CAJ | 학술논문

现有水声通信中的多普勒估计方法一般都假定多径信道每条路径的多普勒因子相等，当各路径多普勒因子存在差异时，该类方法往往无法正确估计出每径的多普勒因子，导致补偿后的信号存在较大误差。为此该文在分析水声信道稀疏特性的基础上，提出一种基于稀疏表示理论的非一致多普勒估计方法。该方法结合水声多径信道与非一致多普勒稀疏特性生成包含信道信息的超完备字典，将每径的非一致多普勒因子估计转化为基于超完备字典的稀疏重构求解，实现非一致多普勒因子的准确估计。仿真结果表明，所提方法不仅能估计出差异较大的非一致多普勒因子，而且对于大多普勒频偏的估计也相当有效，特别适合于高速移动水声通信中的多普勒估计。
현유수성통신중적다보륵고계방법일반도가정다경신도매조로경적다보륵인자상등，당각로경다보륵인자존재차이시，해류방법왕왕무법정학고계출매경적다보륵인자，도치보상후적신호존재교대오차。위차해문재분석수성신도희소특성적기출상，제출일충기우희소표시이론적비일치다보륵고계방법。해방법결합수성다경신도여비일치다보륵희소특성생성포함신도신식적초완비자전，장매경적비일치다보륵인자고계전화위기우초완비자전적희소중구구해，실현비일치다보륵인자적준학고계。방진결과표명，소제방법불부능고계출차이교대적비일치다보륵인자，이차대우대다보륵빈편적고계야상당유효，특별괄합우고속이동수성통신중적다보륵고계。
The existing methods of Doppler estimation in UnderWater Acoustic (UWA) communication generally assume that the Doppler factor of each path is equal in multipath channel. But when the Doppler factors are different from each other, such methods can not estimate the Doppler factor correctly, resulting in significant compensation error. By analyzing the sparsity of the UWA channel, a novel method of non-uniform Doppler estimation is proposed, which is based on the sparse representation theory. By using the over-complete dictionary combining UWA multipath channel and non-uniform Doppler sparsity, the method transforms Doppler estimation of each path into sparse solution reconstruction, achieving accurate estimation of non-uniform Doppler factor. Simulation results show that the proposed method can estimate not onlythe quite different Doppler factors but also the large Doppler frequency offset. Therefore, it is especially important for Doppler estimation in high-speed mobile UWA communication.