The Software Design And Implementation Of Navigation Satellite Signal Simulator

As the increasing demands of satellite navigation services, China will develop its future-generation"BD"navigation satellite system on the basis of its first generation navigation satellite system. And now, it is very meaningful to make research on"BD-2"satellite signal simulator, which is the important measuring instrument of receiver. To meet the test needs of monitoring station receiver and general navigation receiver, two types of satellite navigation signal simulators, especially the software design, were studied in the thesis.Firstly, an introduction of two application types of signal simulators was presented, including monitoring station receiver measurement and general navigation receiver measurement. And then the Testing Simulation System of future"BD"navigation satellite system was briefly introduced. On the basis of analyzing the advantages and disadvantages of Testing Simulation System, the demand and feasibility of separating receiver test function from Testing Simulation System was analyzed, and the structure of Special Signal Simulator used to test monitoring receiver was given then. To test general navigation receiver, after drawing lessons from the signal simulator structure features of Spirent Communications, the structure of General Signal Simulator as well as its difference from Special Signal Simulator was presented.Secondly, the mathematical models of two signal simulators were introduced after studying the features of simulator users, and then the thesis presented the observation generation principles of Special Signal Simulator and analyzed the operating mechanisms of SNSS in three running modes, which is the software of General Signal Simulator.Finally, unit level validations of satellite orbit, atmosphere propagation delay and pseudo-range that generated by SNSS are carried out, and closed-loop positioning tests of several kinds of typical users in three SNSS running modes were processed in order to validate pseudo-range, carrier phase and navigation message in system level. Closed-loop positioning test results indicate that the pseudo-range, carrier phase and navigation message generated by SNSS can meet the needs of general navigation receiver test.