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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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SVPWM Dwell time calculation and switching vector

0 I have modeled a SVPWM for a two-level, three-phase inverter. The modulation index for svpwm is selected as MI = 3Vref/2Vdc, the dwell time is selected based on sector and alpha (angle in each sector), the Vref is selected as 300, and Vdc is given…
무함마드
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How to use the Header/Payload Demux block correctly?

I am trying to implement schemes from two tutorials: Guided Tutorial PSK Demodulation and Packet Communications My scheme: qpsk, packet communications. They work together. As I understand it, the Header/Payload Demux block accepts 1 bit as…
Ice Cool
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Incorrect QPSK constellation. How to fix it?

When transmitting QPSK modulation, I think my signal constellation is far from perfect. I am trying to implement packet data communication using QPSK. When connecting these blocks together, I get the following: a constellation before transmission…
Ice Cool
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How to transmit packet communication using QPSK?

I want to make a full-fledged communication system so that data from one USRP is transferred to another USRP. To do this, I studied two tutorials: QPSK and Packet Communication. At first I tested their work separately. Packet transmission works…
Ice Cool
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what blocks can replace PacketEncoder and Packet decoder in Gnu Radio?

I found a video on Youtube where a person transfers messages from one USRP to another using Packet Encoder and Packet Decoder blocks. I can reproduce most of the scheme, but these blocks are not used in Gnu Radio right now. As there are alternatives…
Ice Cool
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How to get BER for QPSK modulation?

I am trying to compare data before modulation using the BER block. But my probability turns out to be very bad. It should be close to 0. Based on the scheme from the Simulation example: BPSK Demodulator,(Block scheme)I am trying to calculate BER.…
Ice Cool
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What's the difference between sdrTransmitter(txWaveForm) and sdrTransmitter.transmitRepeat(txWaveForm)?

i have a two adalm pluto devices connected to different computers(one is abonent and another is a base station). All of this works via MATLAB on abonent side i create a transmit wave contains consisting of a preamble like: 1 0 1 1 1 0 0 0 1 0 1 1 0…
Count Zero
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Which role sqrt(P) play in the communication model of y = sqrt(P)Hx + n?

I see people just type y=Hx+n when they discribe a communication process, but sometimes they use y=sqrt(P)Hx+n instead. I am not a professional guy in communcation area and confused about that, could anyone help me to answer this question in detail?
HERE
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Simulation of OAM modulation and demodulation

The laser signal is simulated by matlab after OAM multiplexing, through modulation, into the ocean turbulence channel or atmospheric turbulence channel, and then demodulation analysis of transmission error Analog wireless optical communication…
Seven Two
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Extract frequency of sin wav from clean and noisy numpy arrays

Here is a graph that shows a "control" (blue) and "recorded" (orange) signals. Both are numpy arrays with 10,756 items, acquired from a .wav file with the code: from wave import open as open_wave waveFile = open_wave(filename,'rb') nframes =…
ghukill
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Matlab Acoustic Modem with QAM modulation

I am trying to make an acoustic modem with matlab. It records sound an stores it in an array, modulates it using 64-QAM and adds then demodulates it. But the demodulated sound and recorded sound are not the same. Here is the code: clear; clc; M =…
El_Canario
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ESP32 frequency modulation using DAC

Is it possible to generate modulated wave using ESP32 (with or without) it's DAC? I would like to generate signal with carier frequency and modulation frequency.
Andreisk
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FSK modulation matlab code is not working as expected

This is my code for generating a TTL wave with frequency 30 Hz and modulate it with FSK and carrier frequency 400 f=30; T = 1/f; t = linspace(0, T*10, 1000); y = (1/2)*square(t/T*2*pi)+(1/2); plot(t, y); hold on; fc=400; df=20; y_m =…
Phillip A. Hendrick
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phase modulation in LabVIEW

is there a way to implement phase modulation and demodulation in LabVIEW(using NI USRP and without MathScript). I cant seem to be able to convert the block diagrams into useful circuits. Any help is appreciated.
Hani Kanaan
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Why is the AM demodulated signal amplified compared to the message signal for some specific frequency values?

I am modulating and demodulating a signal using built-in ammod and amdemod functions of matlab. Fc is set to 500, when I use Fs=2000, the demodulated signal matches up with the message signal very well. But when I use Fs=1000.. the demodulated…
Fakhar Haider
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