适用于恒定模值调制的OFDM系统的载波频偏跟踪算法  

Carrier Frequency Offset Tracking for Constant Modulus Signaling Based OFDM Systems

作　　者：许炜阳[1] 陆波[1] 洪志良[1] 

机构地区：[1]复旦大学专用集成电路与系统国家重点实验室,上海201203

出　　处：《小型微型计算机系统》2010年第5期1011-1015,共5页Journal of Chinese Computer Systems

基　　金：上海-应用材料与发展基金(0507);英特尔公司研究委员会共同资助

摘　　要：OFDM系统对载波频偏十分敏感.提出一种适用于恒定模值调制的OFDM系统的载波频偏跟踪算法.基于信道频率响应已经由帧前部的训练符号估算出来并且在一个帧内保持不变这一合理假设,本文证明可以通过最小化接收信号和已知信道频率响应的能量差来获得频偏估计.文中详细分析算法的可分辨性问题并且给出算法的简化形式.然后理论推导出算法估计的均值和均方差.最后分析了信道估计误差对算法性能的影响,结果显示本算法对信道估计误差不敏感.仿真结果表明较之于现有方法,该跟踪算法有更好的误码率性能.OFDM is vulnerable to the carrier frequency offset （CFO）. Presented a CFO tracking algorithm for constant modulus signaling based OFDM systems. Based on the reasonable assumption that the channel frequency response （CFR） has been estimated by training symbols and keeps constant during one frame,we prove that the CFO can be estimated through minimizing the power difference between received signal and the CFR. We analyze the identifiability problem and exploit the polynomial rooting method to simplify our algorithm. We derive the theoretical mean and mean square error （MSE） of the proposed method. Also,we analyze the effects of channel estimation error and show that the proposed algorithm is robust to this error. Simulation results show the performance improvement in terms of bit error rate （BER） to the existing methods.

关 键 词：OFDM 恒定模值调制 载波频偏跟踪 信道频率响应 

分 类 号：TP331[自动化与计算机技术—计算机系统结构]