S.MARIRAJAN T.V.SUDHIR
VALLIAMMAI ENGINEERING COLLEGE SRM NAGAR, KATTANKULATHUR 603 203
DEPARTMENT OF ELECTRONICS & COMMUNICATIONENGINEERING
Question Bank
2016 – 2017 Odd Semester
CS6304 – Analog and Digital Communication
Prepared by
Mr.S.Marirajan, A.P (Sr.G)
Mr.T.V.Sudhir, A.P (O.G)
S.MARIRAJAN T.V.SUDHIR
UNIT I – ANALOG COMMUNICATION
Noise: Source of Noise - External Noise- Internal Noise- Noise Calculation. Introduction to Communication Systems: Modulation – Types - Need for Modulation. Theory of Amplitude Modulation - Evolution and Description of SSB
Techniques - Theory of Frequency and Phase Modulation – Comparison of various Analog Communication System (AM
– FM – PM).
PART A
Q.No Questions BT
Level
Competence
1. Can you formulate Noise Figure and Signal to Noise ratio? BTL 6 Create
2. Draw the spectrum of AM signal and explain. BTL 1 Remember
3. Point out the applications of FM. BTL 4 Analyze
4. What is the need for modulation? BTL 1 Remember
5. Explain Noise and list the types of noise? BTL 2 Understand
6. Construct the spectrum of FM signal. BTL 5 Evaluate
7. Define angle modulation. BTL 1 Remember
8. What do you infer about frequency deviation? BTL 4 Analyze
9. How would you show the relationship between frequency and phase modulation? BTL 1 Remember
10. Summarize the advantages of SSBSC modulation. BTL6 Create
11. Distinguish between narrowband and wideband signal. BTL 2 Understand
12. Write about Carson’s rule. BTL 3 Apply
13. Tell modulation index and percent modulation. BTL 5 Evaluate
14. Outline the concept of Phase Modulation. BTL 4 Analyze
15. Compare AM with DSBSC & SSBSC. BTL 1 Remember
16. Show the advantages of SSB. BTL 3 Apply
17. Classify the types of modulation. BTL 2 Understand
18. List the major segments of electromagnetic spectrum and give their frequency
ranges.
BTL 1 Remember
19. Express Modulation & Demodulation. BTL 2 Understand
20. Illustrate amplitude modulation. BTL 3 Apply
S.MARIRAJAN T.V.SUDHIR
PART –B
1. Can you identify the principle of Angle Modulation. Derive phase deviation,
Modulation index, frequency deviation and percent modulation. (16)
BTL 4 Analyze
2. a. Can you recall the phasor diagram of wideband FM and explain about the
bandwidth of FM signal (8)
b. How would you show the difference between phase modulation and frequency
modulation. (8)
BTL 1 Remember
3. For an AM DSBFC wave with peak unmodulated carrier voltage Vc=10Vp, a load
resistance RL = 10 Ω and a modulation coefficient m = 1
a. Can you invent the Power of carrier, upper and lower side band and Total power
of modulate wave (8)
b. Can you invent the total sideband power and draw the power spectrum. (8)
BTL 6 Create
4. A modulating signal of 2 cos5000t is amplitude modulated over acarrier signal of
5cos20000t
a. What approach would you use to find the modulation index, LSB and VSB
frequencies (8)
b. How would you show your understanding of Bandwidth and the ratio of SideBand Power in the Total Power of AM wave. (8)
BTL 3 Apply
5. What is your opinion of the various analog communication systems. (16) BTL 5 Evaluate
6. a. What can you say about the percentage power saving when the carrier and one of
the sidebands are suppressed in an AM wave modulated to a depth of (1) 100 % (2)
50 % . (4)
b. How would you compare frequency modulation and phase modulation and their
inter relationship. (12)
BTL 2 Understand
7. a. What is the relationship between carrier and side band powers in an AM DSBFC
wave. (8)
