Research And Application On Outage Performance Of Cognitive Relay Network With Energy Harvesting

Nowadays,with the development of wireless communication technology,a variety of wireless communication applications and wireless communication devices are emerging.This makes the wireless communication business explosive growth trend,resulting in a shortage of spectrum resources and a serious phenomenon of wireless link blockage.At the same time,the increase of wireless traffic makes the energy consumption of wireless users or wireless devices become more and more serious.How to improve the spectrum utilization and solve the energy consumption is one of the most urgent problems to be solved.The research of this paper is based on the technology of cognitive relay network with energy harvesting.Cognitive radio technology and cooperation communication technology consist of the cognitive relay network technology,which not only has the advantage of high diversity gain,but also improves the utilization of spectrum resources.The wireless energy harvesting technology,which collects energy from the surrounding radio frequency signal and provide a certain protection for the effective use of energy.The integration of wireless energy harvesting technology and cognitive relay network not only solves the problem of shortage of spectrum resources,but also improves the energy efficiency of the system.In this paper,we study the performance of cognitive relay networks under different fading environments based on the wireless energy harvesting and wireless communication protocols.The main contents of this paper are summarized as follows:For the cognitive one-way relay network,the transmission performance of the network is studied over the ?-? fading environment,and some new results are obtained.Specifically,the closed expression for the outage probability of primary user is derived,which is suitable for integer fading parameters.An integral form solution for the outage probability of secondary user is also obtained.The analysis and simulation results verify the accuracy of the theoretical analysis,and all the theoretical results can be used to guide the design and optimization of the cognitive relay communication system over ?-? fading channel.For cognitive communication system with multi relay,we study the transmission performance under Rayleigh fading channel,according to the relay selection strategy that the relay harvests maximum energy will be selected.The outage probability of primary user and secondary user are derived.In this paper,a closed-formed expression for the outage probability of the primary user is obtained.The experimental results show that the outage probability of primary user and secondary user will be affected by the number of relay users.However,in the same conditions,the performance of the secondary user improved is greater than that of the primary user.For the cognitive two-way relay system,the transmission performance of wireless communication network is studied over Nakagami-m fading channels.First,for integer fading parameters,we derive the closed-formed expression for the outage probability of two primary users.Then we derive a closed-formed expression for the upper bound of the outage probability of the secondary user.Analysis and simulation results show that the secondary user does not need to supply additional energy in the cognitive two-way relay network,and does not affect the quality of communication of primary users under the condition of taking power in proper proportion,also can obtain the reasonable outage performance.