Performance Analysis and Optimization of Cooperative Spectrum Sensing based on Soft Combination

The performance of cooperative spectrum sensing was analyzed based on soft combination of data fusion and decision fusion under both imperfect sensing channels and reporting channels in cognitive radio networks, and the closed expression of detection and false alarm probability also given. The optimal soft combination algorithm for maximizing the detection probability was proposed for further, in which the modified deflection coefficient used to obtain the optimal weighting vector based on the NP criticism. The simulation results indicate that the detection performance could be effectively improved by the optimal algorithm. Compared with data fusion, only a little detection performance loss exists in decision fusion.