Cooperative Diversity in Wireless Relay Networks with Multiple-Antenna Nodes
It is known that multiple antennas can greatly increase the capacity and reliability of a wireless communication link in a fading environment using space-time coding. Recently, with the increasing interest in ad hoc networks, researchers have been looking for methods to exploit spatial diversity using the antennas of different users in the network. The authors exploit spatial diversity using the repetition-based and space-time cooperative algorithms. The mutual information and outage probability of the network are analyzed. However, in their model, the relay nodes need to decode their received signals. A network with a single relay under different protocols is analyzed and second order spatial diversity is achieved.