The Research Of Transmission Plan And Relay Selection Optimization Scheme In Wireless Cooperative Communication System

With the rapid development of modern wireless communication, future technology will turn tofaster communication rate, higher system capacity and spectrum efficiency. But multi-path fading ofwireless channel is the main reason affecting its development. Cooperative relay technology canovercome the negative impact of multi-path fading effectively as the fastest growing key technology.As a virtual MIMO, it will be a key technology to solve the future wireless communicationdevelopment bottleneck through wireless network cooperation between the nodes and sharingtransmission path. And the choice of technology collaboration relay nodes is the most importanttechnology. Research report shows that, it can improve communication performance only accordingto the system requirements for relay nodes. But there are still exiting defect research in the field. Ithas a great development prospect and great practical significance to research on relay coordinationtechnology. This paper is mainly researching on relay coordination communication networks. Bebased on traditional scheme, it puts forward a new type of relay selection optimization scheme, newresearch on collaboration communication relay selection algorithm, the analytical cooperativecommunication performance and the relationship between the number of relays. The specificcontent and innovation of this paper as follows:Firstly, this paper introduces the basic wireless cooperative communication system model andcollaborative communication protocols. Then analyze the channel characteristic in multi relay nodesin wireless cooperative network. The simulation results show the more the candidate relays, thebetter the performance of cooperative communication. In addition, it analyzes the relay powerallocation between source node and relay node under limited total power. The simulation resultsshow it should allocated by channel characteristics.Secondly, the paper describes the basic principle of the traditional opportunity relay selectionscheme and its detail based on wireless collaboration system model. Propose a joint optimization ofcollaboration scheme by importing HARQ protocol. Attest the effectiveness and correctness of thescheme via theoretical analysis and simulation study. The results show that the scheme can improvethe system spectrum efficiency and reduce the system outage probability effectively.Finally, this paper derives the capacity expression based on DF strategy for multiple relaysparticipate in cooperative communication system. Then, propose the optimal value of coordinationnumber of relay by comparing the performances of different relay nodes. To compare different relaynodes participate in collaborative communication performance of relay coordination number andthe relationship between communication systems, the simulation verified the correctness and necessity of the proposed SNR threshold. It demonstrates the number of participated relays isregular for guaranteeing the communication performance.