(An) efficient resource allocation in OFDMA hybrid femtocell networks

Abstract

Femtocell networks are defined as low-power wireless access points that operate in the licensed spectrum to connect standard mobile devices to a mobile operator’s network using residential DSL or cable broadband connections. In femtocell networks, electromagnetic interference is the major obstacle for service providers to deploy femtocell networks on existing macrocells. In recent days, interference mitigation by access control methods has been proposed. The hybrid access method provides the advantages of the open access method and the closed access method by proper resource sharing between subscribers and non-subscribers. But re-source sharing between subscribers and non-subscribers in the hybrid access method has not been studied actively up until now. Therefore, this paper proposes a quantitative guideline for femtocell resource allocation between subscribers and non-subscribers considering both enhancing network service quality and main-taining service satisfaction level of subscribers. To do this, network service quality is expressed as the sum of an individual user utility function and, in addition to the utility function, a price effect is also considered to express the service satisfaction level of subscribers and an additional cost for improving the network service quality. Considering these facts, first, a formulation of the price compensated network utility maximization problem is proposed. Also, a low complexity algorithm, which is called the maximum utility improvement method, is proposed to solve the given problem. Simulation results present a performance comparison of the solution from the proposed algorithm and an optimal solution. The proposed algorithm gives a sub-optimal solution with a performance difference of less than 2 % of the optimal solution within reasonable computation time. Simulation results also show that the network service quality is improved with price compensation due to efficient resource allocation.