The Research Of Mechanism And Application Simulation For The New Generation GPS

Global Positioning System(GPS), a advanced navigation system, is the third generation of American aerospace engineering with the ability of global, all-weather, and real-time positioning. So the function of GPS in civil and military area can not be replaced. Considering the defects of traditional GPS system in anti-jamming and expanding ability, and in easy interference in civil and military frequency band, the new generation of GPS system has been put forward with the start-up of GPS modernized process. The cycle of the spread spectrum code signal in the new system is longer, which can increase the anti-jamming ability. Time Division Data Modulation (TDDM) and Binary Offset Carrier (BOC) modulation in the new system can be used to achieve the frequency share in civil and military area. The new frequency band of L4and L5increases the precision of navigation positioning. But the change of the mechanism of navigation signals in the new generation of GPS system has brought huge challenges in receiving technology.Therefore, the key receiving technology of GPS system is studied further on the basis of the analysis of the mechanism of satellite navigation signals in the new generation of GPS system. The characteristics of C/A code, P(Y) code, M code, distance measurement code of L5, BOC modulation signal and TDDM modulation signal are analyzed in the process of study. A model of algorithm for capturing and tracking that is suitable for BOC modulation signal of P code and TDDM-BOC modulation signal is set up based on the analysis of capturing and tracking algorithms of traditional GPS navigation signals. The algorithm of PVT calculation based on the Kalman filter estimation and the least squares-iterative estimation is designed and simulated, and it is analyzed and evaluated further.Furthermore, to validate the correctness of the analysis about the mechanism of the satellite navigation signals in the new generation of GPS system, and to validate the timeliness and rationality of the new synchronization algorithm aimed at the new generation of GPS satellite navigation signals, the signals of navigation, pre-processing, capturing, tracking and demodulation are simulated and tested according to the three kinds of modes of GPS software receivers. At last, the communication integration of the new generation of GPS system is designed and simulated with HLA/RTI. Constellation, orbit, channel and applied platform of receivers of the new generation of GPS navigation system are modeled and simulated by STK.