一种降低复杂度的压缩感知水声信道估计方法

A reduced-complexity compressed sensing channel estimation for underwater acoustic channel

针对浅海的水声信道稀疏特性,提出了一种降低复杂度的前向回溯正交匹配追踪(RC-LABOMP)信道估计方法。首先计算正交匹配追踪和子空间追踪信道估计算法的两类支撑集,接着根据两类支撑集的交集和并集,预处理先验信息,最后利用先验信息完成前向回溯正交匹配追踪信道估计。该算法经过先验信息的预处理,能够减少原LABOMP算法的迭代次数,同时缩小原子的索引范围,因此能够显著降低原LABOMP算法的计算复杂度。此外,将提出的算法与水声Turbo均衡系统相结合,更适用于水声通信系统。仿真结果表明,所提算法在随机信道和水声信道条件下,具有估计精度高、误码率低的特点,同时能够显著降低LABOMP算法的计算复杂度,是一种适用于浅海水声信道的有效估计方法。

Aiming at the sparse characteristics of underwater acoustic channels for shallow seas,a reduced-complexity look-ahead backtracking orthogonal matching pursuit(RC-LABOMP)channel estimation algorithm was proposed.Firstly,two types of support sets of orthogonal matching pursuit and subspace pursuit channel estimation algorithms were calculated,and then prior information based on the intersection and union of the two support sets were preprocessed.At last,the preprocessed prior information was used to complete look-ahead backtracking orthogonal matching pursuit channel estimation.The preprocessed prior information leads to the decrease of the iteration number of original LABOMP,and reduction of the atom index range,thus the proposed algorithm can reduce the computational complexity of original LABOMP significantly.In addition,combining the proposed algorithm with the underwater acoustic Turbo equalization system is more suitable for underwater acoustic communication systems.Simulation results show that the proposed algorithm demonstrates high estimation accuracy and low bit error rate performance under both conditions of random channels and underwater acoustic channels.It also reduces the computational complexity of the LABOMP algorithm.Therefore,it is an effective method for shallow seas underwater acoustic channels estimation algorithm.