In The Cognitive Wireless Network Routing Technology Analysis And Research

Cognitive radio (CR) technique is an emerging technology. It was proposed underthe current circumstance of wireless spectrum resource scarcity and low utilization. Bysensing the spectrum environment in time and space domains, cognitive radio users canopportunistically make use of unoccupied spectrum without making harmful influenceto primary users, in order to make more use of the limited spectrum resource. Based ondistributed network architecture, some research about routing protocol in cognitiveradio network has been done in this thesis.At first, this thesis introduces cognitive radio technique from research background,nowadays research status and the trend of future development. The main researchmotivation of this thesis is also indicated.Followed by a brief introduction about routing protocol in traditional wirelessnetwork, this thesis describes the three different kinds of network architectures incognitive radio network. Some challenges to confront on routing research in cognitiveradio network are proposed and some progresses which have been achieved are alsointroduced.The third chapter proposes a routing protocol based on the requirement of thecognitive users on routing service-time, which applies to cognitive radio wirelessnetwork. The ON/OFF model is used to define the model of primary users occupyauthorized band. And Markov process is also used to describe the state transition.Focusing on routing life-time, as well as spectrum multiplexing and the interference toprimary users, the process of the routing protocol is described in detail. The results ofseveral computerized simulations verify the performance of the proposed routingprotocol, which is that it could choose a route with longer life-time, decrease theinterrupting rate and improve the reliability of the communication.The fourth chapter designs a multipath routing protocol adapts to cognitive radionetwork, focusing on decreasing the possible impact of primary users. A novel conceptof closeness is brought out, which is designed to select the paths together with therouting hops. The performance of the multipath routing protocol is proved through computerized simulations, from which we can verify that the routing protocol couldenhance the network throughout and reduce the number of route discovery.The last chapter summarizes the main contents of the thesis and proposes somesuggestion about future research.