Optimal cooperative sensing and resource allocation in cognitive radio networks

In this paper, the problem of jointly designing sensing parameters (sensing time and sensing threshold) and resource allocation (spectrum and power) is investigated. A cognitive radio network (CRN) with multiple secondary users (SUs) and one potential frequency band is considered. SUs perform cooperative spectrum sensing and report their decisions to the fusion center. Then the fusion center determines the final decision of the status of frequency band. If the frequency band is idle, each SU is assigned a portion of the frequency band to transmit data. Taking the maximization of the CRN´s overall throughput as the design objective, the optimization problem is formulated subject to the total power constraint of the CRN and the average interference power to the primary network. An iterative algorithm is proposed to obtain a locally optimal solution. With the consideration of SUs´ fairness, we formulate another optimization problem which is to maximize the minimum throughput of SUs. Numerical results show that significant throughput gain is achieved through the joint optimization.