‘n-ratio’ logic based cooperative spectrum sensing using double threshold energy detection

In this paper we describe a new cooperating sensing method using double threshold energy detection technique for cognitive radio. Each secondary cognitive user takes a local decision on spectrum occupancy based on two threshold energy detection and uses 1 bit information to convey its decision to the fusion center that collects decisions from all cooperating users who are able to detect presence or absence of signal. Fusion center takes a final decision using what we called dasian-ratiopsila logic. We will show that OR logic proposed in the literature is a special case of the dasian-ratiopsila logic decision. We derive the expression for probability of detection and probability of false alarm for our dasian-ratiopsila logic cooperating sensing method for additive white Gaussian noise (AWGN) and flat fading Rayleigh channels. Finally we present some results that shows improvement in spectrum sensing of the proposed method in comparison to OR logic, while keeping network overhead low.