# Questions tagged [matlab]

MATLAB (MATrix LABoratory) is a numerical computing environment and a fourth-generation programming language. Use this tag with care.. see excerpt.

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### Why MATLAB is considering this differentiator to be stable?

I have a MATLAB code for differentiator , it last line command isstable determines whether system is stable or not. I was surprised by response of MATLAB as according to my understanding ...
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### Am I generating audio signal with a given particular SNR value correctly?

I am using this as my reference: https://www.mathworks.com/help/deeplearning/ug/denoise-speech-using-deep-learning-networks.html Add washing machine noise to the speech signal. Set the noise power ...
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1 vote
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### Non-Causal and Causal Wiener filter for Smoothing

I am trying to solve a smoothing problem using a wiener filter solution. I have tried to setup and compare three different solutions in matlab: A FIR filter solution, a general causal solution, and a ...
1 vote
39 views

### Differences between STFT and DGT

What’s the main difference between short-time Fourier transform (STFT) and discrete Gabor transform (DGT)? Based on the definitions in the Wikipedia page (and other textbooks), it seems that they are ...
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### How to reconstruct an image from s-parameters in MATLAB with datasets are 37 files colleting from 0-360 degree angle (10 degree of increment)?

How to reconstruct an image from s-parameters in MATLAB? My dataset are 37 files colleting from 0-360 degree angle (10 degree of increment) I have a set of data which is the s-parameter (s11) for the ...
87 views

### Why does constellation looks odd when the number of filter span is an odd number?

I use Wireless Waveform Generator app in MATLAB to simulate QPSK. When I select the filter span parameter as an even number, the constellation diagram looks normal. ...
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### Calculating the signal shift of acoustic emissions between a source and an observer

I am attaching two sensors on a body that I would like to investigate for defects. I am creating an impulse response on the first sensor by hitting the bolt that it is fastened by with a sharp object ...
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### Beginner question: Plotting frequency spectrum of a discrete spectrum using Matlab?

First, I apologize for the repost, I got really confused how Stack Exchange works. I tried my best to improve the question! Anyhow - I'm fairly new to the world of DSP, and I'm struggling with finding ...
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### s to z domain transformation

I have $2^{nd}$ order bessel filter transfer function. I want to model this analog bessel filter in FPGA. For this I need its digital or discrete form. I am trying to get digital filter's coefficients ...
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### Difference Data Collected and Reference Sinus

I have a signal generator with 40 MHz bandwidth and 1.2 GSa/s features. I generate a 9.7 MHz sine on this generator. I sample using ADC demo board at 100 MHz. I generate a reference signal in MATLAB ...
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### Two Sinus Multiply and Add

I'm trying to understand the difference between the sums and products of two sine signals. I also wonder where and how these two situations are used in practice. ...
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### lsqcurvefit using dynamic input data

I have input vector $\boldsymbol{u}$ and output vector $\boldsymbol{y}$ of length $N$, and I use $u_k,y_k$ to denote the $k$-th elements of $\boldsymbol{u}$ & $\boldsymbol{y}$ and $u_{k-1}$ as the ...
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### Matlab SNR Function

While examining the snr function in Matlab, I noticed something like this. When I examined the code and output given in their examples, I noticed that the ratio between average noise power and average ...
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### Different FFT results

I am trying to take IQ data from 2 SDRs and process that data in MATLAB. The ultimate goal is to use the Goertzel algorithm to grab the magnitude/phase information at a specific frequency under test. ...
1 vote
52 views

### How to utilize product graphs in graph signal processing?

I'm working with dynamic graph signal processing. How to plot time variation and spatial variation separately and take the cartesian product of those two graphs?
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### Recreating the dwt function from Matlab

I am trying to implement DWT (Discrete Wavelet Transform) on a given signal, without using the dwt function in Matlab. My approach was to get the synthesis filter coefficients using, ...
59 views

### why are the coefficients different when I design an IIR bandpass filter using butter compared to using the Filter Design Toolbox?

In matlab, for the same parameters, why are the coefficients different when I design an IIR bandpass filter using butter compared to using the Filter Design Toolbox? When I run a command in matlab <...
1 vote
73 views

### Minimum Number of Base Accelerations Needed to Simulate Gaussian White Noise in Structural Dynamics?

I am currently working on a scientific paper where I subject a structure to base accelerations modeled as Gaussian white noise. I am relatively new to signal processing and would appreciate some ...
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### How does MATLAB's edgetaper function work?

MATLAB has a function edgetaper that does something I haven't seen before: J = edgetaper(I,PSF) blurs the edges of the input ...
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### Detect and Localize Abrupt Changes on a Noisy Non Periodic Signal

I have a set of some 5000 x,y datapoints. They plot a smooth curve with large gradient and curvature at the right. There is high-freq noise that varies in amplitude from dataset to dataset, but the ...
31 views

### I want to generate a real time fft of vibration data from a triaxial MEMS accelerometer

I have been trying to generate a real-time FFT plot for my final year project on Condition Monitoring using a MEMS accelerometer (an MPU 6050) and an Arduino UNO. My goal is to generate a real-time ...
46 views

### Downconversion and CFO estimation after package detection

I'm currently working on generating a function to simulate a passband transmission. In my simulation, I assume that the received signal is twice of my transmitted signal (without adding any noise and ...
1 vote
54 views

### ML-Classification of Motor Imagery EEG data only at 50% in MatLab

I'm trying to do ML-classification on some Motor Imagery EEG data and for a long time now I've been stuck at ~50% being correctly classified. This is my first time working with EEG data and signal-...
60 views

