining with second order digital phase lock loop(PLL)equalization technology has been done.Using robust sparse underwater acoustic channel estimation algorithm(DAMP)to estimate channels under low SNR.Extracting these channel estimation results to design the feed-forward of equalizer,the feedback of order number,and initial value of equalizer to improve the robustness of the system.We conduct the 10km high-speed underwater acoustic communication experiment in Xiamen Harbor.Results show that 4kbit/s communication data bit error rate is less than 2%and the transmission image is legible under the circumstance of 10km from Xiamen Harbor and about 6dB of the receiving SNR.Bit error rate would be more than 10-4 lower with multi-channel processing.