A Combined Antijamming and Antispoofing Algorithm for GPS Arrays

The Global Positioning System (GPS), with its accurate positioning and timing information, has become a commonly used navigation instrument for many applications. However, it is susceptible to intentional interference such as jamming and spoofing. The conventional antijamming GPS receiver fails to work in a combined jamming and spoofing attack scenario. To solve the problem, a combined antijamming and antispoofing algorithm for a GPS receiver based on an antenna array is proposed. In this method, the jamming is eliminated by subspace projection, and then a compressed sensing framework is adopted to obtain the direction of arrival (DOA) of the despreading satellite navigation signal and detect the spoofing signal. According to the DOA of the authentic and spoofing signals, the receiver uses adaptive multibeamforming to concurrently achieve the undistorted reception of the authentic satellite signal and the suppression of the spoofing. We analyse three aspects of algorithmic performance: the antenna array direction diagram, the spoofing detection and the acquisition results. The simulation results and their analysis preliminarily show that the proposed method can detect and suppress GPS jamming and spoofing effectively.

Best View Based on Occlusion Points

An algorithm of best view based on occlusion points is proposed for current best vision algorithm. Occlusion area is found through analysis of triangulated depth images, mark diagram and occlusion points direction diagram are set up, and best view is determined according to numbers of occlusion points in mark diagram. Experiment result indicated that the algorithm is feasible and efficient.

Research and Analysis about Array Antennas in Mobile Communications

Because the direction of a single antenna is limited, and for strengthening the direct radiant ability of the antenna, we will put the weaker direction antennas together in some way to constitute an antenna array system. The antenna array is also called the array antenna or a disperse antenna array. The antenna cell can be the symmetry center-fed dipole, the aperture antenna, the circle antenna or other forms of the antennas whose direction are limited. In practice, the antenna array is almost constituted of similar antenna cells. I have mainly completed the antenna array direction diagram in conditions of some kinds of parameters. And at last, I get the useful results for practice. This also provides theories basis for the analysis of smart antenna.