Frequency-Spatial Domains Cascade Anti-jamming Algorithm Of Satellite Navigation System And Its Implementation

In the satellite navigation system, due to the weakness of the navigation signal, thereceivers are vulnerable to impact by a variety of intentional or unintentionalinterferences, and resulting in decreasing of navigation sensitivity，even can not locate,so the system’s capability of anti-jamming is one of the key technologies to work stably.This dissertation studies the traditional spatial domain and space-time jointanti-jamming algorithms firstly, then the navigation system’s array signal processingmodel is given and the basic principles of adaptive beamforming and optimumstandards are explained. On the basis of these, three common the adaptive algorithmsare studied in the dissertation. Finally, comparing the spatial domain with space-timejoint anti-jamming algorithms, their advantages and disadvantages in differentinterference environment are given by simulation.In allusion to interference’s bandwidth characteristics, an adaptive notch filtertechnology for narrowband interference is studied.First three basic adaptive notch filtersare given, and then some improvements are made on the lattice IIR notch filter so that itcan accommodate notch filter’s coefficients adaptively based on the input signals. Withthe improved adaptive notch filter and the spatial domain algorithm, a frequency-spatialdomain cascade anti-jamming algorithm is proposed in the dissertation. Firstly, thenarrow-band interference is rejected in frequency domain, and then the widebandinterference and the remaining narrowband interference are suppressed in the spatialdomain. This method, make the loss of navigation signal as less as possible, whileensuring the suppression of interference. Finally, simulation and performance analysisverify the correctness and effectiveness of the presented algorithm.Finally, based on some hardware project, the navigation anti-jamming system’shardware model is described and the specific work flow is given.