### Confusion regarding Z-transform of unit step sequence in MATLAB

I am using MATLAB and trying to find ztransform of heaviside(n) which is unit step sequence I am studying book Signals and Systems Laboratory with MATLAB Book by Alex Palamides and Anastasia Veloni I ...
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1 vote
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### convert ndarray with properties in Matlab

I am testing to call a Scipy function of Decimate from Matlab and get a ndarray from this function with structure as below ...
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1 vote
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### call decimate function from matlab

I tried to call decimate function in Scipy from Matlab but met an error. Can somebody point me in a direction, please? Here is a code of Matlab ...
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### Help regarding a matlab code of Large intelligent surfaces

For my 8th sem project, i was referring to a matlab implementation of a Paper-Transmission Through Large Intelligent Surfaces:A New Frontier in Wireless Communications by Ertugrul Basar. While going ...
27 views

### Rician Frequency Selective Channel Model

I have a question about Rician channel with $L$ taps. The frequency selective Rician fading channels with delay spread of $L = 6$ taps are considered for both direct link and reflecting link, where ...
24 views

### Can you load a WAVES VST plugin with Audio Toolbox?

I'm trying to load a VST3 plugin from WAVES using loadAudioPlugin() from MATLAB Audio Toolbox: ...
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### IFFT return complex values in Matlab

I've been experimenting with the frequency sampling method for designing FIR filters. I created a low-pass filter that has a linear transition band. However, when I performed an IFFT on the frequency ...
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### Why is sampling frequency/rate typically abbreviated Fs and not Sf in English?

This is not a technical question, it is rather a question about the implicit notation used in MATLAB and multiple digital signal processing books to refer to sampling frequency/sampling rate. Why is ...
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1 vote
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### Simultaneous removal of all noises in all channels?

Can MATLAB be able to look at all 16 channels of a bio-amplifier simultaneously and look for the common factor which is the noise which affects all channels simultaneously, and the noises removed from ...
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### Matlab logic of plotting meshgrid formula

There is a code which uses meshgrid which is basicly doing all combination of one vector with the size of the other vector and visa versa. y and z are values of the field in the Y axes and Z axes. In ...
30 views

### Modulating with 64-QAM modulation

I'm new to this community. I'm trying to make a sender receiver device with using 64-QAM modulation. But I don't know how to code it or making the waveform. I am trying to make it on Altera Cyclone IV ...
1k views

### Why doesnt DFT Padding cause sinc like features

I'm new to the land of DSP so any incorrect terms please let me know. It seems padding the time domain signal can make the magnitude spectrum look 'nicer', the fact it doesn't gain any more useful ...
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### Jitter model does not behave as expected after FFT

So I'm currently trying to understand the relationship between jitter and phase noise. To help my understanding I did write a little simulation in matlab. I used this model in the time domain, relying ...
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1 vote
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### Trying to replicate results from tfestimate function in Matlab

I have been trying to replicate the results from the tfestimate function in Matlab by performing, from my understanding, the corresponding signal processing steps in a separate Matlab script file. The ...
74 views

### What function can be used to describe periodicity of the signal

im working on a program in matlab for calculation of sampled signal spectrum, and I have a sinusoidal signal with frequency f=100 Hz, sampling frequency fs=250 Hz, every sample is repeated 4 times (fr=...
1 vote
156 views

### Why i am not getting same convolution plots?

I am trying to implement convolution using fourier transform property but i am not getting exactly same shape of output that i get by using conv command First portion of graph obtained using conv ...
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### instantaneous frequency for a complex signal

Let $s(t)$ be a complex signal. I would like to know how to find a signal from its instantaneous frequency. I programmed the following function which calculates the instantaneous frequency. ...
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### Calculating stopband cut-off frequency and stopband attenuation for FIR lowpass window filter

I am aiming to create a digital windowing FIR filter on MATLAB and have been given specs such as a: sampling frequency of 360Hz maximum filter order of 5 cut-off frequency of 98Hz/ 1.710rad/sample (...
95 views

### Why is my Hard Decision Decoding of Convolutional codes not performing well?

I am encoding and decoding a randomly generated bitstream of data using a [5 7] convolutional code. For the decoding part I am using a Viterbi Decoder and trying both HDD and SDD. However, my results ...
36 views

### Spreading sequence for dsss or cdma

In spread spectrum systems like DSSS or CDMA, we can take a pseudo-random sequence composed of 1 and -1. But can we use a complex number sequence between -1 and 1? Why is this type of sequence never ...
202 views

### 5G BER vs SNR for QPSK, 16QAM, 64QAM

Recently been running simulations where I run through simulating passing random data bits through LDPC Encoding, Modulation (4, 16 or 64) and then AWGN. The code itself is 90% developed by myself with ...
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### How to select the location of submatrices to have specific property in the output of multiplication

I want to set the locations of two submatrices W22 and W21 taken from Hadamard matrix, with respect to ...
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### Result of complex exponential fourier series approximation and trignometric fourier series approximation are not exactly same in MATLAB?

I have a signal and i am trying to observe its approximations using complex exponential fourier series and trignometric fourier series but i am not getting exactly same result(graph of trignometirc ...
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### How can a costas loop work when root raised cosine filter used on QPSK signal?

I just finished a costas loop for QPSK signal,I transmit the baseband signal and sent it into the costas loop, which worked well, but when I filter the baseband signal with root raised cosine filter ...
1 vote
88 views

### In the frequency domain of a phase-shift keyed signal, why there are are prominent frequency components which are multiples of sampling frequency?

In the frequency domain representation of a digital phase modulated signal, why there are prominent other frequency components which are multiples of the sampling frequency, other than the main ...
1 vote