Power control and allocation for MIMO broadcast channels in cognitive radio networks

This paper considers multiple-input multiple-output broadcast channels in cognitive radio networks which consist of a cognitive base station (CBS), K secondary users (SUs) and N primary users (PUs). The multiantenna-based CBS concurrently operates with the PUs. The channel state information for SUs is assumed to be perfectly known at the CBS. To ensure the quality of service of PUs and maximize sum-rate capacity of SUs, two problems are considered: (1) What is the optimal power control of CBS? (2) What are the optimal power allocations of SUs? A two-level game is presented to jointly consider the benefits of power control of CBS and power allocations of SUs. Under this game model, the corresponding game algorithms are also proposed. Finally, numerical simulation results are provided to examine the performance of our proposed algorithms.