Questions tagged [modulation]
Generic term for coding information onto a carrier signal.
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Cannot decode IR signals using IRRemote Library
I'm using RC5 encoding for my project.
I'm sending signals using RC5 Protocol. The transmitter is sending the signals correctly.
But on the receiver node, when I decode the signals, Library is unable ...
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Modifying modulation parameters in RC5 [closed]
I am a computer science student working on a research project that uses IRRemote library for IR communication.
I'm using RC5 modulation and the system is working. However, for the next part of this ...
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Why is my oscilloscope math mode showing an RMS voltage in gigavolts (unexpectedly high value)
I'm experiencing an issue with my Rigol DS1202 oscilloscope. When using the math function to measure the RMS voltage of the difference between two channels (A - B), the RMS value is displayed in ...
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Is the probability transition matrix of M-PSK signaling in AWGN channel invertible?
Consider an AWGN channel with MPSK modulation, and let \$P=[p_{i,j}]\$ denote the corresponding transition probability matrix, where \$p_{i,j}\$ denotes the probability that symbol \$j\$ is detected ...
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How can an audio signal with varying frequency be modulated using FM? [closed]
An audio signal can have varying frequency and amplitude and both are the part of the information. As I understand it, frequency modulation is a technique where the frequency of the carrier wave is ...
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How to properly trigger and measure a modulated square wave signal with an oscilloscope
I'm having trouble getting a stable trigger on my Rigol DS-1202 oscilloscope for a complex waveform. The waveform is composed of a 25.5kHz carrier square wave modulated by a 200Hz square wave, both ...
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How to inject and extract a high frequency modulated signal onto and from the AC powerline?
I'm generating a square wave carrier signal of 125 kHz using 555 timer, I modulate it with a data signal generated from ATmega32 Tx pin (UART 9600 Baudrate) using OOK-Modulation, and now I'm trying to ...
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How do we calculate the amplitude levels in QAM modulation technique
so I came across M-ary Modulation technique in my ADC subject. While I understood the basic principle behind it, I still cant get my head around the amplitude levels taken . Like lets say i am using ...
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Amplitude modulation problems
I am trying to do amplitude modulation using a diode, but my circuit will not work. This is the circuit I am using:
simulate this circuit – Schematic created using CircuitLab
I don't know why ...
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Why 8051 is not detecting logic from circuit's voltage?
I am working on a ASK modulator and demodulator circuit which I wish to interface with a 8051 microcontroller to read serial data from demodulator circuit. The mod/demod circuit is developed and ...
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Must LC resonant frequency be identical to oscillating frequency in RF circuit?
I am developing an RF circuit for 503.3 MHz. It will be an AM RF transmitter. The LC circuit I built into this circuit consists of L = 0.1 μH and C = 1 pF.
The carrier frequency which carries the ...
user321220
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Switching circuit with logic 3.3V control on p-channel JFET
The task is to derive sinewave (of higher frequency) chopped by step-function (also periodic but of lower frequency, i.e. several periods of sine wave are placed in that pulse). So I have a sinewave ...
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Modulate a digital message using FSK/PSK combination
I am beginner and I want to modulate the digital signal: 101101 based on the combination: frequency/phase (2 frequencies/2 phases).
For that, I set the 4 possible combinations: ...
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Error probability of BPSK with intersymbol interference
Consider an AWGN channel with BPSK modulation. Assume that
the information bits are i.i.d. Bernoulli with parameter 0<p<1,
we have ISI due to a timing offset at the transmitter, and
the decoder ...
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Why do we need to transmit in a cable with a digital modulation? Can't we just put high voltage for 1 and no voltage for 0? [closed]
We know that we can't transmit a square wave pulse via EM and we need to convert it to an analog signal via some modulation.
But why can't we just put high voltage in the cable to represent bit 1 and ...
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