Relay selection scheme based on propagation delay for cooperative underwater acoustic network

In recent research of wireless communication, the concept of cooperative diversity has been put forward and used widely. A number of transmission schemes designed for radio communications could not be directly applied to underwater network, where channel characteristics are more complicated. In this paper, we consider a situation comparatively closer to the realistic underwater acoustic communication and investigate the relay selection problem. Considering the long propagation delay caused by low speed of sound, we design a cooperative transmission scheme. In this scheme, the network chooses the optimal relay or the suitable number of nodes adapting to the changes of underwater circumstances. Then the signal-to-noise ratio (SNR) is added to the criterion of relay selection to realize a more effective algorithm.