Analog and Digital Communications Mid - II, November - 2014

1.The interior region of the eye pattern is called the
  • Eye opening
  • eye diagram
  • eye symbol
  • all of these
Answer: A
2.In data transmission systems, eye patterns are used to study about
  • ISI
  • PCM
  • PAM
  • PSK
Answer: A
3.The probability of error is minimum in
  • ASK
  • FSK
  • PSK
  • MSK
Answer: C
4.In QPSK Wave, the number of possible assigned phases for carrier is
  • 1
  • 2
  • 3
  • 4
Answer: D
5.For M ary signaling schemes
  • Bandwidth requirement reduces
  • power required to transmit increases
  • transmission rate increases
  • all of these
Answer: D
6.In systematic linear block code of (7, 4) the number of check bits added are
  • 7
  • 4
  • 3
  • 1
Answer: C
7.Linear block codes capable of correcting single errors must have minimum hamming distance of
  • 3
  • 2
  • 1
  • 0
Answer: A
8.Communication system will transit information with an arbitrarily small probability of error, when information rate(R) and channel capacity(C) are
  • R > C
  • R < C
  • R*C
  • none
Answer: B
9.Identify the source coding technique
  • Shannon Fano coding
  • Linear block codes
  • Convolutional codes
  • all of these
Answer: A
10.Average information per message is called
  • Mutual Information
  • Entropy
  • Information rate
  • bandwidth
Answer: B
11.________________________ is caused by the overlapping tails of other pulses added to a particular pulse.
Answer: Inter symbol interference
12.By adding ISI to the transmitted signals in a controlled manner high speed data transmission is achieved such schemes are called __________________
Answer: Correlative Coding
13.In __________________ Digital modulation scheme, bandwidth requirement is maximum
Answer: FSK
14.______________________ receivers have the reference of the transmitted carrier signal.
Answer: Coherent/Synchronous
15.Syndrome value for error less transmission is ________________
Answer: Zero
16.To reduce the redundancy of the code tree _____________ diagram is used.
Answer: Trellis
17.The generator polynomial of (7, 4) cyclic code is g(x)=1+x+x3, d(x)=1 then codeword is _____________
Answer: 11010000
18.If the source of the messages generates at the rate r messages per sec then information rate is ____________________
Answer: R= r h
19.When the probability of occurrence of message is maximum, then information is _____________
Answer: Minimum/zero
20.The channel capacity of a white band limited Gaussian channel is _____________________
Answer: C = Bw log2(1 + S/N)