Key Technologies Of Vehicular Network Receiver Based On Compass/beidou GBAS

As the developments of vehicular network technology and Beidou satellite positioning system of China, high precision positioning of vehicles based on Beidou ground based augmentation system(BD-GBAS) and Vehicular Ad Hoc Networks(VANETs) will directly improve the vehicle positioning results under the complicated urban environment, which can ensure the safe operation of the vehicles. Therefore, it has an important theoretical guiding significance and a practical application value to study the key techniques of the receiver in vehicular networks and its hardware and software implementations based on BD-GBAS. In this dissertation, with the basis of the theory of vehicular networks and Beidou satellite positioning system, the key techniques of the receiver in vehicular networks based on BD-GBAS are conducted in-depth research. And the main work and innovation points are listed as bellow.(1) Related technical theories and methods of vehicular networks are discussed, including network architecture and protocol stack of vehicular networks, as well as the impact of the key technologies and the corresponding solutions in physical layer, medium access control(MAC) layer and network layer. And the key technologies of physical layer and MAC layer are mainly discussed, including network coding techniques, channel resource allocation methods, broadcast mechanism, etc. Then a mobile relay selection scheme is proposed to ensure the reliability of vehicular cooperative communication system. Finally, the outage performance of a two-way relay system based on network coding techniques is analyzed in the Wei bull fading environment.(2) Channel resource allocation methods of the MAC layer in vehicular networks are analysed, focusing on the wireless access in vehicular environment(WAVE) channel resource allocation mechanism, including the carrier sensing, inter-frame spacing, random back-off and retransmission and so on. With the comprehensive understanding of competitive channel and bandwidth allocation problems, a resource allocation strategy based on the non-cooperative game is proposed to solve the transmission quality and the limited variable packet arrival rate problems. In the proposed strategy, the resource allocation problem is modelled as a non-cooperative static game process, and it is proved that the Nash equilibrium exists for the joint distribution game. Then the convergence and effectiveness of the game are discussed, and two distributed algorithms for perfect and imperfect information respectively are presented to make the node-pair to incline to Nash equilibrium. The simulation results show that the proposed strategy can significantly improve the system performance.(3) Through the analysis of the related technical theories and methods of BD-GBAS, the categories and characteristics of satellite navigation enhancement techniques, the system composition and working principle, calculation models of observations, error sources and their elimination methods of BD-GBAS are described in detail. Simultaneously, considering the virtual reference station(VRS) technique as the main analysis object, the related issues of VRS positioning technology are studied in-depth. The composition of VRS system and data processing procedure are analysed, as well as calculation models of observation data and corrections distribution process. Then the BD-GBAS techniques for vehicular networks are studied, including BD-GBAS, Beidou satellite error sources and elimination methods, VRS technique, calculation models of observations and corrections distribution solution and so on. Finally, a design scheme of network Beidou navigation satellite system/real time kinematic(BDS/RTK) system based on vehicular networks(NBRSBVNs) is proposed, and the feasibility of this scheme is verified by field testing, which can provide a strong support for the high precision positioning of mobile vehicles.(4) A design and implementation scheme of the vehicular positioning receiver based on BD-GBAS is proposed, which give the design and implementation process of the receiver from two aspects of software and hardware, respectively. Then the performance testing and analysis for the receiver are conducted. The results show that the receiver can realize the basic functions, e.g., the BDS data acquisition, dedicated short range communication(DSRC) data transceiver, and so on, and has highly efficient and reliable real-time positioning characteristics, which has a great practical value. Application analysis in the actual environment also indicates that the receiver design can achieve high precision positioning of moving vehicles, and has important practical significances and broad application prospects.