MULTYCHANEL ADAPTIVE PHASE LOCK LOOP SYSTEM FOR GNSS RECEIVER

Satellite navigation equipment often operates under conditions of a priori uncertainty of the parametersof the mutual dynamics between the transmitter and the consumer and the signal-to-noise ratio of thereceived signals of satellite radio navigation systems. Classical Bayesian algorithms for Phase lock loopsystem require a priori knowledge about the parameters of the phase process dynamics and the signal-tonoiseratio (SNR) of the received signals. As a result, the operation of such algorithms under conditionsother than that a priori specified is not optimal to the criterion of minimum error variance. Moreover, asudden change in the signal-to-noise ratio or dynamics can lead to a tracking failure in such a system.The purpose of this work is to develop an optimal phase tracking system that is adaptive to the dynamicsof the phase process and the signal-to-noise ratio in order to maintain phase tracking in the widest possiblerange of operating conditions while tracking global navigation satellite system signal. An adaptivemultichannel phase lock loop system has been synthesized as a result of formulation and solution of signalprocessing problem in terms of the statistical synthesis theory. Adaptivity to the changing power of thereceived signal is achieved by including the signal-to-noise ratio [dBHz] in the vector of estimated filterparameters. Adaptability to the intensity of the phase change dynamics is achieved through the use of amulti-channel filtration system. Statistical modeling of an adaptive multichannel phase lock loop trackingsystem with a complex algorithm for tracking the code delay of the signal of satellite radio navigationsystems has been carried out. The values of the sensitivity of phase tracking under various dynamic conditionsare determined. The adaptive multichannel phase lock loop system is able to withstand an signal-tonoiseratio jump from 50 to 10 dBHz and back without loss of phase tracking in low dynamics conditions(only the drift of the reference quartz oscillator). The AMPLL system is able to withstand abrupt transitionsof dynamics between low and high (the sinusoidal acceleration 10g and sinusoidal jerk 10 g/s) withoutloss of phase tracking under the 24 dBHz signal-to-noise ratio. Thus, in real conditions, when the dynamicsof the GNSS receiver and the SNRs of the received signals change in an unpredictable way, theAMPLL system keep tracking in a much wider range of conditions than the non-adaptive PLL