一种新的快速衰落信道相干时间估计方法  

A new approach for estimating the coherence time of fast fading distortion channels

作　　者：周晓萌[1] 侯朝焕[1] 鄢锦[1] 郝程鹏[1] 

机构地区：[1]中国科学院声学研究所,北京100190

出　　处：《应用声学》2010年第1期23-27,共5页Journal of Applied Acoustics

基　　金：国家自然科学基金资助项目(60802072)

摘　　要：快速衰落信道(FFD)是浅海中常见的畸变信道模型之一,通常用信道相干时间来描述其多普勒扩展程度。分段副本相关器(SRC)是FFD信道的最佳似然比检测器,但当信道相干时间未知时,其性能因失配受到较大影响。针对此种情况,提出了多重假设SRC,该方法能简单有效地估计FFD信道相干时间并解决SRC的失配问题。In shallow water sonar environment, one typical type of channel distortion is the fast fading distortion（FFD）, which is usually characterized by its coherence time. Under the FFD model, an echo from a target will encounter doppler spread, and the likelihood ratio test yields the segmented replica correlator（SRC） detector. However, when the coherence time is unknown, the SRC will not fully exploit its advantage because of mismatching. For this reason, a multihypothesis SRC is proposed. This multihypothesis testing could estimate the coherence time of the fast fading distortion channel, and improve the performance of the mismatched SRC.Simulation results show that the proposed multihypothesis SRC is simple, convenient, and feasible.

关 键 词：快速衰落信道 多普勒扩展 相干时间 多重假设SRC 

分 类 号：TN241[电子电信—物理电子学] TN929.5