Questions tagged [anti-aliasing-filter]
The anti-aliasing-filter tag has no usage guidance.
29
questions
0
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1answer
59 views
How is sampling affecting this sine wave?
I am trying to create a sine wave in python, but when I graph it, it looks like this:
here is the code I used to make the signal:
...
1
vote
1answer
40 views
what is the correct order of applying a nonlinear operation and downsampling (with anti-aliasing)
In UltraSound imaging, after beam-forming and obtaining the envelope, Log-compression which is a non-linear operation and scan conversion which is a 2D interpolation (with inherent down-sampling) is ...
1
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2answers
794 views
How to apply an anti-aliasing filter before downsampling
I have an eeg signal with two channels (f3m2 and f4m1) which is divided into epochs. I want to augment the data by taking every 5th sample. I can re-use the discarded samples to create 5 versions of ...
0
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1answer
57 views
Prefiltering to Avoid Aliasing
In processing analog signals using discrete-time systems, it is generally desirable to
minimize the sampling rate. This is because the amount of arithmetic processing required
to implement the system ...
0
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1answer
265 views
Oversampling, decimation and Nyquist
I know this is a bit of a fundamental DSP question but I want to finally understand this and I think I need some help to finally put it all together.
Let's say I have an RF complex sampling ADC with a ...
1
vote
1answer
109 views
DDS generated chirp and antialiasing filter : what is the best suited filter for a chirp?
I am defining the required antialiasing (analog) filter for a chirp generated by a DDS. The chirp is produced in a FPGA (NCO generation) and forwarded to the DAC for the samples generation (with ...
1
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0answers
43 views
Partially aliasing in Signals
I have read a paper about super resolution where signals are used that are partially aliased. here the paper
If the sampling rate is smaller than the 2*max frequency but greater the max frequency, ...
2
votes
2answers
339 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 ...
0
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2answers
1k views
How do Anti-Aliasing Filters filter the signal?
I have programmed a anti-aliasing filter that uses the fourier-transformation and makes a perfect cutoff on my desired cutoff frequency for downsampling without aliasing.
I have read about other ...
0
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3answers
111 views
does aliasing occur always if i sample a vibration in real world applications?
I was reading about the aliasing effect and nyquist. I understand that aliasing effect occurs if the sampling rate is lower than twice the maximum frequency in the signal I want to sample.
So I was ...
0
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1answer
568 views
IQ Sampling and Oversampling Differences? *Confused*
Two different thought process that produce two different alias band calculations .... What concepts are these?
If I have two 1 GHz ADC's and they sample with 90 degree offset (A comment said this is ...
2
votes
1answer
145 views
Variance of a signal
How to calculate the variance of noise samples modeled as follows:
$n_a(t)$ is a
Gaussian zero-mean white noise process with (two-sided) power spectral density $\frac{N_0}{2}$. $n_a(t)$ is passed ...
0
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2answers
714 views
Where should I set my anti-aliasing filter corner frequency for this signal?
I have a Fourier transform of an arbitrary digital signal. The transform has For 1024 frequency bins. The magnitude plot of the first 100 is below, with no surprises in the unplotted 924 bins.
Now, ...
1
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0answers
194 views
What is the minimum and maximum cutoff frequencies for the antialiasing filter for this ADC?
https://www.analog.com/en/products/ad9675.html
https://www.analog.com/media/en/technical-documentation/data-sheets/AD9675.pdf
It says in the data sheet that the Anti-Aliasing Filter has :
"...
1
vote
1answer
312 views
How do Anti-Aliasing-Filters in audio signal processing work?
I am a little confused about the use of anti-aliasing filters. As on how I am confused, please consider the following task:
Consider a simple sampling rate conversion system with a conversion rate ...
2
votes
1answer
977 views
polyBLAMP anti-aliasing in C++
How should 4 point polyBLAMP work. It does not really seem to dampen aliasing.
I have an floating point digital audio oscillator that makes a +1.0f jump at the end of every period.
My question is, ...
0
votes
1answer
847 views
Understanding anti aliasing filter
I'm working on a project for the university about the anti aliasing filter.
I have a small audio file, which has a sampling rate of 22KHz. Now when I downsample it 8 times, the file sounds weird. So ...
1
vote
1answer
499 views
How can I implement a triangular filter in MatLab, given it's Z-transform representation?
I have to implement an anti-aliasing filter for a certain processing step in MatLab. While searching in literature for inspiration, I came accross a paper in which the authors wrote the following:
We ...
2
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3answers
4k views
What is the filter with the less phase shift?
I have to analyze a dynamic signal but there is too much noise so I applied low pass filter but then there is too much phase shift.So what is the most reactive filter I can apply to my signal ?
Best ...
1
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2answers
502 views
Confused on application of Anti-Aliasing Filter
I have a question about the use of anti-aliasing filters prior to sampling a finite time signal and if they actually help anything.
The point of the anti-aliasing filter is to remove high-frequency ...
0
votes
1answer
596 views
Aliasing in digital communication system
In a digital communication system, is it possible to counteract the aliasing problem by properly tuning the constellation order $M$ and/or the carrier frequency?
Here is my train of thought, please ...
3
votes
2answers
5k views
Why analog anti aliasing filter is used before analog to digital converter when there is already a digital filter after ADC?
Normal data acquisition consist of:
Analog anti aliasing filter( Sampling frequency : $5\textrm{ kHz}$)
ADC - Digital Filter - (Sampling : 200K samples /sec)
Digital low pass filters Filters
DAC
...
0
votes
1answer
566 views
Anti-Aliasing when oversampled
From a comment in another question I read a statement
"In addition, the initial rate of 48kHz is already performing 6 times
oversampling and therefore the subsequent decimation by 6 will not
...
4
votes
3answers
687 views
How do optical anti-aliasing filters work from a frequency domain perspective?
To prevent aliasing caused by the finite number of pixels on a sensor, a blurring filter is commonly used. How does that work from a frequency domain perspective? What is the transfer function of such ...
3
votes
2answers
8k views
Why is a square wave aliased?
I understand an ideal analog square wave contains sine-wave-components above Nyquist frequency (and towards infinity) and is thus subject to aliasing. So obviously we need an anti-aliasing-filter. Or ...
0
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2answers
2k views
Interpolation based on sinc function
I implemented an interpolation method in C++ based on this equation
...
0
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2answers
106 views
Does MSAA make sense in audio / 1d data streams?
In graphics, MSAA is a technique where you take multiple samples of something per pixel and then average the values to get the final pixel value. The image quality improves as a result, and its ...
0
votes
2answers
910 views
Confused about anti-aliasing in analog filters
I'm a newbeginner when it comes to signal processing. I'm reading up about anti-aliasing, Nyquist and band-pass filters. There's something I don't get: Anti-aliasing in analog filters.
Lemme try to ...
1
vote
0answers
231 views
Anti-aliasing requirements for a Muxed Sigma-Delta Converter
It seems to be reasonably well accepted that Sigma-Delta ADCs have much looser requirements for the anti-aliasing filter due to both the noise shaping and high modulation frequency.
However, it seems ...
