Questions tagged [resampling]
The resampling tag has no usage guidance.
139
questions
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22 views
How do I change the sampling rate without changing the speed and pitch in Python?
I am building a voice recognition algorithm, and the use case specifies that it should be able to identify the targeted speaker from various audio sources, which means that it must be able to process ...
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1answer
90 views
How to implement sinc interpolation
I'm trying to write my own high quality audio sample rate converter. I barely know anything about signal processing though so I need help.
From what I understand I need to sum together normalized sinc ...
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1answer
32 views
How to transform a signal to go through specific points?
I have a 1d signal obtained using a Fourier based resample method (TDIFDZP) for which the resampled points don't necessarily go through the original samples. I want to transform the upsampled signal ...
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24 views
Resampling with factor linearly moving from one value to another: calculate expected target length
I am resampling an audio (1D) signal, using a resampling factor that moves linearly from startFactor to endFactor; say the input ...
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1answer
35 views
Oversampling a signal
I’ve built a circuit with an analogue sensor (70 Hz bandwidth) connected to a 24 bit ADC, which is oversampling the signal at 10 kHz. Nyquist sampling theorem implies I should sample by at least 140 ...
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0answers
26 views
Resampling assessment
I'm trying to figure out which of the resampling methods is best in my job. Comparing the original image vs. bilinear, bicubic, bicubic spline, lanczos. For now I have considered metrics like MSE RME ...
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1answer
49 views
Upsampling implementation
I have problem with upsampling implementation in the following way:
My code:
...
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1answer
26 views
Upsampling in Python
I'm trying to perform upsampling in Python. Given the signal 's' and factor of upsampling N, I wrote the following code:
...
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2answers
62 views
Does resampling cause phase shifts?
I have a signal sampled at 40MHz, I would like to resample it to 37MHz. The signal is not periodic, I did resampling with Matalb resample function and it doesn't cause phase shift (as far as I ...
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1answer
42 views
How to correct for delays in a PAM-X signal with orthogonal CDMA?
I have a receiver which receives data bits at a rate of 5kbit/s. The number of data bits per burst is low (say, 16 bits). These databits are obtained after despreading the incoming signal using an ...
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21 views
Evaluate the quality of the satellite image resampling method
I'm evaluating different methods of resampling on Sentinel 2 images for switching from 20m to 10m bands. Comparing bilinear, cubic and lanzcos methods I would like to judge the best result. Several ...
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2answers
45 views
Downsampling issues
I have this data that need to be downsampled so that it can be fed into a classifier. The issue is that I need to downsample from 1000Hz into 20Hz. If you see the graph below, the blue line is the ...
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2answers
94 views
Fourier Transform of sampled reflectance measurements
Goal:
Calculate the complex index of refraction ($\hat n = n +jk)$ from reflectance measurements.
Data:
Reflectance measurements for various materials were taken with a FTIR (Nicolet™ iS50 FTIR, ...
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0answers
13 views
Spectral kurtosis on non-stationary signal
I posted a question some weeks ago I still have not found an answer to. I updated the old question and am hoping someone could help.
Link:
Varying speed of shaft Spectral Kurtosis
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2answers
73 views
Rectify signal basic question
When rectifying a signal by squaring it, is it necessary to upsample by a factor of 2?
Why is this?
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1answer
49 views
Upsampling question- Aliasing/imaging problem
I'm trying to study vibrations in a non-stationary shaft by upsampling the original signal.
The original sample rate is at 25.6kHz, and it is being upsampled to 36kHz. In the FFT of the upsampled ...
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3answers
64 views
Interpretation of sample rate
I'm a little confused about the sample rate:
If I have an audio file that was recorded with a sample rate of 48kHz, this means that there are 48,000 values per second in this file, right?
So when I ...
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1answer
37 views
Obtaining a high sample rate digital approximation to an analog filter from lower frequency measurements
Consider a set of dense, but generally irregularly-spaced frequency response measurements of some real low-pass analog filter. Denote the maximum frequency for which a frequency response measurement ...
