Maximizing throughput of cognitive radio networks with limited primary users' cooperation

We consider a point-to-multipoint cognitive radio network that shares a set of channels with a primary network. Within the cognitive radio network, a base station (BS) controls and supports a set of fixed wireless subscribers. The objective is to maximize the downlink throughput of the cognitive network without affecting the performance of primary users. For this, we propose a mixed distributed/centralized control algorithm that requires minimal interaction between cognitive and primary devices. First, a distributed power updating process is employed at the cognitive and primary nodes to maximize the coverage of the cognitive network while always maintaining the constrained signal to interference plus noise ratios (SINR) of primary transmissions. After that, centralized channel assignment is carried out within the cognitive network to maximize its downlink throughput. Numerical results are obtained for the behaviors and performance of our proposed algorithm.