Research On Multi-relay Cooperative Diversity Of Wireless Communication System

Wireless communication technology is at a rapid development stage,the communication quality and the data transmission rate are becoming more and more popular demand.However,the multipath fading effect of wireless channel has been impeding the progress of wireless communication technology.Multipath fading can be overcome by MIMO technology,but the development of MIMO technology is limited by the small size of the mobile terminal and the constant transmission power.Cooperative diversity technology arises at the historic moment,in a wireless communication system,the user through sharing partnership of antenna to help send their information,by sharing formed MIMO is very similar with the system,it can overcome the limitations of MIMO technology,and access to certain system performance gain,and improve the effective transmission of wireless communication system performance and reliable communication performance.Firstly,this paper introduces the current situation of development at home and abroad based on the research background of collaborative diversity technology,and gives the focus of the research of collaborative diversity technology at present.Secondly,the MIMO system is introduced briefly,and the capacity of the MIMO system is directly proportional to the lower end of the receiving antenna by theoretical analysis.Several kinds of integration technologies are simulated and analyzed,and then several common cooperative diversity forwarding protocols are introduced,including amplification forwarding,decoding and forwarding,coding and collaboration.Through theoretical and simulation analysis,the advantages and disadvantages of each agreement are compared.After introducing the Alamouti space-time block code,and the system of double-and double-antenna double-receiving antenna is simulated and analyzed,the conclusion that the maximum diversity gain can be obtained by the Alamouti space block code is obtained.Finally,based on the Alamouti space-time code,the system based on the multi-relay cooperative communication is presented,from the establishment of the model to the analysis of performance,and finally the detailed simulation analysis and verification.Safely draw the conclusion that the system can obtain and MIMO system gain the same performance at the same time,and easy to implement,with the introduction of relay nodes between each other,we will save the transmitted power,and is more effective to reduce the error rate of signal transmission,so as to improve the reliability and validity of wireless transmission system.