MIMO DS／CDMA系统中基于信号周期平稳特性的频偏盲估计算法

A Blind Frequency Offset Estimating Based on the Signal's Cyclostationarity in MIMO DS/CDMA System

MIMO DS／CDMA通信系统中,每对收发天线间的载波频偏各不相同,这使得频偏估计变得异常困难。该 文基于DS／CDMA信号的周期平稳特性提出了一种适用于该系统的频偏盲估计算法。该算法主要特点在于:(1)它 能够分别估计每对收发天线间的载波频偏;(2)综合利用了信号在所有非零周期频率处的周期自相关函数值;(3)它 是一种盲估计算法,不需要专门的训练序列,不会降低系统的带宽利用率。仿真结果表明在FIR信道模型下,该 算法能够准确地估计出系统中各个收发天线对间的载波频偏。

In MIMO DS/CDMA systems, the different transmit/receive antenna pairs have different frequency offset, which increases the complexity of the frequency offset estimating. Based on the cyclostationarity of the signal, a blind frequency offset estimating is proposed in this paper. The advantages of the estimating are： （1） it can separately estimate the frequency offset of the different antenna pair; （2） It is a blind estimator and does not need training sequence which lower the efficiency of the wireless bandwidth; （3） It can fully utilize the cyclic correlation of the received signal at all nonzero cyclic frequency. The simulation results provided in this paper show that the estimating has good performance in the FIR channel environment.