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2answers
45 views
Resampling of DTFT
I have a constant digital signal that is 1 for every sample and of length 4.
4 point DFT coefficients are $$[4,0,0,0]^T$$ Obviously. I wonder, if I resample the DTFT such that samples are taken at $$...
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42 views
Composition of interpolation and decimation matrices
I understand that interpolation is a linear transformation of a signal vector that combines interleaving the elements of the input vector with zeros followed by a filtering operation to remove any ...
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1answer
81 views
How to Emulate Sample Frequency Offset for OFDM in Matlab?
I am studying the effect of sampling frequency offset on OFDM, and in order to emulate SFO, I have to slightly change the sampling rate of the signal. In order to have a +5ppm offset, I have to change ...
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25 views
resample interpolation decimation filters algorithm
I'm creating a program in order to perform Resample, Interpolation and Decimation Frequency.
...
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0answers
46 views
Weird resampling artifacts of a periodic signal
I am trying to grab time series data from a database storing data on a propritary format. When i chose a resolution which is not a multiple of the power of two of the sampling resolution i get these ...
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1answer
23 views
Decimating by last interpolating factor? (Multi-stage)
Let's say I have a multi-stage interpolator at the transmitter, which interpolates by 2, 4 and 8 (that is, 64). When decimating (at the receiver) why should I start decimating by 8, then 4, then 2, ...
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29 views
Where to do timing synchronization?
I'm trying to do timing synchronization. I was wondering where in the receiver chain I should put this.
At the moment, I have (in order, so the first thing in the receiver is 1 and the last is 4):
...
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1answer
214 views
How to prevent distortion after down-sampling?
I am new to audio signal processing, but in one of my machine learning projects that I am working on, I need to down-sample my audio somewhere in the middle of my neural network. Therefore, I need a ...
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0answers
41 views
Interpolation FIR filter Remez design criteria
I want to upsample an audio signal by a factor of 8.
The technique I was going to use was to upsample by zero stuffing and then interopolate using a low pass anti-aliasing FIR filter designed using ...
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0answers
57 views
Delay of non-polyphase vs polyphase FIR filters
I implemented a polyphase filter function for interpolating and decimating. It works great (I compared it to what I'd get by interp/decim by inserting L-1 zeros and I get the same results) except for ...
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146 views
Polyphase resampling delay
I want to implement polyphase resampling.
For this, I wrote a script in matlab.
The script performs the following sequence of actions:
...
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3answers
421 views
Resampling and removing high frequency noise?
I am currently working on a simple sampler that will allow me to load in a wav file and use my MIDI keyboard to play the loaded wav sample at the frequency according to the note played.
Now I need ...
0
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1answer
100 views
Upsampling and pulse duration
How does upsampling factor relate to pulse duration?
If I want to do pulse shaping and I have rcosdesign(beta,span=8,sps=4) should I upsample by ...
3
votes
1answer
194 views
Optimal trade-off between oversampling and filter length
For some sampling-frequency-preserving operations on Nyquist–Shannon sampled signals, such as:
a shift a.k.a. translation, and
differentiation by applying a derivative filter a.k.a. gradient filter,
...
1
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1answer
31 views
Method to rescale signals to mean length
I have a set of signals of varying lengths. I have provided an example of the same below -
Their lengths vary between 186 to 202, with a mean length of 197. I am looking to rescale them to the mean ...
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0answers
21 views
Converting the equalizer coefficients from VSA at 2 sample/Symbol to 1.5 sample/Symbol
I was looking for some feedback on conversion of equalizer/filter coefficients at different sampler rate.
Problem Statement:
We have built a transmitter system whose output is at 1.5 sample/symbol (...
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3answers
463 views
Absolute convergence of periodic sinc interpolation
An $N$-periodic complex discrete-time sequence $[x_0, \dots, x_{N-1}]$ can be resampled to an $M$-periodic sequence $[y_0, \dots, y_{M-1}]$ with $M>N$, using sinc interpolation:
$$\begin{align}y_m ...
