Research Of Selection Cooperation Transmission Methods For Multi-source Cooperative Networks

Cooperative communication technology has the similar diversity performance with multiple-input multiple-output(MIMO)systems and only needs to configure single antenna at the sender and receiver.And it can also effectively against multipath fading for wireless communication networks thus has become a favored research object in the communication field.Selection cooperation adopts single relay cooperative way,which plays an important role in cooperative communication with the advantage of simpleness and efficiency.Multi-source cooperative network is a common communication scenario,and there have been some researches on selection cooperation transmission methods in multi-source cooperative networks so far.However,there still exists a great space of exploration and development.According to the number of destination node,the multi-source cooperative networks can be divided into multi-source multi-destination cooperative networks and multi-source single-destination cooperative networks.For multi-source multi-destination cooperative networks,several source nodes may choose the same node as best relay under selection cooperation methods,which leads to the best relay collision issue so that affects the communication effect.And for multi-source single-destination cooperative networks,the system performance can be maintained at a high level with the use of tranditional selection cooperation methods,and usually the obtained transmission reliability is at the expense of the spectral efficiency.According to the issues mentioned above,for the two application scenarios of multi-source cooperative networks,multi-source multi-destination cooperative networks and multi-source single-destination cooperative networks,the selection cooperation transmission methods are investigated in this thesis,and the main works are as follows:Firstly,the thesis introduces the basic idea and key technologies of cooperative communication,mainly analyzes the transmission principle and relay selection mechanism of selection cooperation.Secondly,to improve the best relay collision issue of multi-source multi-destination cooperative networks,two low-collision relay selection schemes are proposed and their expansion versions in the power allocation scenario are taken into account.Besides,a distributed relay selection scheme with power allocation is also proposed.The proposed methods make reasonable use of feedback mechanism,by the coordination selection among multiple effective relays to avoid collision as much as possible,thus the methods can effectively reduce collision.In addition,the proposed power allocation methods not only guarantee the transmission reliability,but also reduce the energy loss of the system.Thirdly,to improve the spectral efficiency of multi-source single-destination cooperative networks,a selection cooperation transmission mechanism for industrial wireless sensor networks(IWSNs)is proposed.The proposed transmission mechanism adopts packet aggregation method to achieve relay forwarding,which halves the number of transmission slots.In addition,in order to solve the collision issue of aggregation carrier under this transmission mechanism,three relay forwarding and packet aggregation schemes are also proposed.The proposed methods can effectively improve spectral efficiency and meet the communication reliability demand of most industrial wireless sensor networks.Finally,the simulation and experiment verifications of the proposed methods are given in different scenarios,and the verification results show that the proposed methods can achieve the expected goals.This thesis designs and analyzes the selection cooperation transmission methods in different cooperative scenarios,which contributes to the practical process of selection cooperation technology.