The Design And Implement Of Positioning Algorithm Module In GNSS Software Receiver

In recent years, with the progress of science and technology, satellite navigationtechnology plays a decisive role in the military and civil fields, more and more countriespay attention to the research and development of satellite navigation technology. At present,most field adopt GNSS software receiver which based on the idea of software radio becauseof its advantages in openness, modification, strong adaptability and short development cycleetc, it can easily achieve a compatible GNSS system with complex and high-precisionpositioning algorithm. Based on this deployment, doing the research on software receiverand exploring the positioning solution method have great significance in the development ofsatellite navigation system.Thesis starts from the software receiver positioning principle and creates positioningresolution model, the inter-satellite differential least squares method and the Newtoniterative differential method based on the least squares are proposed after the research ontraditional method, the new method is validated by simulation,completing the basebandplatform software design and real-time display of the PC interface design, final realizationof high precision and rapid positioning in different conditions.Firstly, this paper gives an account of the composition of the GNSS system andcompares the characteristics of various systems. It introduces the basic principle of GPSsoftware receiver location and establishes two kinds of common positioning model, thencarries out relevant research about the satellite signal, finally discusses the carrier, rangingcode and the generation of navigation message, structure and characteristics in detail.Secondly, the article does an overview about composition of the whole GNSS receiversoftware, especially focus on the principle, process and the realization method of capturingand tracking. The receiver structure is analyzed and divided into several independentmodules; each module is understood in depth, the researches of signal RF processing andvarious methods of tracking are done, and ensures the successful capture of the satellitesignal, finally after the tracking outputs the navigation message then to demodulate.Finally, this paper discusses the related content of the position resolution in detail,does the research about traditional algorithm, later proposes the inter satellite differentialleast squares method and Newton iteration difference algorithm based on the method ofleast squares, does the research in depth and applicate it in positioning model. At the same time, according to a large number of satellites receiver datas, proving the improved methodeffective and feasible by Matlab simulation. Introducing the software receiver hardwarebriefly and achieving algorithm transplantation on DSP module through softwareprogramming and design, and using the VC6.0software to design the PC platform,achieving the real-time display about positioning results on the computer.