Line 6: Line 6:
  
 
This is the process of varying the properties of a specific waveform, also called the carrier signal, using a modulating signal that contains information that is trying to be transmitted. This allows for the signal to be transmitted over an electronic medium. In the real world modulation is used to send radio signals and other TV signals as well.  
 
This is the process of varying the properties of a specific waveform, also called the carrier signal, using a modulating signal that contains information that is trying to be transmitted. This allows for the signal to be transmitted over an electronic medium. In the real world modulation is used to send radio signals and other TV signals as well.  
 +
 +
Below is the general form for how a signal is modulated.
 +
Keep in mind that when there is a specific frequency channel specified, a Bandpass filter must be added at the end of the pulse train example in order to get the proper modulated signal.
  
 
[[File:Modulation.jpg|thumbnail]]
 
[[File:Modulation.jpg|thumbnail]]
Line 12: Line 15:
 
'''Demodulation'''
 
'''Demodulation'''
  
This is the process of extracting the original information out from the modulated signal.  
+
This is the process of extracting the original information out from the modulated signal. This will allow for a person to grab the proper information from the transmitted modulated signal. Below are examples of how to modulate a general signal in terms of sinusoidal, exponential and pulse train. Keep in mind that when there is a specific frequency channel specified, a Bandpass filter must be added in before multiplying by the carrier. Also, a signal that was shifted to begin with, must be shifted after filtering as well in order to maintain the proper information.
 +
 
 
[[File:DemodCosCos.jpg|thumbnail]]
 
[[File:DemodCosCos.jpg|thumbnail]]
 
[[File:DemodExp.jpg|thumbnail]]
 
[[File:DemodExp.jpg|thumbnail]]

Revision as of 21:53, 2 December 2018

Summary

The aim of this project is to explain what Modulation and Demodulation are and to show how a signal can be both modulated and demodulated using different methods. I will also attempt to show how these methods are used in real world scenarios

Modulation

This is the process of varying the properties of a specific waveform, also called the carrier signal, using a modulating signal that contains information that is trying to be transmitted. This allows for the signal to be transmitted over an electronic medium. In the real world modulation is used to send radio signals and other TV signals as well.

Below is the general form for how a signal is modulated. Keep in mind that when there is a specific frequency channel specified, a Bandpass filter must be added at the end of the pulse train example in order to get the proper modulated signal.

Modulation.jpg


Demodulation

This is the process of extracting the original information out from the modulated signal. This will allow for a person to grab the proper information from the transmitted modulated signal. Below are examples of how to modulate a general signal in terms of sinusoidal, exponential and pulse train. Keep in mind that when there is a specific frequency channel specified, a Bandpass filter must be added in before multiplying by the carrier. Also, a signal that was shifted to begin with, must be shifted after filtering as well in order to maintain the proper information.

DemodCosCos.jpg
DemodExp.jpg

EXAMPLES

Exponential Carrier


Cosine Carrier


Pulse-Train Carrier

Alumni Liaison

Correspondence Chess Grandmaster and Purdue Alumni

Prof. Dan Fleetwood