Linear Fusion of Interrupted Reports in Cooperative Spectrum Sensing for Cognitive Radio Networks

Interrupted reporting has recently been introduced as an effective method to increase the energy efficiency of cooperative spectrum sensing schemes in cognitive radio networks. In this paper, joint optimization of the reporting and fusion phases in a cooperative sensing with interrupted reporting is considered. This optimization aims at finding the best weights used at the fusion center to construct a linear fusion of the received interrupted reports, jointly with Bernoulli distributions governing the statistical behavior of the interruptions. The problem is formulated by using the deflection criterion and as a nonconvex quadratic program which is then solved for a suboptimal solution, in a computationally-affordable fashion, by a semidefinite relaxation technique. The system performance is then demonstrated by a set of numerical results which compare the performance of the system for the cases with and without the optimal linear fusion.