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36 views

Where to apply zero-padding for convolution dealiasing and appropriate scale

After hours of browsing the DSP posts and resources online, I still struggle to understand why my code diverges when I activate zero-padding dealiasing. When I deactivate it, everything 'works well', ...
0
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0answers
26 views

I want to invert my fourier transform components to waves again

Hi I am using R to analyze some data I basically did fft(data) and got a vector of complex numbers but from that now I want to remove certain harmonics from my actual wave but how do I convert one of ...
2
votes
2answers
72 views

Why is my signal attenuated after applying a HighPass-filter?

I am new to DSP, but I've been attempting apply a butterworth high-pass filter on a 1D array (Values peeking at 300~) to eliminate any noise, yet when applying a high pass filter, I'm ending up with ...
0
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1answer
32 views

How to chose a kernel function for a FIR low pass filter in audio processing?

As the answer of a previous question, I was suggested to use a FIR filter to act as a low-pass filter to reconstruct the envelope of a sound wave (edited, emphasis mine): As I said in a comment, ...
-1
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0answers
5 views

How to convert a signal from analog values to gray color scale image? [closed]

Hi have some wireless signals and I have one idea that I want to test. For that idea, I need to make a gray (monochromatic) image of the signals I am reading from the wireless sensors which make an x ...
2
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0answers
16 views

Simulink cross correlation issue

here is the Simulink model that i'm using : The matlab function script : function tau = fcn(sig,refsig) tau = gccphat(sig,refsig); The errors :
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0answers
5 views

control points and concentration of sampled points in a parametric curve

Can anybody explain to me what the following sentence means? "In cubic Hermite, as any parametric curve, the control points density reflect in the concentration of sampled points in more dense parts ...
0
votes
1answer
22 views

I have the following accelerometer signal, I want to segment or slice the signal into Red parts and Green parts

I want to count steps which are basically represented by peaks in the signal. the red part in the signal doesnt correspond to any walking activity, I want to ignore them. Any help on segmenting or ...
0
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4answers
79 views

What does the convolution mean, what is the convolution philosophy [closed]

I would like to know why the convolution is necessary. that is, who said that multiplying numbers with others and then adding them would tell us something? If you could give me analogies without ...
0
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2answers
67 views

downsample signal to a specific number of samples in Python

The Python Scipy library provides several functions to downsample signals, but they all have limitations: The resample function is based on Fourier method, which means it assumes periodic signals. ...
4
votes
3answers
91 views

Digital to analog aliasing or mirror query… DAC can output negative frequency?

Using a clock Fs = 1 MHz. The Digital to Analog (DAC) can make frequencies upto 500 KHz. 500 kHz to 1 MHz is an alias? Or is it called a mirror?? Is aliasing a concept only on the ADC and sampling ...
2
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0answers
20 views

Problem Involving Aliasing and Critical Fusion Frequency Concepts

I have been trying to study a course from MIT on Biomedical Signal Processing and I thought that the best way to learn would be to solve some problems. Although they might be out of my depth, I am not ...
0
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0answers
38 views

Implementing cross-correlation with argmax in Simulink [closed]

How can I implement this in a Simulink block? I want to create a block that has two inputs (two signals, one of them is delayed) where the output is the value of the delay that gives me the maximum ...
2
votes
1answer
28 views

Synchronising audio in realtime without knowledge of original signal

Was doubting whether this is the right SE forum to ask my (elaborate) question, so don’t hesitate to let me know if it’s not. Also, if anyone knows of a better way to title the question, feel free to ...
0
votes
1answer
21 views

Does constant Q transform have linearity property in the transformed domain?

With FFT, I sometimes take advantage of the fact that I can pre-calculate a signals Fourier Transform, and then you can add the noise in the spectral domain: $$ \mathscr{F} (x[n] + h[n]) = \mathscr{F}...
1
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2answers
22 views

How to calculate the Gain (in dB) given ω₁ and sampling time, T, of a discrete transfer function?

Having the Transfer Function of a discrete system as such: $$H(z) = (1.011)\frac{z-0.9756}{z-0.9975}$$ How would you find the gain at ω₁=3 rad/s at a sampling time of T=0.25 seconds. The answer to ...
2
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0answers
29 views

How to work with portaudio?

