Subject : Principle of Communication Engineering

Topic : Introduction to Electronic Communication

Difficulty : Low

• In analog transmission, the entire signal must be reconstructed accurately at the receiver. However in digital transmission, only the discrete levels of the signal need to be reproduced.
• It is much simpler to store digital signals compared to analog signals.
• Analog transmission systems require amplifiers which add noise and distortion to the signal that increases the channel loss. However in digital systems there are no such losses due to which it is possible to attain the theoretical channel loss of 0 dB.
• It is simpler to measure and evaluate digital signals than analog signals, and also easier to compare the error performance of one digital system to another digital system.
• Transmission error can be detected and corrected more easily and more accurately in digital systems which gives very low error rate and high fidelity.
• Modulation of the signal in digital transmission system provides more information capacity, compatibility with digital data services, better data security and improved communication quality than analog modulation.
• Advanced techniques such as encryption, compression and error correction and detection are easily incorporated in the digital transmission systems for its application on the digital data and processing.
• Digital signals are advantageous than analog signals for processing and combining for multiplexing purpose.
• Digital systems have the ability to carry a combination of traffics, e.g. telephone signals, data, coded video and teletext, if the medium has enough capacity.
• Digital transmission systems require clock synchronization of the transmitter and receiver which makes the digital circuit complex than the analog one.
• Transmission of digitally encoded analog signals requires significantly more bandwidth than simply transmitting the original analog signal.
• The digital transmission systems are more reliable than their analog counterparts.