Online Detection and SNR Estimation in Cooperative Spectrum Sensing

Cooperative spectrum sensing has proved to be an effective method improve the detection performance in cognitive radio systems. This work focuses on centralized cooperative schemes based soft fusion of energy measurements at radios (CRs). In these systems, likelihood ratio test (LRT) is optimal rule, but sufficient statistic depends local signal-to-noise (SNR) CRs, which are unknown most practical cases. Therefore, problem becomes a composite hypothesis test. The generalized LRT popular approach those Unfortunately, mobile environments, its well below because energies measured under varying SNRs. this work, we present new algorithm that jointly estimates instantaneous SNRs and detects presence primary signals. Due adaptive nature, suited for scenarios where time-varying. Simulation results show close realistic conditions.