I am working in a project to record audio and process in real-time in C.For starting, I wanted to check how it works. I downloaded the pa_stable_v190600_20161030.tgz from here. I ran ,/configure and ...
3
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3answers
97 views

How to use a FIR on a signal with a drifting central frequency?

I have been working on this subject for a while and I couldn't get a proper answer. I am trying to estimate the phase of the input signal : $x(t)=Ae^{j(at^2+bt+c)}+n(t)+i(t)$ Where $n(t)$ is a ...
0
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0answers
21 views

resample interpolation decimation filters algorithm

I'm creating a program in order to perform Resample, Interpolation and Decimation Frequency. ...
-1
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0answers
18 views

Pulse Repetition Frequency [closed]

Looking for the equation of how to calculate pulse repetition frequency. I’m looking to solve the maximum pulse repetition with a range of 300km.
2
votes
1answer
57 views

How to obtain an envelope of my mas-spring damping curve?

I have my program for mass spring system made with Euler method...and I can't menage to obtain envelope of the BLUE damping curve. Can you help me? ...
0
votes
1answer
48 views

How can I correctly plot an impulse_response() of a discrete transfer function?

I posted this question on stack overflow and I think it was the wrong place so I moved it here. Hello, I'm new to python, I just want to use the control library and I'm slowly learning, I did my ...
0
votes
1answer
29 views

Cut-off frequency in Fourier-Spectrum of a noise message

I have a problem involving cut-off frequency. I have a voice message in an audio file .mat which have an eletromagnetic noise. I am trying to recover the original message by applying digital ...
0
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0answers
10 views

What is the definition of the bsd68 dataset?

If I just google "bsd68 dataset", I find this page which allows to download the whole BSD dataset, with all 300 images (potentially 500). However, I have no idea which of the 100 test images are ...
0
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0answers
18 views

Advantages of triphone model in speech recognition [closed]

I am a complete beginner in speech recognition. I would like to know what are the advantages of using a triphone model versus monophone model, please. I have seen in a lecture that replacing ...
0
votes
1answer
60 views

Microlabbox vs dsp kit? [closed]

I am working on real time application of PWM methods for inverters. Time response of the switching devices is quite important (required response time is 1 to 5ms). Most of the research articles have ...
0
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0answers
44 views

Second (numerical) derivative as estimation of oscillation

I have a discrete signal (vector of numbers) coming from a measurement. This signal has been filtered so that the noise has been removed. Now I am looking for an analytical representation of the ...
3
votes
2answers
70 views

Downsample: resample vs antialias fitlering + decimation

I have a discrete signal sampled @Fs. I need to downsample it to Fs/k. Main reason is to reduce signal bandwidth and speed up computation : I'm only interested in a reduced bandwidth < Fs/2k. Some ...
3
votes
1answer
55 views

Difference between Fourier-Transform and FFT of rectangular pulse

I'm trying to find a link between the Fourier-Transformation of aperiodic Signals and the FFT of them. So to start with a basic example, let's take a rectangular pulse with width 0.1s and amplitude of ...
0
votes
2answers
25 views

Using the traditional instruments for measuring high frequency signal

All we know that we can not use the probe for measuring the high-frequency signal (microwave signals). I still can not understand the reason. I have read that the reason because of the wavelength size ...
0
votes
2answers
53 views

Impulse Response of a Moving Average System

According to Discrete Time Signal Processing by Al Oppenheim 3rd Edition, the impulse response of a moving average filter is as below My question is that shouldn't h[n] be having the dirac delta ...
5
votes
4answers
110 views

redundancy of sin and cos waves with real data

I have the following question. Isn't it true that when applying a fourier transform to a real function (i.e. computing a characteristic function for a density), we only ever need one of the two waves: ...
0
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0answers
11 views

audio quality evaluation of Linear prediction resynthesized signal

Does anybody try the audio quality of linear prediction resynthesized signal using a music file? Using the frame length of 50 or 20 ms. And have you ever tried the objective evaluation using the ...
1
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0answers
16 views

