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.

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The relation between throughput, SNR and bits per channel use

Typically when describing a new scheme of modulation we see how many bits can be encoded on a particular symbol. This is dependent on the size of the constellation in the complex plane and we say $$ ...
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SNR After Multiplying Two Noisy Signals

If I have two noisy signals where the noise is not correlated and I know the SNR of each signal, how would I find the SNR after multiplying the two signals together?
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Why the SNR is very high?

In a cellular network, let us say that I have these parameters: Transmit power = 30dBm Noise spectral density = -174dBm/Hz (AWGN) Bandwidth = 10MHz Let us say ...
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SNR and noise in Simulations

I've always taken the definition of noise and SNR for granted in doing BER simulations in an AWGN channel. I would usually use the AWGN noise function and make a loop with varying SNR values. However,...
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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: ...
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46 views

How to evaluate quality of signal?

I'm trying to evaluate received signals from a transceiver. I want to make a threshold of received signals so that we can say some signals are meaningless. I have learnt something about Signal-to-...
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66 views

Sampling Rate and SNR

Assume I have a signal that oscillates between 10KHz and 9Khz every 500msec (Change happens linearly, so at t=0, it is 10KHz and it goes to 9.5Kz at t=250msec and 9KHz at t=500msec and frequency start ...
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Adding two audio files at a predefined SNR level

I have two speech audio wav files. file1 is primary speech, file2 is supposed to be interference. I want to add them so that ...
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43 views

What is signal to noise per sample?

We have heard about SNR. The ratio of signal power to noise power. As such we should calculate the powers of the signal and the noise and take the ratio of them. But in MATLAB documentation - in ...
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Why does increased kernel bandwidth equate to increased SNR values?

If I apply a Gaussian Kernel to an image with some noise applied to it and I want to remove that noise, why does the Signal to Noise Ratio increase as I apply kernel's with higher and higher sigma ...
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103 views

how do i calsulate SNR of a noisy signal without having the noise?

i want to calculate the SNR value of a speech signal in matlab having only the clean and the noisy one and not the noise.what should i do?
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36 views

Basics of signal simulation in MATLAB

I'm trying to get my head around signal simulation in MATLAB/octave and generation of AWGN using 1: n = sqrt(1/EbN0)*randn(1,N); vs 2: ...
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172 views

CQI to SNR mapping in LTE

I would like to understand how the CQI-SNR mapping changes according to the type of channel. I guess, the mapping presented in 3GPP TS 36.213 that goes from CQI=0 to CQI=15 and efficiency from 0.1523 ...
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Calculating the SNR from the power spectrum

I have a signal that is sampled at 20 Hz. It has almost stationary behavior, with a main frequency around 1.0-1.5 Hz. This frequency range is to be expected and is of interest for further processing. ...
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Understanding “voltage” and “power” in SNR of a sampled signal

I'm facing a gap in my understanding of when a signal is a "voltage" signal and when it is a "power" signal that I've always managed to avoid resolving until now... First what I think I understand, ...
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49 views

Quantization SNR of bipolar signal

I want to estimate the SNR of a bipolar signal. I know that each bit increases the SNR at 6 dB. Do i have to subtract one bit for sign, so that for bipolar signals the SNR is (n-1) x 6 dB ?
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Why does the BER rate change randomly versus the SNR?

I have altered a MATLAB code that simulates the BPSK modulation using a raised cosine filter at the transmitter and a matched filter at the receiver to study how the signal changes in each step. But, ...
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Obtaining SNR from SINR - 802.15.4

In the 802.15.4 standard, the following equation is used to calculate the BER: $$BER = 0.5 e^{-SINR/2} $$ I would however for my simulations like to avoid using SINR but rather SNR. I would like to ...
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How do I calculate the noise variance in this problem?

In a paper about radar, the transmitted signal expressed in low-pass equivalent form is given by $\sqrt{E}s(t)$, where $E$ is the transmitted energy, $s(t)$ satisfies $$ \int_T | s(t) |^2 dt = 1, $$ ...
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Question about SNR in continuous and discrete domain

How to make sure the discrete domain's SNR equals to the corresponding SNR of continuous domain? If the definition of SNR in continuous domain is: $$SNR=\frac{\int_T|s(t)|^2dt}{noiseVariance} ...
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Understanding SNR in fading channels and MIMO systems

Signal to Noise ratio plays an important role in understanding the performance of any communication system. I understand the basic concepts of SNR but I am having trouble when trying to bring in a ...
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265 views

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 ...
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24 views

Signal to noise ratio for Word in noise

I want to mix several monosyllabic word with multitalker babble. I uses Adobe audition for measuring rms of the both. Duration of the word is less than 600 ms. Could I use this equation for SNR?: SNR=...
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How to get SNR if we only have output noisy signal?

