瑞利衰落信道中OFDM自适应频率同步算法

提出了一种新的频偏差值表达式,在此基础上构造了自适应跟踪算法,对频偏进行跟踪,从而减小OFDM系统中载波频率偏差对系统性能的影响,并运用该算法对瑞利衰落信道中多种时变频偏的情况进行了仿真,获得了频偏跟踪曲线.理论分析和仿真结果表明,由于算法复杂度低,收敛速度快,对时变频偏的跟踪达到了较好的效果.将跟踪到的频偏补偿后,提高了系统解调性能.

Adaptive Frequency Offset Synchronization Algorithm for OFDM in Rayleigh Fading Channels

Carrier frequency offset (CFO) has severe influences on the performance of OFDM systems. To alleviate this effect, a new expression for the difference between estimated and actual values of CFO is proposed and upon which an adaptive frequency offset tracking algorithm established. Simulation is carried out to study tracking performance of the proposed algorithm for several types of time-varying frequency offsets in a Rayleigh fading channel. The tracking curve and MSE are presented. Theoretical analysis and simulation results confirm that the algorithm has low complexity, fast convergence and good tracking performance. Demodulation performance of OFDM systems can be improved after CFO is compensated.