Optimal Power Allocation for Relayed Transmission through a Mobile Relay Node

Relayed transmission is an interesting topic in cooperative diversity. Some researchers propose power allocation schemes for relayed transmission by only considering transmission through a fixed relay node. In our paper, we analyze a relayed transmission through a mobile relay node. We build up a transmission system model and determine the long term distribution characteristics of the movement of the mobile node. We also calculate the time-varying data rate for transmission through the mobile relay node and demonstrate the improvements due to mobility. Moreover, we illustrate the optimal power allocation for relayed transmission through the mobile relay node. Our results show that under some practical data rate requirements, we have 3 dB gain compared with transmission under even power allocation.