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0answers
115 views
Why do I have to scale filter coefficients during bandlimited sample rate conversion?
I am writing an example for how to perform sample rate conversion using windowed sinc and polyphase filters.
Here is the C++ code as a github gist.
So far, this works, and I think I have understood ...
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0answers
30 views
delayed result in sinc upsampled signal
I have implemented an infinite kernel sinc interpolation.
For some signals I notice an artifact, visible at the right end of the plot.
I am wondering: is it a bug in my code or a phenomenon usual for ...
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0answers
241 views
signal interpolation (upsampling) by factor 2
The task is to interpolate the signal by increasing the sampling rate by factor 2.
Matlab has a dsp.FIRHalfbandInterpolator function.
Let's try using it.
...
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1answer
364 views
Extrapolate a 2D array using Fourier Transform
I need to extrapolate a given 2D array to a larger domain, keeping the spatial frequency. This is the original field:
(the data file in numpy npz format and a Jupyter notebook to plot it can be found ...
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0answers
53 views
How should I modify my filter coefficients for the filter to be unaltered, when I change my sample rate
I am guessing this is a commonly encountered problem, but I am lost on how to really solve it.
I have FIR filter coefficients that are used to match the frequency response of data sampled at 3 kHz. I ...
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1answer
261 views
Best way to resample an OFDM signal without interpolating + filtering?
I am working on a custom transceiver with a sampling rate of 3.84 MHz (256 OFDM subcarriers at 15 kHz, although 56 subcarriers are null). I would like to resample the signal to 5 MHz, in order to use ...
1
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1answer
170 views
Is it possible to lose half the samples, and yet see the full spectrogram as the original signal?
Consider an speech audio signal sampled at 16,000 samples per second. Plot its spctrogram.
If we delete every other sample from input signal, we get y[n] = x[2n] for all n.
It seems that if we plot ...
0
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1answer
92 views
Having Glitches trying to use a Sinc Function Interpolation on a Signal, by chunks of 1024 samples
I am trying to interpolate a signal using a third party lib that performs Sinc Function Interpolation on a signal. It works well if I input all the samples at once but introduce phase distortion if I ...
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0answers
138 views
Matching two signals with small time drift
I have two time-domain signals sampled at 100 Hz that were measured using two different oscillators and therefore have a time drift between them. I have two synchronization points, one at the start ...
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1answer
735 views
The condition in order to not loose information after upsampling and downsampling [closed]
If you have a signal x[n] and it is upsampled by N and then downsampled by M. what is the condition for not losing any information in x[n]
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1answer
1k views
Resampling from variable to fixed-rate [closed]
I have a gyroscope which reports x,y,z values to my embedded device.
The rate that one sample appears is variable and has a jitter of around 10ms.
However I later want to have a log file with a fixed ...
0
votes
1answer
463 views
Convert 96 Khz to 48 Khz audio: is this simple downsampling method ok?
I have an audio signal x sampled at 96 Khz. I have already lowpassed it with a cutoff somewhere between 20 Khz and 22 Khz, so there should be nothing left of ...
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0answers
132 views
Resampling or interpolating non-uniform 2D measurements
I am not sure what I should call what I am looking for, but I have some measurements that have 2 independent variables and I would like to get an interpolated value at a specified x,y coordinate. My ...
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0answers
64 views
How can I extract the 2 polyphase components of a signal after sampling at the half of sampling rate
Suppose I have a continuous signal $x(t)$, which was sampled using sampling function $s(t)$ whose sampling rate is $T_s$.How can I sample the continuous signal by Ts/2 instead of Ts in order to get ...
0
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3answers
148 views
Various size arrays interpolation - resampling
sorry if it's stupid question but it’s third day that I try to figure it out how to do that. And just can’t find the solution.
Let’s say I have array $A$ size 4, and $B$ size 8. And I need to put/...
