Modulation? Modulation is the addition of information (or the signal) to an electronic or optical...
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Transcript of Modulation? Modulation is the addition of information (or the signal) to an electronic or optical...
![Page 1: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/1.jpg)
![Page 2: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/2.jpg)
Modulation is the addition of information (or the signal) to an electronic or optical signal carrier.
In electronics, modulation is the process of varying one or more properties of a high frequency periodic waveform, called the carrier signal, with respect to a modulating signal.
In telecommunications, modulation is the process of conveying a message signal, for example a digital bit stream or an analog audio signal, inside another signal that can be physically transmitted.
![Page 3: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/3.jpg)
![Page 4: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/4.jpg)
A carrier frequency is an electronic wave that is combined with the information signal and carries it across the communication channel.
A carrier signal is a single frequency that is used to carry the intelligence (data).
For digital, the intelligence is either a 1 or 0. When we modulate the carrier , we are changing its characteristics to correspond to either a 1 or 0.
![Page 5: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/5.jpg)
There are three aspects of the basic carrier wave that can be modulated:
-Amplitude-Frequency-Phase (or angle)
![Page 6: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/6.jpg)
The three corresponding techniques are as follows:-Amplitude Modulation(AM)-Frequency Modulation(FM)-Phase Modulation(PM)
Other modulation techniques are:- Amplitude shift keying(ASK)- Frequency shift keying(FSK)- Phase shift keying(PSK)
![Page 7: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/7.jpg)
Amplitude modulation (AM) is a method of impressing data onto an alternating-current (AC) carrier waveform.
![Page 8: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/8.jpg)
In the above example, a 1 is represented by the presence of the carrier for a predefined period of 3 cycles of carrier. Absence or no carrier indicates a 0.
In AM, the carrier itself does not fluctuate in amplitude. Instead, the modulating data appears in the form of signal components at frequencies slightly higher and lower than that of the carrier.
![Page 9: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/9.jpg)
Frequency modulation (FM) is a method of impressing data onto an alternating-current (AC) wave by varying the instantaneous frequency of the wave.
![Page 10: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/10.jpg)
Frequency Modulation modifies the frequency of the carrier to represent the 1s or 0s.
In the above example, a 0 is represented by the original carrier frequency and a 1 by a much higher frequency ( the cycles are spaced closer together).
![Page 11: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/11.jpg)
Phase modulation (PM) is a method of impressing data onto an alternating-current (AC) waveform by varying the instantaneous phase of the wave.
![Page 12: Modulation? Modulation is the addition of information (or the signal) to an electronic or optical signal carrier. In electronics, modulation is the process.](https://reader033.fdocuments.us/reader033/viewer/2022051622/5697c01c1a28abf838cd004f/html5/thumbnails/12.jpg)
The carrier phase is switched at every occurrence of a 1 bit but remains unaffected for a 0 bit.
The phase of the signal is measured relative to the phase of the preceding bit.
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