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• MULTYCHANEL ADAPTIVE PHASE LOCK LOOP SYSTEM FOR GNSS RECEIVER

  А. А. Cherkasova, А. Y. Shatilov

  2025-04-27

  Abstract ▼

  Satellite navigation equipment often operates under conditions of a priori uncertainty of the parameters
  of the mutual dynamics between the transmitter and the consumer and the signal-to-noise ratio of the
  received signals of satellite radio navigation systems. Classical Bayesian algorithms for Phase lock loop
  system require a priori knowledge about the parameters of the phase process dynamics and the signal-tonoise
  ratio (SNR) of the received signals. As a result, the operation of such algorithms under conditions
  other than that a priori specified is not optimal to the criterion of minimum error variance. Moreover, a
  sudden 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 dynamics
  of the phase process and the signal-to-noise ratio in order to maintain phase tracking in the widest possible
  range of operating conditions while tracking global navigation satellite system signal. An adaptive
  multichannel phase lock loop system has been synthesized as a result of formulation and solution of signal
  processing problem in terms of the statistical synthesis theory. Adaptivity to the changing power of the
  received signal is achieved by including the signal-to-noise ratio [dBHz] in the vector of estimated filter
  parameters. Adaptability to the intensity of the phase change dynamics is achieved through the use of a
  multi-channel filtration system. Statistical modeling of an adaptive multichannel phase lock loop tracking
  system with a complex algorithm for tracking the code delay of the signal of satellite radio navigation
  systems has been carried out. The values of the sensitivity of phase tracking under various dynamic conditions
  are determined. The adaptive multichannel phase lock loop system is able to withstand an signal-tonoise
  ratio 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 transitions
  of dynamics between low and high (the sinusoidal acceleration 10g and sinusoidal jerk 10 g/s) without
  loss of phase tracking under the 24 dBHz signal-to-noise ratio. Thus, in real conditions, when the dynamics
  of the GNSS receiver and the SNRs of the received signals change in an unpredictable way, the
  AMPLL system keep tracking in a much wider range of conditions than the non-adaptive PLL