Capacity Improvement via Phantom Cells

Vastly increasing capacity and coverage demand in communication networks accompanied by energy efficiency challenge is getting attraction in research topics. Phantom cells based heterogeneous networks (HetNets) is a new idea which proposed to fulfil these requirements in the next generation cellular networks. In this paper, the resource allocation problem in an orthogonal frequency-division multiple access (OFDMA) based Macrocell/Phantom cell heterogeneous network is investigated in downlink path. Specifically, a proper algorithm is presented in order to maximize the total throughput of all phantom cell users equipments with regard to the protected minimum network capacity of the existing macrocell. To fulfil the objective goal, an iterative approach is employed in which OFDM subchannels and power transmitted by base stations are sequentially assigned and optimized at each step for each frequency band. It is showed that the overall joint subchannel and power allocation algorithm converges to local maximum of the original designed problem. Performance improvement of proposed algorithm is confirmed by numerical results