All Questions

1
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0answers
23 views

How to get an interpolation weight from a mathematical definition

It was recently explained to me that a "Nearest neighbor" kernel for 1D interpolation can be implemented like this using NumPy ...
0
votes
0answers
4 views

Frequency selective channel modeling using rayleighchan object in matlab

I intend to model a frequency selective channel using matlab "comm.RayleighChannel" object. Consider the following command, which sets the parameters of Rayleigh channel : ...
1
vote
3answers
29 views

Why only odd harmonics after non-linear amplification?

Why do I get only odd harmonics appearing? This not only happens at saturation of the transfer curve, but also in the linear portion of the curve. I make a input signal that has too high power that ...
0
votes
1answer
16 views

How to find spectral density of a signal whose correlation depends on time?

Suppose we have two uncorrelated, real white noise $\xi_1(t)$ and $\xi_2(t)$, with zero mean, and equal variance. Now, I create the signal $\xi(t) = a\xi_1(t)\cos(\omega_0 t) + b\xi_2(t) \sin(\...
0
votes
1answer
8 views

BER performance of a space-time code over Rayleigh channel model

For a given space-time code, and in general terms, how would one proceed in the evaluation of the BER performance of this code ? In order to be more clear, say i have 16 code matrices(who's elements ...
0
votes
2answers
19 views

I am trying to convert a signal into another unit, but the error keeps increasing during each iteration

I have a signal, A, and I want to convert it into another unit by using a formula: $$s_i = \frac{(1+x_i)}{(1-x_i)}\cdot s_{i-1}$$ where $x_i$ is each sample of ...
0
votes
0answers
5 views

When we set a State vector during bayesian process, can we use only velocity or location?

When we use a bayesian framework, We firstly set a state. The state is what we want to know.. At this time, Can we use just location or velocity like belows? (X is state vector) For example, X = (x,...
0
votes
0answers
23 views

How do I filter out the specific components at 20MHz, in this figure?

I used the filter builder (lowpass) , to cut off the frequency at 0.5 MHz, and thus used a stopband of 0.1pi, and a passband of 0.0125pi. (Sampling Frequency= 80MHz). However, the output was still ...
0
votes
0answers
13 views

Kalman Filter State Covariance Matrix

If I have a discrete time process model of the form: $$x_{k+1} = x_{k} + v_{k}\cos(\theta_{k})dt$$ $$y_{k+1} = y_{k} + v_{k}\sin(\theta_{k})dt$$ $$v_{k+1} = v_{k} $$ $$\theta_{k+1} = \theta_{k}$$ ...
0
votes
1answer
21 views

How to calculate SNR with sample noise and noisy signal only

I want to calculate the SNR for a speech signal recorded within a noisy environment. I also sampled purely the noise within the environment. The SNR is based on the ratio of power of clean signal ...
2
votes
1answer
27 views

How to detect algebraic loop in a system

I came across a system (screen below) that looks like it should result in a algebraic loop, but when writing the equations using the Z-transform, it obviously does not (calculation below too). But I ...
0
votes
0answers
21 views

Plot Frequency Spectrum of Binary Sequence in Matlab

I am new to Matlab and I am trying to implement a section of a published paper, the basic idea of the part that i am implementing is to show the frequency spectrum of camera aperture. The shutter ...
0
votes
0answers
29 views

Aliasing from downsampling and Nyquist

In a book Conceptual Wavelets in Digital Signal Processing by Lee Fugal 2009 on page 246 the author talks about aliasing present in DWT subbands due to downsampling by 2 and states: Recall from DSP ...
-3
votes
0answers
27 views

Proof of time-invariance of discrete time system

I'm looking at this discrete time system: y[n] − 4y[n−1] + 4y[n−2] = 20x[n] + 10x[n−1] how do I proof that it time-invariance? Thanks!
0
votes
1answer
30 views

IIR filter with circular buffer - Arduino

I am trying to implement a butterworth lowpass filter with a circular buffer. The code below does not filter as intended and I am not really able to understand what is wrong. Any suggestion? ...
1
vote
0answers
10 views

How to express STFT and ISTFT as a 1d convolution and 1d deconvolution in tensorflow/keras

I'm trying to implement this paper in tensorflow and keras. At the end of section 3 it says. ...
0
votes
1answer
49 views

Sum of cosines as squashed as possible

I have 10 cosine waves of the form $\cos(2\pi(x f_n+\varphi_n))$, where $f_n$, the frequency, is an integer from 1 to 10 and $\varphi_i$, the phase, is a number from 0 to 1: $$s(x) = \sum\limits_{n=1}...
0
votes
0answers
16 views

What does the offloading and local computing do?

