Analytical investigation on DL MU-MIMO performance with increased feedback bits

Abstract

This paper investigates downlink MU-MIMO for further improvement using an analytical method. The method shows that the potential benefit for MU-MIMO with increased feedback is strongly dependant to channel frequency selectivity. The introduced codebook with 8- and 12-bt PMI cases are shown to exploit the structure to significantly lower the complexity of PMI searches. Link level simulations confirm our findings.