Reliable detection of the existence of primary users is a primary requirement for the minimization of interference to existing primary networks. Cognitive radio (CR) systems need to detect the presence of licensed primary user (PU) reliably. Spectrum sensing is one of the systems which checks the vacancy of primary user designated to particular frequency spectrum. Cooperation among multiple CRs helps to enhance the reliability of detection of the PU in case of unreliable decision by a single CR due to channel uncertainties. In a real communication environment, the local sensing performance of individual users may severely degrade due to deep fading/shadowing. In this paper, we consider cooperative spectrum sensing (CSS) based on energy detection in cognitive radio networks (CRN) which uses soft combination of the observed energy values from different CRs. More precisely, we study CSS with soft data fusion scheme namely, Equal GainCombining (EGC) that can be implemented at fusion centre (FC). The performance of CSS has been assessed under AWGN Channel.
Cognitive radio, Spectrum Sensing, SNR, radio-frequency spectra, Energy detection, Equal gain combining
