B.H. Kulbikayan

Demodulation of the navigation signals (NS) is one of the final stages of satellite radio navigation systems emissions monitoring (RM). The variety of formulations of the problem of NS demodulation due to the use in the formation and processing of radio signals of navigation satellite various carriers and clock frequencies, the laws of formation of manipulating sequences, levels of prior uncertainty about the spatial, energy, time and frequency characteristics of the NS and the various structures and algorithms device demodulator. When the demodulation phase-shifted signals (FMS), comprising a radio emission of satellite of space segment of SRNS, commonly used algorithms for quasi-coherent processing. This article analyzes the features of the functioning and the main characteristics of the devices included in the channel with quasi-coherent demodulation (QCD) navigation signals. In general form considered a quasi-demodulation algorithm for PMS, the structure of the channel with quasi-coherent demodulation of navigation signals. In the carried out researches described construction principles, methods of analysis of the functioning and the main characteristics of the devices included in the channel with quasi-coherent demodulation: carrier recovery device, the coherent detector implemented in accordance with the Costas scheme, while providing simultaneous frequency tuning, as well as manipulating the selection assessment sequence, the device clock based on the autocorrelation processing.