Optimal Linear Cooperative Spectrum Sensing for Wideband Cognitive Radios

This paper proposes two optimal cooperative wideband spectrum sensing schemes for cognitive radios. Multiple cooperative secondary users serve in the cognitive radio network to provide space diversity for spectrum sensing. After the fusion center acquires the optimal fusion weights, a global threshold is utilized to obtain the final global decision. Since the proposed optimal cooperative sensing scheme requires precise estimations of primary user signal strengths and the noise variances, an improved sensing algorithm is also proposed to facilitate the practical implementation. Simulations illustrate the proposed schemes significantly improve the spectrum sensing performance and outperform the conventional equal gain combining scheme. The proposed sensing algorithm can effectively implement the optimal cooperative sensing scheme.