Optimized collaborative spectrum sensing in energy harvesting cognitive radio networks

Abstract

We study the probability of error optimization problem in collaborative spectrum sensing (CSS) with limited time and energy resources in energy harvesting cognitive radio (CR) networks. The frame structures for sensing and data transmission, if the spectrum is identified as vacant, are both supposed to be fixed. This implies that the time resource dedicated for CSS is limited and shared between spectrum sensing time and results reporting time, which depends on the number of sensing users. We consider an optimization problem containing network constraints on time and energy resources for an energy harvesting secondary user (SU) which cooperates with other users using an ‘OR’ fusion rule. It is assumed that the SU, with arbitrary signal to noise ratio, is in energy deficit regime and a predefined constraint on probability of collision is satisfied to protect the cooperative network performance quality. We analytically prove convexity of the considered optimization problem ensuring a global solution can be obtained. Analytical results in addition to simulation results are provided to prove our claims.