Comparative Study of Influence of Noise on Power Frequency Estimation of Sine wave Using Interpolation FFT
20 Jul 2014-Fluctuation and Noise Letters (World Scientific Publishing Company)-Vol. 13, Iss: 03, pp 1450019
TL;DR: In this article, the authors compared the performance of different interpolation fast Fourier transform (FFT) algorithms under white Gaussian noises and showed that the trade-off between biases and variances of frequency estimation is unavoidable.
Abstract: This paper compares performances of frequency estimations provided by different interpolation fast Fourier transform (FFT) algorithms under white Gaussian noises. Firstly, accuracies of frequency estimation algorithms are evaluated by deriving analytical expressions of variances of frequency estimation. Then, theoretical results are validated by means of computer simulations. It is shown that the trade-off between biases and variances of frequency estimation is unavoidable. From both theoretical and simulation results, it can be concluded that variances of frequency estimation are proportional to the noise variance and inverse proportional to the length of FFT.
Citations
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20 Jul 2016
TL;DR: Some of the most used Least Mean Squares (LMS) based Finite Impulse Response (FIR) Adaptive Filters are introduced and which of them are the most effective under varying circumstances is determined.
Abstract: The extraction of the Fetal Electrocardiogram (fECG) from the composite Electrocardiogram (ECG) signal obtained from the abdominal lead is discussed. The main point of this paper is to introduce some of the most used Least Mean Squares (LMS) based Finite Impulse Response (FIR) Adaptive Filters and to determine which of them are the most effective under varying circumstances. Experimental results suggest the ideal combination of the chosen settings for these functions. Results of fECG extraction are assessed by Percentage Root-Mean-Square Difference (PRD), input and output Signal to Noise Ratios (SNRs), and Root Mean Square Error (RMSE). Based on simulations conclusions, optimal convergence constant value and filter order were empirically determined. Setting the optimal value of the convergence constant and filter order of adaptive algorithm can be considered a contribution to original results. These results can be used on real records fECG, where it is difficult to determine because of the missing reference.
17 citations
Cites background from "Comparative Study of Influence of N..."
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20 Jul 2016
TL;DR: Experimental results indicate that ANFIS have the potential to improve the diagnostic and monitoring quality of fECG signals while preserving their clinically important features.
Abstract: The aim of this paper is evaluation of the best setting options for adaptive neuro-fuzzy interference system (ANFIS) in case of fetal electrocardiogram (fECG) elicitation from two ECG signals. Thoracic ECG (tECG) signal represents maternal ECG (mECG). Abdominal ECG (aECG) signal is a mixture of mECG, fECG and additive noises (e.g. power line interference, motion artifact, ambient noise…). While additive noises can be easily eliminated by ordinary linear filters, relationship between tECG and maternal component of aECG is fully nonlinear. ANFIS is able to handle this nonlinear relationship. Quality of mECG suppression by ANFIS is affected by changing ANFIS parameters, namely number of membership functions (mf), type of mf and number of epochs. The influence of each ANFIS parameter on suppression result is described in the paper. Results of fECG filtering are assessed by signal to noise ratio (SNR) and root mean square error (RMSE). Experimental results indicate that ANFIS have the potential to improve the diagnostic and monitoring quality of fECG signals while preserving their clinically important features.
12 citations
TL;DR: In this paper, the authors proposed a new acquisition algorithm called PMF-FC-BA-FFT method to acquire the carrier frequency accurately with lower computational load in a weak signal environment.
Abstract: A novel communication and navigation fusion system (CNFS) was developed to realized high accuracy positioning in constrained conditions. Communication and navigation fusion signal transmitted by base stations are in the same time and frequency band but are allocated different power levels. The positioning receiver of CNFS requires signal coverage of at least four base stations to realize positioning. The improvement of receiver sensitivity is an important way to expand signal coverage of base station. As an essential stage of signal processing in CNFS positioning receiver, signal acquisition requires a trade-off between improvement of acquisition frequency accuracy and reduction in computational load. A new acquisition algorithm called PMF-FC-BA-FFT method is proposed to acquire the carrier frequency accurately with lower computational load in a weak signal environment. The received signal is firstly filtered by partially matched filters (PMF) with local replica pseudorandom noise (PRN) sequences being coefficients to strip off the PRN code in the signal. Frequency compensation (FC) was performed to avoid the large attenuation in block accumulation (BA) and generate a series of signals with a small frequency offset step. Block accumulation was then executed. Finally, the acquisition detection was performed based on a series of fast Fourier transformation (FFT) outputs to obtain acquisition results with fine frequency estimation. Simulations and experimental tests results show that the proposed method can realize high accuracy frequency acquisition in a weak signal environment with fewer computational resources compared with existing acquisition methods.
11 citations
21 Jul 2016
TL;DR: The investigation and experimental results by using clinicalquality synthetic data generated by the novel fECG signal generator suggest that adaptive neuro-fuzzy inference systems could produce a significant advancement in fetal monitoring during pregnancy and childbirth.
