Performance analysis of superior selective reporting-based energy efficient cooperative spectrum sensing in cognitive radio networks

We study the energy efficiency of superior selective reporting-based schemes for spectrum sensing in cognitive radio networks. We first consider the superior selective reporting (SSR) scheme proposed earlier in the literature, and derive the achievable throughput, energy consumption and energy efficiency (EE) of the SSR scheme. We propose the maximization of EE for the SSR scheme as a multiple variable-based, non-convex optimization problem and provide approximations to reduce it to a quasi-convex optimization. We highlight that the errors due to these approximations are negligible. The SSR scheme is designed to optimize the energy consumption, which enhances the EE. Alternatively, EE can be improved by increasing the achievable throughput. Towards this end, we propose a novel variation on the SSR scheme called the opportunistic SSR (OSSR) scheme, and carry out its EE analysis. We study the tradeoff between performances of the SSR and OSSR schemes - the implicit tradeoff between achievable throughput and energy consumption, and discuss the regimes where OSSR is preferred over SSR and vice-versa, in terms of the EE. Also, through an extensive numerical study, we show that both schemes outperform the conventional schemes that employ the OR and AND fusion rules, in terms of energy efficiency.