FRFT Based Method to Estimate DOA for Wideband Signal

2013 ◽  
Vol 712-715 ◽  
pp. 2716-2720 ◽  
Author(s):  
Wei Yang ◽  
Yao Wu Shi
Keyword(s):  
Fractional Fourier Transform ◽  
Signal To Noise Ratio ◽  
Doa Estimation ◽  
New Method ◽  
New Technique ◽  
Signal Frequency ◽  
Signal To Noise ◽  
One Dimensional ◽  
Time Frequency ◽  
Better Than

This paper presents a new direction-of-arrival (DOA) estimation for wideband sources, using fractional Fourier transform with fitting angle (F3A). Unlike other coherent wideband methods, the new method does not require any preprocessing for initial values and decomposing into narrowband components. This new technique estimates DOA by rotating the time frequency plate with the fitting angle to fit the time frequency distribution approximately. The algorithm can be applied to arbitrary shaped one dimensional or two dimensional arrays. The signal frequency can be higher than the frequencies in many wideband algorithms. The performance of this wideband technique is compared with that of the new method through simulations. The simulations show that this new technique performs better than others, while this algorithm does not apparently vary with signal-to-noise ratio (SNR).

Time-Frequency Correlation Method for Improving the Accuracy in Detecting Leaks in Pipelines

2013 ◽  
Vol 650 ◽  
pp. 443-446 ◽  
Author(s):  
Valeriy Stepanovich Avramchuk ◽  
Valeriy Ivanovich Goncharov
Keyword(s):  
Signal Analysis ◽  
Method Development ◽  
Signal To Noise Ratio ◽  
Correlation Method ◽  
Signal Frequency ◽  
Signal To Noise ◽  
Frequency Correlation ◽  
Time Frequency ◽  
Valid Signal ◽  
Spectrum Data

This report offers the solution that allows increasing the correlation leak detectors accuracy to a certain extend. This solution is based on signals frequency spectrum data and signal analysis time-frequency correlation method development. The idea is to analyze the correlation of two signals, to determine valid signal frequency limits and to set on this basis frequency filters parameters to improve signal-to-noise ratio.

Estimating Optimum Filter Length in Linear Prediction

1997 ◽  
Vol 51 (5) ◽  
pp. 718-720 ◽  
Author(s):  
O.-P. Sievänen
Keyword(s):  
Raman Spectra ◽  
Prediction Error ◽  
Linear Prediction ◽  
Signal To Noise Ratio ◽  
New Method ◽  
Signal To Noise ◽  
Filter Length ◽  
Optimum Filter ◽  
Good Signal ◽  
Prediction Filter

In this article a new method to estimate optimum filter length in linear prediction is described. Linear prediction was used to enhance resolution of a spectrum. In particular, the dependence of prediction error on filter length has been studied. With calculations of simulated spectra it is shown that the prediction error falls rapidly when the filter length attains its optimum value. This effect is quite pronounced when the spectrum has a good signal-to-noise ratio and the modified covariance method is used to calculate prediction filter coefficients. The method is illustrated with applications to real Raman spectra.

scholarly journals A method for presenting biomedical images based on a model of receptive fields of human visual perception

2021 ◽  
Vol 2091 (1) ◽  
pp. 012027
Author(s):  
V E Antsiperov ◽  
V A Kershner
Keyword(s):  
Image Processing ◽  
Visual Perception ◽  
Bayesian Learning ◽  
Signal To Noise Ratio ◽  
Receptive Fields ◽  
New Method ◽  
Human Visual Perception ◽  
Signal To Noise ◽  
Biomedical Images ◽  
Local Characteristics

Abstract The paper is devoted to the development of a new method for presenting biomedical images based on local characteristics of the intensity of their shape. The proposed method of image processing is focused on images that have low indicators of the intensity of the recorded radiation, resolution, contrast and signal-to-noise ratio. The method is based on the principles of machine (Bayesian) learning and on samples of random photo reports. This paper presents the results of the method and its connection with modern approaches in the field of image processing.

