Energy efficiency in a delay constrained wireless network

This paper investigates the energy efficiency in a wireless channel with delay requirement. We address the energy efficiency transmission by considering both transmission power and circuit power consumptions based on the effective capacity approach. Effective capacity has been widely used to incorporate QoS requirements in the wireless communication and is an effective approach to modeling the physical layer wireless fading channel with the link layer parameters. We first derive the quasi-convex generalized form of energy efficiency formulation based on effective capacity under delay constraints. The general expression can be applied to various fading scenarios. We further develop a two-step binary search algorithm to find the best energy efficiency and the corresponding optimal transmission signal-to-noise ratio (SNR). The numerical results show that both the circuit power and queuing delay requirement have a big impact on the overall wireless channel energy efficiency.