The University of British Columbia

In this paper, we present an extension to our previous work on distributed space-time block coding where we considered cooperative networks with a large set of single-antenna decode-and-forward relays N. Here, we consider the general case where each relay node is equipped with NT antennas and the destination node has NR antennas. It is assumed that at any given time only a small, a priori unknown subset of nodes S C N is active. In the proposed scheme, the signal transmitted by an active node is the product of an information-carrying space-time block code (STBC) matrix, which is identical for all nodes, and a unique node signature matrix. It is shown that existing STBCs designed for Nc ge; 2 co-located antennas are a favorable choice for the code matrix guaranteeing a diversity order of d = min {NcNR, NTNSNR} if ns nodes are active. Simulation results show that a considerable gain can be achieved by using multiple-antenna nodes even if the antennas are highly correlated.