Related Experiment Video
Updated: Mar 11, 2026

06:04
Functional Near-Infrared Spectroscopy Hyperscanning Study in Psychological Counseling
Published on: January 17, 2025
1.7K
A frequency measurement algorithm for non-stationary signals by using wavelet transform.
Seong-Heon Seo1, Dong Keun Oh1
1KSTAR Research Center, NFRI, Daejeon 34133, South Korea.
The Review of Scientific Instruments
|December 3, 2016
Summary
This study analytically derives a scalogram property for non-stationary signals, enabling a new frequency measurement algorithm. A wavelet transform-based filter is also developed for separating similar frequency signals.
Area of Science:
- Signal Processing
- Wavelet Theory
- Time-Frequency Analysis
Background:
- Scalograms are commonly used for measuring instantaneous frequencies, but their properties are primarily understood for stationary signals.
- Existing methods struggle with accurate frequency analysis of non-stationary signals.
Purpose of the Study:
- To analytically derive a fundamental property of the scalogram for non-stationary signals.
- To propose a novel frequency measurement algorithm based on this derived property.
- To develop a wavelet transform-based filter for distinguishing signals with similar frequencies.
Main Methods:
- Analytical derivation of scalogram properties for non-stationary signals.
- Development of a new algorithm for instantaneous frequency measurement.
- Application of wavelet transform to design a signal separation filter.
Main Results:
- An intrinsic property of the scalogram for non-stationary signals has been analytically established.
- A new, effective algorithm for measuring instantaneous frequencies in complex signals is proposed.
- A novel filter capable of separating signals with closely related frequencies was successfully developed.
Conclusions:
- The derived scalogram property provides a theoretical foundation for analyzing non-stationary signals.
- The proposed algorithm enhances the accuracy of frequency measurement in dynamic systems.
- The developed wavelet-based filter offers improved resolution for signal discrimination.
Related Concept Videos
Sampling Theorem
1.5K
In signal processing, the analysis of continuous-time signals, denoted as x(t), often involves sampling techniques to convert these signals into discrete-time signals. This process is essential for digital representation and manipulation. A critical component in sampling is the train of impulses, characterized by the sampling interval and the sampling frequency. The relationship between these parameters and the original signal's properties dictates the success of the sampling process.
1.5K
Discrete Fourier Transform
1.0K
The Discrete Fourier Transform (DFT) is a fundamental tool in signal processing, extending the discrete-time Fourier transform by evaluating discrete signals at uniformly spaced frequency intervals. This transformation converts a finite sequence of time-domain samples into frequency components, each representing complex sinusoids ordered by frequency. The DFT translates these sequences into the frequency domain, effectively indicating the magnitude and phase of each frequency component present...
1.0K
Sampling Continuous Time Signal
808
In signal processing, a continuous-time signal can be sampled using an impulse-train sampling technique, followed by the zero-order hold method. Impulse-train sampling involves the use of a periodic impulse train, which consists of a series of delta functions spaced at regular intervals determined by the sampling period. When a continuous-time signal is multiplied by this impulse train, it generates impulses with amplitudes corresponding to the signal's values at the sampling points.
In the...
In the...
808
Bandpass Sampling
599
In signal processing, bandpass sampling is an effective technique for sampling signals that have most of their energy concentrated within a narrow frequency band. This type of signal is known as a bandpass signal. The key principle of bandpass sampling involves sampling the signal at a rate that is greater than twice the signal's bandwidth to prevent aliasing.
A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2....
A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2....
599
Properties of Fourier Transform I
757
The application of Fourier Transform properties in radio broadcasting is multifaceted, enabling significant advancements in the way signals are transmitted and received. Key areas where these properties are utilized include simultaneous multi-channel transmission, audio clip speed adjustments, live broadcast delays for different time zones, audio frequency adjustments, and signal demodulation.
In radio broadcasting, multiple audio signals often need to be transmitted simultaneously. The Fourier...
In radio broadcasting, multiple audio signals often need to be transmitted simultaneously. The Fourier...
757
Discrete-Time Fourier Series
799
The Discrete-Time Fourier Series (DTFS) is a fundamental concept in signal processing, serving as the discrete-time counterpart to the continuous-time Fourier series. It allows for the representation and analysis of discrete-time periodic signals in terms of their frequency components. Unlike its continuous counterpart, which utilizes integrals, the calculation of DTFS expansion coefficients involves summations due to the discrete nature of the signal.
For a discrete-time periodic signal x[n]...
For a discrete-time periodic signal x[n]...
799