I only have access to a noisy signal obtained from a sensor which was kept static. I did apply filters to smoothen the signal: Zoomed in: So, it is visible that the amount of variation in the ...
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GNSS carrier to noise ratio in digital

I'd like to know, how can I calculate the carrier-to-noise ratio (C/N0 in db-hz) of the GNSS signal. For example I have a 2048 complex samples of the signal right after the matched filter. So I have ...
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63 views

Calculate signal to noise ratio from the Hillbert envelope of a stacked signal

I am working with seismic waveforms and more specifically with a stack of years of daily seismograms, that I would call the reference waveform. I am trying to calculate the SNR for each daily ...
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How to calculate SIR when the min signal level is greater than 0?

I want to calculate the signal to interference ratio. The type of noise I consider here is the intersymbol interference (ISI). Usually the SNR is calculated as the ratio between the integral (i.e. ...
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Does the quality of the pictures taken by a USB 3.0 camera depend on cable length?

I've got a JAI GO-5000-USB camera and have tried several cable lengths, ranging from 40cm to 5m. So far, I haven't observed many differences in the quality of the pictures I've taken. Since I want ...
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808 views

Calculating SNR for ECG signals

I'm reading through the literature for finding the best way to calculate SNR for a ECG signal. While there are many algorithms for improving SNR, I couldn't find any that details any standard ...
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289 views

How to calculate SNR before and after filtering for noise cancellation in an ecg signal in matlab?

I am working on noise cancellation in ecg signal and I want to calculate the Signal to noise ratio(SNR) before applying filter to the signal and after applying filter i.e., snr_before and snr_after. I ...
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How can noise be added to a signal to obtain a specific SNR?

How can I add noise to a recording to obtain a SNR value provided by the user? I am tryin to test the effects of noise on my algorithm. Is there any function or app for doing that kind of task? Thank ...
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463 views

Sampling rate effect on quantizer SNR

I am currently reading the 'Coding' chapter on Rabiner & Schafer's Book on speech processing. In one of its exercises, the reader is given a simple A/D converter using 16-bit uniform ...
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How to determine SNR from FFT of measured data?

I am doing impedance measurements, where I do a frequency sweep of a test current, and I measure the resulting voltage. Offline, I compute the FFTs of the voltage and current, and I want to make sure ...
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snr calculation when noiseless signal is not known

I have a noisy signal.Then using filtering techniques i got the estimated noiseless signal.I dont have the original noiseless signal.I have calculated snr the following way: $SNR=10log(...
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'A priori' and 'a posteriori' SNR

I am reading this paper about speech enhancement using a minimum mean square error short time spectral amplitude estimator for our speech enhancement project. Basically in the paper they mix a clean ...
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Confusion about how to calculate signal to noise ratio(SNR)?

I searched a lot but I didn't find a good answer. According to wikipedia SNR page, SNR can be calculated by both ratio of Power of clean signal to its noise Power either ratio of variance of clean ...
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Compare Overlapping FFTs to a longer FFT

How would you compare the SNR gain from a longer FFT (more samples) to overlapping FFTs? Given the choice, which one would you pick and why? Update: Suppose you have 2048 samples of a signal. ...
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300 views

Fixed SNR with unitary noise variance

I've just one question : How can I write a model like y = x + w,( with w a white gaussian noise) with a fixed SNR and a noise variance equal to 1. What coefficient may I have before x ? Thanks !
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How to calculate Signal-To-Noise Ratio

I am doing some analysis in python working with a photodiode. The signal is more or less periodic with some phase shifting in certain areas that give rise to faster or slower periods but overall still ...
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Generation of noise floor file for estimating signal-to-noise ratio of a wave file

I am trying to estimate the signal-to-noise ratio of a wave file (The wave file is a recording of a conversation in a room). I found examples where the Matlab scripts compare the wave file data to a ...
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Effect of noise and entropy

Relation of Entropy and SNR : Based on this question and answer, I had another question that struck me and I am curious to know, if somebody can shed some light, on the following situation: $y= ...
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Exercise related to frequency resolution and SNR

I'm studying a book aboud dsp and trying to make excercises. Here is one I'm interested in: A scientist acquires 65,536 samples from an experiment at a sampling rate of 1 MHz. He knows that the ...
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101 views

SINR averaging in communication system

Under the simulation of a communication system suffering from noise (AWGN) and co-channel interference, what is the appropriate way of calculating SINR? Could one calculate it at a packet level as: $...
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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?
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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 ...
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Can I compute signal-to-noise ratio on a vector-valued or multi-channel signal?

I have a dataset that contains multiple channels recorded over time (think EEG or EMG), and I'm working on a computational model for this data. When I have a working version of the model, I'd like to ...
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5k views

Measure the SNR of a signal in the frequency domain?

How do you measure the SNR of a sinewave in the frequency domain? (Assuming no filtering.) Suppose: $$x(n) = s(n) + n(n)$$ Create the signal (nCycles of a sinewave) in MATLAB...: ...
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High SNR value unacceptable

I am stuck in a situation here while calculating received SNR in AWGN channel. When I performed calculations directly in decibels, I got very high SNR value for instance 140 dB. I am using the ...
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How to separate a low amplitude signal of same frequency but different phase

I have a signal consisting of two sine waves of same frequency but have different phase (and also a lot of hf noise). Their amplitudes differ by about 120dB. How to I go about separating them? SNR is ...
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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 ...