一种新的恒模信号OFDM系统的盲频偏估计算法  

Novel blind carrier frequency offset estimation algorithm for OFDM systems with constant modulus signaling

作　　者：周游[1] 朱世磊[1] 胡捍英[1] 

机构地区：[1]解放军信息工程大学,郑州450002

出　　处：《吉林大学学报（工学版）》2014年第5期1512-1516,共5页Journal of Jilin University:Engineering and Technology Edition

基　　金：'863'国家高技术研究发展计划项目(2012AA01A502;2012AA01A505)

摘　　要：载波频偏(CFO)的存在直接影响正交频分复用(OFDM)系统的性能,为了提高CFO的估计精度,提出一种新的适用于恒模信号OFDM系统的盲频偏估计算法。该算法假设连续两个OFDM符号之间的信道变化缓慢,根据相邻OFDM符号各子载波的信号功率差建立代价函数,通过使得代价函数最小化完成CFO的盲估计。通过理论分析获得了该代价函数的闭式解,从而达到有效降低算法复杂度的目的。仿真结果表明:所提算法在高信噪比下与经典算法相比具有较高的估计精度,且对信道阶数变化具有鲁棒性。Carrier Frequency Offset （CFO） has great influence on the performance of OFDM system. In order to improve the accuracy of the CFO estimation, a novel blind CFO estimation algorithm is proposed for OFDM systems with constant modulus signaling. It is assumed that the channel changes slowly in time domain. The cost function based on the difference between signal powers of the two consecutive OFDM symbols in the frequency domain is derived, and the blind CFO estimation is accomplished by minimizing the cost function. Closed form solution to the proposed cost function is given theoretically, which greatly reduces the complexity. Simulation results show the performance of proposed algorithm is better than that of the classical one in high SNR circumstances, and it is robust to the changing order of channel responses.

关 键 词：通信技术 恒模信号 正交频分复用 盲频偏估计 代价函数 闭式解 

分 类 号：TN929.5[电子电信—通信与信息系统]