  Vastly increasing capacity and coverage demand in communication networks
accompanied by energy efficiency challenge is getting attraction in research
topics of this area. In this paper, an improved structure of Phantom cell
heterogeneous networks (HetNets) is proposed to fulfil these requirements in
the next generation cellular networks.It will be shown that the proposed
orthogonal frequency-division multiple access (OFDMA) based structure can be
employed in both indoor and outdoor environments by applying two individual
frequency bands. Furthermore, the resource allocation problem of the proposed
structure is investigated in downlink path. To this aim, 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 every single 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 the proposed algorithm is confirmed in both indoor
and outdoor environments by numerical results.
