Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Xiamen 361005, China.
J Acoust Soc Am. 2010 Feb;127(2):909-19. doi: 10.1121/1.3278604.
The deconvolution of multipath underwater acoustic channel with a large time-delay spread is investigated. The channel deconvolution involves estimating the multipath time-delays and attenuation factors from a noisy received signal consisting of multiple overlapped signals. Similar to conventional deconvolution methods, the proposed method estimates channel impulse response based on least-squares criterion. However, the proposed method harnesses the sparse structure of an underwater acoustic channel, and script-l-norm of the channel impulse response is adopted as the cost function to be minimized. In addition, the available a priori knowledge of support constraint and attenuation factor constraint are imposed and channel deconvolution problem is converted to a convex optimization problem. Instead of employing the existing standard algorithms, which require huge storage space and high computational complexity, a simple iterative algorithm for solving the optimization problem with fast convergence rate and low complexity is developed. The computational complexity of the proposed algorithm is O(N log(2)(N)) per iteration with N being the length of the received signal. Simulation results confirm that the proposed method provides better performance in terms of temporal resolution and robustness to noise compared with other extant multipath channel deconvolution techniques.
研究了具有大时散扩展的多径水声信道的反卷积。信道反卷积涉及从由多个重叠信号组成的噪声接收信号中估计多径时延和衰减因子。与传统的反卷积方法类似，所提出的方法基于最小二乘准则估计信道冲激响应。然而，所提出的方法利用了水声信道的稀疏结构，并且采用信道冲激响应的script-l-范数作为要最小化的代价函数。此外，施加了支持约束和衰减因子约束的可用先验知识，并且将信道反卷积问题转换为凸优化问题。与需要巨大存储空间和高计算复杂度的现有标准算法不同，开发了一种具有快速收敛速度和低复杂度的用于求解优化问题的简单迭代算法。所提出的算法的计算复杂度为每迭代 O(Nlog(2)(N))，其中 N 是接收信号的长度。仿真结果证实，与其他现有的多径信道反卷积技术相比，所提出的方法在时间分辨率和抗噪声鲁棒性方面具有更好的性能。
