Research Of Gnss High Dynamic Software Receiver

After many years’development, Global Position System (GPS) has solved the problem of navigation under the height of two thousand kilometers. GPS has provided high precision navigation and positioning information to the people all over the world. At present, it has played an important role in geological prospecting, transportation and space air and national defense.GPS receiver is a part of GPS system. In domestic, GPS receiver developed slowly because of blanking off by developed country, especially in aviation and aerospace areas, in these areas GPS receiver need to adapt to high dynamic scene. GLONASS positioning system is also the global satellite navigation system and controlled by Russia, this system is improving. GLONASS system is similar with GPS system in structures, principle of navigation and function. GLONASS system can present position and speed services no matter the users from the sea, air and land, and no matter for military or civilian purpose. As the only system which is able to compete with GPS satellite navigation system at present, GLONASS system has broken the situation of satellite navigation controlled by USA. Therefore, the research and implement of GNSS (GPS and GLONASS combination) high dynamic receiver algorithm are very important. Using software radio hardware platforms is also important, for we can extend the receiver’s function not by modifying the hardware but by updating program. The thesis carries out the research and design of GNSS high dynamic receiver for aerospace vehicle in the background of above.This thesis first discusses the hardware design of GNSS receiver, researches the method of design receiver hardware with software radio hardware platform. The platform uses DSP and FPGA architecture, allocates hardware resource dynamically, and meets the demand of extending function by updating program. I am incharge of implementing the digital circuit design. The codes can be downloaded into the hardware, and the platform runs stable.Then this thesis researches the method of GNSS combination navigation, on the base of GPS navigation principle. The method makes the observation formulas linear, and calculates with least-squares estimate. This method implements compatibility of the two navigation systems (GPS and GLONASS). Navigation with two satellite systems can decrease the PDOP is good for navigation precision.Finally the thesis analyses the loop filter algorithm. The algorithm determines the receiver’s dynamic characteristic. The dynamic characteristic of three order loop filter is analysed and simulated. The simulation result shows that using three order loop filter in high dynamic scene is good for tracking precision.