Abstract: Dynamic resource allocation algorithms are investigated for downlink multiuser Multiple Input Multiple Output Orthogonal Frequency Division Multiple Access and Space Division Multiple Access (MIMO-OFDMA/SDMA) systems. Firstly, a mathematical formulation is provided with the goal of maximizing throughput under various constraints. Secondly, since the optimal solution is difficult to obtain, the optimization procedure is divided into two steps. In the first step, a metric is derived to measure the spatial compatibility of users with multiple antennas, and then a scheduling algorithm is developed based on the proposed metric. In the second step, two suboptimal algorithms are developed to assign resources for the scheduled users. Simulation results demonstrate that proposed algorithms outperform random scheduling scheme. When combined with power reuse strategy, proposed algorithms obtain performances close to the optimal scheme based on user selection.