Questions tagged [noise]

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

Filter by
Sorted by
Tagged with
0
votes
0answers
19 views

Filtering a noise of F[sig] frequency [Example 20Khz] in measurement system

I am developing a system where there is inherent noise of F[sig] frequency. This is a DC measurement system and want to get rid of the noise by sampling at F[samp] samples per rate and taking multiple ...
0
votes
1answer
65 views

noise floor of attenuator

NF of attenuator is same as the attenuation value as the noise floor remains same but signal level gets attenuated? But NF of amplifier depends on the device as it increases both signal and noise?
0
votes
0answers
23 views

“How is the noise floor of RF section is mapped to ADC noise floor for a 10MHz BW?”

My interpretation is if a gain of 40 is used before AGC -40 dBm become 0 dBm and -121dBm (noise level) becomes -81dBm SNR remain same (assuming NF =0 for theretical purposes). Noise floor of ADC is (6....
0
votes
0answers
23 views

Legacy LongRange Mode information (mode 1 in the my attached link)

Mode 1- Legacy Long Range Packet Format and Im attaching a photo of ti reference: link for more information about this mode category : TI SWRA642 I want to understand the packet format, what's my ...
0
votes
0answers
22 views

Why does this maximum entropy method for noise removal not work?

I am trying implement the maximum entropy method (MEM) for image reconstruction or spectral filtering (based on various papers, e.g. "Image Restoration by a Powerful Maximum Entropy Method" ...
1
vote
1answer
43 views

Conceptual Questions on Colored Noise Process

I am having a tough time finding answers to some specific questions and finding references where there is information regarding Brownian noise or Red Noise. I'm referring to white and colored noises ...
1
vote
0answers
54 views

Respiration (breathing) signal movement artifact removal

Situation: I have breathing data of participants who have done different things during the study which caused their breathing change; watching mindless video to which resulted in unconscious regular ...
0
votes
1answer
57 views

How to calculate variance of noise on a noisy image (Noise+Signal)

I have a long exposure image captured at 70ms. (I1) (As attached) I also have another image captured at 0.7ms with Gain24. (I2) (As attached) This image has both noise and signal together. I would ...
0
votes
1answer
39 views

How to check my CRC of my RF packet? [duplicate]

The "problem" is that I want to validate if my received RF packet is valid or not valid, in other words I want to validate if my RF packet corrupted or not corrupted . the transmitter that ...
0
votes
0answers
46 views

Can adaptive filters filter noises that are of two different frequencies?

I am testing an adaptive filter using 5 different algorithms (LMS,NLMS,SE-LMS,SD-LMS,SS-LMS)to find which would be better fit for my application. The filter has 8 taps and my input are brain recorded ...
3
votes
3answers
309 views

Is white noise WSS by nature or not?

I want to know what is the difference between white noise and WSS white noise. is there any difference between them or they're equal? and what about white Gaussian Noise?
0
votes
0answers
18 views

How NLMS/LMS adaptive filter used for noise reduction acts on input signal with low frequencies(DC offset/baseline wander)?

I am using Matlab to implement a real-time adaptive filter of length 4 for noise cancellation using the NLMS method/ I also tried the LMS method. My aim is to denoise biomedical signals, and for the ...
-1
votes
1answer
42 views

LPF Filtering without changing DC value of signal

I have sampled my transmitted signal, it's looks like sinusoidal , frequency sampling is =2048Khz, bitrate of transmittion=100Kbaud , and my problem is that I have designed in matlab my LPF filter ...
1
vote
1answer
52 views

Low pass equivalent of bandpass white noise

Let $$n(t) = Re\{z(t)e^{j2\pi f_ct}\},\ $$ where $z(t)$ is the low pass equivalent of white noise $n(t)$. We know the autocorrelation of $n(t)$ is $$R_n(\tau) = \frac{N_0}{2} \delta(\tau),\ $$ $\delta(...
0
votes
1answer
26 views

Matched filter for recieved RF digital packet by LPF

Im transmitting by cc1350 launchpad microprocessor digital RF Packets, transmitted modulation FSK. bit rate of transmitting is 50Kbouad, frequency of transmitting is 868MHZ . Im sampling the signal(...
0
votes
1answer
27 views

How does filter works in noise reduction?

