DIGITAL COMMUNICATION MCQ

The process of converting the analog sample into discrete form is called

• Modulation
•  Multiplexing
• Quantization
• Sampling

The negative statement for Shannon's theorem states that

• If R > C, the error probability increases towards Unity
•  If R < C, the error probability is very small
•  Both a & b
• None of the above

The technique that may be used to increase average information per bit is

• Shannon-Fano algorithm
•  ASK
• FSK
• Digital modulation techniques

 For a binary symmetric channel, the random bits are given as

• Logic 1 given by probability P and logic 0 by (1-P)
• Logic 1 given by probability 1-P and logic 0 by P
• Logic 1 given by probability P2 and logic 0 by 1-P
• Logic 1 given by probability P and logic 0 by (1-P)2

Information rate is defined as

• Information per unit time
•  Average number of bits of information per second
•  rH
• All of the above

The relation between entropy and mutual information is

•  I(X;Y) = H(X) - H(X/Y)
• I(X;Y) = H(X/Y) - H(Y/X)
• I(X;Y) = H(X) - H(Y)
• I(X;Y) = H(Y) - H(X)

The memory less source refers to

• No previous information
• No message storage
• Emitted message is independent of previous message
• None of the above

Synchronization of signals is done using

• Pilot clock
• Extracting timing information from the received signal
• Transmitter and receiver connected to master timing source
• All of the above

QPSK is a modulation scheme where each symbol consists of

• 4 bits
•  2 bits
• 1 bits
• M number of bits, depending upon the requirement

The binary waveform used to generate BPSK signal is encoded in

• Bipolar NRZ format
• Manchester coding
• Differential coding
• None of the above