Performance optimization of cooperative spectrum sensing in cognitive radio networks

Cooperative spectrum sensing has been proposed to significantly improve spectrum sensing accuracy by taking advantage of the cooperation among multiple secondary users (SUs). Most of existing work assumes that all SUs have the same SNR values of primary users´ signal while the difference of SNR values among SUs, although it is very common in practice, is largely ignored. In this paper, we investigate two cooperative spectrum sensing scenarios where multiple geographically diverse SUs may have different SNR values. In the first scenario a cognitive radio network (CRN) with a single primary channel is considered. We aim to optimize the individual thresholds of SUs to maximize SU throughput subject to the constraint of missed detection probability. In the second scenario where there are multiple channels in a CRN, we jointly optimize the allocation of SUs to sense different channels and the individual detection thresholds of SUs. Our objective is to maximize total SU throughput over multiple channels while guaranteeing the missed detection probability below a given threshold. Simulation results demonstrate that our proposed schemes achieve significant improvements in SU throughput over the existing schemes.