b. What conclusions can you draw from the power distribution in AM DSB FC
system. (8)
BTL 4 Analyze
8. a. How would you show your understanding of the frequency analysis of Angle
modulated waves. (12)
b. you’ve learned Bandwidth requirements for the above. (4)
BTL 3 Apply
9. A. The first stage of a two stage amplifier has a voltage gain of 10, a 600 Ω input
resistor , a 1600 Ω equivalent noise resistance and a 27 kΩ output resistor . For the
second stage these values are 25, 81kΩ , 10kΩ and 1 MΩ respectively. What is the
equivalent input noise resistance of this two stage amplifier and also what is the
noise figure of the amplifier if it is driven by a generator whose output impedance
is 50 Ω. (8)
BTL 1 Remember
S.MARIRAJAN T.V.SUDHIR
b. How would you show the expression for instantaneous voltage of AM wave? (8)
10. a. State in your own words about internal noise (8)
b. In modulation by several sine waves simultaneously, in AM, the bandwidth
required is twice the highest modulating frequency. How would you summarize
using appropriate expressions to prove this concept (8)
BTL 2 Understand
11. a. How would you explain the nature of SSB spectrum if the modulating signal is
m(t)= cos2𝜋.100t + cos2π.2000t and carrier is given by c(t) = cos2π.10000t. (8)
b. Can you recall the relationship between the instantaneous carrier frequency and
modulating signal for FM. (8)
BTL 1 Remember
12. State in your own words about the noise with suitable examples. (16) BTL 2 Understand
13. a. Can you distinguish between modulation index for FM and PM. (4)
b. What is the relationship between modulation index and modulating signal for
FM and PM. (12)
BTL 4 Analyze
14. How would you explain Amplitude modulation, its generation and detection with the
help of mathematical expressions. (16)
BTL 1 Remember
UNIT II - DIGITAL COMMUNICATION
Amplitude Shift Keying (ASK) – Frequency Shift Keying (FSK) Minimum Shift Keying (MSK) –Phase Shift Keying
(PSK) – BPSK – QPSK – 8 PSK – 16 PSK - Quadrature Amplitude Modulation (QAM) – 8 QAM – 16 QAM – Bandwidth Efficiency– Comparison of various Digital Communication System (ASK – FSK – PSK – QAM).
PART A
Q.No Questions BT
Level
Competence
1. Analyze the relationship between bit rate and baud for a FSK system? BTL 4 Analyze
2. Draw the ASK signal for the given message signal 101101.
BTL 1 Remember
3. Show the difference between QPSK and BPSK. BTL 3 Apply
4. Can you formulate the advantages of BPSK BTL 6 Create
5. Tell the advantage of QPSK? BTL 5 Evaluate
6. Summarize the advantages of digital communication. BTL 2 Understand
7. Outline the constellation diagram of QPSK signal. BTL 1 Remember
8. Devise the concept of MSK. BTL 6 Create
S.MARIRAJAN T.V.SUDHIR
9. Illustrate your understanding of Nyquist sampling theorem.
BTL 3 Apply
10. Give the main idea of ASK. BTL 2 Understand
11. List the function of FSK? BTL 4 Analyze
12. State bandwidth efficiency.
BTL 1 Remember
13. Compare ASK and FSK. BTL 5 Evaluate
14. How would you show the QPSK signal for the binary sequence 11001100?
BTL 1 Remember
15. What facts would you select to show ASK as ON-OFF keying? BTL 3 Apply
16. State in your own words about information capacity and bit rate. BTL 2 Understand
17. Identify how QPSK is different from 16 PSK signal in terms of bandwidth?
BTL 1 Remember
18. Point out the concept of Aliasing. BTL 4 Analyze
19. What is meant by PSK and draw its waveform for the data 10110.
BTL 2 Understand
20. Cite the difference between standard FSK and MSK ? Also write the advantage of
MSK ?
