Interference Alignment in Partially Connected Interfering Multiple-Access and Broadcast Channels

We consider interference alignment (IA) in the L-interfering multiple access channels (MACs) network, a particular case of the partially connected interfering MACs network whereby the number of interference links per MAC is bounded regardless of the total number of MACs in the network. Conversely to the fully-connected case, we show that interference alignment can be achievable in a network of arbitrary size, while the per-user signaling dimension remains bounded. We provide necessary conditions for the feasibility of IA, discuss their sufficiency, and introduce an algorithm capable of providing practical solutions. These results also apply to the dual case of partially connected interfering broadcast channels (IBCs), and have practical applications to both the uplink and downlink of large cellular networks.