In signal processing noise can be considered random unwanted data without meaning.

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2
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45 views

Noise analysis with periodogram. problem with different resolutions

I don't understand what happened in my simulation. I would like to perform a trade off between 2 ways to estimate power in frequency bands. I want to detect spurious frequencies. First method: I ...
0
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1answer
35 views

What is best practice to remove static noise?

What is best practice/algorithms to remove static noise from speech ? static noise aka Stationary Signal/static noise due to 1.humming sound due to of telephonic line/channel, 2.moving Vehicle,or ...
0
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1answer
64 views

Autocorrelation of white noise

Autocorrelation of white noise should have a strong peak at '0' and absolutely zero for all other $\tau according to this. Then why is output of this code a cone shape(with the expected 'strong peak' ...
-2
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2answers
57 views

Denosing signal using soft and hard thresholding

Let us consider following code: fs=100; N=1000; t=0:1/fs:N-1; y=10*sin(2*pi*100*t)+0.5*randn(size(t)); plot(y) plot(t,y) I have applied following threshold ...
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0answers
22 views

Open Source libraries to noise gate wav files [closed]

I am looking for a noisegate (rather "mute" audio ABOVE a particular threshold) to a particular level. Are there any open sourced code related to this ? Specifically, audacity has a popgate nyquist ...
1
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1answer
55 views

Digital Gaussian White noise signal generation in C++

I am trying to generate a band limited noise signal on a Raspberry Pi. I calculate samples at every 1/48000 sec on the Pi. If I generate normally distributed random numbers as data points at every ...
-1
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1answer
41 views

Parameters for signal analysis

I am extremely new to signal analysis. And before posting I did a lot of reading on signal analysis, FFT and windowing. I am working on my thesis which involves comparison of speech signals lets say ...
1
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0answers
25 views

What is OSNR in Fiber Optics?

I have seen that the SNR is measured for optical fibers "OSNR". What is the difference? Is there any equivalent?
0
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2answers
55 views

noise cancellation of non-repetitive noise

There are a new noise cancellation headphones that almost fully cancel human noise. What kinds of algorithms could achieve that ? EDIT:by human noise , i mean talking. In general, previous audio ...
0
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1answer
31 views

simulating range-bearing sensor with Matlab with Gaussian noise

I would like to simulate a sensor that provides range and direction of a beacon. This is for EKF localization, so the noise must be Gaussian (i.e. $\mathcal{N}(0, \sigma^{2})$. Also, I would like to ...
1
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0answers
28 views

Help in system identification

I am trying to study how to estimate parameters when the signal of interest is embedded in deterministic (chaotic signal) noise and additive white gaussian noise as the measurement noise. A ...
3
votes
1answer
64 views

Maximum likelihood estimation in presence of colored noise

I am trying to test system identification in presence of measurement noise (1) A white Gaussian noise (2) Colored noise - pink, violet. When we are estimating parameters we do so in presence of iid, ...
1
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1answer
98 views

How to filter uniform noise in a microcontroller?

By uniform noise I mean a band of a fixed width, no spikes, etc. This has to be one of the simplest examples. I'm looking for the appropriate theoretical approach as much as something relatively ...
2
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1answer
92 views

What is obtained from the cross correlation plot?

Let’s assume that we have two audio signals, x(t) and y(t) affected by the noise as shown below. And we would like to cross-correlate these two signals and the cross-correlation plot is shown as ...
0
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1answer
42 views

How to implement simple noise filter based on the frequency domain information?

