# Questions tagged [noise]

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

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### Measuring level of background noise in a recording of a known audio file being played in an environment

I'm trying to solve the following scenario: A digital music player plays audio in a public space I have a microphone recording that audio in the space I want to compare the noisy recording and the ...
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### How to use numpy covariance result to get a correction factor and make my second signal to exactly overlap on my first signal?

covariance = np.cov(y1_interp, y2_interp) print('covariance is', covariance) covariance is 0.00010861874695023591 This number shows how different my signal 2 ...
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### $\frac{\mathbb{E}[P]}{\mathbb{E}[N]}$ vs. $\mathbb{E}\left[\frac{P}{N}\right]$

This is a very simple question arised from my considerations in here: Log-normal shadowing and mean power. I have understood that SNR is often defined as $$\frac{\mathbb{E}[P]}{\mathbb{E}[N]},$$ but ...
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### How to remove noise from the signal?

I'm new to DSP and currently working on time-series data. The mentioned time series (of Toe) is extracted from a video tracking various body parts of an athlete. Ideally, there shouldn't be any ...
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### Noise variance and sampling

I am new to signal processing, so please bear with me. My question applies to any general problem of estimation from noisy measurements but I will like to understand this through a problem given here. ...
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### Generating violet noise with a specific PSD coefficient

I am trying to generate a time-domain violet noise signal with the following power spectral density (PSD): $$S_n(f) = A^2f^2$$ Unfortunately, I am having trouble finding the right amplitude ...
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### Estimating shot noise - what's the origin?

If I have some photon detector, say a CCD, how do I estimate the error introduced by shot noise correctly? Typically, sources found on the internet say that the shot noise is the square root of the ...
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### Help generating non-Gaussian noise

I'm trying to add non-Gaussian noise to an image. The purpose is to synthesize realistic camera noise. I am doing the following: Obtain a noisy image sample by subtracting a low ISO photo from a high ...
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### What kind of noise features should I know before removing them programmatically?

This is my first question here in DSP StackExchange and honestly speaking I don't have any experience in this field, but one of the school project I'm currently working in is building an application ...
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### Time warping / frequency modulation natural examples?

"Time warping" defined as $$x(t) \rightarrow x(t - \tau(t))$$ where $|\tau'(t)| < 1$ ($=1$ is time stopping, $=0$ is time shift, $>1$ is time reversal). Where can this occur? A ...
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### How to smooth wiener deconvolution result in Python?

I'm wondering if it is possible to smooth the estimated response from a Wiener deconvolution in order to have a better representation of the original signal and to remove the side lobes. (Here an ...
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### Noise model as Sinc function

In "Fundamentals of signal processing: estimation theory", example 3.13 Kay has used a model of band-limited Gaussian noise with a uniform PSD and a sinc autocorrelation function. I expected ...
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### How to convert SNR to Eb/N0 in Chirp Spread Spectrum modulations

This question is related to Conversion between Eb/N0 and SNR in spread-spectrum modulation like LoRa CSS?. However I couldn't solve my issue. I'm simulating a Binary Orthognal Chirp Keying ...
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### A filter removing forbidden information in the stop-band

Is it possible, and how could it be done, to make an extension of filters that converts the signal in the filter's stop-band into noise with no information content or at least with zero correlation to ...
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### Impulse response $h[n]$ of a non linear I/O equation

my question concerns an assignment that was given to us at school. We have been given a list of I/O equations and it is required, for each of them, to find the impulse response $h[n]$ and the ratio ...
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### Having trouble working understanding a noise shaping filter

As context, I'm trying to understand and implement this Von Karman turbulence model in a simulation I'm working on. In order to generate turbulence velocities on the fly using the model, a ...
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### Calculating threshold in white noise for multiple pulses

I want to calculate the threshold for a given probability of false alarm (PFA) in a system, in which the noise is given by a coherent summation of three white Gaussian noise signals. Of course, there ...
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### Remove Noise from Discrete Signal with given Noise Model

I am interested in finding the true signal $p \in \mathbb{R}^D$ of an observed discrete signal $t \in \mathbb{Z}_{+}^D$. I know that each observed $t_{i}$ with $1 \leq i \leq D$ is the result of a ...
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### The power of signal processing when faced with hardware constraints

I am currently studying interferometry, but I have only just begun studying signal processing. I want to better understand the effect signal processing can have in maximising signal detection from ...
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### Classification of very noisy EMG signals

I'm an absolutely newbie to signal processing. I'm trying to classify EMG signals which are very noisy (decibel values are more than -70 dB in some cases). After applying EMD technique these values ...
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### How to extract noise from a signal in order to get both noise power and signal power

I have to implement a function to get an accurate SNR value. For that, I would need a separate noise signal to get the signal power and noise power but I have only one noisy signal (a .wav file.) ...
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### How to Remove Temporal and Fixed Pattern Noise and Apply Tone Mapping?

I have a video, whose frames I have extracted and require to work with. 16 bits and grayscale images. My task is to improve the quality of the images, by removing the noise + adding tone mapping and ...
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### Change spectrum and normalization

I have a question about magnitude of a spectrum. My task is to build the spectrum and make IFFT - the result waveform should have unity amplitude. For example: Create 2 arrays with Magnitudes and ...
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### Noise Removal and Signal Decomposition

I am quite new to DSP but its tools are required for my current project. I need advice on how to approach certain issues. I have multiple experimental datasets, which can be split in to three ...
In my work I need to use this signal of complex symmetric gaussian noise signal represented as $w$. But I don't know exactly how to represent it