W numerze 2/2026 kwartalnika PAN "Metrology and Measurement Systems" (IF: 1.1, 100 pkt MNiSW) ukazały się dwa artykuły pracowników naszej katedry:
Hanus R.: Accuracy comparison of time delay estimation of random signals using the single-point cross-spectrum phase and direct cross-correlation. Metrology and Measurement Systems 33(2) (2026), 1–14. (https://wydawnictwo.pan.pl/index.php/mms/article/view/3049/5981)
Abstract
Time delay estimation (TDE) is a common issue in signal processing. For random signals, various statistical methods of analysis are used. In this work, standard uncertainties (standard deviations) of the TDE were analytically analysed and compared for two methods: direct cross-correlation function (CCF) and phase of the cross-spectral density function (CSDF). In the frequency domain, the CSDF-phase single-point method was considered, consisting of determining the time delay for one selected frequency. The metrological properties of the CCF and the single-point phase method are presented for three models of stochastic signals contaminated with white noise interferences. For these models, the standard uncertainties of the TDE have been compared taking advantage phase CSDF and CCF for the signal-to-noise ratio (SNR) in the range 0.1 ≤ SNR ≤ 100. It was found that for small SNR values (SNR < 1) the CCF method is more accurate. On the other hand, for larger SNR values (especially above one), lower values of the standard uncertainty of the time delay are obtained for the phase method. Specific SNR values for which the single-point phase method is more accurate depend on the adopted models and parameters of the signals and on the parameters of the analysis.
Dorozhovets M., Kubiszyn P.: Suppression of periodic interference in the input signal of a precision pulse width modulator using an S&H circuit and weighted averaging. Metrology and Measurement Systems 33(2) (2026), 1–16. (https://wydawnictwo.pan.pl/index.php/mms/article/view/3051/5984)
Abstract
The results of theoretical and simulation studies concerning the occurrence of nonlinear distortions and the reduction of their impact during pulse width modulation of variable measurement signals are presented in this article. It has been shown that when input signal is variable, the classic PWM method may be inaccurate due to addition intense modulation distortion, which may be caused by noise or interference (e.g., power lines). The level of these distortions is dependent on the level and speed of the input signal changes, as well as the modulation frequency. In order to reduce the impact of those distortions, the use of the sampling and holding circuit at the input of the pulse width modulator, and weight averaging of the output pulses have been proposed. The effectiveness of the suppression of the periodic interferences in both narrow and wide bands was investigated through theoretical research and through simulations conducted in the LTSpice software using uniform, triangular, Hamming, and Blackman weighting functions for the classic PWM, and for one with the addition of the S&H circuit.
