Questions tagged [matlab]
MATLAB (MATrix LABoratory) is a numerical computing environment and a fourth-generation programming language. Use this tag with care.. see excerpt.
2,998
questions
-2
votes
1
answer
19
views
confusion understanding/interpreting power spectrum of audio in MATLAB?
Please find attached snapshot. I am confused regarding power spectrum in MATLAB as according to google definition in attached snapshot"the distribution of the energy of a waveform among its ...
- 1,001
0
votes
0
answers
17
views
How can I plot the power spectra of a ST (Stratosphere Troposphere) Radar in MATLAB to estimate the doppler shift
Respected all,
I am trying to plot the power spectra of a ST (Stratosphere Troposphere) Radar to estimate the doppler shift. I am able to obtain a 3D plot between range, FFT point and Power density ...
- 1
0
votes
0
answers
38
views
How to draw a phase diagram in MATLAB (picture attached) for 3 variables (x, y and mean squared error)?
I am trying to make a phase diagram for three variables .
a=[0.01 0.5 1 1.5 2]; b=[0.1 1 2 5 10];
and their mean squared error value in variable 3 (having 5 rows and 5 columns)
mse =
...
- 107
-1
votes
0
answers
50
views
Comparison of matched filter methods
I recently asked a question about the identity $\mathscr{F}\big\{x^\ast(-t)\big\}=\mathscr{F}\big\{x(t)\big\}^\ast$. Based on the feedback I got, I tested out the dicrete version of this identity in ...
- 83
0
votes
0
answers
9
views
Spark of the array manifold of a random antenna array
let's consider I have an antenna array with N-elements, and its sensors are not placed in a uniform linear array fashion (may be randomly placed, a coprime array, or a nested array, for example). What ...
0
votes
1
answer
28
views
Displaying and analyzing an audio file in MATLAB
I was given the following problem at my university:
We are given an audio file which we have to download. Following that we have to create a MATLAB code that can create a discrete-time graph of the ...
1
vote
1
answer
269
views
Fourier transform identity not working in Matlab
$F^\ast(x(t))=F(x^\ast(-t))$
I'm trying to use this identity in Matlab. I expect this should translate to:
conj(fft(x)) == fft(conj(flip(x)))
It doesn't work out. ...
- 83
0
votes
1
answer
19
views
Modeling an OFDM signal and comparing it with QPSK
I am trying to model an OFDM signal based on original QPSK stream and compare their baseband spectrums.
I've used this article as a reference for plotting spectrum and this as a MATLAB OFDM reference
...
- 5
0
votes
0
answers
40
views
Significantly different results between matlab's fft and FFTW for FIR-filter implementation
I am trying to implement the fast fir-filter in a C++ application.
I have implemented the same code in matlab as a way to double-check my implementation and have ran into a problem.
When running ...
0
votes
0
answers
13
views
Design Broadband Matching Networks for Amplifier Mathworks Example
Does someone have full code for this example :
https://ch.mathworks.com/help/rf/ug/designing-broadband-matching-networks-part-2-amplifier.html
I get Error:
File: hw.m Line: 10 Column: 36 The ...
- 13
0
votes
1
answer
25
views
What filtering I could use to save my displacement data?
I am double integrating my acceleration to obtain the displacement. However, the displacement looks so strange.
Basically this is the measured acceleration of a system under a impulse movement. and I ...
- 1
4
votes
1
answer
310
views
Gradient descent algorithm not converging
I wish to use the gradient descent algorithm to minimize the cost function
$$J(\mathbf{w}) = (\mathbf{w} - \mathbf{w}_{o})^{T} \mathbf{A}(\mathbf{w} - \mathbf{w}_{o})$$
where $\mathbf{w} \in \mathbb{R}...
- 359
0
votes
0
answers
16
views
Advices to Improve Carrier Aggregation Matlab Code
I'm doing a university project on Carrier Aggregation and I'm using a Matlab code to simulate the process.
There's already a complete code about Carrier Aggregation in Matlab Library, but when I asked ...
0
votes
0
answers
25
views
Modulating and transmitting three different voice signals (in MATLAB)
I want to record, modulate and transmit three different voice signals. I will be doing this in MATLAB.
Please can you help me figure out how can I do this?
Or give me a block diagram that can show ...
1
vote
1
answer
56
views
Python's equivalent of MATLAB's cwtfilterbank
I am learning signal processing and would like to know what's the python equivalent of matlab's cwtfilterbank.
I looked through pywt but did not find anything.
Some ...
