Delay Spread and its Effect on Bandwidth in Gaussian Parallel Relay Networks

We consider a Gaussian parallel relay network where multiple wireless relays forward cooperatively so that a destination receives a superposition of signals propagated through multiple distinct relay paths. Previous research often assumes that the relayed signals arrive synchronously in the receiver. This is not feasible in practical wireless networks, because spatial separation causes different propagation delays for the signal components and the destination observes a multipath channel. We model the effect of signal delays by introducing spatial separation to the network geometry and present trade-off analysis between diversity, signal bandwidth, relay density, and the number of relays for both narrowband and wideband reception at the destination