Research On Relay Selection Scheme For Energy Harvesting Wireless Cooperative Communication

Energy harvesting has always been an effective technology to solve energy problems in wireless networks.The development of radio frequency energy harvesting has greatly extended the service life of the network and expanded the application range of wireless sensor networks.When the distance between nodes is far apart,wireless cooperative communication networks are proposed and widely studied.The wireless cooperative communication network can increase the throughput of the network by increasing the diversity gain,and the cooperative communication network has good flexibility and feasibility.Diversity technology is a basic technology in wireless communication systems to combat fading and improve transmission performance.In a cooperative communication network,how to choose a relay node to forward data from a source node to a destination node is a problem that deserves attention.There are generally two ways to choose a relay node.One is to select one among multiple nodes.The best relay node forwards data.The other is to directly select multiple relays from multiple relay nodes for data forwarding.This thesis will select single relays in a system scenario based on double buffer queues.To conduct research with multi-relay selection,the main work of this article is as follows:First of all,research on single relay node selection,this thesis proposes a double buffer queue energy capture network relay node selection strategy,the design of data packets to the source node and data packets from the source node to the relay node into two queuing models,By analyzing the average delay of the data packets in the source node and the relay node,an appropriate relay node is selected to forward the data packet.This thesis also gives the state transition balance equation of the data packet in the system,and finds the state probability of the data packet in the steady state,so as to obtain the average delay of the data packet in the system.Finally,a complete relay node selection algorithm is given.Numerical simulation verifies the effectiveness of this strategy.Then the research on the selection of multiple relay nodes is carried out.In order to prevent the sub-optimal results caused by the selection of a single relay node and toconform to the trend of today's big data,multiple relay nodes are selected on the basis of single relay selection.Collaborative forwarding of data.Find all the relay nodes that minimize the average transmission delay of the relay nodes,and then use these nodes as the required target nodes.According to the system model,the mathematical model of the cache queue is given.The average delay when the system reaches the steady state is used to find all the satisfied relay nodes that reach the minimum average delay.Based on the minimum average transmission delay,a cache queue-based algorithm is proposed.Multi-relay node selection strategy.Finally,the feasibility of this strategy is verified by numerical simulation.