Research On Cooperative Networking In Wireless Multihop Network

Due to the broadcast nature of wireless signals, a wireless transmission intendedfor a particular destination station can be overheard by other neighboring stations. Afocus of recent research activities in cooperative communication is to achieve spatialdiversity gains by requiring these neighboring stations to retransmit the overheardinformation to the final destination.Howerer, the existing research on cooperative communication, mostly concernterdin physical layer, or just invlolve a layer in the protocol layer, the impact of cooperativecommunication on the design of cross-layer protocol has not been well-understood yet.In this article, we first introduce an existing cooperative-based routing algorithm andthen give the analysis and performance evaluation.Then, inspired by this, using the characteristic of the IEEE802.11wireless mediaaccess standard supports multiple data rates at the physical layer, we propose a mediaaccess protocol-cooperative MAC, automatically adapting the transmission rate to bestmatch the channel conditions. Its key idea is that high data rate stations assist low datarate stations in their transmission by forwarding their traffic, in order to enhance thenetwork performance. According to this protocol, each node in the networktransmission listens to the ongoing transmission. Through the RTS/CTS interactionprocedure, to obtain the channel state information between the source-destination node,and then distributed decide whether as a relay, involved in the data the cooperativetransmission process.Broadly speaking, the main research work of this thesis as follows:The first chapter introduces the research background, and the major work andstructure are also described.Chapter2from cooperative diversity, cooperative MAC protocol and cooperativerouting algorithm three different aspects introduce the cooperative communication.Chapter3introduces an existing cooperative-based routing algorithm, then give theanalysis and performance evaluation, verified by simulation. Chapter4design an cooperative MAC protocol, its architecture and protocol andthe design of the frame structure and function are described in detail. Finally, thesimulation verifies the validity and reliability of the designed protocolsChapter5cooperative MAC protocol designed in the previous chapter outageprobability analysis, simulation and its performance.Chapter6concludes this dissertation and discusses the possible future researchdirections.