Interference Alignment With Finite Extensions in Partially Connected Networks
Abstract: In this paper, we investigate the interference alignment (IA) for a class of partially connected multi-input input multi-output multi output heterogeneous networks, which consist of L fully connected pico cells, J partially connected pico cells, and one macro cell. In particular, ular, we investigate the feasibility of IA conditions with no channel extensions, T-independent independent channel extensions, and T-dependent T dependent channel extensions, respectively, for the single beam case. We present three theorems to characterize some necessary conditi conditions, which L, J, T, and the channel diversity order L$ must jointly sa&sfy when IA condi&ons are feasible feasible. These necessary conditions also implicitly impose the constraints on the upper bounds of achievable degrees of freedom with different channel extensions. extensions.