MIMO-OFDM通信系统中频域均衡方法消除ICI干扰

通过对MIMO-OFDM系统模型的分析,尝试了两种对抗由于信道的时变和频率选择性引起的ICI干扰的频域均衡方法。本文利用了MIMO-OFDM通信系统的ICI干扰模型的特点,采用逐个分组做频域均衡的方法,而非一个符号一个符号地均衡。仿真结果表明,这两种方法在一定程度上改善了系统性能。

Frequency Domain Equalization Techniques to Mitigate ICI in MIMO-OFDM Systems

Orthogonal Frequency Division Multiplexing(OFDM) systems require a perfect orthogonality between subcarriers,and the failure to maintain orthogonality between subcarriers can cause severe Inter-Carrier Interference(ICI),which would significantly degrade the system performance.The ICI may come from two sources:one is the Doppler spread of the channel due to the movement,i.e.channel parameters are time-variant within a transmission OFDM block and the other is the synchronization errors(e.g.,frequency offset).The mitigation of ICI due to the time-variant frequency-selective channel is an important and challenging problem in mobile communications, especially for MIMO systems.In this paper two frequency-domain equalization techniques to fight against ICI are introduced in the time- variant channel in MIMO-OFDM systems through the analysis of the system model.Due to the characteristics of ICI in MIMO-OFDM systems,the equalization techniques are applied block-by-block instead of symbol-by-symbol.Simulation results are presented and the BER performance of the two candidate techniques are compared.