ANALYZING A JOINT ADAPTIVE ALGORITHM IN COHERENT MODE FOR FILTERING RADIO-NAVIGATION PARAMETERS OF GNSS SIGNALS IN AN AUTONOMOUS SPACE NAVIGATION SYSTEM

摘要

The algorithm of a multi-loop tracking filter for radio-navigation parameters of navigation satellites on the space GNSS receiver equipment is considered. The tracking loop examined does not contain radio-navigation parameter discriminators. The estimates of time delay, Doppler shift, and phase are made during the joint processing of quadrature signals of three correlators in a adaptive filter. The adaptive filter consist of several partial tracking filters. Each of this filters is tuned in a different estimates of the input signal carrier phase. Quasi-optimal joint estimates of parameters are made with help of the algorithm of the sigma-point Kalman filter. Root mean square errors of estimates and the probability of divergence at different signal-to-noise energy ratios are researched. Comparison with the discriminator architecture of a tracking system is made.