The Time-Frequency Analysis for Energy Dissipation Shed-Tunnel’s Rockfall Impact Signal Based on Wavelet Theory

2011 ◽  
Vol 243-249 ◽  
pp. 5085-5088
Author(s):  
Lin Feng Wang ◽  
Hong Mei Tang ◽  
Hong Kai Chen
Keyword(s):  
Energy Dissipation ◽  
Frequency Analysis ◽  
Calculation Result ◽  
Signal To Noise Ratio ◽  
Prevention Measures ◽  
Autocorrelation Analysis ◽  
Wavelet Theory ◽  
Signal To Noise ◽  
Time Frequency Analysis ◽  
Time Frequency

Shed-tunnel is one of common prevention measures along the highway. Through the wavelet theory we denoised the rockfall impact signal when the rock impact the ordinary shed-tunnel and the energy dissipation shed-tunnel. And then we evaluated the wavelet theory’s denoise effect by the signal-to-noise ratio. The calculation result indicated that the denoise effect is very good. At last, through the autocorrelation analysis and time-frequency analysis for the rockfall impact signal, it was found that the ordinary shed-tunnel’s impact signals didn’t have obvious frequency and the frequency contained many component,but the energy dissipation shed-tunnel’s impact signals had obvious frequency. So the energy dissipation shed-tunnel’s impact signals had a relatively fixed cycle and frequency. The received frequency of rockfall impact by the time-frequency analysis could provide the basis for the design of energy dissipation shed-tunnel’s natural frequency.

ROBUST SVD FILTERING FOR LOW SIGNAL-TO-NOISE RATIO SEISMIC DATA

Geophysics ◽  
2021 ◽  
pp. 1-51
Author(s):  
Chao Wang ◽  
Yun Wang
Keyword(s):  
Seismic Data ◽  
Signal To Noise Ratio ◽  
Singular Values ◽  
New Method ◽  
Signal To Noise ◽  
Coherent Noise ◽  
Edge Preserving ◽  
Singular Vectors ◽  
Reduced Rank ◽  
Noise Ratio

Reduced-rank filtering is a common method for attenuating noise in seismic data. As conventional reduced-rank filtering distinguishes signals from noises only according to singular values, it performs poorly when the signal-to-noise ratio is very low, or when data contain high levels of isolate or coherent noise. Therefore, we developed a novel and robust reduced-rank filtering based on the singular value decomposition in the time-space domain. In this method, noise is recognized and attenuated according to the characteristics of both singular values and singular vectors. The left and right singular vectors corresponding to large singular values are selected firstly. Then, the right singular vectors are classified into different categories according to their curve characteristics, such as jump, pulse, and smooth. Each kind of right singular vector is related to a type of noise or seismic event, and is corrected by using a different filtering technology, such as mean filtering, edge-preserving smoothing or edge-preserving median filtering. The left singular vectors are also corrected by using the filtering methods based on frequency attributes like main-frequency and frequency bandwidth. To process seismic data containing a variety of events, local data are extracted along the local dip of event. The optimal local dip is identified according to the singular values and singular vectors of the data matrices that are extracted along different trial directions. This new filtering method has been applied to synthetic and field seismic data, and its performance is compared with that of several conventional filtering methods. The results indicate that the new method is more robust for data with a low signal-to-noise ratio, strong isolate noise, or coherent noise. The new method also overcomes the difficulties associated with selecting an optimal rank.

MIMO Detectors: A Comprehensive Performance Analysis

2021 ◽  
Vol 16 (3) ◽  
pp. 24-27
Author(s):  
E. Obi ◽  
B.O. Sadiq ◽  
O.S . Zakariyya ◽  
A. Theresa
Keyword(s):  
Error Rate ◽  
Mimo Systems ◽  
Signal To Noise Ratio ◽  
Minimum Mean Square Error ◽  
Multiple Input Multiple Output ◽  
Symbol Error Rate ◽  
Signal To Noise ◽  
High Data ◽  
Noise Ratio ◽  
Better Than

Multiple-input multiple-output (MIMO) systems are increasingly becoming popular due to their ability to multiply data rates without any expansion in the bandwidth. This is critical in this era of high-data rate applications but limited bandwidth. MIMO detectors play an important role in ensuring effective communication in such systems and as such the performance of the following are compared in this paper with respect to symbol error rate (SER) versus signal-to-noise ratio (SNR): maximum likelihood (ML), zero forcing (ZF), minimum mean square error (MMSE) and vertical Bell laboratories layered space time (VBLAST). Results showed that the ML has the best performance as it has the least Symbol Error Rate (SER) for all values of Signal to Noise Ratio (SNR) as it was 91.9% better than MMSE, 99.6% better than VBLAST and 99.8% better than ZF at 20db for a 2x2 antenna configuration., it can also be deduced that the performance increased with increase in number of antenna for all detectors except the V-BLAST detector.

