Energy-Saving Relay Selection Of Wireless EH Cooperative Communication System

In the traditional wireless cooperative communication system,because of the power supply from the grid,the relay selection does not need to consider whether the power of the nodes is enough.In recent years,Energy Harvesting(EH)node using renewable Energy to provide their own power,has the characteristics of low carbon environmental protection,at the same time reduce the dependence on the grid,communication system and wireless EH collaboration system of communication research has received the widespread attention.In wireless EH cooperative communication system,mobile relay node brings flexibility to network deployment,and EH relay node just provides possibility for the mobility of relay node.Mobile relay nodes need to rely on their own collection of energy to provide electric drive,while collecting energy is random changes,so the relay node for collecting energy using a crucial,collaboration and traditional wireless communication system of relay nodes don't have the ability to EH and relay factors to consider when the choice is relatively small.Based on this,the energy saving relay selection in the wireless EH cooperative communication system was studied in this paper,and the following progress was made:Firstly,in the wireless EH cooperative communication system composed of grid-powered source nodes,EH relay nodes and battery-powered target nodes,an energy-saving relay selection method was proposed to optimize the transmitted power of source nodes and relay nodes in view of the potential energy bottlenecks and data congestion in EH relay nodes.Different from existing methods,this method is based on EH relay node energy collection situation determine the transmission power of EH relay nodes,then the source node and EH was derived using the relationship between the relay node transmission power ratio of the transmitted power source node,select channel capacity of the largest relay link for data forwarding,considering both the source node and EH relay node transmission power constraint.The mathematical expressions of the average channel capacity and interrupt probability are derived.Simulation results show that the energy efficiency and average channel capacity of the proposed method increase with the increase of average channel gain,and the interruption probability of the system decreases with the increase of average channel gain.The proposed method can effectively improve the system performance and save the energy of the source node while making reasonable use of the energy collected by the EH relay node.Secondly,in the wireless EH cooperative communication system composed ofgrid powered source nodes,EH relay nodes and battery-powered target nodes,an adaptive energy-saving relay selection method is proposed considering that the source nodes transmit at fixed power.This method deduces the transmitting power of EH relay node from the transmitting power of source node according to the maximum channel capacity criterion,and then calculates the energy storage due to EH relay node according to the length of time slot.The EH relay node that meets the energy requirements is the candidate relay node,and a relay node that meets the speed requirements and saves the most energy is selected for data forwarding.When there is no candidate relay node,the combination of several EH relay nodes that meet the rate requirement and save the most energy is selected for data forwarding.The simulation results show that the average channel capacity and energy efficiency of the system increase with the increase of the average channel capacity,and the interrupt probability decreases with the increase of the average channel capacity.And have good performance,have application value and practical significance.