文档介绍：南京邮电大学硕士研究生学位论文AbstractIIAbstractThe fading of wireless channel is a huge factor work performance in wireless wireless fadingeffectivel y,diversityis employed. mon and effective techniqueof diversity is the space diversity, whichemploys multiple , It’s difficult to employ multiple antennas on work terminal ,the scheme achieves fictitious multi-antenna diversity by introducing relay nodes in workbetween receiver and relaytechnology, wecan improve the transmission rate,the reliability of wireless link,and the coverage coding scheme of Constant Bit Rate(CBR) which is used in most of cooperative transmission project misfitswireless systems,because of the statistics of wireless channel has its temporal spatial coding scheme with CBRcan have good performances usually if we know Channel State Information(CSI) it is hard to get CSIusing feedback which source nodes send,and also it will waste a lot of fountain codes is a rateless coding which is appropriate invarying channel and this paper,fountain codes based munication was can be effective in reducing feedback information and copingwith a rapidly changing wireless channel by using digital fountain codes.(1)First of all,two methods ofselectingcooperative relay nodes are analyzed in multiple relay cooperative system,., instant signal to noise ratio based fixed relayandthreshold based self-adapting former method forwardsinformation with fixed numbersof relay nodewhich have the biggest signal noise ratio at the destination;and the latter selectscooperativenodesbased on threshold in order to reduce interrupt possibility and have fewer numbersof relay node.(2)Applyingfountain codes inmultiple relay cooperative system,In view of the ing of broadcast, multicast is adopted in sending out information of the source node. We analyzetwo transmission ways:synchronous& asynchronous tra