Brief introduction: I am working on my university project. My task is to develop application that captures sound from mobile phone and removes/reduces noise (this simpilied version of task). I never ...
1
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0answers
18 views

Conceptual doubts on blind system identification

In some scenarios, a signal may be corrupted by chaotic noise (radar application) as $y = x + \text{chaotic noise} + AWGN$ Chaotic signal is deterministic, so in my opinion it will not have a pdf. ...
0
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0answers
20 views

What is deterministic noise and its effect

I have few conceptual questions related to application of chaos in communications. Kolmogorov-Sinai Entropy1 , Kolmogorov-Sinai Entropy2 and Kolmogorov-Sinai Entropy3 KS is an entropy metric for ...
1
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1answer
50 views

What is uncorrelated noise

In many applications such as estimation theory, when we need to estimate a parameter then we usually consider in presence of white gaussian noise of zero mean and some standard deviation. During ...
0
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0answers
36 views

Noisy Signal auto/cross-correlation

I am trying to understand the basics of the cross/auto-correlation if the noisy signal $y(t)$ which is received from the channel at the receiver. Here at receiver we want to estimate the noise in the ...
1
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0answers
44 views

Spectral estimation from noisy time-series data

This is the first time I'm posting a question on here so I hope I'm doing it right. I've tried searching on here for an answer but haven't found anything particularly relevant. I have some data ...
1
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2answers
100 views

Derivative of noisy signal

My input signal is phase vector. I want to differentiate it to get frequency vector. My input signal is somewhat noisy. Here is the input signal. This is the derivative of the input signal as ...
0
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1answer
41 views

Extract signal from big gaussian noise

I have signal, periodic with amplitude 10 with frequency about 10 kHz. It is hidden in Gaussian noise with standard deviation 100. Some idea how to extract periodic signal? Thanks in advance.
0
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2answers
40 views

Reason of circular conv in OFDM

In OFDM system, after IFFT a CP is added at the beginning of the OFDM symbol by copying it from the end of the symbol.My question is that with CP why we use cyclic convolution instead of linear ...
1
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2answers
66 views

A [Very] Rough Approximation to “White Noise” with Sine Waves

This might be a silly question, but I'm pretty rusty on my signals. The problem is the following: I'm using a program which does not have a random signal generator, but I can sum up sines; and I need ...
0
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1answer
61 views

Adding measuruments noises to kalman filter

I'm implementing navigation system for my robot. There are two ways to get data from it: odometry(encoders from motors) and camera. Both of information sources can give me estimate of robot's ...
2
votes
1answer
57 views

Determining power of white noise component of an incomplete time signal

I want to determine the power of the noise component of a time dependend signal x(t) (similar to picture below) With constant sampling rate I use Parceval's Therorem and calculate the standard ...
2
votes
1answer
76 views

Removing baseline drift from ECG signal

I am trying to design a high pass filter to remove baseline drift from an ECG signal. the baseline drift is of very low frequency like 0.3Hz or so with an amplitude of 25% of the ECG signal. But the ...
1
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2answers
51 views

Adaptive gaussian filter for noise image

I am looking for methods to enhance noisy images, where: some pixels in the image are very noise, some other pixels do not contain so much noise. My first thought is to build an adaptive Gaussian ...
2
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0answers
43 views

Performance of adaptive signal processiong algorithm in noise not working

I am taking a course on signal processing and have been looking at various algorithms performance in presence of additive noise of different SNR. I was implementing Least Mean Square (LMS) algorithm ...
0
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2answers
102 views

Adding white noise to complex signal (complex envelope)

Good day everyone. So, i run in to trouble - how to add white noise to signal samples? For now i'm working with MSK signal - quadrature modulator and quadrature demodulator + viterbi processor. My ...
2
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1answer
51 views

Forecasting noisy data with polynomials

What's the best way to incorporate polynomials or sinusoidal equations into a linear model to predict a future amplitude in this sort of data? You can see that if those polynomials continued to go on, ...
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2answers
92 views

Poisson noise and curve fitting - denoise first?

If I have an image that is severely corrupted by Poisson noise, and I want to fit a function to the image, is it "better" to attempt to denoise the signal first before fitting, or should I move ...
2
votes
1answer
67 views

Generating a time series given a transfer function

I'm trying to work my way through a paper I found online, titled "Three Models of Wind-Gust Disturbances for the Analysis of Antenna Pointing Accuracy" by W. Gawronski, 2002. ...
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2answers
201 views

How to find peaks and periods?

