C-RAN协作通信系统中基于正交预编码的同步算法

在C-RAN(Centralized,Cooperative,Cloud RAN)无线网络架构中，协作多点传输受到符号定时偏差和载波频率偏差的影响。为了降低联合传输协作系统对异步信号的敏感性，将正交预编码的同步算法应用到联合传输协作系统中。首先，发射机发送经过重复编码和正交预编码矩阵处理后的数据信息；然后，接收机利用特定的接收矩阵，实现分离相互叠加的异步协作信号；最后，完成对协作信号载波频率偏差和符号定时偏差的估计和补偿。理论分析和仿真结果表明：该方法能够有效解决协作传输中信号异步问题，改善系统性能。

A synchronization algorithm based on orthogonal pre-coding in C-RAN cooperative communication system

Cooperative multi-point processing(CoMP) technology is influenced by symbol timing offset and carrier frequency offset in the wireless network infrastructure centralized,cooperative,cloud radio access network(C-RAN). In order to reduce the sensitivity to asynchronous signal in joint transmission system,the orthogonal pre-coding synchronization algorithm is used to mitigate the effect of asynchronous signals. Firstly,the transmitter sends data which has been processed by repetition coding and orthogonal pre-coding matrix. Then,the receiver estimates and compensates the frequency and time offset for the cooperative signals which been separated by a particular accepting matrix. Simulation results demonstrate that this method can effectively solve the problem of asynchronous transmission and improve the performance of collaborative transmission systems.