OFDM系统的两种频率跟踪算法的性能比较  

Performance Comparison of Two Frequency Tracking Algorithms for OFDM Systems

作　　者：蓝兴[1] 李颖[1] 魏急波[1] 

机构地区：[1]国防科技大学电子科学与工程学院,长沙410073

出　　处：《无线通信技术》2005年第1期13-17,共5页Wireless Communication Technology

摘　　要：本文分析了残余频偏对OFDM系统性能的影响,针对OFDM系统中常见的两种频率跟踪算法,比较了它们在加性高斯白噪声信道、SUI- 2和SUI- 5信道环境下的性能。仿真表明,采用计算相位旋转的频率跟踪算法比基于循环前缀的频率跟踪算法的估计精度高。在信道最大多径时延较循环前缀长度小时,两种算法对系统性能影响均较小;在信道最大多径时延接近循环前缀长度时,基于循环前缀的频率跟踪算法的估计误差的标准偏差通常超过子载波间隔的1 %。In this paper the effect of residual frequency offset (RFO) on OFDM systems is analyzed. The performance of the two frequency tracking algorithms based on phase rotation calculation and cyclic prefix (CP) are compared in AWGN, SUI-2 and SUI-5 channels. Simulations show that the performance of frequency tracking algorithm based on phase rotation calculation is better than the other. If the length of channel-impulse response is shorter than that of cyclic prefix, both of the algorithms have little influence on OFDM systems. Otherwise, the standard deviation of the RFO estimation based on cyclic prefix exceeds 1% sub-carrier spacing, which causes an obvious SNR lost.

关 键 词：正交频分复用 残余频偏 频率跟踪算法 OFDM系统 

分 类 号：TN929.53[电子电信—通信与信息系统]