Primary user capacity maximization in cooperative detection network using m out of N fusion rule

Cooperative detection is a well accepted notion for alleviating the “hidden terminal problem” in cognitive radio (CR) networks. Furthermore, a number of CRs cooperating with each other significantly boosts the reliability of identification of any spectral opportunity. We consider a situation in which the primary user (PU) of the spectrum tries to communicate at a maximum possible rate with the primary receiver which could be a base station (BS) in presence of an N number of energy detector based CRs. Deploying the m out of N fusion rule at the BS, we formulate the problem of allocating the total PU power across its different transmission slots in a bid to maximize the PUBS capacity such that the fused probability of detection is lower bounded by a specific level guaranteeing a prescribed reliability of detection. The problem is shown to possess convexity and is solved to allocate the available PU transmission power optimally. Analysis of m out of N fusion rule on the PU capacity and on the fused detection probability is presented. The effect of time-bandwidth product of the energy detector on the system metrics is also analyzed.