QIS COLLEGE OF ENGINEERING AND TECHNOLOGY

(AUTONOMOUS)
Permanent Affiliation: JNTU-Kakinada | UGC-Recognized
Vengamukkapalem(V), Ongole, Prakasam Dist., Andhra Pradesh-523272
COMMON TO ME, CSE AND ALLIED BRANCHES

COMMUNICATION ENGINEERING (20E02019)

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING

Question Bank
UNIT- I

1 a) Define Continuous time signal and discrete time signal CO-1 BTL-1
b Explain about i) Periodic and Non periodic signals ii) Deterministic CO-1
BTL-2
) and Random signals

2 a) Define Fourier transform and inverse Fourier transform of a signal CO-1 BTL-1
b CO-1
Explain about various types of signals. BTL-2
)

3 a) Define Causal, Non causal signals and anti-causal signals. CO-1 BTL-1
b CO-1
Explain about Energy and Power Signals BTL-2
)

4 a) Define Unit step and Ramp Functions and its importance in Systems. CO-1 BTL-1
b CO-1
Explain about Exponential, Sinusoidal Functions. BTL-2
)

5 a) Define the even and odd signals with examples. CO-1 BTL-1
b CO-1
Explain about Signum and Sync functions. BTL-2
)

6 a) Define Fourier Series and its representation for Periodic Signals CO-1 BTL-1
b CO-1
Write Short notes on elementary of Signals BTL-2
)

7 a) Explain about analog and digital signals CO-1 BTL-2

b CO-1
Explain about discrete time step function BTL-2
)

8 a) Write Short notes on Impulse Signal CO-1 BTL-2

b CO-1
Explain about Unit Ramp function. BTL-2
)
UNIT- II
1. a) With a neat Block diagram, explain the about communication
CO-2 BTL-2
system.
 b BTL-2
Explain about need for modulation. CO-2
)

2. a) Define Standard form of amplitude modulation and explain the time BTL-5
CO-2
and frequency domain expressions of AM wave
b BTL-5
Explain amplitude modulation for single tone information CO-2
)

3. a) Explain the generation technique of an AM wave using the square BTL-5

CO-2
law modulator.
b Explain the generation technique of an AM wave using the BTL-5
CO-2
) Switching modulator.

4. a) Explain the Detection of message signal from amplitude modulated BTL-5

CO-2
signal using an envelope detector.
b Explain the Detection of message signal from amplitude modulated BTL-5
CO-2
) signal using square law demodulator.

5. a) What is DSB- SC modulation? Explain the time and Frequency BTL-5

CO-2
domain expressions of DSB-SC wave.
b BTL-5
Explain DSB- SC modulation for single tone information. CO-2
)

6. a) With a neat Block diagram, explain the balanced modulator method BTL-5
CO-2
of generating DSB-SC wave.
b Briefly explain generation of DSB-SC modulated wave using Ring BTL-5
CO-2
) modulator.

a) Describe about the methods for generation of DSB-SC signal and BTL-5
CO-2
explain any one of the method.
8. b With a neat block diagram, explain the operation of phase BTL-5
CO-2
) discrimination method.
b Explain single tone modulation for transmitting only upper side BTL-5
) frequency of SSB modulation CO-2

UNIT- III
1. a) Define Phase Modulation. Derive the equation of PM wave. CO-3 BTL-3
b BTL -
Define Frequency Modulation. Derive the equation of FM wave. CO-3
) 3

2. a) Derive expression for the single tone modulated FM waves. CO-3 BTL-3
b BTL-3
Distinguish between FM and AM CO-3
)

3. a) Describes with necessary equations and block diagram, the BTL-5

CO-3
generation of Narrow Band FM
b BTL-6
Explain about Wide Band FM CO-3
)
4. a) Comparisons between Wide Band FM and Narrow Band FM CO-3 BTL-4
b BTL-4
Distinguish between FM and PM CO-3
)

5. a) Explain the generation FM using direct method CO-3 BTL-5

b BTL-5
Explain the generation FM using indirect method CO-3
)

6. a) Explain the working of a balanced frequency discriminator with the BTL-4

CO-3
help of circuit diagram.
b Explain the Detection of message signal from frequency modulated BTL-5
CO-3
) signal using zero crossing detector

7. a) Discuss the process of Detection of FM Waves by Phase locked loop CO-3 BTL-5
b Derive time domain and frequency domain expressions for a Wide BTL-3
CO-3
) Band FM Wave

8. Distinguish between AM, FM and PM CO-3 BTL-4

UNIT- IV
1. a) Explain the generation of PAM with a neat circuit diagram and draw
CO-4 BTL-4
its wave forms.
b Explain the detection of PAM with a neat circuit diagram and draw BTL-4
CO-4
) its wave forms.