- 55
0
votes
0
answers
38
views
Construction of Room Impulse Response - Short-Time-Fourier-Transform and Inverse-STFT - Matlab and NWaves (C#) Implementation
Background:
I am working on a Unity Project (C#) and implementing a Room Impulse Response synthesis.
I do ray tracing to create energy histogram for different bands.
With these histograms it is ...
0
votes
0
answers
24
views
Applying a frequency and phase sensitivity post-recording
I have a particle velocity sensor that I'm recording, which has a non-linear frequency and phase response. I have frequency and phase correction curves for it, however, the proprietary acquisition ...
- 11
0
votes
0
answers
22
views
Sysgen vs. Pure VHDL for Image Processing Implementation
We're evaluating whether to implement a complex image processing algorithm using Matlab's Sysgen or translate it directly into VHDL.
As a start, the algorithm is given to us in Matlab.
Traditionally, ...
- 101
3
votes
1
answer
323
views
Which FFT algorithm does Matlab use?
Exactly which FFT algorithm does Matlab use for the fft function? I though originally it was the Cooley-Tukey Decimation in Time algorithm but the Matlab ...
1
vote
3
answers
120
views
Half length inverse DFT to obtain half of the concatenation of a signal with negative of itself
I used to read some white papers online, where they mention the below statement:
If we have a real vector $\mathbf{y} \in \mathbb{R}^{N \times 1}$ which is an output of $IFFT$ process with size $N \...
- 133
0
votes
1
answer
51
views
Power spectral density of melodic contours
DESCRIPTION OF SIGNALS
I have several sung melodies under each of nine experimental contexts ("conditions"). The melodies are all of slightly different lengths (ranging more or less from 3s ...
- 51
0
votes
1
answer
73
views
Why are the PSDs off by 100 times
I produced the "elevation vs distance" profile data and their PSD plots, I am trying to get the smartphone estimated profile close to the reference profile.
As you can see, the PSD of the ...
- 1
0
votes
0
answers
38
views
model of a quasi static block fading channel in MIMO system
can I know what is the model of a quasi static block fading channel in a MIMO system, in function of angle of departure and arrival?
1
vote
0
answers
42
views
Tap and Impulse Response of MATLAB Filter
This is a simplified version of the Savitzky-Golay MATLAB functions (sgolayfilt, sgolay).
...
- 165
3
votes
1
answer
222
views
Plotting beam pattern of uniform linear array
I am trying to reproduce Fig. 2.17 from the book 'Optimum Array Processing' by Van Trees.
The figure is a polar plot of the beam pattern $B_{\theta}(\theta)$ given by
$$B_{\theta}(\theta) = \frac{1}{...
- 359
0
votes
2
answers
105
views
Optimize FIR filter kernel in Matlab
I am currently using the firls function in Matlab to create my FIR filter kernel. This works well but I typically have to play with the filter order to get the gain to 1 and the shape to be somewhat ...
- 131
0
votes
0
answers
60
views
How can I find peaks in an EKG when the polarity may be inverted?
I am working on finding the peaks in EKGs using Matlab. I have a couple of hundred of recordings. The problem is that some of them have their peaks inverted (so they are negative.) The goal is to be ...
- 163
0
votes
1
answer
35
views
Frequency Translation after FIR Filter
I am trying to translate a signal to baseband by multiplying by the complex exponential. The issue is when I do the calculation in MATLAB the signal seems to disappear. I originally thought the signal ...
- 131
0
votes
0
answers
18
views
Doubt related to simulating the given wireless system?
I am trying to simulate the following wireless system in MATLAB but not getting it correctly.
Consider a wireless system consisting of four base stations (BS) and one Fiber base station (FBS). We ...
- 33
1
vote
1
answer
28
views
Integral Calculation in Matlab for Filter Optimization
I am trying to calculate the area under my FIR filter kernel using trapz but I'm getting weird results. The reason I want to know the area is eventually I would ...
- 131
0
votes
2
answers
119
views
Frequency shifting with complex exponential
I'm trying to frequency shift a sine wave at 50kHz by using a complex exponential at 15kHz. I should be getting an FFT with a peak at 65kHz.
Instead I'm getting a strange looking peak at 52.4kHz. ...
- 131
3
votes
1
answer
68
views
Understanding Maximum likelihood detector expression?
Consider the MIMO system which has $N_t$ antennas at transmitter and $N_r$ antennas at receiver and uses Generalized space shift keying (GSSK) modulation. The received signal is given by:
$$Y = H X + ...
- 33
0
votes
2
answers
53
views
How can i get a growing sinusoid in matlab?(by incorporating real part into exp command besides imaginary part which is already there)
I am trying to display a growing sinusoid in MATLAB and i know that imaginary part corresponds to oscillations but i am confused how can i incorporate real part in ...
