Questions tagged [snr]
Signal-to-Noise Ratio
106 questions
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Lowest processable signal level after FFT with given noise level
I have the following problem:
I have to amplify a low voltage level signal which is the output signal of a sensor. The signal is always a sine wave with f = 1 kHz and no DC offset. After amplifying ...
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Can the transmitter verify the correctness of the SNR reported by the receiver?
Consider a point-to-point communication system, in which the receiver reports an incorrect SNR (deliberate/undeliberate) to the transmitter. Is there a way for the transmitter to verify this? (In HARQ ...
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Fundamental Question on Noise Figure
I'm doing a course on noise and came across Noise Figure. It is said that noise figure for a circuit can never be less than 1.
But we typically say we remove noise by using filters.
So if the output ...
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SNR calculation
I want to calculate the SNR of the following signal (the blue signal):
The signal peak value is: 0.0292 V
The noise peak value is: 0.0012 V
Based on the following formula:
SNR=20 log(Vp-Signal/Vp-...
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Noise added by an amplifier when deriving Friis's formula
I have been asked to derive the equivalent noise factor for a cascaded system of two amplifiers. Here is the figure of the system (assuming a general configuration where \$ G_1 \$ and \$ G_2 \$ are ...
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Plotting signal to noise ration (SNR) in SPICE softwares
I want to plot SNR in TINA TI software, do you have an idea how can I plot do it?
In this software I just have access to total noise plot and data as follows: (what would be the relationship between ...
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SNR simulation and "desired output signal"
I'm simulating an amplifier and want to know if it is possible to define its SNR. A simulation in LTSpice shows that the circuit generates 42nV/Hz, but this value is independent from the input/output ...
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Why does this ADC noise calculation divide by 6?
I'm reading an article about ADC noise from ADI:
Seven Steps to Successful Analog-to-Digital Signal Conversion (Noise Calculation for Proper Signal Conditioning)
Let’s assume that we have a sensor ...
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Eliminating noise from ADC readings using digital filters
I need to take some measurements using MCU internal ADC from the following circuit, to be able to calculate the amount of current produced from the programmable current source which discharging the C2 ...
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How to calculate RMS noise from datasheet?
I am using an AD9833 DDS as a sine signal source for my circuit. The bandwidth will be 3.5MHz. I would like to calculate the RMS noise of the DDS for my bandwidth. The datasheet has a SNR ...
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DVB reception: Why do I need to add a coaxial cable to my installation to improve SNR of the signal?
I have the following installation:
Dipole antenna <------> Coaxial cable (3 m) <-----> DVB receiver
If I connect my dipole antenna directly to the DVB receiver, removing the coaxial cable (...
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Which noise sources dominate in a receiver?
For a radio receiver that digitizes over-the-air RF signals (such as an SDR), my assumption (as a DSP guy; pardon my hardware ignorance!) has been that thermal noise dominates total receiver noise, ...
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Confused about deriving the SNR at the input for an amplifier circuit
I'm learning about noise sources in circuits (and minimising them) but I'm having trouble understanding how I would derive the input SNR for an amplifier circuit with a voltage divided input. Without ...
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Why have a filter before the LNA in LoRa boards?
I've looked through some Semtech reference board schematics and found one strange thing: they put SAW filters both before and after the LNA. For example here is part from a Semtech reference board ...
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SNR (Signal noise ratio) calculation (RC filter)
I would like to know how to calculate the SNR after a RC filter (let's say 1k-100nF as example). My input signal is 0.5Vrms, and the noise of the signal is 1mVrms, that's give me SNR = 54dB.
But what ...
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How is a GPS receiver able to calculate SNR?
I know that there is a certain relation between bit error rate and SNR for every modulation scheme. But i wonder how a GPS receiver can measure bit error rate and how it able to calculate SNR (I could ...
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What is SNR in this case?
I try to measure the SNR for a light input from a system. I will use a photodetector/photodiode which is a current source(linearly proportional to the to optical signal).
