A Joint Unitary Precoding and Scheduling Algorithm for MIMO-OFDM System with Limited Feedback

Abstract

The capacity of MIMO-OFDM system can be increased substantially through spatial multiplexing with linear unitary precoding technique which requires that full channel state information should be sent back to transmitter. To reduce the feedback overhead, we give a codebook of precoding matrices that is known to both transmitter and receiver. A matrix is selected at the receiver, and then its index is conveyed to the transmitter using a small number of bits. In this work, we propose a new proportional fairness scheduler integrated with unitary precoding for MIMO-OFDM downlink system. The system-level simulation results show that the proposed scheduler achieves a better balance between optimizing cell throughput and guaranteeing fairness among users than other existing scheduler.