CSI Feedback for Imperfect Multi-Polarized Massive MIMO System

The leakage between two polarization directions can be substantial if the number of transmit antennas (<i<T</i<x) at eNodeB increases significantly. As a result, these codeword models may not be as efficient as in current MIMO system. In this paper, the characteristics of practical dual-polarized massive MIMO system with imperfect channel was investingated. To improve CSI accuracy, a multi-component feedback scheme was proposed, in which two CSI components target the perfect part and imperfect part of polarized channel respectively. A linear combination of the two components was assumed at both eNodeB and UE. Moreover, efficient feedback models were also formulated for the two parts. Finally, the performance of the proposed scheme is evaluated through extensive simulation.