Layered Feedback Design for Close-Loop MIMO System

In close-loop MIMO system, transmitter can obtain instantaneous CSI by a feedback link from receiver. Then the CSI is used to beamform or precode the transmitting signal, achieving performance gain. In real application, limited codebook will lead to quantized error and loss of performance, so optimized feedback design becomes the key of close-loop MIMO system. Current feedback schemes are analyzed in this paper. To the questions of them, layered feedback is proposed. These feedback schemes are simulated in link level simulation to compare the performance of MIMO system. Simulation results show that, for different spatial correlations, comparing to current feedback schemes, the proposed feedback can obtain lower PER and higher capacity, with 1 or 2dB SNR gain, generally.