I am looking at data like this: Source data: http://pastebin.com/raw.php?i=L6cd8d5K The data is quasi-periodic, there is a distinct cycle but it is not an exact repeat, and the period changes ...
0
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2answers
130 views

Using Matlab xcorr to find a signal hidden behind noise

I am trying to develop some code to find a transient signal in a data set I have. Before I get there however I am trying to write code using simulated data. I first am creating a signal with a ...
-1
votes
1answer
108 views

How can I reduce noise errors when detecting DTMF with the Goertzel algorithm?

Thanks a lot to whoever downvoted my question for no good reason. I wrote an implementation of the Goertzel algorithm in JavaScript and made a demo that detects DTMF dial-tones. You can find the ...
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0answers
36 views

understanding 1D wavelet analysis

i would like to understand how should i use following code for code for detection of uknown frequencies?let us consider following signal ...
0
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0answers
28 views

Correcting outliers using the standard deviation of a two-point different function?

I recently read a research paper that discussed how to correct lightcurve data (flux vs. time) by using the method as explained below: We have considered as outliers in the datasets the individ- ...
0
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1answer
90 views

denosing given signal using wavelet

let us suppose that we have given following model $y(t)=A_1 \sin(\omega_1*t+\phi_1) + A_2 \sin(\omega_2*t+\phi_2) + A_3 \sin(\omega_3*t+\phi_3)+ \ldots +A_p \sin(\omega_p*t+\phi_p)+z(t)$ where ...
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0answers
58 views

Finding a signal in noisy data

I have a large data set that was collected by a 5 GHz oscilloscope, so I basically have an array of voltages with each index being a very small time step apart. I am looking for a specific signal in ...
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2answers
130 views

Audio signal dither and noise shaping

I'm trying to get a handle on the importance of the error feedback term in noise shaping operation in typical audio dither algorithms. I'm thinking in terms of four signals. The original signal, the ...
2
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2answers
103 views

How to understand the type of noise

Suppose that I am receiving RF signals contaminated with noise through antenna. This signal is digitally sampled. How can I understand the type of noise(Gaussian,Uniform etc). Any algorithm is there ...
0
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1answer
31 views

Finding correct values based on information from two arrays

Consider the following scenario: Say, one machine is sending out a beep signal every 10 seconds in a very noisy environment. I have two sensors which detects these beeps independently. Device A is ...
2
votes
1answer
71 views

Autocorrelation of noise - negative correlation

I am investigating autocorrelation of electrical noise as part of an undergraduate experiment (as detailed in http://physlab.lums.edu.pk/images/a/ab/Correlation.pdf). I sampled noise voltages using an ...
1
vote
1answer
46 views

Best Guess Rectangle

I am using openCV to find a particular object, and am trying to find a way to make it locate the object consistently. The object's location will be determined by taking 30 frames and trying to find ...
0
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1answer
111 views

ARMA models for non stationary signals

let us suppose that we have non stationary signal,whose value is given by ...
3
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4answers
125 views

Is there an algorithm for second order filtering of data where the filter frequency is not known a priori?

It is well known that a moving average algorithm done in the time domain is equivalent to a filter with frequency response $\mathrm{sinc}(\omega\tau)$ where $\tau$ is the averaging time. (see this ...
0
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2answers
137 views

Image Noise Detection Using MATLAB

I want to implement the following algorithm. Let I denote noisy image and for each pixel of I is represented by I(x,y). A Sliding window of size 3X3 centered at I(x, y) is defined. At first ...
5
votes
2answers
463 views

What is the math behind median filter's noise reduction property?

I am interested in understanding the mathematical reason for why does applying a median filter on an image (or signal) result in reduction of noise.
0
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1answer
54 views

Is the quantization noise white here?

If I have the following power spectral density of the quantization error can I tell that quantization noise is approximately white? Can you please provide some justification?