A New Method Using Chirp-Matching OPCPA Scheme for Improving Signal-to-Noise Ratio of Ultrashort Laser Pulse

2011 ◽  
Vol 31 (7) ◽  
pp. 0719001
Author(s):  
曾曙光 Zeng Shuguang ◽  
张彬 Zhang Bin ◽  
李现华 Li Xianhua ◽  
孙年春 Sun Nianchun ◽  
隋展 Sui Zhan
Keyword(s):  
Laser Pulse ◽  
Ultrashort Laser Pulse ◽  
Signal To Noise Ratio ◽  
New Method ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Ultrashort Laser

scholarly journals DOA Estimation for UCAs Based on Virtual Subarray Beamforming Technique

2018 ◽  
Vol 232 ◽  
pp. 01012
Author(s):  
Bo Xu ◽  
Zhigang Huang
Keyword(s):  
Signal To Noise Ratio ◽  
Estimation Method ◽  
Direction Of Arrival ◽  
Doa Estimation ◽  
Signal To Noise ◽  
Circular Arrays ◽  
Noise Ratio ◽  
Subarray Beamforming ◽  
Beamforming Technique

Direction-of-arrival (DOA) estimation is always a hotspot research in the fields of radar, sonar, communication and so on. And uniform circular arrays (UCAs) are more attractive in the context of DOA estimation since their symmetrical structures have potential to provide two directions coverage. This paper proposed a new DOA estimation method for UCAs via virtual subarray beamforming technique. The method would provide an acceptable DOA estimate even if the number of sources is great than the number of array elements. Also, the performance of the proposed method would hold good when the snapshot length or the signal-to-noise ratio (SNR) is small. Simulations show that the proposed technique offers significantly improved estimation resolution, capacity, and accuracy relative to the existing techniques.

scholarly journals Energetic and Informational Components of Speech-on-Speech Masking in Binaural Speech Intelligibility and Perceived Listening Effort

2019 ◽  
Vol 23 ◽  
pp. 233121651985459 ◽  
Author(s):  
Jan Rennies ◽  
Virginia Best ◽  
Elin Roverud ◽  
Gerald Kidd
Keyword(s):  
Speech Intelligibility ◽  
Signal To Noise Ratio ◽  
Spatial Separation ◽  
Signal To Noise ◽  
Listening Effort ◽  
Complex Sound ◽  
Time Frequency ◽  
Sound Fields ◽  
Energetic Masking

Speech perception in complex sound fields can greatly benefit from different unmasking cues to segregate the target from interfering voices. This study investigated the role of three unmasking cues (spatial separation, gender differences, and masker time reversal) on speech intelligibility and perceived listening effort in normal-hearing listeners. Speech intelligibility and categorically scaled listening effort were measured for a female target talker masked by two competing talkers with no unmasking cues or one to three unmasking cues. In addition to natural stimuli, all measurements were also conducted with glimpsed speech—which was created by removing the time–frequency tiles of the speech mixture in which the maskers dominated the mixture—to estimate the relative amounts of informational and energetic masking as well as the effort associated with source segregation. The results showed that all unmasking cues as well as glimpsing improved intelligibility and reduced listening effort and that providing more than one cue was beneficial in overcoming informational masking. The reduction in listening effort due to glimpsing corresponded to increases in signal-to-noise ratio of 8 to 18 dB, indicating that a significant amount of listening effort was devoted to segregating the target from the maskers. Furthermore, the benefit in listening effort for all unmasking cues extended well into the range of positive signal-to-noise ratios at which speech intelligibility was at ceiling, suggesting that listening effort is a useful tool for evaluating speech-on-speech masking conditions at typical conversational levels.

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