It only mention that the advantage of giving the bit to offloading and local computing at the same time in this paper: Joint Offloading and Computing Optimization in Wireless Powered Mobile-Edge ...
-2
votes
1answer
69 views

What does a fractional frequency (for discrete-time signals) mean/how to interpret it?

This question has bugged me for a while as it's not addressed in any books I've read. I was wondering how folks from this community interpreted it. Below are my personal notes on the matter (please ...
0
votes
2answers
42 views

Decoding .wav file to bit level data

I have been given the following waveform and asked to read the data and write to a buffer using Java. The .wav file has a sampling rate of 44100 Hz, 2 channel and 16-bit depth. From the waveform, I ...
0
votes
0answers
29 views

Audio signal similarity percentage

My problem is to find a way to classify audio files, and after that I need to test my machine with an audio file whose similarity percentage I need to find. I tried to do it using MFCCs first ...
1
vote
1answer
49 views

What kind of power spectrum implies uncorrelation in time?

I am new in signal processing field, and actually I just need some basic tools for what I am working on. I've learnt that the autocorrelation function is the inverse Fourier transform of the signal's ...
0
votes
1answer
29 views

Hilbert transform of symbolic function in Matlab

I have a signal of the form $f(\omega,x) = g(\omega) e^{i \omega (x +c)},$ for $g: [\omega_1 , \omega_2] \rightarrow C, \, x\in R$ and some constant $c.$ I want to get the function $$ F (\omega,x) = \...
1
vote
1answer
15 views

Separability vs. Resolution - Synonymous terms?

In terms of discrete representation of a variable, let's say time measurements in absolute values in [seconds], is there a difference between separability and resolution? When do speak of either ...
3
votes
1answer
26 views

Limiter, compressor, AGC, dynamics processor?

What are the primary differences between the usage or definitions of the terms “AGC”, “compressor”, “limiter”, and dynamics processor? They all seem to be forms of playing with gain knobs.
7
votes
1answer
1k views

Why sampling a periodic signal doesn't yield a periodic discrete signal?

I've been studying Signals and systems lately and I've came across a bullet point in a slide that claims "The uniform sampling of a periodic continuous-time signal may not be periodic!". Can someone ...
0
votes
0answers
29 views

duration for a signal

I am a beginner in the signal processing and I have questions for the duration of a signal. My system has a bandwidth $B$. I have a signal $s(t)$, the duration for this signal is $T$. The signal $s(t)...
3
votes
0answers
21 views

Efficient implementation of 2-d circularly symmetric low-pass filter

How can a two-dimensional ideal circularly symmetric low-pass filter or its approximation be efficiently implemented on data sampled on a square grid? I'm referring to an ideal filter with a spatial ...
0
votes
1answer
19 views

MRI image reconstruction - reduced scan pecentage

I have an MRI kspace from a siemens 1.5 T scanner with reduced scan percentage ( sampled truncation by not acquiring the most peripheral lines in kspace). The kspace plot in matlab look like below. I ...
1
vote
0answers
28 views

DFT equivalent circular convolution weight matrix with a symmetric filter of length 2K+1

$\DeclareMathOperator{\diag}{diag}$In a research paper, I read that: For optimization, the $n\times n$ weight matrix of DFT can be equivalent to circular convolution with a symmetric filter of length ...
1
vote
2answers
48 views

How to deal with the mirrored components of a FFT? And another question

I'm trying to simulate the behavior of my FFT spectrum analyzer, I am using Mathematica, but my questions are more conceptual than technical implementation of code...I hope. If we consider a simple ...
0
votes
1answer
22 views

How to get maxima of rho in hough table

i applyed hough transform in my image and this is the result of hough table, i must get the maxima of rho in two basic angles of theta , the one is around -65 : -60 and the other is round 30:35 How ...
0
votes
0answers
29 views

Negative Exponential Filter SciPy

I'm trying to transform a time series with a recursive filter to model a feedback. I was able to do a simple filter like : ...
0
votes
1answer
50 views

Fixed-point Exponential Moving Average filter with given cutoff frequency

I want to implement in fixed point arithmetic an exponential moving average filter, with a specific cutoff frequency for a given sampling rate. The formula for the filter is $$ y_n = \alpha x_n + (1 -...
1
vote
1answer
242 views

