An Effective IQ Imbalance Compensation Scheme for MIMO-OFDM Communication System

MIMO communication systems can provide high channel capacity and is considered as a candidate for the next generation wireless systems. However, there is insufficient investigation about effects of the imperfection caused by the RF hardware on the MIMO systems. In this paper, we focus on the influence of the IQ imbalance on a MIMO-OFDM communication system. As a result, it is found that the IQ imbalance causes both inter-subcarrier and inter-stream interferences in the MIMO-OFDM system, and severely degrades the performance of the system. To combat this problem, a new extended channel matrix including the influence of IQ imbalance is introduced. Then the method of IQ imbalance compensation by using the extended channel matrix is proposed in this paper. The validity of the proposed IQ imbalance compensation scheme on the MIMO-OFDM system is investigated by computer simulation.