Research And Implementation Of Narrowband Interference Suppression Techniques For Navigation Receiver

Global Navigation Satellite System(GNSS) is developed on the basis of advanced modern science and technology. It has all-functional, all-weather, continuous and real-time characteristics, and can provide the precise position, velocity and timing information for the users. GNSS has been widely used in military and civil application. Therefore, many countries in the world are developing their own Global Navigation Satellite System. Such as the GPS system of America, the GLONASS system of Russia, the GALILEO system of EU, and Beidou system of China. The environments where the receiver of satellite navigation system works become more and more complex, and the satellite signals are susceptible to intentional or unintentional interferences, so the anti-jamming ability of the satellite navigation receiver has become an important issue, which is related to whether the receiver can work or not. It is significant to research the anti-jamming techniques for the receiver of satellite navigation system, which can improve the work performance of satellite navigation system under the complex electromagnetic environments, and enhance the adaptability for various conditions.Narrow-band interference(NBI) is a very important problem in Navigation Satellite System, which affects the performance of the whole system. The system will not function property sometimes even malfunction when the power of narrowband interference surpasses the jamming margin. The thesis studies the NBI suppression algorithm in GNSS, designs and implements the GNSS NBI suppression algorithm based on the FPGA which can be applied in practice. The key work of the thesis is included as fallow:1. Analysis the characteristics of navigation receiver and the characteristics of interference signal. Set up the model of the interference signals. And discuss the composition and characteristics of satellite signals.2. Study narrowband interference suppression technology for navigation receiver based on the time domain and frequency domain. In the time domain narrow-band interference suppression, IIR adaptive notch filter based on the Gauss-Newton algorithm and FIR adaptive filter based on LMS algorithm?RLS algorithm and MWF algorithm are studied in detail. These algorithms were applied to navigation receiver to verify the effectiveness in Matlab, and analyses the performance and defects of these algorithms. Study frequency domain narrow-band interference suppression technology for navigation receiver and discuss how to select the parameters of it. This thesis proposes a adaptive narrow-band interference suppression technique based on FFT transform, and complete feasibility validation and analysis.3. Using FPGA technology, the interference suppression system for navigation receiver was made according to the theoretical analysis. System is designed around the ZYNQ-7000 chip and the integrated signal processing function Microblaze soft core. Then using the CSA-MWF algorithm to complete the project implementation. Finally, debug the system, a large number of system simulations and tests were done to certify the system could work well.