Weighted Bandwidth–Power Product Optimization in Downlink Femtocell Networks

Abstract

In order to develop a completely distributed resource allocation scheme to improve data rates and mitigate mutual interference across orthogonal frequency-division multiple access (OFDMA)-based femtocell networks, a space–bandwidth product (SBP) has been proposed as an effective measurement of network coverage. Intuitively, a femtocell minimizing its SBP tends to utilize subchannels experiencing less interference and will thus minimize its interference on other femtocells, which represents good self-organizing performance and enables a completely distributed resource allocation algorithm. However, for an OFDMA-based femtocell, most existing studies have applied the same weights on the bandwidth and the power without distinguishing the different significance on them. In this letter, we first formulate a weighted bandwidth–power product minimization problem for an OFDMA-based femtocell, applying different emphases on the consumed bandwidth and power while satisfying all users' data rate requirements. Then, in this direction, we further reformulate and iteratively solve this nonconvex problem via the Successive Convex Approximation for Low-complExity (SCALE) approach. Simulation results show that our proposed algorithm converges to stable solutions in a finite number of iterations.