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Questions tagged [modulation]

Anything related to *signal modulation*, i.e. the process of encoding the information provided by some source into the variations of some property (e.g. amplitude, frequency, phase, polarization, etc.) of a carrier signal suitable to be transmitted over a communication channel.

Anything related to signal modulation, i.e. the process of encoding the information provided by some source into the variations of some property (e.g. amplitude, frequency, phase, polarization, etc.) of a carrier signal suitable to be transmitted over a communication channel.

See Wikipedia page on signal modulation.

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High-frequency spur after performing an FFT in MATLAB

I have a modulated signal, and now I want to perform an FFT. However, I am getting a spur at a high frequency, which should not be there (and if it should, I have no clue as to why). Lvl=[0.5,0.9,0.5,0.5,0.1,0.1,0.9,0.5]; fa=60; %the frequency of…
Christiana S. F. Chamon
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How to print a amplitude modulated signal using python

I have an matlab example of this program but I can't do it in Python. How it must look like (mathlab example) https://i.stack.imgur.com/H0WWa.jpg. import numpy as np import matplotlib.pyplot as plt from scipy.signal import hilbert, chirp duration =…
Datel666
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Python: translate sensor data into continuous frequency modulated audio

I have a piece of python script that runs through a continuous loop (~5Hz) to obtain data from a set of sensors connected to my PC, much like a proximity sensor. I would like to translate this sensor data into audio output, using python and in a…
MTDJassen
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Calculating Error Rates for QPSK(for AWGN channel) in MATLAB

I want to simulate the QPSK for AWGN Channel and compare the errors I get with the theoritical ones on a plot. I want to do this on MATLAB for different SNR values from 1 to 10. When I plot this I get a huge difference between simulated and…
user6210457
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Getting matrix dimension error while modulating audio waveform on matlab

I am getting the matrix dimension error for the following code. What I am trying to do below is modulation of an audio waveform but I could not get passed the error I specified. I have checked the length of the sample.wav and adjusted time axis(t)…
Furkan Ülger
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Amplitude modulation of a brown noise generated with acoustics package in python

I am totally new to python, so I tried to read and learn what I could but I cannot seem to do what I want, and I haven't found a solution on Stack Overflow or other sources. My aim is to create a wave file of brown noise with amplitude modulation at…
Pyxel
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QPSK function operation/MATLAB

QPSK Modulation its supposed to use 2 bits for each symbol, but wheter I use pskmod or comm.QPSKModulator, I'm still getting the same amount of symbols as bits. Am i doing something wrong? Is something wrong with the function? Thanks in…
Bryan Carrión
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Frequency of the signals transmitted & modulation scheme (FSK, ASK)

How is the frequency of the signals transmitted reflected on the modulation scheme (eg: FSK, ASK)? Say if I want to transmit a sequence of signal with a frequency of 20kHz(an amplitude of 7V is 1, no amplitude is 0), is there any requirement of the…
Stephanie
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BPSK modulation and SNR : Matlab

Considering an Additive White Gaussian Noise (AWGN) communication channel where a signal taking values from BPSK modulation is being transmitted. Then, the received noisy signal is :y[k] = s[k] + w[k] where s[k] is either +1,-1 symbol and w[k] is…
SKM
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8dpsk. How to "improve" constellation diagram?

I try to demodulate 8dpsk in software. Carrier frequency=1800 Hz, modulation rate=1600 bauds, i.e. itu-t v.27. Demodulator has the following properties: Input passband hardware filter 50...3600 Hz; sampling frequency - 9600 Hz; Matched filter -…
user8142579
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Audio signal modulation to produce voice changing effects

As a study exercise I am trying to implement a java class that is able to apply some voice changes according to another audio effect file. E.G. let's say I have a audio sample of my voice saying "hello world" and another audio sample of some…
ChaSIem
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Octave-Online Frequency Demodulation Plotting Error

I have a signal which is defined as x , I want to modulate it than demodulate it to get my very first signal.To see what is going on i need to sketch out my x, my modualted x and my demodulated x. fs = 5000; %sampling frequency in Hz fc = 1000;…
Emre Hayırcı
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Manipulating an .m file from another function

So i Created an .m file that has a sawtooth signal wave that i am trying to modulate. I have no Problem producing the wave form but when i try to take the .m file and multiply it by "c" MATLAB returns the original waveform. This specific program is…
Zanderg
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Mutichannel Audio Output in Simulink

I'm using Simulink to output 2 sine waves through my audio output (headphones) 3.5mm jack. I want one of the sinusoids to be sent out Channel 1, and the other sinusoid sent out Channel 2. I have tried using 2 sine wave blocks wired to 2 "To Audio…
ronan
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FSK Demodulation and Data Recovery

I'm trying to implement a FSK demodulator in R. The audio is some text data, and as an exercise I converted the text to raw binary (0s and 1s) to be able to check the output of the demodulator. So far I've been able to come up with some…
Evan
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