Performance Analysis and Optimization of Multiselective Scheme for Cooperative Sensing in Fading Channels

We propose a multiselective sensing scheme where the primary-user (PU) activity is detected in cognitive radio through cooperation among the different sensing nodes and the fusion center. The proposed cooperative sensing scheme is based on order statistics of the reporting links between the cooperative nodes and fusion center where the links with high signal-to-noise ratios (SNRs) are selected as reliable reporting links. The performance of the proposed scheme is compared with other existing schemes in terms of the probability of detection and probability of false alarm over independent and identically distributed (i.i.d.) and independent nonidentical distributed (i.n.d.) Rayleigh fading channels. Both simulations and analytical results show that the proposed scheme outperforms conventional sensing schemes under different system parameters. Furthermore, we examine the optimum N-out-of-K rule of our scheme under different detection threshold and SNR. Our results show that the proposed multiselective scheme offers improvement in terms of the probability of detection when compared with other existing schemes, such as selection combining (SC), square-law selection (SLS), and general N-out-of-K rule.