Adaptive Subcarrier, Bit and Power Allocation for MIMO-OFDMA Systems

Abstract

This paper investigates the subcarrier and power allocation for multiple-input multiple-output (MIMO)-orthogonal frequency division multiple access (OFDMA) systems in order to optimize the system-level performance subject to the constraints of the total power on each subcarrier and rate requirement of each user. With attempt to solve the subcarrier allocation and bit loading nonlinear programming problem, two novel adaptive subcarrier, bit and power allocation schemes are proposed to determine subcarriers for each user and then assign the bits and power for each subcarrier. The first one has higher complex, but achieves a much better performance than the second one. Simulation results show that both the proposed schemes exhibit perfect system performance compared with static resource allocation method, especially under high signal to noise ratio (SNR) condition.