Abstract: The abdominal fetal electrocardiogram (fECG) conveys valuable information that can aid clinicians with the diagnosis and monitoring of a potentially at risk fetus during pregnancy and in childbirth. This chapter primarily focuses on noninvasive (external and indirect) transabdominal fECG monitoring. Even though it is the preferred monitoring method, unlike its classical invasive (internal and direct) counterpart (transvaginal monitoring), it may be contaminated by a variety of undesirable signals that deteriorate its quality and reduce its value in reliable detection of hypoxic conditions in the fetus. A stronger maternal electrocardiogram (the mECG signal) along with technical and biological artifacts constitutes the main interfering signal components that diminish the diagnostic quality of the transabdominal fECG recordings. Currently, transabdominal fECG monitoring relies solely on the determination of the fetus’ pulse or heart rate (FHR) by detecting RR intervals and does not take into account the morphology and duration of the fECG waves (P, QRS, T), intervals, and segments, which collectively convey very useful diagnostic information in adult cardiology. The main reason for the exclusion of these valuable pieces of information in the determination of the fetus’ status from clinical practice is the fact that there are no sufficiently reliable and well-proven techniques for accurate extraction of fECG signals and robust derivation of these informative features. To address this shortcoming in fetal cardiology, we focus on adaptive signal processing methods and pay particular attention to nonlinear approaches that carry great promise in improving the quality of transabdominal fECG monitoring and consequently impacting fetal cardiolo‐ gy in clinical practice. Our investigation and experimental results by using clinicalquality synthetic data generated by our novel fECG signal generator suggest that adaptive neuro-fuzzy inference systems could produce a significant advancement in fetal monitoring during pregnancy and childbirth. The possibility of using a single device to © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. leverage two advanced methods of fetal monitoring, namely noninvasive cardiotocog‐ raphy (CTG) and ST segment analysis (STAN) simultaneously, to detect fetal hypoxic conditions is very promising.
2 citations
01 Nov 2019
TL;DR: All three ICA-based algorithms could be used for fECG extraction but the lowest accuracy was achieved by the algorithm called kurtosis maximization ICA, which indicates that signals after filtration are almost similar to the reference signals.
Abstract: This article deals with fetal electrocardiography (fECG) processing using independent component analysis (ICA). Testing is performed on 7 synthetic recordings with a different level of signal-to-noise ratio (SNR) and the evaluation is performed on calculation of improvement SNR and root mean square error (RMSE). The experiment was based on testing multiple algorithms based on the ICA method, such as the algorithm based on kurtosis value, the algorithm based on negentropy value and the algorithm called kurtosis maximization ICA. The results showed that all ICA-based algorithms a lot improve SNR and have a low value of RMSE, which indicates that signals after filtration are almost similar to the reference signals. All three ICA-based algorithms could be used for fECG extraction, but the lowest accuracy was achieved by the algorithm called kurtosis maximization ICA.
1 citations
Cites background from "Comparative Study of Influence of N..."
...It is true that the more the prediction error approaches zero, the better predicted signal corresponds to the original signal [16]....
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References
More filters
01 Jan 1978
TL;DR: A comprehensive catalog of data windows along with their significant performance parameters from which the different windows can be compared is included, and an example demonstrates the use and value of windows to resolve closely spaced harmonic signals characterized by large differences in amplitude.
Abstract: This paper makes available a concise review of data windows and their affect on the detection of harmonic signals in the presence of broad-band noise, and in the presence of nearby strong harmonic interference. We also call attention to a number of common errors in the application of windows when used with the fast Fourier transform. This paper includes a comprehensive catalog of data windows along with their significant performance parameters from which the different windows can be compared. Finally, an example demonstrates the use and value of windows to resolve closely spaced harmonic signals characterized by large differences in amplitude.
7,130 citations
TL;DR: In this article, several methods of power system harmonics estimation are critically reviewed and classified based on the type of analysis tool and applications and the key issues and challenges in harmonics estimations are highlighted.
185 citations
25 Apr 1989
TL;DR: It is shown that some relationships used in interpolation are affected very little by the number of processed samples, so that only the characteristics of the analyzed signal and the required accuracy affect the choice of this parameter.
Abstract: It is well-known that in discrete-Fourier-transform- (DFT-) based waveform analysis of multifrequency signals, spectral parameter accuracy can be increased by windowing the time samples and interpolating the DFT coefficients. It is shown that some relationships used in interpolation are affected very little by the number of processed samples, so that only the characteristics of the analyzed signal and the required accuracy affect the choice of this parameter. In particular, this makes the approach well suited for real-time analysis of signals with slowly time-varying spectra. Polynomial approximations of some relationships reduce the processing effort and, allow a greater freedom in the choice of the window functions, improving both accuracy and frequency resolution. >
184 citations
01 Apr 1992
TL;DR: In this article, the influence of windowing on the accuracy of a frequency-domain procedure suitable for real-time estimations of multifrequency signal parameters was investigated, and simple and accurate expressions for the estimator variances were established.
Abstract: The author investigates the influence of windowing on the accuracy of a frequency-domain procedure suitable for real-time estimations of multifrequency signal parameters. Imposing very weak assumptions about the statistical description of the noise, simple and accurate expressions for the estimator variances are established. They allow both the evaluation of the result accuracy and the design of the measurement procedure. Simulation results confirm the validity of the presented analysis. >
167 citations
TL;DR: A new technique for estimation of the instantaneous frequency based on simultaneous sampling of three-phase voltage signals is presented, which provides better performance, compared with the technique based on a single-phase signal in relation to waveforms with noise.
Abstract: A new technique for estimation of the instantaneous frequency based on simultaneous sampling of three-phase voltage signals is presented. The structure consists of two decoupled modules: the first is for adaptive filtering of input signals, and the second is for frequency estimation. A suitable and robust algorithm for frequency estimation is obtained. This technique provides better performance, compared with the technique based on a single-phase signal in relation to waveforms with noise. The technique is particularly important when asymmetric sags generate zero voltage in one of the three phases. In addition, it allows the measurement of the instantaneous frequency value of real signals for single- or three-phase systems. To demonstrate the performance of the developed algorithm, computer-simulated data records and calibrator-generated signals are processed. The proposed algorithm has been put to test with distorted three-phase voltage signals.
98 citations