On page 22 of the slide, the 1D array is [1, 1, 1, 1, 1], but the dots are uneven. Then why their values are the same? What's the value of the point that the arrow is pointing at? Though it gives ...
0
votes
2answers
49 views

filtering my received Signal by LPF

I've received my transmitted signal that I sampled it on 20480000 frequency , transmitted frequency 868MHZ , bitrate 100KHZ , I see the "bits" that Im transmitting in my plot in matlab it ...
0
votes
0answers
20 views

Converting Received RF packets to binary file that RF packets sampled by dongle rtl-sdr

Im using #SDR software that I transmit packets from cc1350 launchpad to the air and I want to validate that if those packets are valid or not by checking its CRC. my problem is actually the step to ...
0
votes
1answer
25 views

Plotting a Time Frequency contour/colormesh plot of a Discrete Wavelet Transform

I have a pressure vs time data of a noise on which I wish to perform discrete wavelet transform. I have divided my frequency range into 1/3rd Octave Bands and have calculated sound pressure level at ...
0
votes
1answer
65 views

Showing that the sum of zero-mean noise is zero. Then computing the convolution of zero-mean noise with a given function

This is likely to be a quick fix for people with experience in stochastic processes. Let $ \eta[k] $ be a sequence of Uniform noise, $ \eta \sim U([-M,M]) $. I want to test if the following is correct ...
0
votes
1answer
42 views

How can I objectively measure train noise from a sound recording?

I have made an audio clip of some local train noise, and run it through a spectral analyser: https://youtu.be/ily4VEoEuSc Here's a screen-capture if you can't view that: As I watch the graph while ...
4
votes
1answer
133 views

A-weighted Digital Filter for 1/3rd Octave Band Analysis

I want to do a 1/3rd Octave band analysis on a noise signal. But the sound pressure levels should be in dB(A), i.e., and it should be A-weighted. For this, I am using the A-weight function from this ...
0
votes
0answers
50 views

Welch's method, no windowing function

I'm trying to pick a method to increase the bin-width on several discrete Fourier transforms I'm incorporating into some scientific analysis code. I have several questions about how this could work ...
0
votes
0answers
40 views

How to water level deconvolve a noisy signal if i have a zeros and poles file?

Thanks for your time and help! I am working with Apollo project passive seismic experiment (PSE) data, and I have a large set of seismic records (on digital counts) and the corresponding file of poles ...
0
votes
0answers
23 views

Filtering out symmetric noise from an oscilloscope reading

I have a signal that looks like this: The data is readings from two oscilloscope channels, one color coded blue, the other color coded orange. I would like to filter out the supply noise (all the ...
0
votes
1answer
26 views

SINAD calculation in MATLAB

I want to understand how SINAD is calculated. In MATLAB there is a funciton called SINAD and I would like to see if I can obtain "the same" answer as the inbuilt function does. From the ...
1
vote
0answers
15 views

Can thresholding in wavelet transform be implemented on the approximation coefficients?

Sorry as it might be a silly question since I am a beginner in wavelets. I have been using the matlab wavelet toolbox for denoising purposes and saw that thresholding is only applied on the detail (...
1
vote
2answers
49 views

Can discrete wavelet transform for denoising purposes be implemented in real time? [closed]

I have been researching effective algorithms for denoising biomedical signals (non-stationary) that can be implemented in real time either using FPGA or DSP. I can across many suggestions for ...
0
votes
1answer
29 views

Calculating the bit period

I want to calculate the bit period in my RF packets that I transmit them with 50Kbaud (Symbol rate=bit rate in my case) , how can I calculate the bit period?
1
vote
2answers
40 views

Discrete-time sampling of filtered white noise

I am trying to understand how I can relate a discrete-time random process to a continuous-time random process sampled at discrete times. Suppose I have a noise source $N_\tau(t)$ which is derived ...
0
votes
0answers
21 views

SNR in case of complex channel and fading

I am trying to estimate SNR mathematically given in a paper. $$ y = hx + n$$ $h$ is channel fading, that is Rayleigh in my case, while $n$. Both $h$ and $n$ are random variables. ...
0
votes
0answers
13 views

Red noise estimation in power spectra. How to model the red noise component of data and derive corresponding confidence levels.?

