基于时域过采样的OFDM频偏校正体制

A Carrier Synchronization Technique for OFDM Based on Time Oversampling

本文提出了一种新的适用于OFDM调制体制的频偏估计算法,这种算法建立在时域信号两倍过采样的基础上.它对过采样后产生的奇、偶序列做FFT变换,利用奇、偶序列所产生频域序列在不同子载波处的相关性,首先估计出整数频偏(是指最接近归一化频偏的整数部分) ,进行校正,然后通过跟踪环路完成小数频偏跟踪(是指归一化频偏的绝对值小于0 .5的部分) .这种算法不依赖于信道,所以同样适用于频率选择性衰落信道,仿真证明,所提出的算法在衰落信道情况下,仍能纠正较大的频偏.

This paper presents a new frequency offset correction technique for OFDM receivers,which is based on time oversampling.The proposed technique uses the correlation property of frequency domain sequences corresponding to odd and even sequences.It estimates integer frequency offset first,then it uses the tracking loop to track the fraction frequency offset.This technique doesn't depend on the channel,so it adapts to multipath fading channel.Simulation demonstrates that proposed method can still correct large frequency offset under multipath fading channel.