# All Questions

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7 views

### Compressed Channel Sensing

I am going through the fundamentals and the state-of-the-art mmwave protocols and research. I came across Compressed Channel Sensing. For sparse multipath structured channel compresssed sensing is ...
23 views

### How do I find the value of the gain that makes the closed loop stable?

Suppose I have a plant and a controller with gain $k$, and I want to find the value of $k$ such that the closed loop is stable. I know that I could use the Routh Criterion to do so, but when I have ...
15 views

### Time variant frecuency selective fading in matlab

I am traying to simulate a frequency selective fading channel in Matlab and I have faced with some issue/questions during the implementation. It is a DSSS (BPSK) modulation and the code is organized ...
22 views

21 views

### Detect vehicles from arial images

I have images collected from google earth pro of a particular locality. How can i detect / segment the vehicles from the arial image using kmeans? Any leads would be really helpful.
35 views

### Identifying impulse based on experimental data

I have conducted an experiment in which the impulse was exerted on sound bowl (it was hit by a hammer). As a result I have obtained acceleration from accelerometer on 3 axis, calculated net ...
14 views

### Detect fixed overlay on set of images

This is quite an "applied" question, but I don't see any more appropriate StackExchange, so here it goes. My situation is the following: I have a sizeable (> 40) set of images (photos) that have been ...
23 views

### Hand implementation of Fourier transform have small peaks unseen in Python package

I've implemented the basic version of discrete Fourier Transform and I'm testing it using a pure sinusoid. However, small bumps show up in addition to the large peak. I tried Numpy.fft for this and I ...
17 views

### Wireless Channel Multiplicative Model

Let's assume a SISO channel in the equivalent baseband, the standard channel model (discrete) is: \begin{align} y(k) = h(k)x(k) + z(k) \tag1 \end{align} Where $y(k)$ is the detected signal, $h(k)$ ...
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### The binary input frequency, should be equal, greater, or minor than the carrier's frequency? [closed]

The binary input frequency, should be equal, greater, or minor than the carrier's frequency? And about the length and amplitude of the binary input, any similar observations? Edit: In context of ...
29 views

### filterbank: understand the different responses at the center frequency of each filter

I'm computing filterbank by applying 26 triangular filters on a Mel-scale to the power spectrum of an audio frame to extract frequency bands, and I found that some references use filterbank with equal ...
20 views

### Using clustering to detect anomalies in vibration data

I'm looking into using clustering-based method to detect anomalies in vibration signals. The idea is to extract features for every single sliding time-window of a time series of normal vibration data, ...
51 views

### Deconvolution of an Image Acquired by a Square Uniform Detector

So, I acquired some images by scanning a radiation source with a square detector like in the following gif. Where the dashed grid represents reality, the 3x3 square my detector, and the 4x4 my ...
45 views

### Finite sequence input to DTFT

i'm studying the practical utility of Fourier transforms and i have some questions. I hope to receive answers in layman terms. 1) Does the DTFT take only infinite input sequences? 2) If i apply the ...
39 views

### Autocorrelation to diagnose faults

I'm attending a very practical course on signals and i have some doubts, i hope to receive answers in layman terms. 1) My prof said i can use the autocorrelation of the output of a process to ...
30 views

### Aliasing and DTFT of a real signal

We are analyzing a real signal with the DTFT. Since we are using a limited number of samples it's like we are transforming a finite signal. As I remember, the FT of a finite signal has an infinite ...
15 views

### synchronization with 2 users

I have $2$ users with different distance from the receiver and each user's message is spread with a different waveform. The $2$ waveforms are orthogonals. With a perfect synchronization, I don't have ...
55 views

### spectral leakage for integral number of periods

I'm attempting to understand spectral leakage and read the following quote on wikipedia: Windowing a sinusoid causes spectral leakage, even if the sinusoid has an integer number of cycles within a ...
25 views

### Absolute value based AM envelope detection viewed in the frequency domain

In my understanding when a passband AM signal is demodulated with an envelope detector taking the absolute value restores the original baseband version of the signal and the low-pass filter removes ...
48 views

### Lightweight test for bimodal distributions?

Here, and in the stats stackexchange, seem to be answers that reference tests for bimodal distributions that involve iterative binning or iterative curve fitting methods. However "eyeballing" a plot ...
60 views

### Sequence expansion by zeros and interpolation - does it insert additional frequencies?

I am struggling with understanding the consequences of oversampling on the frequency spectrum of the signal. If I understand correctly, with an oversampling rate of 8X we insert 7 new values for each ...
36 views

### If the frequency response of a system is time-independent, is this system LTI?

Intuitively, I feel like a time-variant system would necessarily have a time-dependent frequency response, and vice-versa. So, is the time-independence of the frequency response necessary and ...
17 views

