Research On Multi-hop Relay Wireless Transmission Technology Based On Cache Assistance

With the rapid development of communication and Internet technology,wireless communication technology is facing great challenges.Multi-hop relay wireless network is an important transmission form of modern wireless communication,which can effectively improve the system transmission quality and system coverage.On the one hand,without the deployment of infrastructure,when the distance between the two sides of communication further increases,how to improve the communication quality of the two sides of communication has become a key problem in the field of wireless communication.As an effective technology to combat fading and improve the transmission reliability of the system,buffer-aided relay has attracted extensive attention in recent years.On the other hand,with the rapid development of wireless technology,massive information needs to be exchanged with each other through the transmission of wireless network.Due to the limitation of distance,when direct communication cannot be carried out,how to use the relay system to carry out efficient information interaction,improve the transmission quality of the system,and transfer information according to the different needs of both sides of the communication,so as to achieve efficient non-interference communication Wire transmission has become a key problem in the field of wireless communication.In this paper,multi-hop buffer-aided wireless network is taken as the research object,and the transmission technologies in the scenarios of multi-hop buffer-aided relay network and multi-hop buffer-aided two-way relay network are studied respectively.In this paper,the multi-hop buffer-aided wireless network is studied from three aspects: system model,transmission scheme and system performance analysis.Firstly,this paper introduces the main key technologies involved in the related research,buffer-aided relay technology,relay forwarding strategy,etc.Secondly,this paper focuses on buffer-aided multi-hop relay network,in which the source node and destination node transfer information with the help of buffer-aided relay nodes.In order to realize the information transfer between users when the source node and the relay node cannot communicate directly,a buffer-aided optimal three-hop relay design is proposed,in which two relay nodes are connected in series to forward the information to the destination node by decode-and-forward.The end-to-end achieved rate is maximized by fully considering the impact of data buffe and energy consumption,as well as meeting the average power constraint and peak power constraint.By using Lyapunov optimization framework,a multi-hop buffer-aided adaptive relaying(MHBAAR)scheme is proposed.According to the channel status information(CSI),buffer status information(BSI)and energy state information(ESI),the transmission mode selection and power allocation are adaptively adjusted.Based on this,an online distributed multi-hop bufferaided adaptive relaying(DMH-BAAR)scheme is proposed for general multi-hop relay networks.This scheme only needs local CSI,ESI and BSI to realize multi-hop buffer-aided adaptive transmission in a distributed way.This scheme is the key to realize multi-hop bufferaided adaptive relay design.Simulation results show that the proposed scheme can significantly improve the end-to-end achievable rate,and reveal the inherent tradeoff among transmission rate,power consumption and delay.Finally,the multi-hop buffer-aided relay network is further expanded,and the buffer-aided multi-hop two-way relay network is studied,in which two users exchange information by decode-and-forward with the help of two buffer-aided relays.Considering the limitations of average power and peak power,buffer-aided and energy consumption,and transmission mode constraints,this paper analyzes the sum rate maximization problem.Based on Lyapunov optimization framework,an online multi-hop buffer-aided twoway adaptive relaying(MH-BTAR)scheme is proposed.The transmission mode selection,power allocation and rate allocation are adaptively adjusted according to channel state information(CSI),buffer state information(BSI)and energy state information(ESI).The results show that the proposed scheme can significantly improve the average achievable rate region,and reveal the tradeoff relationship among transmission rate,power consumption and delay.The analysis results show that MH-BTWR scheme can significantly improve the average achievable rate area.The tradeoff among transmission rate,power consumption and delay is analyzed under the condition of multi-hop two-way buffer-aided relay network.In a word,the research work on multi-hop buffer-aided relay network in this paper has important reference value for exploring multi hop buffer-aided wireless relay network.The impact of buffer-aided on user scheduling,power allocation and transmission mode selection,as well as the trade-off relationship among transmission rate,power consumption and delay are revealed in this paper,which has reference and guidance value for the design of practical multi hop buffer-aided wireless relay communication system.