Energy-efficient subchannel allocation scheme based on adaptive base station cooperation in downlink cellular networks

An inter-cell interference (ICI) problem between co-channel BSs has been one of main challenging research issues in downlink cellular networks. Fractional frequency reuse (FFR) and BS cooperation are useful techniques to manage the ICI problem. By combining the BS cooperation and FFR techniques, we propose to determine an efficient cooperation mode and the type of subchannels, i.e., reusable subchannels or exclusively used subchannels. The optimization problem to minimize the total power consumption in a cooperative cluster is formulated while satisfying a given constraint in terms of the number of subchannels. When the number of users is 20, our proposed energy-efficient subchannel allocation (EESA) scheme consumes 21%, 25%, 43%, and 43% less power than the conventional resource minimization (RM), fractional frequency reuse (FFR), exclusive (EX), and full cooperation (FCO) scheme respectively. Moreover, our proposed EESA scheme outperforms the other four schemes in terms of outage probability.