All Questions
22 questions
0
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0
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29
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How to band pass only on positive frequency [duplicate]
I've posed the similiar question
I appreciate that the former replier tells me the process is about Hilber transform,but I'm still confused with the positive frequency.
The paper process a cardiac ...
- 11
1
vote
1
answer
272
views
fast fourier transform band pass filter only on positive frequency
Recently, I came across a paper that focuses on signal processing using lock-in amplification.
the algorithm involves applying the Fast Fourier Transform (FFT) to a time-domain biosignal.
A band-pass ...
- 11
0
votes
1
answer
90
views
Bandpass function in Matlab inverting the Frequency spectrum when using a hermitic transformed signal
I have a VNA response (S11 parameters) from 3.5 to 40 GHz. Then I apply a hermitic transformation (complex conjugate) to it since we only have the spectrum for the positive frequencies. Then I use ...
2
votes
1
answer
77
views
Doubts about digital signal processing methodology
Disclaimer: I'm a beginner at all of this.
I am working with vibration data from accelerometers recorded at a sampling rate of 1600 Hz and the vibrations are induced by a source within the range of 20-...
- 33
1
vote
1
answer
612
views
Bandpass filter equivalent for amplitude
I have a signal where I am using a bandpass filter to limit the frequency range. I am also interested in filtering the remaining frequencies (after bandpass filtering) within the signal by their ...
- 115
-1
votes
1
answer
227
views
power spectrum of passband of ofdm is it right shape or not?
I tried to get power spectrum of ofdm passband signal.
Below is the whole matlab code for that with BPSK+ofdm.
and I got the power spectrum as below.
I wonder that is that right form or not?
...
- 109
-1
votes
1
answer
191
views
How to calculate SNR variation with period?
I want to calculate the SNR variation of a signal with respect to the period. The current technique I am using is calculating SNR iteratively by applying narrow bandpass filters of different range, ...
- 101
1
vote
1
answer
950
views
Filtering sidelobes
Good evening to everyone,
my question is probably trivial, but I'm new to DSP. I have a tone at the frequency 0.5 Hz, amplitude 0.001 V, and with a big DC component of 0.5 V. This signal is sampled at ...
2
votes
2
answers
7k
views
Difference between bandpass filter and using fast fourier transform to extract power of frequency bands
In signal processing, I have heard of two terms:
Using band-pass filter to extract some frequency bands.
Using Discrete/Fast Fourier Transform (DFT/FFT) to extract some frequency bands.
Are these ...
- 149
1
vote
1
answer
253
views
Plotting curved peaks on PSD graph
I am a PhD student with little engineering experience, currently attempting to recreate the signal processing techniques used in this paper: Monitoring Vital Signs and Postures During Sleep Using WiFi ...
- 135
0
votes
2
answers
742
views
Manually creating a lowpass filter from the frequency domain: what phase?
In an attempt to gain a better understanding of DSP, I want to create a very simple (1D) lowpass, or I think more correctly "stop-band" or "band-reject" filter, to filter out a single frequency, e.g., ...
- 683
0
votes
0
answers
90
views
Causal bandpass using fft?
I would like to take a time series of several spikes or narrow Gaussians and bandpass using an ift/ifft together with a frequency domain mask to create a series containing band-limited spikes. This is ...
- 101
1
vote
1
answer
1k
views
Remove Frequency Range
I got a signal and I would like to remove a specific frequency range.
I am a frequency noob, so I will explain it by images:
I have a frequency filter (butter bandpass):
I have a signal and it's ...
- 23
1
vote
1
answer
434
views
Band energy and Parseval theorem
In Python, I consider a dummy signal as follows:
fs = 512
sig = np.random.standard_normal((fs,))
sig corresponds to 1s of ...
- 49
3
votes
1
answer
2k
views
Bandpass filter to get EEG frequency bands?
I'm doing a project with an EEG to detect driver drowsiness and learned about EEG frequency bands (alpha, beta, gamma...).
As the frequency bands are simple frequency ranges, I wonder if I can use ...
- 239
1
vote
0
answers
166
views
Are wavelets for audio spectrograms available as a simple FIR filter?
I have read that "Debauchies Wavelet is simply a short FIR" so i am searching for a single FIR that i can make into a filterbank, a precise "bandpass filter" that detects narrow ...
- 105
0
votes
1
answer
1k
views
Normalizing the magnitude of Goertzel Filter c#
I'm trying to detect some frequencies of 18Khz with sample rate of 44100 [samples/sec].
When I pass a buffer(~4500 samples) to the algorithm it returns a magnitude in a very strange range. Sometimes ...
- 195
6
votes
2
answers
3k
views
What is the right way to extract particular frequency phase information from FFT?
Signals acquisition:
Two proximity sensors are positioned Orthogonal to each other. These would be measuring the vibrations of a rotating shaft.
Problem:
Each of these 2 signals has two dominant ...
- 115
2
votes
2
answers
1k
views
Apply FIR filters to Extract Stego from WAV data
I appreciate anyone that takes a moment to help me with this problem. I've been banging my head against the keyboard for a while, searching forums and DSP tutorials and I can't figure this problem out....
- 23
0
votes
1
answer
859
views
How to convert a filtered time-domain signal into frequency one? [closed]
I have a signal in matlab like this:
I have designed a band-pass filter in 16-32 MHz range:
and applied the filter to the signal,
the result is like this :
My Question:
what is the easiest way to ...
1
vote
2
answers
218
views
Finding audio data in recording
I am trying to find a specific block of data that should hold valid audio data that I want to process. For instance, I record at 44.1kHz, but I only transmit a .5s of content. Since the buffer I store ...
- 61
3
votes
2
answers
1k
views
change the frequency component of a spectrum in an audio file
I am working on an audio dynamic range compressor using Matlab.
After calculating the FFT of the audio file, I use several bandpass filters to amplify specific bands separately.
What I want to do then ...
- 71