Resource allocation for multiuser MIMO-OFDM systems with various suboptimal detectors

Abstract

The performance of multiuser multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) systems can be significantly improved by using efficient resource allocation schemes. There are a lot of resource allocation schemes to maximize the system capacity. However, under a practical circumstance of employing a suboptimal MIMO detector, optimizing for maximum capacity may not be proper. In this paper, we investigate resource allocation schemes to minimize the bit error rate (BER) for various suboptimal detectors, including the zero forcing (ZF) detector, the successive interference cancellation (SIC) detector, the lattice reduction (LR) based ZF detector, and the LR based SIC detector. For the ZF and SIC detectors, we study the subcarrier allocation among users and power allocation over subcarriers and antennas. The optimal algorithm is investigated and a suboptimal scheme with low complexity is proposed for each detector. For the LR based ZF and SIC detectors, we propose suboptimal schemes with allocating power equally over antennas. Simulation results confirm that the proposed scheme improves the BER performance for each detector.