Relaying and Power Control Strategy for 2-Hop Distributed Cooperative Communication

This paper analyses the effect of relay node and the importance of power allocation scheme in cooperative relay networks. It is shown that adding relay node alone is not sufficient to improve system performance. Under a simplest scenario where relay node adopts decode and forward relaying, direct transmission may perform better under certain cases with equal total power constraints. Furthermore, in practical scenario when source node has to transmit its message to relay node before cooperatively transmitting it to destination, the existence of relay node may even degrade system performance. By adopting the right relaying technique and proper power allocation scheme, it is shown that cooperative relay transmission can be made strictly better than direct transmission.