Gps Receiver Anti-jamming Algorithm And Its Implementation

Global Navigation Satellite System (GNSS) is developed on the basis of advanced morden science and technology. Navigation signals transmitted by Navigation Satellite are received, anti-jamming processed, captured and tracked by recievers on earth. These processed signals can determine the position of objects (moving or still). The Global Navigation Satellite System is widely used in civil and military affairs, for example, geodesy, geodynamics, geophysics, Aeronautics and Astronautics, marine science, Meteorology, as well as wars. 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 the Beidou system of China.The anti-jamming processing is an important part of GPS receivers. The performance of it directly influences the effect of the follow-up signal acquisition and tracking. Bad anti-jamming performance may lead to a failure of signal acquisition. This thesis delivers a detail introduction to the characteristics of GPS signals and interferences. Based on the characteristics, many adaptive anti-jamming algorithms are introduced and simulated in Matlab. And some of the algorithms are implemented in DSP.First, this thesis introduces the power inversion algorithm, which is simulated in different arrays. The simulation results indicate that the power inversion algorithm both has advantages and disadvantages, and then, the space-time adaptive technology (STAP) is delivered. By changing the number of arrays and delays, STAP algorithm is simulated in Matlab, and the result indicates that STAP has a better anti-jamming capability than space filtering. But the calculation of STAP is quite complicated for application. Therefore, to simplify the calculation, some reduced-rank algorithms are introduced and simulated in this thesis. Especially, the multistage nedted wiener filtering (MNWF) reduced-rank algorithm is highlighted.In the final part, this thesis introduces the hardware platform used for the implementation of GPS anti-jamming. In the platform, the chip ADSPTS201 is choosed for its powerful signal processing ability. Based on the platform, the space filtering, STAP algotithm, and MNWF algorithm are implemented: first software simulation in computer, and then hardware simulation in the platform.