Coordinated Uplink Scheduling and Beamforming for Wireless Cellular Networks Via Sum-of-Ratio Programming and Matching

Abstract

This paper proposes a joint uplink scheduling, transmit power and beamforming optimization algorithm for a multiple-input multiple-output (MIMO) wireless multicell network. We show that coordinated uplink user scheduling and transmit optimization can significantly alleviate intercell interference, thereby improving the cell-edge rates in a multicell network. Unlike the downlink case, coordinating uplink transmission in a multicell network is significantly more challenging, because uplink intercell interference depends strongly on the schedule and beamformers of neighboring cells. The main contribution of this paper is the recasting of the problem in terms of sum-of-ratio programming and a subsequent quadratic reformulation which allows scheduling and beamforming to be optimized through solving a matching problem. This problem reformulation also provides a new interpretation of the well-known weighted minimum mean square error (WMMSE) algorithm. Simulation results show that the proposed approach significantly outperforms both the WMMSE algorithm and the existing per-cell scheduling approach of assuming fixed interference pattern from neighboring cells.