Research Of GPS/Galileo Dual-system Navigation Message And Combined Positioning

In recent years,with starting the modernization process of GPS system,Russia's GLONASS system had been activated and provided the service to the world.The EU's Galileo System also has made great progress.The most exciting event is that Beidou system of our country start operation.Four navigation systems provide a large number of navigation signal and navigation message.On a whole,the design of the new navigation message always make best use of the advantages and bypass the disadvantages of the old navigation message.Perhaps there will have new navigation signal and message broadcast.So it is urgent to analyze the performance of the existing navigation message.As also,the research in channel decoding technology of new navigation message and the combined solution technique of GPS/Galileo Dual-System is very urgent.This thesis mainly studies on the analysis and comparison the navigation message of GPS/Galileo Dual-System,researches into the channel decoding algorithm and the combined solution model of GPS/Galileo Dual-System based on the design of the receiver of GPS/Galileo Dual-System.The main contributions are listed below:Firstly,this thesis researches into the functional needs of navigation receiver and proposes the main points and framework of the design of navigation message.Through the introduction of navigation message structure of GPS/Galileo Dual-System and the analysis of functional needs,this thesis summarizes the performance which navigation message should possess.Than this thesis analyze the disadvantages of the existing navigation evaluation model.Finally this thesis builds comprehensive analysis model,proposes the main points and framework of the design of navigation message and contrast five kinds navigation message of GPS/Galileo Dual-System.Secondly,this thesis designs and realizes the efficient channel decoding of GPS/Galileo Dual-System based on the analysis of the navigation message of GPS/Galileo Dual-System.Preamble-10001011 of GPS CNAV is no longer exposed in the convolution code.With researching into the characteristic information of GPS CNAV message,this thesis reconstructs the preamble and proposes the channel decoding algorithm with synchronization and decoding in order.This method avoids performance degradation of decoding process caused by the unbeknown initial state and final state of Viterbi decoding trellis diagram.There is no fixed synchronous code in GPS CNAV-2.Than aim at navigation message of GPS L1C,this thesis proposes a new frame synchronization algorithm based on combine.of navigation data of data/pilot signal and a new LDPC decoding algorithm based on statistic characteristics of slope.Thirdly,this thesis researches into the the combined solution model of GPS/Galileo Dual-System through the introduction of the principle of single satellite positioning system,space and time coordinate conversion of different systems.Than aim at the information fusion of multiple systems,this thesis proposes a new information fusion methods based on weight algorithm of a set of smallish GDOP.