Throughput Analysis In Cooperative Communication Based On Relay Energy Harvesting

In the wireless communication network,how to improve energy efficiency and information throughput has become a concerning issue owing to the rapid development of information technology.Generally,we are surround with radio frequency(RF)signals.If the relay node could harvest energy from the environment,forwarding the information using the collected energy.It can save the energy consumed by charging,and improve energy utilization efficiency.Meanwhile,it can also reduce the time which the relay node is charged,causing to the longer lifecycle of the entire wireless communication network.As the techniques for extracting energy and information forwarding in the RF signal is getting more and more mature,it provides practically feasibility for our proposal.This paper has an analysis of the system information throughput,based on different energy collection schemes on relay in the continuous and discrete time,which the source is equipped with the single antenna and dual antennas.Firstly,this paper propose a throughput analysis based on continuous-time energy harvesting with single-antenna at the source.Because the throughput in this protocol is usually low,and different energy harvest modes at relay will bring different effects.The following step is to propose a protocol based on discrete time energy harvest for relay nodes.Through the mathematic expression,we could acquire that the protocol is indeed superior to the continuous time energy harvesting protocol in performance analysis.The existed protocol based on the source transmitting RF signal with single antenna and the relay harvesting energy in discrete or continuous time,whose throughput couldn't meet the requirement under some high throughput cases.Thus we propose the protocol based the discrete and continuous time at source with double antennas—the source transmits RF signals through two independent antennas,and the relay harvests energy from the received RF signals.After the two antennas simultaneously transmit information,the relay forward the information under the condition that the harvested energy reaches the threshold.When both links are in outage,there is no information throughput.The time for information transmission increases in the entire time block,as the outage probability gets reduced and throughput gets improved.Finally,we have a simulation on the derived expressions,and the simulation results show that the throughput performance of the dual antennas is better than that of the single antenna under the same relay energy harvest mode.Regard of single-antenna or dual-antenna,the throughput in the discrete-time mode of the relay has a better performance than in the continuous-time mode.And when the relay transmission power threshold is-4 dBm,the throughput is the largest both for the discrete-time mode and continuous-time mode.