基于KF和虚拟技术的最优盲水声信道均衡算法

Blind adaptive channel equalization algorithm for underwater acoustic communication based on KF and virtual technology

为了准确估计水声信道的多途数和多途时延,将虚拟技术和卡尔曼滤波(KF)盲自适应算法相结合,提出基于虚拟技术和KF的盲自适应水声信道均衡算法.采用虚拟技术将多途干扰和系统电噪声虚拟成环境噪声,基于最小均方误差(MMSE)准则下KF的最优估计特性,实现水声数据传输在信道环节的最优盲估计.短途水声通信试验(收发节点水平距离14 m,载波频率10 kHz,采样频率100 kHz,码元速率64.5 bit/s)和长途水声通信试验(收发节点水平距离5 km,载波频率6 kHz,采样频率48 kHz,码元速率11.8 bit/s)结果验证了所提算法的有效性.

As it is difficult to accurately estimate the number and time delay of the multipath,and electrical noise will occur when the system works,the underwater acoustic channels were complicated.Therefore,a virtual technology and Kalman filter(KF) blind adaptive algorithm were combined to construct a blind adaptive channel equalization algorithm both for short distance and for long distance underwater acoustic communications in this paper.The virtual technology treated multipath interference and electrical noise as environmental noise. And the optimal estimation of underwater acoustic data was achieved by using the optimal estimation property of KF under the minimum mean square error(MMSE) criterion. The satisfactory result of short distance(the horizontal distance between the source and receiver is 14 m,the carrier frequency is 10 kHz,the sampling frequency is 100 kHz,and the symbol rate is 64.5 bit/s) and long distance(the horizontal distance between the source and receiver is 5 km,the carrier frequency is 6 kHz,the sampling frequency is 48 kHz,and the symbol rate is 11.8 bit/s) experiments verify the effectiveness of the proposed algorithm.