Energy-optimized cooperative relay network over Nakagami-m fading channels

Recently, due to the exponentially increasing overall energy consumption of the wireless networks, much attention has been directed to the energy efficiency metrics and minimization of energy consumption, both in battery powered terminal devices as well as in infrastructure devices. In this article, we present an analysis of energy-optimized cooperative network where nodes in the environment share and coordinate their resources to relay the source signal, and compare the achievable performance with the reference performance of direct transmission alone. To improve the energy-efficiency further, the optimal power allocation (OPA) scheme to minimize the energy consumption under certain quality-of-service (QoS) constraint, namely destination symbol error rate (SER), over the Nakagami-m fading channels is derived. Stemming from these derivations, we show that depending on the fading parameter m, significant performance gain can be achieved over the equal power allocation (EPA) scenario and direct transmission schemes. Moreover, the effect of relay location on the energy efficiency over the Nakagami-m fading environment is investigated.