- 1,001
1
vote
1
answer
61
views
Confusion implementing DFT circular frequency shift property in MATLAB 2015a?
I am trying to implement the DFT circular frequency shift property in MATLAB and my code is below. I have also attached a snapshot from the Proakis book where this property is highlighted but I am ...
- 669
8
votes
1
answer
183
views
Noise leakage problem with least square estimation in the frequency-distance domain
I have data $d$ recorded from an antenna of sensors. These data are composed of a Gaussian noise $n$ and a signal $s$ which I try to estimate. This signal propagates on the antenna with frequency ...
- 95
2
votes
1
answer
142
views
Confusion regarding usage of MATLAB for Z domain?
How we can use MATLAB for z domain especially in scenarios where we have two different expressions of Z transform(one has negative powers of z and other has positive powers of z)
I have added a link ...
- 669
1
vote
1
answer
81
views
Ambiguity function information
For a course that i'm taking im asked a question about the ambiguity function of a FMCW radar. However i have not found a good source for reading about this so don't quite understand it.
I get given ...
- 11
0
votes
0
answers
38
views
Symbol timing synchronization with delay
I’m trying to simulate a TLL loop using Gardner TED. I set symbol rate is 1000 and 8 samples for 1 symbol. First I use Root-raised-cosine filter to shape the symbols, then I use interp1 in matlab to ...
- 21
-2
votes
1
answer
45
views
Matlab command "iztrans"only applicable for causal signals? [closed]
Matlab command for inverse z transform iztransonly applicable for causal signals? or also valid for non causal signals?
Actually i want to find inverse z transform ...
- 1,001
2
votes
1
answer
89
views
Correct Windowing Effect at Amplitude Scale
I am trying verify the noise floor returned by Matlab sinad(). I am able to get the results matching by summing power spectrum density with $\frac{f_\text{s}}{N}$. ...
- 21
0
votes
2
answers
233
views
Scipy and Matlab Spectrogram not matching
I am trying to replicate a spectrogram from MATLAB in Python. I've read other posts but they either don't use complex data or the data doesn't match between languages.
I've defined my FFT length (<...
- 131
-1
votes
1
answer
53
views
Problem with starting values when recreating the matlab envelope function in python
I am trying to recreate the envelope function from matlab in python, but I have a problem with the initial values. I have a window of 1000 and the first 1000 values won't show up. Here is a snippet of ...
- 1
2
votes
0
answers
38
views
Why am I not getting proper values of power(Px) and energy(Ex) signal as per book?
I am considering an energy signal in MATLAB as I am going through the book Signals and Systems Laboratory with MATLAB by Alex Palamides.
My Matlab code is below:
...
- 21
1
vote
0
answers
50
views
Wigner-Ville distrubution on large data signal analysis
I have a touch signal on a plate recorded with 3 accelerometers with a sample rate of 150kHz over a duration of 5 seconds (so 750k samples). The goal is to localize the position of the touch in the ...
- 46
0
votes
2
answers
81
views
Confusion regarding MATLAB code of convolution animation?
I am trying to understand a MATLAB code of convolution animation.
Please check above link especially code in lines 15 and 16. I think author has mistakenly swapped comments of line 15 and 16. Please ...
- 1,001
1
vote
1
answer
137
views
How can I convert the sweep signal into the impulse response?
Does someone know, how to convert the sweep signal into the impulse response?
What kind of results will come out?
I generated a sweep signal from REW software and then correct the output value sweep ...
- 11
0
votes
0
answers
40
views
convert the Sweep signal into impulse response [duplicate]
Does someone know, how to convert the Sweep signal into Impulse response
I am testing that comparing software and hardware compressor with sweep signal
I generated a sweep signal from REW software and ...
- 11
1
vote
0
answers
72
views
IFFT confusion, sampling frequency
I made a previous post about what I am trying to do
Previous Post
I have band-limited data in the frequency domain from a VNA and I am trying to convert it into the time domain. VNA data saved in .s2p ...
- 33
1
vote
1
answer
30
views
Confusion regarding "step value" of time in discrete time signals?
I am reading book"Signals and Systems Laboratory with Matlab" and i am studying about discrete time signals
I have also attached a snap and highlighted a line:
The definition of the time. ...
- 11
0
votes
3
answers
117
views
Confusion regarding MATLAB?Can't we represent continous time signals properly(fully and completely)?
Which command should be used for quantization of a signal in MATLAB?
Please check above question link especially answer of @Hilmar, especially the first paragraph of answer and especially the ...
- 1,001