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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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gnuradio: how to change the noutput_items dynamically when writing OOT block?

When I make a OOT block in gnuradio class mod(gr.sync_block): """ docstring for block mod """ def __init__(self): gr.sync_block.__init__(self, name="mod", in_sig=[np.byte], out_sig=[np.complex64]) def work(self,…
yun.fu
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Source of crackle in phase modulation synthesis

I'm trying to make a simple phase modulation synthesizer based on wavetables and DDS. I have a 12bit wavetable containing 4096 sample of a sine wave and I'm using a 32bit phase accumulator. Implementing my idea works but it seems to have a lot of…
Pyrohaz
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Setting the modulation index (10% or 100%) for ISO/IEC 15693 programatically on Android

Is possible set modulation index (10% or 100%) for ISO/IEC 15693 reading on Android devices programatically? Otherwise, is there a way to redo the tag through code without manually reconnecting the device again?
Chianta
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Half Sine Pulse Shaping - Matlab

The standard of 802.15.4 specfies the following: The chip sequences representing each data symbol are modulated onto the carrier using O-QPSK with halfsine pulse shaping. For pulse shaping the following is mentioned: The half-sine pulse shape…
smyslov
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Python: list comparison vs integer comparison which is more efficient?

I am currently implementing the LTE physical layer in Python (ver 2.7.7). For the qpsk, 16qam and 64qam modulation I would like to know which is more efficient to use between an integer comparison and a list comparison: Integer comparison:…
Austin Aigbe
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I get error with my 8psk modulation code

I'am trying to code a 8PSK modulation system,this is the code: custMap = [0 2 4 6 7 5 3 1]; hChan = comm.AWGNChannel('BitsPerSymbol',log2(8)); hErr = comm.ErrorRate; % Initialize the simulation vectors. The Eb/No is varied from 0 to 10 dB in % 1 dB…
Lina
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Sinusoidal Pulse Width Modulation in FPGA Device - OK in Simulation, Unmodulated in Device

Below is my top-level module: module spwm(clk, p1, sine_a, tri_out); input clk; //16MHz reg tick = 0; reg [7:0] theta_a = 8'd0; reg [7:0] theta_tri = 8'd0; output [8:0] sine_a; output [9:0] tri_out; integer div = 42; integer r = 0; output…
JR Galia
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Trouble doing fourier transform of ASK using MATLAB

We have a ASK modulated signal. We need the Fourier Transform, therefore I used FFT, but do I need to abs() for only one side? And is my code complete? I'm also not sure how to transfer from time domain (t) to frequency domain (f) in order to do the…
user276372
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modem.oqpsk with half sine wave

hi i was using the following h = modem.oqpskmod; but it constructs it with default settings, i wanted to model zigbee one which is oqpsk with half sine waves... how could i do it? thanks a lot!
kl.
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Amplitude modulation using builtin octave functions

I am using the following code for modulating and demodulating a simple waveform. Fs = 44100; T = 1; Fc = 15000; t=[0:1/Fs:T]; x=cos(20*pi*t); y=ammod(x,Fc,Fs); z=amdemod(y,Fc,Fs); plot(z); When Fc is around 12k, 'z' is same as 'x' but when Fc is…
BaluRaman
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frequency demodulation in matlab

how can i do frequency demodulation in matlab i have already done frequency modulation, but i can't do frequency demodulation this is matlab code clear all close all recorder = audiorecorder(44100,16,1); recordblocking(recorder,2); xtmessage =…
user3088987
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Matlab Integration in a loop

I am working in matlab the M-QAM modulation with Rayleigh fading, and i have a little problem with the integration part, i have made that code with an aproximation: function y = m_qam_ray( M ) %UNTITLED4 Summary of this function goes here % …
Merck
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To find FM signal's phase in Matlab

I want to find the phase of an FM signal. Matlab code of message signal is m= ones(1,Fs); m= [m(1:round(.4*Fs))*1, m(round(.4*Fs)+1:round(.7*Fs))*-2 ... m(round(.7*Fs)+1:Fs)*0]; How can I find phase of FM signal?
user2979746
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Pulse Width Modulation (PWM) with Vb.net

I am able to control the output on some pins on a board using a function with Boolean parameters. Would it be possible to use Vb.Net to send PWM signals out?
user2005848
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BER result in MATLAB

I build a pam-2 modulation, then I make a pulse shaping with half sine (matched filter). Then I send it through the AWGN channel. At the end I do down sampling and demodulation. But i have problem with plotting BER. I don't understand what I'm doing…
Rory
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