Coverage improvement in femtocell networks via efficient utility pricing

Abstract

Employing femtocell technology noticeably improves both the indoor coverage and the overall cellular network's capacity. In the downlink scenario, when macrocell users (MUs) are far from the macro base station (MBS) and close to the femto access points (FAPs), the transmitted signals of FAPs to their users cause severe interference on MUs. One solution to overcome this issue is serving MUs by neighbouring FAPs. Generally femtocells are selfish and have no desire to allocate their resources to MUs. In this study, a framework to motivate femtocells to share their free resources with MUs is proposed. In this framework, the femtocells are assumed to belong to a specific unit. The unit encourages and manages the femtocells to share their resources, and in exchange receives a monetary utility from the MBS, and as a result improves the performance of the network. A computationally-efficient algorithm is proposed, which approximates the complete search algorithm, and their solutions coincide with each other in many cases. After FAPs assignment, the authors try to allocate the optimal power to MUs served by each femtocell to further improve their coverage probability through a bargaining game. The simulation results verify the performance of the proposed model and confirm the coverage improvement obtained in the network.