A novel resource allocation algorithm for multiuser downlink MIMO-OFDMA

In this paper, dynamic resource allocation problems for multi-user downlink MIMO-OFDMA are investigated. With the goal of minimizing the total transmit power under condition that QoS of different users can be guaranteed, a novel dynamic resource allocation algorithm is proposed. First of all, a new subcarrier allocation policy is given based on the perfect CSI. And then a spatial subchannels grouping mechanism is proposed for bit allocation. In order to utilize the spatial resource efficiently, the proposed algorithm exploits all non-zero spatial subchannels to transmit data. The proposed scheme reduces the computational complexity significantly at little expense of the system performance. Numerical simulations show that the proposed algorithm is a good tradeoff between system performance and computational complexity.