A Rate-Difference Based Energy-Efficient Resource Allocation Algorithm for Downlink OFDMA Systems

For the limitation of resource and the requirement of environment, energy-efficient OFDMA systems gradually play an important role in wireless communication. In this paper, we present a novel resource allocation algorithm for downlink energy-efficient OFDMA systems, under the given QoS requirement and power limitation constraints. Compared with the existing works, we propose a sub carrier and power allocation scheme from the perspective of rate-difference and suggest a simple algorithm to find the solution with fewer iteration times. The algorithm includes two parts: the Rate-Difference Based Sub carrier Assignment Algorithm (RBSA) and the Rate-Difference Based Power Allocation Algorithm (RBPA). It can be seen that the general trend of maximum energy efficiency decreases with larger ε and fluctuates between the maximum value and zero, where ε is the proportional power parameter. The simulation results show the significant improvement of energy efficiency with the proposed schemes and demonstrate the effectiveness of the proposed algorithms.