Design and Experiment of Adaptive Anti-saturation and Anti-jamming Modules for GPS Receiver Based on 4-antenna Array

Abstract

Abstract. Antenna array with adaptive beam forming technique is an effect way for GPS receiver to suppress the ambient interference, which, however, would be malfunctioning due to the saturation problem in radio frequency (RF) front or intermediate frequency (IF) front caused by the strong interference. To tackle it, this paper demonstrates a scenario consisting of two stages processing, i.e. two anti-saturation modules in RF-front and one anti-jamming module in IF front. The anti-saturation module based on two antennas, is realized with the RF phase shifter and amplifier and capable of forming a deep null in the direction of the strong interference, while the anti-jamming module employs the blind space time adaptive processing (STAP) algorithm to improve the anti-jamming capability. Compared to the RF-front beam former or the IF-front anti-jamming algorithm, not only can the proposed system achieve the anti-saturation and anti-jamming performance but also has more degrees of freedom to suppress interferences. The feasibility is proved by the experiment, exhibiting at least 21 dB anti-saturation improvement and nearly 60 dB interference mitigation.