Algorithms for searching and detecting navigation signals with double meander modulation with a different number of spectral components

Abstract

One of the main directions of improving the accuracy characteristics of navigation equipment of consumers of global navigation satellite systems is the use of new types of navigation signals, in particular, signals with double meander modulation. However, these signals have a relatively high level of closely spaced side lobes of the autocorrelation function, which makes it difficult to solve the problem of unambiguous measurements during search and tracking. To conduct a study of the noise immunity of algorithms for searching and detecting navigation signals by double meter modulation. Analytical expressions are obtained for calculating the total envelope at the detector output using four and two spectral components of a navigation signal with double meander modulation. It is revealed that the detection algorithm using four spectral components of a signal with double meander modulation to form the total envelope has better noise immunity than the detection algorithm using two spectral components. It is shown that the detection algorithm using two spectral signal components with double meander modulation, due to the simplicity of implementation, ensures compatibility with the existing navigation equipment of consumers of global navigation satellite systems. As a result of mathematical modeling, the dependences of the probability of the search ending with the correct detection on the signal/interference ratio are obtained. The presented research results can be used by specialists in the field of satellite radio navigation in the modernization of global navigation satellite systems, as well as in the development of advanced navigation equipment for consumers working with signals with double meander modulation.