Cloud-Based Topological Interference Management: A Case with No Cooperative Transmission Gain

We study the problem of managing interference in linear networks, with backhaul constraints that admit centralized allocation of messages to transmitters through the cloud. Our setting is that of a generic channel, where no channel state information is available at the transmitters. Knowing only the network topology, we characterize the optimal decisions for assigning messages to transmitters, given that each receiver is interested in one message that can be available at N transmitters. We show that using linear cooperation schemes, the per user degrees of freedom does not increase as we increase N beyond unity. Hence, we conclude for the considered problem that linear cooperative transmission does not increase the degrees of freedom.