基于LS的OFDM零中频接收机IQ不平衡数字补偿技术

I/Q imbalance digital compensation based LS method for OFDM zero IF receivers

零中频接收机已成为未来无线终端发展潮流,但是零中频的结构会引入较大的射频损伤;本文首先介绍了射频I/Q不平衡时对高斯以及频率选择性信道下OFDM接收机性能的影响;通过特殊导频设计,解耦合I、Q路的相互影响;如此可以方便地估计和补偿射频I/Q不平衡对高斯以及频率选择性信道的影响。仿真表明本文所示方法大大提高了OFDM零中频接收机的性能。

Zero IF receiver becomes the trends about the wireless terminals. However, zero IF architecture suffers from greater RF impairment. The paper introduces the effect of I/Q imbalance about OFDM receiver in AWGN and frequency selective fading channel firstly; And through the particular pilot structure, the interaction of I and Q paths is decomposed; Thus, the effect of I/Q imbalance is estimated and compensated in AWGN and frequency selective fading channel conveniently. The simulation results show that the above method greatly improves the performance of the zero IF OFDM receiver.