With 50 Ohm termination, I ...
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How to estimate SNR on a spectrum analyser
In the picture, the spectrum analyser shows 1kHz has about -5dB and noise between -40dB and -60dB (I'll just pick a value somewhere in the middle, or -50dB). So the SNR according to the equation:
$$ ...
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Noise Figure of an Attenuator
it is known that the noise figure of an attenuator is equal to its attenuation coefficient L. A proof of this statement is provided here.
Basically, it uses the formula (Reference):
$$F = 1 + \frac{...
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Difference between a lock in amplifier and an oscilloscope
I'm a physics student and in my lab we are currently dealing with lock-in amplifiers.
So far the thing that I found out is that an oscilloscope displays a signal in the time domain and a lock-in ...
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Improving SNR by increasing resistor value
I was doing some reading on noise improvement and stumbled on an article by Scott Hunt at Analog Devices.
Here is the reference link: https://www.analog.com/en/technical-articles/11-myths-about-analog-...
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Measuring SNR on a mulltiplexed coax power and data cable
Please excuse the basic knowledge I have in this field.
Within my workplace, we constantly use long 300m-6km coax cable which carries HV (Up to 400VDC) and DSL data.
We have encountered problems ...
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GNSS module direct grounding to ESP32 increase sensitivity
I have a simple cirquit that composes of the following :
ESP32-DevKit-LiPo (ESP32-WROOM)
GNSS Module Beitian BN-357P with ufl connector for external antenna
GNSS Active Patch Antenna
My simple is ...
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Signal to noise degradation based on noise temperature vs noise figure
I have a question regarding the signal to noise degradation after a device with a known noise figure.
I must be wrong in some of the assumptions I'm making. As far as I know, the S/N degradation ...
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What is a good SNR for a medical device like a pulse oximeter?
What is a good SNR for a medical device like a pulse oximeter?
Is there a U.S. Federal standard for this?
Thanks!
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How to add SNR for elements in series
Say I have a signal with a SNR of 100 dB. I pass it through an ADC with 16 bits. Since the ADC will have a SNR of 6*N + 1.77 dB, how can I calculate the final SNR of the signal?
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Complete ADC SNR formula when signal is not full scale
I am very in pain to find a (any) paper giving more than the traditional SNR for full-scale wave sampled by ADC
$$ SNR(Full Scale Waveform) = 6.02N + 1.76 (dB)$$
As far as I can remember if the signal ...
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what is the SNDR of non linear response
i have an input of
$$v_{in} = \sin{(2\pi\cdot f\cdot t)}$$
$$V_{out}=0.5+10\cdot V_{in} +0.1 \cdot V_{in}^3$$
SNDR is the ration between the power of the signal and the power of the noise .
in the ...
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The relationship between bit depth and SNR in ADC
An 8-bit audio signal has a theoretical maximum SNR of 48.16 dB (20log(2^8)).
My question then would be, does this work in reverse, i.e. would an analogue audio (or video) signal with an SNR of <=...
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How calculate the error offset or the noise threshold for MyoWare and FSR sensors?
I am working on EMG and FMG signals to extract time domine features and i need a threshold value for some features. I must calculate it from the characteristics of MyoWare and FSR sensors.For the ...
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Does dividing a clock increase its jitter?
I want to have my microcontroller and ADC using a clock derived from the same source in an effort to avoid intermodulation effects. All clocks are under 50 MHz.
The maximum SNR out of an ADC is ...
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How to plot BER Vs SNR of a received signal
I am using USRP to transmit and received MIMO frames similar to Wi-Fi standard that I created on my own. After receiving the signal, it is processed as described in the standard.
While I plot the ...
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Detection of signals buried in noise
This is more of a general question to see which methods are the most common to improve the detection of a signal which is buried in noise. Currently, we are building an optical system for medical ...
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Concept of matched filter maximising SNR
The above question is a solved question from Digital Communication by Proakis . The question is about matched filter where I know matched filter is used to maximise the signal to noise ratio at the ...
