Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [snr]

Signal-to-noise ratio (often abbreviated SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise.

SNR is defined as the ratio of signal power to the noise power. A ratio higher than 1:1 indicates more signal than noise. While SNR is commonly quoted for electrical signals, it can be applied to any form of signal (such as isotope levels in an ice core or biochemical signaling between cells). Signal-to-noise ratio is sometimes used informally to refer to the ratio of useful information to false or irrelevant data in a conversation or exchange.

Source: Wikipedia – Signal-to-noise ratio

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how do I calculate SNR of noisy signal?

I am having problems in understanding how to do it practically I have a wav file that contains pure speech and another ave file that just contains the background noise (can be various things, such as white noise, crowd noise, a recording of blowing…
user13267
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Relationship between entropy and SNR

In general any form of enropy is defined as uncertainty or randomness. In a noisy environment, with increase in noise, I believe that entropy increases since we are more uncertain about the information content of the desired signal. What is the…
Ria George
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What are the various definitions for $\rm SNR$, and their associated methods for measuring it?

The definition of $\rm SNR$ seems to be somewhat of a tower of babel in industry. What definitions of $\rm SNR$ are there (feel free to site application), and how exactly can it be measured for that applications? My specific questions on $\rm SNR$…
Spacey
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What is meant by 20 dB signal-to-noise ratio?

I'm reading a paper in which a discrete signal $$x(n) = s(n) + w(n)$$ is considered. $s(n)$ is a known, deterministic series, and $w(n)$ is white noise with zero mean. The authors write that signals were generated with an SNR of 20 dB What does…
Anna
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How can you tell whether there's a signal (when your signal looks a lot like noise)?

This is my snoring detector again. I've gotten pretty good at detecting a signal when there's anything there -- can track from a wall-peeling snore down to breathing you can't even hear in the recording. The problem is, I can't tell when the signal…
Daniel R Hicks
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What is the connection between analog signal to noise ratio and signal to noise ratio in the IQ plane in a quadrature demodulation system?

We would like to compute the quantitative relation between analog noise near the LO frequency and the statistics of points found in the IQ plane after IQ demodulation. In order to completely understand the question we first give a detailed…
DanielSank
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How to estimate the signal-to-noise ratio of a waveform?

I have a signal: $f_i(t_i=i\Delta t)$, where $i = 0\ldots n-1$. The signal seems to vary quickly around a slower varying "trend". I am assuming that the quickly varying part is noise and the slowly varying part is the real signal. How do I estimate…
Andy
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Why is PSNR used for image quality metrics instead of SNR?

I have been trying to determine why is PSNR used instead of SNR for image quality metrics? I have read through several books and most just say that PSNR is used instead of SNR, but don't give a reason as to why. I also read these posts: Signal…
Veridian
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Quantization SNR of sine wave doesn't match 1.761 + 6.02 * Q

I am trying to show with numpy that the quantization noise of a sine wave matches the SNR formula of SNR = 1.761 + 6.02 * Q. The numpy code is simple: import numpy as np import matplotlib from matplotlib import pylab, mlab, pyplot plt =…
Tom Verbeure
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Calculating the SNR of Audio Signal (Recommended Libraries)

Are there any open source packages or libraries available which can be useful in calculating the SNR(signal to noise ratio) of an audio signal. The input will be just an audio signal and I have to calculate the SNR of that signal. Can anyone suggest…
shresthsoni
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How to define SNR for multiple signals in noise?

I have to estimate the number of signals present in a measurement contaminated by additive noise given $n$-dimensional snapshot vectors $\bf x$, modeled as $ \bf x = \bf A \bf s + \bf z $ where $\bf s$ is a $k \times 1$ vector representing $k$…
sauravrt
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Optimal amplitude of an $m$-bit sinusoid

A continuous-time sinusoid of zero-to-peak real amplitude $A \le 2^{m-1}-0.5$ (e.g., for $m=16$, $A \le 32767.5$) is quantized to $m$-bit resolution by rounding it to the nearest integer (Fig. 1). What is the optimal amplitude for different $m \le…
Olli Niemitalo
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Reducing noise from the same frequency band as signal

Sorry for the vague question (as I'm not even quite sure what I want to do is possible), just asking for some general direction to take my research. For a brief description, my signal resembles exponentially distributed noise, bandlimited, with a…
Luis Costa
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How to detect continuous noise in audio call?

We want to detect bad audio quality in audio call. Should we extract this information from amplitude or frequency spectrum ? Is there any technique/transform/filter available for this ? Example: I am attaching two signal graph(Clean Signal vs Noisy…
user31281
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Acoustic Scenarios With Negative SNR

For all the practicing engineers out there: Where have you encountered a negative SNR? How negative, in dB, was it or estimated to be? Where would you expect to encounter a negative SNR? Note: I am also counting interference signals as noise,…
The Dude
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