S.M. Kazaryan, G.L. Pavlov

With the advent of cheap jammers navigation receivers had the tools to suppress these interferences. We can distinguish two groups of noise reduction: based on space-time processing and time-frequency rejection. Space-time processing presupposes an antenna array that serves as the sensor spatial differences of incoming signals. Time-frequency rejection is to use a transversal filter or an algorithm based on fast Fourier transform. With the first method of noise reduction can be countered by a large number of jammers airborne creating a spatially-distributed clutter background. A second method of suppressing interference can be combated by applying complex noise with a big band, thus eliminating the possibility of its frequency rejection. Below is regarded as a complex interference signal with linear frequency modulation. As complex interference signal is considered to chirp. The results show that interference in the form of chirp signal inhibits the operation of the receiver. The system PLL and DLL cease to function normally, giving false information. Demodulation of the navigation message are violated.