ICA School Project

I have been stuck on my school project that consists of independent component analysis. My code will run, but only 50-60% of the time it unmixes the signals. Another problem I have is the amplitudes ...
0
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0answers
17 views

In terms of second-order phase lock loop receiver, finding bandwidth of message such that 99% of signal energy is contained in bandwidth [closed]

complete txt, need help finding Wm, I know Parsevals theorem needs to be applied, and im assuming if i find max freq deviation and use 2*pi*f and substitute for samll w, Im stuck on how theorem ...
0
votes
1answer
34 views

Detection of “constant” signal

I have the positions of a computer mouse, sampled at a high frequency, with a good amount of noise. When the user stops moving the mouse, instead of going to zero the velocity reported by the mouse is ...
2
votes
1answer
31 views

Sample & Hold: Estimate jitter delay of an ADC

I've got a question regarding the effects of sample and hold. My input signal is $x$, and my output signal $x_{SH}$. The error between the signals is $e_{SH} = x_{SH}-x$. The sampling frequency is ...
0
votes
2answers
35 views

How are CDMA codes distributed?

I think this question is so trivial that it's nowhere explained (I would not find it) and the answer is probably trivial too. But I still wonder how codes in a typical CDMA system are distributed? ...
0
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0answers
11 views

Texture Synthesis using Heeger siggraph paper

i am implementing texture synthesis using steerable pyramid using Heeger Siggraph et. Al. paper, link for the paper is here https://www.cns.nyu.edu/heegerlab/content/publications/Heeger-siggraph95.pdf ...
0
votes
2answers
41 views

Definition of Perfect Code (and example of Hamming Code)

Let's consider the following sentences about coding a message before transmitting it in a communication system (here you find the complete pdf) First question: can you explain me these two ...
1
vote
1answer
50 views

Got stack in calculating state-space representation

I got stack in the process of deriving a state-space representation of the following system: There is an electrical oven described as follows: control of the power supply $u$, heating efficiency ...
0
votes
2answers
67 views

Envelope reconstruction algorithm for audio processing

I need to reconstruct the envelope of a sound. Audio data are professionally-recorded natural sounds (speech, bird songs) with very little noise. I would prefer working in the time domain rather ...
0
votes
0answers
9 views

Precoder selection in LTE

I am reading papers about LTE and "resource block (RB)" was mentioned in each of them and also "precoder selection" What kind of parameter is used to select precoder for each of RB? What is ...
2
votes
1answer
51 views

Large spike at beginning of signal after applying Bandpass filter

Foreword: I am a PhD student and fairly unexperienced with many signal processing and engineering concepts, please be gentle. I am attempting to filter out a frequency range of 1Hz to 2Hz from a 2....
1
vote
1answer
23 views

Applying a 2D band pass filter (Butterworth ?) to an array with NaNs

I am trying to filter out the low frequencies of an array looking like this : For now, I am taking transects of this array and applying a 1D - butterworth band pass filter : ...
0
votes
0answers
17 views

Create QPSK data In Matlab

How to form QPSK data in Matlab? I have written it as: Mod=4; s = randi([0 Mod-1], N*MT, 1 data=pskmod(s,Mod); Will be it enough to form QPSK data?
0
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0answers
71 views

extracting mfccs after beamforming

I have a deep network for sound classification with mfccs as features. I wish to go through the process of beamforming before applying the classification. The original network uses ...
0
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0answers
11 views

How to use rayleighchan(ts,fd,tau,pdb) to form a channel matrix?

I am starting a transmission system simulation. To create a channel matrix I have used rand function in Matlab. But Matlab has a ...
0
votes
0answers
10 views

Is there a way to get output in second order sections (SOS) format from Scipy's signal.firwin

I am using Scipy's signal.firwin to implement a lowpass filter. Using the rule of thumb formula(s) to estimate the order of the filter, I am getting a very high number. I looked into this question, ...
2
votes
2answers
43 views

LTI system output given input and frequency response

The question I'm trying to understand is as follows: A linear time-invariant continuous-time system has the frequency response function $$H(\omega)=\frac{1}{j\omega+1} $$ Compute the output response $...

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