Non-coherent wireless networks

Current wireless networks estimate network state including channel strengths and topology through training. In point-to-point channels the cost of training is small for large coherence times and is ignored typically. But in a network the channels states may be needed at a different location in a network. In relay networks the destination needs to know the channel states at the relays for achieving close to capacity rates. We study the problem of how to operate wireless networks accounting for the network learning costs. The weak and strong links in the network are quantified using generalized degrees of freedom (gDoF) charecterization, and we study which links to use and how to estimate the channel states for best gDoF performance for the network. The cut set bound analysis of the network leads to the non-coherent MIMO problem and its gDoF is studied. Novel strategies are developed for achieving the gDoF in relay networks and non-coherent MIMO with varied link strengths.