### what are the vector formats similar to hash codes to store user's voice for future voice verification?

I have wav file of ~2-10sec of user's voice, taken from a conversation. Maybe it's SIMILAR TO a hash code. the general voice verification should look like: wav file -> vector new wav file ->vector ...
36 views

### Channel noise - A misnomer?

I was discussing with a colleague with background in communication about white Gaussian (WG) channel noise. He said noise is not added by the channel and it's just a misnomer. Noise, which is thermal ...
34 views

### Fourier transform of a noisy signal

Let's suppose i have a sensor that measures the output of a process and this cause a not negligible noise that affects my signal. My goal is to analyze the process signal in order to find faults. How ...
56 views

### Choosing Right Type of Filter for time series data

I am working on a temperature time-series data which is very noisy. I am trying to measure true low and ...
9 views

### Measure that Compares an Actual Old Document from a Synthetic Old Document

I have collected dirty background images, below is the sample: I have also a collection of an actual image of a dirty document with text on it, just like below: My problem with my actual image of a ...
734 views

### Spectral Leakage in layman's terms

I'm trying to understand the concept of spectral leakage for the DFT, without going deep to the mathematical intricacies (it's for practical purposes). I've read from the book "Introduction to Digital ...
50 views

### How do I normalize a predesigned IIR filter?

Obviously my question here is very similar to this previously asked question: How to normalize predesigned IIR filter coefficients to have unity gain? Unfortunately, in the responses available to ...
18 views

### Smoothing a discrete function with point wise variances

In Stark's Introduction to numerical methods [1970] it suggests fitting local polynomials to smooth discrete data before the Fourier transform using least squares minimisation. This gives the ...
23 views

### Step-by-Step calculation of stationary wavelet transform gives shifted results?

Good morning, I am doing an SWT by hand to understand it better, and have a couple of questions. Maybe someone here has experience with this? I am using the book "Conceptual Wavelets" by Fugal, ...
28 views

### ADSR parameter identification from envelope data

I'm trying to work out how to identify (or predict) ADSR parameters (attack time, decay time, sustain level and release time) from envelope data of real signal (or 'raw' data, but I think getting it ...
23 views

### How to allign audio signals after DTW?

Hello I am not a domain expert in signal processing but I need to align two audio signals. I have seen the following page https://librosa.github.io/librosa_gallery/auto_examples/plot_music_sync I ...
22 views

### Linearity and time-shifting of $\mathcal{F}\{0.8^n\cos(0.1πn)u[n]\}$

To preface, this is not a homework related question but purely for self-study purposes. Hi there, I try to calculate $\mathcal{F}\{0.8^n\cos(0.1πn)u[n]\}$ by using the properties of Discrete time ...
12 views

### Frequency domain channel coefficients in OFDM

I want to find frequency domain channel coefficients in OFDM in matlab. The channel is multipath rayleigh in nature. I had tried the following code but not getting the results. ...
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### Change phase of the output of a buffer

I have a question about changing the phase of a buffer. Question - How to change the output phase of a buffer by 90 degrees, 180 degrees, and 270 degrees? I know to change the phase by 180 degrees, ...
33 views

### How CDMA receiver extract it's corresponding data from the receiving modulated & superposition-ed signal?

I have difficulty understanding CDMA. I have read all those PN/walsh code things, and understand orthogonality very well. But none of the resources I found demonstrate how a receiver end extract ...
24 views

### Property of odd and even discrete signals [closed]

Given a discrete signal X[n] let Xe[n] be the even part of the signal and Xo[n] be the odd part. Prove That :: Σ(X[n])^2 = Σ(Xe[n])^2 + Σ(Xo[n])^2
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### How to applly Hanning window on S parameter results?

I am working on Time domain computation. I have S parameter results simulated, using these results I do the Inverse FFT to get results in time domain. I want to filter/window results using Hanning ...
23 views

### Is there an industry standard audio data processing library for C/C++? [closed]

I'm new to audio signal processing and want to work towards using DSP to develop effect/synthesizer plugins. Are there any industry standards I should know about going into this type of project? ...
18 views

### Find common features across images

Consider multiple images that share a common feature. More specifically, they are the sum of multiple features, and I know that one of those is present in all. What is the best method to extract this ...
27 views

### How should I model my low-pass filter to get best SNR of a peak?

So, I'm trying to understand how to use a low-pass filter and optimize the cut-off frequency while getting the "best" amplitude of a peak I am interested in. I have attached picture 1 which shows the ...
8 views

### What features capture the semantics of a sentence from a gien audio?

I have been thinking lately and looking up on what could be the possible features that capture the semantics of an audio and came across MFCC: MFCC features represent phonemes (distinct units of sound)...

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