Research On Performance Of Hybrid Protocol In Wireless Energy Harvesting Communication System

In wireless sensor networks,it will cost a lot to replace the batteries manually.If the nodes are in a toxic environment or embedded in the building,it will be difficult or even dangerous to replace the batteries.In this case,harvesting energy from the environment has become a more safe and convenient choice.In addition to traditional energy harvesting methods(such as solar energy,wind energy,etc.),a new technology is to harvest energy from radio frequency(RF)signals.The advantage of this method is that it can realize Simultaneous Wireless Information and Power Transfer(SWIPT).For the energy-constrained three node SWIPT communication system,this paper mainly studies the outage probability and throughput of the system when the relay node adopts Hybrid Power-Time Switching based Relaying(HPTSR)transmission.In the hybrid protocol,one part of block time is used for energy harvesting and information processing,the other part is used for information transmission from the relay node to the destination node.In the block time part of energy harvesting and information processing,one part of the received signal is used for energy acquisition and the other part is used for information processing.The details are as follows:Firstly,in the three-node SWIPT system,there is no direct link between the source node and the destination node,and information transmission through the relay node is required.The relay node is a Decode-and-Forward(DF)mode relay,and is an energy-constrained node.It needs to harvest energy while acquiring information from the RF signal sent by the source node,and then use the harvested energy to forward the information to the destination node.In this paper,through theoretical derivation and analysis,the end-to-end outage probability and throughput of the relay using the hybrid protocol transmission are obtained,and the results are simulated and analyzed using MATLAB.The results show that the performance of the hybrid protocol is significantly better than the time switching relay protocol and the power splitting relay protocol.Secondly,in the three-node SWIPT system,a direct path exists between the source node and the destination node,and the relay node assists the source node in communication.The relay is a passive node and adopts a hybrid protocol.Its working mode is Amplify-and-Forward(AF).In this paper,the analytical expression and throughput of the system outage probability are obtained through theoretical derivation analysis.The outage probability of the system is verified and analyzed by MATLAB.The results show that the existence of the direct link can improve the system performance.