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How to improve SNR by averaging multiple identical sensors - hardware or software?
My application uses a MEMS microphone amplified by an AD8429 instrumentation amplifier with a bandpass filter to acquire signals. The phenomena I'm measuring occurs at a specific frequency and so I ...
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Can Decimation be used to improve the SNR of a signal?
While researching SNR improvement techniques, I came across many techniques, mostly the application of digital filters and windowing. Shortly, I read an article that said that performing decimation ...
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What could potentially affect some specific LoRa frequencies among others and how to mitigate it?
I have started a small LoRaWAN network. I already have setup:
1x LoRaWAN gateway (LAIRD RG186, using EU863-870);
4x T/RH Nodes (Dragino LHT65, same standard);
LoRa ...
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To find theRMS noise voltage in a circuit, can the measured RMS voltage be subtracted from the RMS voltage of shorted probes?
I'm trying to estimate the SNR of a circuit, which includes measuring the noise power of an analog trace. Right now, I'm attempting to measure the noise with a high bandwidth scope probe, ac coupled, ...
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Definition of ENOB, SNDR for sigma-delta ADC
The general definition of each are the following:
\$ENOB=\frac{SNDR_{max}-1.76}{6.02}\$
Where
\$SNDR_{max}=10 \log{\frac{S_{s,max}}{S_n}}\$
And
\$S_{s,max}\$ : maximum signal power
\$S_n\$ : ...
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How to approach the SNR needed for this electronic instrumentation
I have an issue with using concept of SNR in many instrumentation. To ask the question more clear, I want to go with a particular example.
Let's say a Wheatstone bridge type 500N nominal force ...
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Why would smaller LSB reduce SNR performance in an ADC?
As a follow up to my previous question there is another argument I have difficulty to understand. First here the related information from the text:
Above what I understand is there are two ways to ...
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DC Free Transmission SNR
My SNR is better with DC Free transmission. Why?
Example:
1.) Datasignal with DC:
Datastream consisting of 0V and 1V.
2.) Datasignal without DC:
Datastream consisting of -0.5V and 0.5V.
The ...
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How to find the source of a noise in a particular band
The problem:
The ADSL2+ service at home is not performing up to its potential. The modem is supposed to sync at 16 Mbps (downstream) but the it does only up to 11.5 Mbps. Using the diagnostic tools ...
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Determining required signal SNR (beat signal from FMCW RADAR)
I'm trying to determine the SNR required for signal outcoming from FMCW Radar.
This is the chain: signal will created by "24 GHz VCO and PGA with 2-Channel PA Output" by triangle shape frequency ...
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Maximum rate Shanon Hartley
i am reading computer networks and i am trying to solve an excercise.
the excercise is
What is the theoretically the maximum rate at which data can be transmitted to a 4000Hz bandwidth ...
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How to improve this microphone phantom power supply to have better SNR?
I built this power supply for my Schoeps CMT30F vintage microphones:
It works, but it's not the best I can expect in terms of SNR.
What would do you to ensure the SNR is the best possible?
Use 0,1% ...
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SNR wall definition
I want to ask you if my understanding of the definition of the so called "SNR wall" is correct and complete. The SNR wall phenomenon is described here and here. If one has further information that ...
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Why is the dB of the FFT plots exceeding 96dB for these signals sampled by an 16 bit ADC
There is a 16-bit data acquisition board and below is the recording of 120 seconds of voltage input at 500Hz sampling rate. The blue plot corresponds to the input voltage Vin and the green plot output ...
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Does SNR improve at higher sampling rates for a low pass filtered signal?
Let's say we want to extract 1Hz signal from a noisy signal by using a LPF.
And assume we have sampled it with 100Hz sampling rate.
If we would have sampled it with 1kHz sampling rate and use the ...
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Effects of increasing current on external noise and SNR for analog transmission
This is a conceptual question about long analog signal transmission exposed to capacitive coupling and EMI noise as shown in below figures:
simulate this circuit – Schematic created using ...
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