A dynamic resource allocation scheme in femtocell networks considering user mobility

This paper addresses the spectral efficiency in dynamic femtocell networks, where users leave and/or enter their serving femtocells frequently. The overall system bandwidth is divided into several subchannels. The spectral efficiency would be decreased if no appropriate resource allocation designed to manage the topology variation due to user mobility. We thus propose a three-step dynamic frequency allocation algorithm to manage the co-channel interference more effectively. First, a weighted clustering of femtocells is centrally utilized to avoid the co-channel interference among clusters. Secondly, each FBS assigns subchannels to its served users. Thirdly, if there is a new user and no available subchannel for assignment, spectrum stealing is processed by reusing a subchannel, which belongs to another cluster while satisfying the interference constraints. Numerical results demonstrate that the proposed algorithm can not only enhance the system throughput but also decrease the outage probability of user accesses.