Transmitter cooperation in interference channel with delayed CSIT

In this work we study the impact of limited transmitter cooperation on interference management in two-user interference channel. In particular, we consider the two-user interference channel with delayed channel state information at the transmitters (delayed CSIT). We first present a model to capture and quantify the amount of cooperation between the transmitters. In this model we denote the fraction of shared messages that are intended for Rx₁, Rx₂ by ρ₁,ρ₂, respectively, and then, characterize the degrees of freedom (DoF) region as a function of ρ₁, ρ₂. As a result, the two-user interference channel and two-user multiple-input single-output (MISO) broadcast channel become special cases of no cooperation (ρ₁ = ρ₂ = 0) and full cooperation (ρ₁ = ρ₂ = 1) in our framework. Moreover, our result indicates that the maximum benefit of cooperation from the DoF perspective is achieved by sharing only half of the messages between the transmitters.