Analysis of the influence of phase noise on the operation parameters of cognitive radio network synchronization systems in conditions of instability of the power supply voltage of reference generators

The paper analyzes the influence of phase noise on the operation parameters of cognitive radio network synchronization systems against the background of instability of the power supply voltage of reference generators. In the first part of the study, the influence of the errors of the phase synchronization device and the clock synchronization device on the reliability of the received message was assessed. The dependences of the probability of error of coherent reception of opposite binary signals in the presence of phase and clock synchronization errors were obtained by numerical methods. In the second part, a simulation model was developed to assess the influence of phase noise on the parameters of the synchronization systems of cognitive radio networks against the background of instability of the supply voltage of the reference generators. The basis was taken as a linear model of the phase loop (PLL) with a PI filter (proportional-integral filter). The novelty of the study lies in the development of a simulation model of the phase loop with a PI filter, which allows to assess the influence of phase noise and instability of the supply voltage of the reference generators on the synchronization parameters. The dependences of the spectral density of the phase error and the transfer function from the supply noise to the phase error were obtained, which allows to quantitatively assess the mechanism of penetration of the supply instability into the frequency characteristics of the PLL. A numerical comparison of the influence of PI filter parameters (Tᵢ, Kf) on the quality of PLL operation and the system's resistance to power supply noise was carried out, which deepens the methodology for optimizing synchronizer parameters. Practical value: the developed model allows predicting the stability of synchronization systems of cognitive radio networks in real conditions, when reference oscillators are affected by power supply instability. The results obtained can be used in the design of PLL structures for cognitive receivers, where it is critically important to maintain reception coherence under the influence of internal noise and interference. The determined criteria (spectral density, RMS phase error) can be used as reliability and quality metrics for comparing different architectures of synchronization systems. In the third part, a methodology for assessing the influence of voltage stabilizer accuracy on the phase stability of the synchronization system is developed. Scientific novelty of the developed methodology: a new approach to quantitatively assessing the influence of power supply stabilizer instability on the phase stability of synchronization systems is proposed; A MATLAB model has been developed that allows for virtual experiments and the determination of acceptable limits for power supply instability, taking into account specific PLL and VCO parameters.