Abstract: Frequency synchronization has become one of the foci of the research in cooperative communication. Due to the nature of cooperative communications, multiple frequency offsets may occur. For this problem, a novel frequency synchronization algorithm ECR used for cooperative communication is proposed. Before forwarding signals to re-compensation frequency through a relay node, the frequency of the signals which are from relay node is consistent with the frequency of signals which are from the source node. So the frequency synchronization problem of destination node is predigested, as well as, the system will not become complex when the number of relay nodes is increasing. Simulation results show that the proposed synchronization algorithm can achieve better system performance in the cooperative communication system.

Key words: cooperative communication, frequency synchronization, frequency offset estimation

摘要： 在协作通信领域中频率同步已成为研究的焦点之一。由于其系统特性，载波频率偏移（Carrier Frequency Offset，CFO）普遍存在。考虑了协作通信系统中的多频偏估计问题，提出了一种新的用于协作通信系统的频率同步算法ECR，通过中继节点在转发前进行频率再补偿，使得中继节点转发的信号的发送频率均与源节点的发送频率保持一致，继而目的节点的频率同步问题得以简化，同时系统不会随着中继节点的增多而变得复杂。仿真结果表明，所提出的同步方法在协作通信系统中可以取得较好的系统性能。

关键词: 协作通信, 频率同步, 频偏估计