作为一种降低因水声多途引起的码间干扰的有效手段,水声信道均衡技术正引起广泛关注.现有的算法中,最小均方算法及其变型因其计算量低而被广为应用.而采用平行滤波器组的变步长法可提高该算法在时变环境中的性能,却未出现该类算法在水声信道动态阶数下的性能研究.本文提出将滤波器步长和长度双参数进行调节的平行滤波器组用于时变水声信道均衡.双参数调整机制能有效增强算法对时变水声信道的容忍度.仿真和真实数据的实验验证了新算法的优越性.As a potentially effective method to mitigate inter symbol interference caused by multi-path,channel equalization of underwater acoustic communication has attracted considerable attention.Among existing algorithms that can be found in the literature,the classic least mean square(LMS)and various variants of it are of particular interest for practical implementation due to their low computational complexity.However,as the variable step size as well as the parallel filter bank structure can improve the performance of LMS type algorithms under time varying environment,there is a lack of investigation on their adaptability to the dynamic order of underwater acoustic channels.In this paper,a new dual-parameter,adjustable method is presented which embeds the variable step size and filter length into the parallel filter bank LMS algorithm for equalization of time varying underwater acoustic channel.The mechanism of dual parameter(step size and filter length)adjustment ensures that the proposed algorithm has better tolerance upon the time variations caused by either specific coefficients or the order of the channel response.Both numerical simulations and real data experiments show that the performance of the new method outperforms the classic methods.NationalNaturalScienceFoundationofChina(11274259); NaturalScienceFoundationofFujianProvince;China(2011J01275); ScienceandTechnologyProjectofXiamenCity(3502z20113008