I have generated a power spectrum using fft (python) and now I want to estimate the confidence levels with respect to red noise. Something like this: https://static-01.hindawi.com/articles/jcli/volume-...
1
vote
0answers
85 views

Find Syncword (pattern) in signal, using Correlation

I have a signal which always has the same syncword ([93 0b 51 de] in hexa). I also have a signal with additive noise(attacing it, and I want to find my syncword in that a noisy signal using corelation(...
0
votes
0answers
18 views

calculate decibel SNR in percent

i have the following metric for calculating the SNR for my predictions: i basically dont calculate signal to noise but signal to error. x is my prediction and y is the true signal. When i have an ...
0
votes
0answers
59 views

Probability of similarity for two random white noises

I'm looking for the method to calculate theoretical similarity of two random noises $x$ and $y$ with mean $0$ and standard deviation $1$, I've got also $12500$ samples of signal, sampled $2.5$ Ga/s. ...
0
votes
0answers
32 views

DETECTION the start of my packets

I'm spending some time in understanding L1 PHY development and have some questions on the start of packet detection in an IQ capture Let's say I have a WiFi IQ capture which consists of 600 packets ...
0
votes
1answer
29 views

simulation of lin-log amplification

I struggle with two simple questions. First. What is the distribution of the signal on the output of the lin-log amplifier if Rayleigh noise is driven to the input of it. Using an approach with ...
0
votes
1answer
34 views

Discretize process noise in Kalman filter

Reading P. Andrews et al. I see that it is very common to do the following approximation of the process noise covariance matrix: $$Q_{k} = G_{k-1}QG_{k-1}^{T}\Delta t$$ so that the propagation ...
0
votes
0answers
51 views

What is the name of signal / (signal + noise)

Signal-To-Noise ratio is defined as $$SNR = \frac{P_{signal}}{P_{noise}}$$ For my application, I find the following metric to be more useful $$\frac{P_{signal}}{P_{signal} + P_{noise}}$$ Does it ...
0
votes
1answer
24 views

Oversample or undersample correlated noise?

I wish to measure nontrivial (non-Gaussian) broadband current noise for its distribution and power spectral density. The noise is amplified (with transimpedance amplifier) with some characteristic ...
0
votes
1answer
20 views

I want to get tilt sensor value for a given time t_0, but the tilt sensor data points are discrete. How do I interpolate between the discrete points?

I have 3-dimensional readings from a tilt sensor (specifically these are rotational angles about X, Y, and Z axes) over time. Let's call these angles S. I want to infer S at a specific time t_0, but ...
0
votes
0answers
24 views

Eliminate small measurement error

I have a 3D-printer z-axis noisy signal. What I am trying to achieve is to detect each printed layer according to the z-value (e.g. z = -53.5 -> 1st layer, z = -52.5 -> 2nd layer ...). However, due ...
3
votes
2answers
47 views

Matched filter for “amplitude SNR” vs power SNR

I am working on an application for which a matched filter seems like the right concept. In the derivation for the matched filter which I went through (here), they define the SNR as the ratio of ...
2
votes
1answer
33 views

denoising floor function

Suppose that $y(t) = \lfloor x(t) + \epsilon(t) \rfloor$, where $\epsilon(t)$ is zero mean, independent noise. Is there any techniques on recovering $x(t)$ from $y(t)$?
0
votes
0answers
21 views

How to identify the frequencies of periodic peak signals in a noisy time series?

Suppose to have two time series with peak signals at different frequencies, like these two: ...
2
votes
1answer
222 views

Super basic questions on statistical process

Before starting: I am really a beginner in statistical process in time. I mainly do quantum information and while learning aspect of quantum noise I realized that I am actually too weak on basics of ...
0
votes
1answer
45 views

Get the lag of a signal with respect to the other with cross correlation

I have 2 vector of length 20 each. The first 15 entries of $a$ are exactly the same as the last 15 entries of $b$. There is random noise in the 5 last entries of $a$ as well as the 5 first entries of $...
0
votes
1answer
32 views

Cepstrum of white gaussian noise

What are the statistics of the cepstrum of gaussian white noise? \begin{align}\newcommand{\Nfft}{ {N_{\mathrm{FFT}} }}\DeclareMathOperator{\FFT}{FFT}\DeclareMathOperator{\IFFT}{IFFT} x_i &\sim \...
0
votes
1answer
20 views

Regarding the nature of white noise in images

I have just started learning the very basics of noise. I have come to understand what white noise is in sound samples, but I do not understand the meaning of white noise in images. In sound samples, ...
0
votes
0answers
28 views

How to measure Noise

If I have a model that determines the current flowing through a membrane - how can I find out how big the random fluctuations in the current are? so how big is the noise level?

1
2 3 4 5
19