OFDM系统频偏自适应跟踪算法的研究  

Research of Adaptive Frequency Offset Tracking Algorithm in OFDM System

作　　者：莫宁春 蒋锋聚 田江 

机构地区：[1]上海美多通信设备有限公司,上海200333

出　　处：《现代电子技术》2008年第3期89-90,共2页Modern Electronics Technique

摘　　要：为了减小正交频分复用系统受频率偏差的影响,在OFDM系统中设计了一种新的载波频偏估计算法。频偏估计包括跟踪和捕获两个阶段,文中采用变步长自适应算法来进行跟踪,这个跟踪算法的捕捉范围是整个信号带宽的一半。通过此方法,不但可以利用前向纠错的方式来避免反馈,而且可以缩减复数乘法的次数以降低计算复杂度和系统功耗。该方法运算复杂度低,并具有较好的收敛性,能改善ODFM的解调性能。从计算机的仿真效果可以看出无论是在AWGN信道上还是在多径信道上都表现出了卓越的性能。To reduce the impact of carrier frequency offset in OFDM system, this thesis designs a new carrier frequency off- set estimation scheme for OFDM system. The carrier frequency offset estimation includes acquisition and tracking, we adopt variable step size adaptive algorithm. The acquisition range of the proposed algorithm is as large as one half of the overall signal bandwidth. Through this method we can not only avoid the feedback by using forward error correction, but also reduce the times of complex multiplication in order to reduce the power consumption of the system. This algorithm not only has low complexity and fast convergence nut also can improve the demodulation performance of OFDM system. Computer simulation illustrates the superior performance of the proposed algorithm with regard to estimation accuracy in both AWGN channel and multi - path channel.

关 键 词：OFDM技术 频率偏差 自适应跟踪 变步长自适应算法 

分 类 号：TN929.5[电子电信—通信与信息系统]