Layered Interference Networks With Delayed CSI: DoF Scaling With Distributed Transmitters

The layered interference network is investigated with delayed channel state information (CSI) at all nodes. It is demonstrated how multihopping can be utilized to increase the achievable degrees of freedom (DoF). In particular, a multiphase transmission scheme is proposed for the K-user 2K-hop interference network to systematically exploit the layered structure of the network and delayed CSI to achieve DoF values that scale with K. This result provides the first example of a network with distributed transmitters and delayed CSI whose DoF scales with the number of users.