一种IQ delay不平衡估计与补偿方法

A Mothed for IQ Delay Imbalance Estimation and Compensation

在有线信道OFDM传输系统中,IQ不平衡一直是影响系统接收性能的一个重要因素。自从OFDM进入实用化以来,人们对IQ不平衡研究的比较多。但是大多都关注于IQ的幅度和相位的不平衡的研究。对于IQ时延不平衡(IQ delay imbal-ance)的研究则相对较少。IQ delay imbalance也会对系统的接收性能造成较大的影响。本文分析了IQ delay imbalanc对OFDM系统接收的影响,提出了一种在接收端存在IQ幅度和相位不平衡情况下估计和补偿接收端delay不平衡的方法。仿真结果表明,该算法可以改善系统的性能。

In OFDM（ Orthogonal Frequency Division Multiplexing） system for cable application, IQ imbalance is always an important factor to influence system performance. Although a lot of research has been done for OFDM regarding IQ amplitude and phase imbal- ance, IQ delay imbalance also has a big influence on system performance. In this paper, we analyze the affect of IQ delay imbalance, propose an algorithm to estimate the IQ delay imbalance and a method to compensate this affect. Simulation results show that the meth- od can improve system performance obviously.