Distributed Interference Pricing Algorithm for Energy-Efficient Heterogeneous Networks with Rate Constraints

In this paper, we investigate the energy efficiency of downlink transmissions in heterogeneous networks (HetNets). Our objective is to satisfy the rate requirement of users while maximizing the energy efficiency of the network. We employ the fractional frequency reuse (FFR) scheme to increase the energy efficiency of downlink transmissions and to eliminate outages for the cell-edge users. The problem is decomposed into sequentially solved subproblems in the frequency and power domains. MaxMin Fair scheduler is incorporated to satisfy rate requirements of users. We propose an algorithm that is based on the LevenbergMarquardt method combined with Lagrange relaxation to solve the power control subproblem. In order to make the base stations further reduce intercell interference, interference pricing is applied. This scheme penalizes the utility of a base station with the interference it creates. The performance of the proposed algorithm is simulated in a Long Term Evolution (LTE) network. Our numerical results reveal that significant gains in terms of energy efficiency can be achieved with proposed algorithm. The outage probability is also reduced compared to the no power control and non-cooperative power control algorithms.