Maximizing degrees of freedom in wireless networks

Abstract

We consider communication from a single source to a single destination in a wireless network with fading. Both source and destination have multiple antennas. The information reaches the destination through a sequence of layers of single-antenna relays. A non-separation-based strategy is proposed and shown to achieve a rate equal to the capacity of a point-to-point multiantenna system in the high SNR regime. This implies that lack of coordination between relay nodes does not reduce the achievable rate at high SNR. We then derive the tradeoffs between network size and rate. We also derive the rate-diversity tradeoff for this network and study how it is affected by the network size. This shows that increasing network size is much more difficult when the codelength does not span a large number of fading realizations. Finally some implications to ad-hoc networks are discussed.