Energy Efficiency Analysis and Power Allocation of Cooperative Communications in Wireless Sensor Networks

In order to improve the energy saving performance of cooperative communication, a novel power allocation solution, named Half Transmission Power Allocation Solution (HTPAS), is proposed in this paper. In this solution, the transmission power of the relay for forwarding the packet is half of the transmission power of the source. Based on the energy efficiency analysis, HTPAS outperforms the equal transmission power allocation solution in energy saving of relay and cooperation gain, meanwhile the proposed solution is easy to be implemented. The numerical results also show that the SDF cooperative transmission is more energy efficient than the direct and multi-hop transmission when the source-destination distances is larger than a small threshold.