Research On High-efficient Jamming Patterns To GPS Signals

Global Positioning System (GPS) is capable of providing precise information of real-time position, velocity and time for users all over the world. How to effectively jam GPS receivers has become an urgent task due to GPS’s great effectiveness in modern local war. On the other hand, with the rapid development of time-frequency distribution and wavelet theory, the non-stationary characteristics of signals is believed to play an important role in communication counterwork. This thesis aims to explore the most efficient jamming patterns to GPS.Based on the analysis of system architecture, principles and signal characteristics of GPS, this thesis puts emphases on the jamming patterns based on high-energy time-frequency atoms. The main research of this thesis consists of the following three aspects:1. Through theoretical analysis and a lot of simulation experiments, various methods of jamming and anti-jamming to GPS are compared. A model is designed to calculate GPS Doppler shift. An efficient anti-jamming algorithm of frequency domain excision is presented and the retransmitted jamming to GPS is developed.2. An analysis on time-frequency characteristics of C/A codes and Chirplet atoms is made in depth based on a simulated GPS signal generating model and Chirplet time-frequency atoms, and a high efficient jamming pattern is found. The jamming pattern is of high randomness in time-frequency domain, high peak power, low occupancy and low average power.3. A base band processing circuit board for generating the jamming designed above is developed, including FPGA implementation of its kernel units. The experimentation verified the performance of jamming patterns.