相关干扰情况下MIMO系统频偏的测量与补偿

摘要

准确的频偏测量与补偿对于MIMO系统获得好的性能具有重要作用.在实际的环境中,信道中可能还存在空间相关的干扰.如果将相关干扰按白噪声来处理,那么频偏测量与补偿的精度会下降.如果干扰相关矩阵已知,它可直接用于频偏测量以提高精度;而通常情况下,干扰相关矩阵是未知的,对于这种情况提出一种迭代的频偏测量方法,以迭代方式估计和利用干扰相关矩阵,使频偏测量精度不断得到提高.频偏补偿分成粗补偿以及基于锁相环的精补偿,并在锁相环中加入干扰抑制处理.仿真结果表明,本文方法可以有效提高相关干扰情况下MIMO系统频偏测量与补偿的精度.%Accurate frequency offset measurement and compensation is important for MIMO (multiple input multiple output) system to achieve good performance. In real environment, spatially correlated interference may exist in the channel. If the correlated interference is treated as white noise, the accuracy of frequency offset measurement and compensation will be degraded. The covariance matrix of interference can be directly used in frequency offset measurement to improve the accuracy provided that the covariance matrix is known. However,in general case, the covariance matrix of interference is unknown. In this case, an iterative frequency offset measurement method to improve the accuracy by estimating and utilizing the covariance matrix of interference in iterative way is presented. The compensation for frequency offset is divided into course compensation and precise compensation based on phase locked loop with the process of interference suppression. Simulation re-suits show that the method is valid to improve the accuracy of frequency offset measurement and compensation for MIMO system in the presence of correlated interference.