Adaptive joint subchannel and power allocation for multi-user MIMO-OFDM systems

Abstract

In this paper, we investigate the resource allocation issue in spatial-multiplexing based downlink multiuser multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. The key issue is the allocation of subchannels and power among users to share the system. Previous literature mainly focus on maximizing capacity but ignore the intrinsic coverage shrinkage problem in a MIMO system. Particularly, we formulate a system with larger coverage and link reliability under a proportional rate requirement among users. To alleviate the complexity of jointly optimal subchannel and power allocation, we at first propose two suboptimal subchannel allocation algorithms, namely, user-oriented and subchannel-oriented allocations. We next propose a low-complexity power allocation method.