A Multi-Frequency-Point Algorithm for Frequency-Selective IQ imbalance Estimation in Massive MIMO System

Massive MIMO is a key technology of future wireless communication systems to obtain high data rate and high spectrum efficiency. However, our effort was destroyed by hardware nonlinearity including IQ Imbalance especially. When spectrum in usage is wide, frequency dependent IQ imbalance is more serious and it is difficult to combat with the performance degradation caused by that. In this paper, we proposed a method based on interpolation of sub-band results to mitigate the effects of frequency dependent IQ imbalance, which is independent with modulation method of data symbols and has higher channel rate. The theory analysis and simulation results both show that our algorithm can decrease the estimation MSE, and improve the overall performance including data rates and spectrum efficiency proofed by simulation.