Degrees of freedom region for an interference network with general message demands

We consider a single hop interference network with K transmitters, each with an independent message and J receivers, all having the same number (M) of antennas. Each receiver requests an arbitrary subset of the messages. This generalizes the well-known K user M antenna interference channel, where each message is requested by a unique receiver. For this setup, we derive the exact degrees of freedom (DoF) region. Our achievability scheme generalizes the interference alignment scheme proposed by Cadambe and Jafar ´08. In particular, we achieve general points in the DoF region by using multiple base vectors and aligning the interference at each receiver to its largest (in the DoF sense) interferer. As a byproduct of our analysis, we recover the DoF region for the original interference channel.