CSIT-Adaptive Multiuser Resource Management for Space-Time Coded MIMO/OFDM Systems

Efficient resource management is a major issue in the operation of wireless communication systems given the limited resource availability. In contrast to most existing resource allocation techniques that assume perfect channel state information at the transmitter (CSIT), a novel adaptive resource management algorithm is proposed to optimize the spectral efficiency of a multiuser multi-input multi-output (MIMO)/orthogonal frequency division multiplexing (OFDM) system where only partial channel state information is available. With a space-time-block-coded beamformer employed at each mobile station, the proposed algorithm adaptively allocates subcarrier, bit, and power to realize efficient resource utilization. A distinctive feature of the proposed method is that the allocation strategy is directly related to the users´ spatial correlation and the quality of channel feedback information. Numerical results will show that the proposed scheme achieves significant throughput improvement compared to non-adaptive systems. It will be also demonstrated that our proposed method outperforms a scheme which decouples the allocation problem into single-user optimization problems by introducing user-grouping.