Power Allocation for Downlink Path-Based Precoding in Multiuser FDD Massive MIMO Systems Without CSI Feedback

In this paper, a downlink path-based precoding method for multiuser FDD massive MIMO systems is studied. Due to the huge feedback overhead of acquiring channel state information at the transmitter (CSI-T), FDD massive MIMO was usually considered impractical. In order to enhance the feasibility of such systems, a recent work proposed a precoding method without requiring CSI feedback by taking advantage of FDD reciprocity. Here, a power allocation scheme aimed at minimizing symbol error rate (SER) of each user is proposed for improving this method. Simulation results confirm that the proposed scheme improves the SER performance.