Efficiency and fairness aware resource allocations for energy and spectrum in downlink OFDMA systems

Energy has newly become a scarcer resource for the wireless networks, like spectrum. To utilise the limited resources efficiently and fairly in the downlink OFDMA systems, a novel resource allocation problem is investigated to make the balance between energy efficiency (EE) and spectrum efficiency (SE), the tradeoff between fairness and SE/EE. The problem is first formulated as an optimisation problem, which is NP-hard. Then, the existence of an optimal solution is proved, and an algorithm is designed to obtain the optimal solution. Finally, the numerical results show that the proposed algorithm achieves the SE-EE balance and provides a good tradeoff between fairness and SE/EE.