Energy-efficient resource allocation in ultra-dense networks

In this paper, we propose a novel energy-efficient resource allocation scheme based on the orthogonal frequency-division multiple-access (OFDMA) in downlink ultra-dense networks (UDNs). To reduce the computational complexity, then it is decomposed into two subproblems: subcarrier allocation and power allocation. First, we propose subcarrier allocation algorithm based on the user resource proportional fairness under given power allocation. Second, we employ a quantum-behaved particle swarm optimization (QPSO) algorithm to solve the power allocation problem under the assumption of known the subcarrier allocation. Simulation results demonstrate that the proposed algorithm can achieve higher energy efficiency (EE) than the conventional particle swarm optimization (PSO) approach and the equal power allocation algorithm.