Timing Synchronization in Decode-and-Forward Cooperative Communication Systems
Timing Synchronization in Decode-and-Forward Cooperative Communication Systems
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DOI：
10.1109/tsp.2008.2011834
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发表时间：
2009-04
影响因子：
5.4
通讯作者：
Xiao Li;Yik-Chung Wu;E. Serpedin
中科院分区：
文献类型：
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作者：
Xiao Li;Yik-Chung Wu;E. Serpedin
协作通信系统由于在使用单天线终端的同时具有良好的性能增益，近年来引起了人们的广泛关注。本文研究了协作中继系统中的联合定时和信道估计问题，并进一步研究了多个定时偏差的消除问题。定时和信道的估计分两个阶段进行，并推导出这两个阶段的克拉美-罗界（CRB）。证明了传统的CRB在衰落条件下对定时参数是无效的，并提出了一个新的界称为加权贝叶斯CRB。在定时和信道估计的基础上，提出了一个通用的滤波器设计框架，以补偿目的地的多个定时偏移。所提出的方法被应用到不同的情况下，具有不同程度的定时不对准，并在数值上显示出提供优良的性能，接近完美同步的情况下。
Cooperative communication systems have attracted much attention recently due to their desirable performance gain while using single antenna terminals. This paper addresses the joint timing and channel estimation problem, and furthermore the resynchronization of multiple timing offsets in a cooperative relay system. The estimations of timing and channel are conducted in two phases and the associated Cramer-Rao bounds (CRB) are derived for both phases. It is demonstrated that the conventional CRB is not valid for timing parameters under fading conditions, and a new bound called weighted Bayesian CRB is proposed. With the timing and channel estimates, a general framework of the resynchronization filter design is developed in order to compensate the multiple timing offsets at the destination. The proposed methods are applied to different scenarios with varying degrees of timing misalignment and are numerically shown to provide excellent performances that approach the perfectly synchronized case.