Optimal muting ratio for Enhanced Inter-Cell Interference Coordination (eICIC) in HetNets

We calculate the optimal muting ratio for time domain Enhanced Inter-Cell Interference Coordination (TDM eICIC) in a downlink HetNet scenario, consisting of macrocell and femtocell users. First we derive analytically the optimal muting ratio in a simplified scenario, and identify a particular case where all macro users are either strongly or not at all affected by the presence of femtocells. In this case, the optimal muting ratio can be calculated from parameters that can be simply estimated by the network. Furthermore, we solve by numerical optimization the optimal muting ratio in a simulated HetNet scenario, and find that most of the network instances are described by this particular case. We conclude that in a typical femto-macro heterogeneous network, an optimal muting ratio can be approximated by a simple calculation based on parameters that can be estimated by the network.