Research On Routing Algorithm In Cognitive Radio Network Based On Link Stability

With the development of wireless communication technology and wireless business expansion, available unauthorized spectrum resources reduced and tends to saturation, and according to related studies, authorized spectrum don’t get effective use, so the reason of the shortage of spectrum resources is wireless spectrum resources are not reasonable fully utilized. As an emerging wireless communication technology, cognitive radio can make full use of spectrum resources, sense free authorized spectrum and in the case of not to disturb primary users to use authorized spectrum, improve the utilization rate of spectrum. Therefore, cognitive radio technology becomes an effective solution to the rare of spectrum resources.Routing technology as one of the key technologies in cognitive radio networks(CRNs) is the foundation of Ad Hoc network communication in CRNs. However CRNs has spectrum characteristics of dynamic, difference and diversity, the traditional Ad Hoc network routing protocol don’t consider these factors which make the routing protocol in CRNs environment facing new problems. This paper mainly discusses mobile Ad Hoc network routing protocol in CRNs, draws lessons from the existing mature Ad Hoc network routing protocols and the existing CRNs routing protocols and combines spectrum dynamic of CRNs and node mobility to design routing algorithm which can be applied in CRNs environment.Firstly, this paper introduces the research background and significance of cognitive radio technology, the key technologies of CRNs and the research status in the domestic and overseas, and then discusses the existing mature Ad Hoc network and CRNs routing protocols in detail classification. Thus, clear what the paper focuses on: uses the framework of AODV routing protocol and from the angle of link stability to design routing protocol.Secondly, according to the above discussed and in order to improve the link stability, a routing algorithm based on Kalman filter for CRNs was proposed to resolve the problem of dynamic spectrum in CRNs and node mobility. The algorithm considers spectrum idle probability of primary users and the distance between nodes, both the end-to-end transmission delay, and then designs a routing metric to select a higher stability path to communicate. In the routing maintenance phase, nodes in the path predict the relative distance through Kalman filter and start the routing repair before link broke. NS2 simulation results show that the algorithm in the stability of the communication link, packet delivery ratio, throughput, etc have obvious improvement, improves the overall performance of the network.Finally, based on SEARCH location routing protocol, the paper proposes a routing algorithm based on virtual channel and multipath fusion for CRNs by introducing the concept of virtual channel which is used to solve the problem of channel synchronization between source node and destination node. In the process of route setup, through the neighbor node lists to determine channel switch and path integration nodes. Compared with SEARCH, this algorithm reduces the hardware cost of GPS positioning, routing overhead and the complexity of algorithm. NS2 simulations show that the algorithm effectively improves the link stability.