瑞利衰落信道下改进的OFDM符号定时算法  

An improved symbol timing recovery algorithm for OFDM systems in rayleigh fading channels

作　　者：吴赟[1] 罗汉文[1] 宋文涛[1] 

机构地区：[1]上海交通大学电子工程系,上海200240

出　　处：《电波科学学报》2006年第6期825-829,共5页Chinese Journal of Radio Science

基　　金：国家高科技研究和发展项目(2003AA12331007);国家自然科学资金项目(60272079)

摘　　要：对相干OFDM系统中结合循环前缀和导频信息的传统符号定时同步算法进行了分析和研究,提出了一种改进的符号定时同步算法。此算法相对于传统算法由于更加有效的利用了观察样本信息,具有更大的定时同步范围。同时考虑时间偏移参数在若干OFDM符号区间内不变,给出了一种利用连续多个OFDM符号的算法,以提高定时同步的准确度。仿真验证了所提出算法在瑞利衰落信道下可以有效地改进传统算法的定时性能。The conventional algorithm, which exploits both the redundancy in the cyclic prefix and available pilot symbols for symbol time recovery, is analyzed and an improved symbol time recovery algorithm is proposed. By utilizing the correlation property of the observation samples more efficiently, the proposed algorithm has a larger time offset estimation range. On the other hand, by considering the symbol timing offset as a fixed value over several OFDM symbol blocks, the estimation performance is improved further by using the information of the multiple OFDM symbol blocks. Simulation results demonstrate the proposed symbol timing recovery method in Rayleigh fading channel has an improved performance over the conventional algorithm.

关 键 词：OFDM 符号定时同步 最大似然函数 循环前缀 

分 类 号：TN929.5[电子电信—通信与信息系统]