Comparison of Digital Hilbert Transform Implementations for Ultrasonic Flow Meter

Signal processing in frequency modulated continuous wave (FMCW) systems is an important tool in modern measurement systems where high accuracy is required. One of the key tasks in such systems is to obtain an analytical signal. The Hilbert transform is widely used for this purpose. In FMCW systems, the signal is processed digitally, which makes it necessary to use efficient algorithms to minimize errors and improve measurement accuracy. This paper compares two digital Hilbert transform (DHT) implementations: frequency-domain (DHT 71) and time-domain (DHT 72). Both methods have their advantages and disadvantages, which will be discussed in detail in this paper. This work has been studied in the context of ultrasonic flow meters. In [1], [2], [11], methods were proposed to improve the accuracy of measurements by using chirp signals and digital processing. However, the issues related to the effect of noise and interference on the accuracy of the Hilbert transform remain poorly understood, especially in real-world industrial applications. The purpose of this work is to compare the accuracy and effectiveness of two DHT methods in conditions of different signal-to-noise ratios (SNR), signal-to-interference ratios (SIR) and signal parameters. The results obtained provide a reasonable choice of one of the methods under the given conditions and task.