Space-Frequency Processing Methods for Satellite Navigation Signals

Relevance . Quite low power of the global satellite navigation systems’ useful informational signals near the Earth surface along with an ongoing noticeable increase of the number of easily available and efficient portable means of blocking wideband energetic interference radiation make the problem of radionavigational satellite devices antijamming capabilities improvement especially relevant both from practical and scientific points of view. Therefore, the goal of this research was to increase the antijamming capabilities of the global satellite navigation systems via processing of the corresponding receiving apparatus’ input signals by special spatial filters. To achieve the work goal the scientific task of researching on the antijamming capability improvement in radionavigational devices by means of space-frequency signal processing was solved. The methods used . During the research, different spatial signal processing algorithms were considered, among them both the ones functioning without any information about interference situation, external with respect to the receiving radionavigational system, and the ones using the knowledge about the number and relative disposition of the jamming sources. Additionally different methods of interference sources number and angular directions finding were studied, as well as modern cost function optimization algorithms which are used for signal sources’ location determination. Scientific novelty of this work consists of usage of new algorithms that implement separate signal processing stages and that provide necessary information to the filtering algorithms during the problem solution, as well as of combining known methods with new approaches to their design. The results. During the scientific task solution, the performance quality metrics comparison was carried out for all the considered algorithms via the computer modeling method that employed recordings of real satellite navigational signals with addition of varying number of uncorrelated energetic interferences sources. As a result of modeling, the performance quality measure values were obtained for all the investigated algorithms and the comparative analysis thereof was conducted, at the end whereof the methods with the best characteristics were picked out. The significance of the work results consists of possibility of using the considered algorithms in real antijamming satellite navigation devices design.