3. a) Explain the modulation of PCM, with a neat circuit diagram and BTL-4
CO-4
draw its waveforms.
b Explain the demodulation of PCM, with a neat circuit diagram and BTL-4
CO-4
) draw its waveforms.

3. a) With a neat sketch explain the Time Division Multiplexing CO-4 BTL-5
b BTL-1
List out the advantages and disadvantages of TDM over FDM. CO-4
)

4. a) With a neat sketch explain the Frequency Division Multiplexing CO-4 BTL-5
b BTL-1
List out the advantages and disadvantages of FDM. CO-4
)

5. a) With a neat block diagram explain PCM transmitter and receiver? CO-4 BTL-5
b BTL-4
Explain the Process of Quantization through one Example? CO-4
)

6. a) Explain the following line codes for 110101101 BTL-4

CO-4
i) Unipolar RZ & NRZ ii) polar RZ & NRZ iii) Bipolar RZ &NRZ
b BTL-1
State sampling theorem. CO-4
)

7. Explain different line coding techniques in detail. CO-4 BTL-4

8. a) State and Explain low pass sampling theorem. CO-4 BTL-1

 b BTL-
Compare TDM & FDM CO-4
)

UNIT- V
1. Explain the generation and detection of BPSK. CO-5 BTL-5

2. With a neat block diagram Explain the generation and detection of BTL-1
CO-5
DPSK

3. Draw the block diagram of QPSK transmitter & receiver and explain BTL-3
CO-5
each block In detail

4. a) Draw block diagram of DPSK generator with waveforms CO-5 BTL-5

b BTL-5
Compare BPSK and QPSK CO-5
)

5. Draw the block diagram of QAM transmitter & receiver and explain BTL-5
CO-5
each block In detail

6. a) Draw block diagram of QPSK generator with waveforms CO-5 BTL-1

b BTL-3
Compare DPSK and QPSK CO-5
)

7. a) Draw block diagram of BPSK generator with waveforms CO-5 BTL-5

b BTL-5
Compare BPSK and DPSK CO-5
)

8. a) Explain the principles of M array signaling? CO-5 BTL-5

b BTL-3
Compare BPSK, DPSK and QPSK CO-5
)

UNIT- VI
1. Define amount of information. Sate and prove its properties CO-6 BTL-5

2 a) State and prove properties of entropy CO-6 BTL-1

b Prove that H(X,Y) = H(X / Y) + H(Y)
CO-6 BTL-3
)

3. a) Explain the concept of Average information. CO-6 BTL-5

b An analog signal band limited to 10kHz is quantized in 8 levels of a BTL-5
) PCM system with probabilities of 1/4, 1/5, 1/5, 1/10, 1/10, 1/30, 1/30
CO-6
and 1/30 respectively. Calculate the entropy and the rate of
information.

4. a) A code is composed of dots and dashes. Assume that the dash is 3

times of as long as dots and it has one third the probability of
CO-6 BTL-3
occurrence. Calculate a) Information in a dot and dash
b) Average Information in a dot and dash
b Define entropy and explain it briefly. CO-6 BTL-5
 )

5. a) Define source coding and explain the significance of source coding CO-6 BTL-5
b Find the entropy of the source alphapet { s0,s1,s2} with respective BTL-3
CO-6
) probabilities {1/4,1/4,1/2}.

6. Explain Shannon fanon’s algorithm with suitable example CO-6 BTL-5

7. Explain Huffman’s algorithm with suitable example CO-6 BTL-1

8. a) Compress the code “aadabeacda” by using Shannon fanon’s BTL-3

CO-6
algorithm
b BTL-1
Explain various steps involved in Shannon fanon’s algorithm. CO-6
)