Bilinear Transform (Tustin's Method) applied to the Derivative

I hope that I have not misunderstood something terribly wrong, but the continuous derivative $D=d/dt$ can be considered a transfer function in Laplace space $D(s) = s$, right? So when I try to ...
0
votes
0answers
22 views

Convex Optimisation and Python [on hold]

I was tweaking with CVX Toolbar in MATLAB. While running a simple example (available on CVX Documentation), I keep getting errors. I am writing a MWE below: ...
0
votes
0answers
6 views

Pascal Voc 2012 Annotaions for 6D viewpoint(pose) estimation

Everyone, I am working on 6D pose estimation and I have to predict a rotation matrix (Euler angle) and translation. Now In Pascal Voc annotations are in the form of azimuth, elevation and distance ...
0
votes
0answers
45 views

How can I generate an IF signal of 70MHz, with a bandwidth of 1MHz, on MATLAB?

I am a beginner in MATLAB, and have a fair grip on the theoretical concepts of up conversion, etc. So the problem statement is that, a 70MHz, IF signal, of 1MHz BW is obtained from a satellite, and ...
0
votes
0answers
17 views

PulseAudio cannot read buffers at consistent rate [on hold]

I want to record my microphone and process in real time, eg. show an oscilloscope view of the microphone signal. I've tried 3 ways to get the data out of PulseAudio and they all perform the same. ...
0
votes
1answer
21 views

How to draw the magnitude plot of a variable slope low/high pass shelving filter? (eg. as a function of cascaded shelving filters)

I am interested in making a magnitude graph of a variable slope low/high pass filter. I would like to set slope in dB/oct and a cutoff pitch. The y-axis should be amplitude from 0 to 1, and the x-axis ...
0
votes
2answers
48 views

What Is the Relation Between Deblurring and Deconvolution in Computer Vision and Image Processing?

The deblurring problem can be modelled as follows $$ f = \phi u + \epsilon, \; \epsilon \sim N(0, \sigma) $$ where $\phi$ is a filter (e.g. a low-pass filter) and $\epsilon$ is a Gaussian noise. In ...
1
vote
1answer
66 views

Calculating Data Rate using Bandwidth, Transmission Power, Noise Power Spectrum Density and Channel Gain

I'm a Software Engineering student researching on Load Balancing in IoT and I need to calculate data rate. However, I don't know how to use these values to attain data rate despite searching on the ...
0
votes
0answers
28 views

Audio callback function for Windows in c++

I'm writing a cross platform c++ based audio library for an app I am creating. For the audio component I am not using any platform specific code. I have a test harness that outputs audio using device ...
0
votes
0answers
37 views

Upsampling and downsampling signals as a preprocessing step for a neural network

I have audio data acquired from a 4 channels sensors array. As a preprocessing step for a neural network, I want to beamform and focus on the sound source. For higher resolution in the beamforming ...
2
votes
1answer
67 views

Basic difference between Fourier transform and laplace transform? [duplicate]

I have read few links about difference between Fourier transform and Laplace transform but still not satisfied Please correct me if i am wrong Simply put, the main difference between Fourier ...
0
votes
1answer
35 views

Conversion from continuous to sampled signal?

I am bit confused regarding sampling as i read different types of statements in different texts Forexample i have a continous time signal $x=sin(t)$ defined for $t=0:10$ and i want to sample it with ...
-1
votes
1answer
40 views

What does this spectrogram mean?This is spectrogram of a multitone FM signal

! The spectrogram of FM signal has been generated by using Matlab.Now I want to what does these scratch like lined represent, though I have only two frequency components in my message signal(https://i....
1
vote
1answer
29 views

Extract frequency data from MP3 file

I want to do frequency analysis of audio data, basically trying to figure out what the notes are in a song algorithmically. The standard approach is to decode the MP3 into PCM data and run it through ...
1
vote
1answer
21 views

is there a use for a changing kernel in image convolution

I understand the principle of image convolution. Maybe. I think it is this: You use a small matrix with numbers in it, then take a sample of an image with as many pixels as you have numbers in your ...
1
vote
2answers
59 views

Bilinear transform with pre-warping for systems other than classical filters

I only seem to be able to find online information about applying bilinear transform + pre-warping to filters (like butterworth, etc.) with only one edge frequency that is purposely 'designed' into it. ...

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