UNIT 3

Block Diagram

3.1 Block diagram of communication system

Fig. 1 Block diagram of elements of analog communication (ref 3)

      Information Source

It produces a message that is analog in nature, i.e., the output of the information source is a continuous signal.

      Analog carrier source

Sine wave is used as a carrier signal which will help in analog modulation.

      Analog modulation

The carrier signal is superimposed with the message signal and then the modulated signal is obtained which is also analog in nature.

      Communication channel

The analog modulated signal is transmitted via the communication channel towards the receiver end after addition of the requisite power levels.

      Analog demodulation

At the receiver end, the incoming modulated signal is passed through an analog demodulation process which extracts the analog message signal. The analog message is then passed onto the final destination.

      Destination

The nature of signal starting from the information source till the final destination is analog.

3.2 Comparative study of analog and digital communication.

References:

1. Communication system by Bruce carison . TMH.
2. Electronic Communication system by Kennedy IV Edition. TMH.
3. Electronic Communication system by Roddey & Coolen, Pearson.
4. Telecommunication system Engg. By Freeman John Wiley
5. Communication system by Haykin,Wiley