Reducing Impact of Phase Noise on Accuracy of Measured MIMO Channel Capacity

Despite the fact that time-division multiplexed switching (TDMS) based multiple-input multiple-output (MIMO) wireless channel sounders are cost effective implementation techniques, they may result in significant measurement errors due to phase noise (PN) in the local oscillators. In this paper the impact of PN on the accuracy of measured MIMO channel capacity is studied by considering its effect on both the spatial multiplexing gain and on the power gain. We show that in case of a low rank physical channel matrix the PN impact is more pronounced on the spatial multiplexing gain than on the power gain. Based on that we propose an eigenvalue filtering (EVF) technique to improve the accuracy of measured channel capacity. Numerical results supporting our theoretical observations are presented.