Cooperative wireless networks based on distributed space-time coding

The aim of this paper is to show how cooperation among nodes of a wireless network can be useful to reduce the overall radiated power necessary to guarantee reliable links among the network nodes. The basic idea is that if the links between cooperating nodes are sufficiently reliable, the cooperating nodes can transmit in a coordinated manner in order to emulate a virtual MIMO system that can yield considerable gains in terms of diversity or capacity. In this paper, we provide first a theoretical analysis of a single-user scenario showing how the cooperation gain is related to the spatial density of the cooperating nodes. Then, we compare alternative distributed space-time coding strategies aimed at achieving the promised advantages in a multi-user context.