Energy-efficient resource allocation in multi-user OFDMA systems

Energy efficiency is becoming increasingly important for wireless communications as mobile devices are battery-constrained. Unfortunately, the improvement in battery technology is much slow, leading to an exponentially increasing gap between the demand for energy and battery capacity offered. Motivated by this, in this paper we consider energy-efficient design of resource allocation for a multi-user OFDMA. Assuming full CSI at the transmitter, schemes of user selection, rate allocation and power allocation under QoS requirement are proposed to maximize the energy efficiency in unit of throughput per Joule. Simulation results demonstrate that the system energy efficiency of the proposed algorithms is close to the optimal performance without any constraints, while having low complexity.