BTL 1 Remember
PART –B
1. Can you formulate a theory for amplitude shift keying systems with neat diagram.
(16)
BTL 6 Create
2. How would you explain the constellation diagram of QPSK modulation and it’s
modulator and demodulator. (16)
BTL 1 Remember
3. How would you show your understanding of the operations of Non-coherent and
coherent ASK modulators. (16)
BTL 3 Apply
4. What is your opinion of minimum shift keying with suitable diagrams (16) BTL 5 Evaluate
5. For a BPSK modulator with a Carrier frequency of 70 MHz and an input bit rate of
10 Mbps,
a.What can you say about the maximum and minimum upper and lower side
frequencies, draw the output spectrum, (8)
b. How would you summarize the minimum Nyquist bandwidth, and calculate the
baud rate (Assume f= 5MHz) (8)
BTL 2 Understand
6. a. Can you identify the principle of Binary phase shift keying? also obtain the
minimum double sided Nyquist bandwidth. (8)
b. Discuss in detail the BPSK transmitter and Receiver (8)
BTL 4 Analyze
S.MARIRAJAN T.V.SUDHIR
7. a. How would you show the working of BFSK transmitter and receiver with
necessary equations and block diagram. (8)
b. How would you describe coherent and non coherent detection and compare the
various digital communication systems. (8)
BTL 1 Remember
8. Can you identify the bandwidth considerations of 8-PSK system. (16) BTL 4 Analyze
9. State in your own words
a. QPSK transmitter with relevant expressions and figures (8)
b. Receiver and bandwidth considerations of QPSK with relevant expressions and
figures (8)
BTL 2 Understand
10. What approach would you use to explain the principle of
a. FSK transmitter (8)
b. FSK receiver. (8)
BTL 3 Apply
11. What is the significance of QAM? Can you recall the operation of 8 QAM
transmitter and receiver using block diagram and truth table. (16)
BTL 1 Remember
12. What inference can you make on carrier recovery? Discuss how carrier recovery is
achieved by the squaring loop and Costas loop circuits. (16)
BTL 4 Analyze
13. How would you compare the various digital communication systems. (16) BTL 2 Understand
14. How would you explain the method of generation of QAM and demodulation of
the same. (16)
BTL 1 Remember
UNIT III - DATA AND PULSE COMMUNICATION
Data Communication: History of Data Communication - Standards Organizations for Data Communication- Data
Communication Circuits - Data Communication Codes - Error Detection and Correction Techniques - Data communication
Hardware - serial and parallel interfaces. Pulse Communication: Pulse Amplitude Modulation (PAM) – Pulse Time Modulation (PTM) – Pulse code Modulation (PCM) - Comparison of various Pulse Communication System (PAM – PTM
– PCM).
PART A
Q.No Questions BT
Level
Competence
1. Outline the function of ASCII code.
BTL 4 Analyze
2. What is the need for companding in a PCM system? BTL 1 Remember
S.MARIRAJAN T.V.SUDHIR
3. Justify why the quantization noise cannot be removed completely in PCM. How
do you reduce this noise?
BTL 6 Create
4. Classify the two primary methods used for error correction. BTL 2 Understand
5. What facts would you select to show the types of Data Transmission? BTL 3 Apply
6. How would you prove which error detection is simple and which one is more
reliable?
BTL 5 Evaluate
7. How would you show PPM is derived from PWM? BTL 1 Remember
8. What is your opinion of Data Terminal Equipment? Give examples. BTL 5 Evaluate
9. Distinguish the advantages and disadvantages of error detection? BTL 2 Understand
10. Can you list out the common features provided by data communication
MODEMS.
BTL 4 Analyze
11. State sampling rate. BTL 1 Remember
12. Compile a theory for forward error correction. BTL 6 Create
13. Identify why we encounter aperture effect in PAM? How will you rectify it? BTL 1 Remember
14. Compare error detection & error correction. BTL 4 Analyze
15. What can you say about the ODD and EVEN parity bits for the ASCII character R
whose hex code is 52?
BTL 2 Understand
16. Illustrate non-linear encoding in PCM system. BTL 3 Apply
17. Can you recall sampling theorem for band limited signal of finite energy? BTL 1 Remember
18. State in your own words about the types of pulse modulation systems? BTL 2 Understand
19. Interpret the concept of CRC? BTL 3 Apply
20. Write about slope overload error. BTL 1 Remember
PART –B
1. Recall the differentiate between serial and parallel interfaces. (16) BTL 1 Remember
2. Estimate the VRC and LRC for the following ASCII encoded message
“THE CAT”. Use odd parity for VRC and even parity for LRC. (16)
BTL 2 Understand
3. Analyze the Longitudinal redundancy checking and Checksum with example. (16) BTL 4 Analyze
4. a. Interpret the History of Data Communication. (8)
b.Illustrate the Data Communication codes. (8)
BTL 3 Apply
5. Summarize about parallel interface with its features. (16) BTL 5 Evaluate
S.MARIRAJAN T.V.SUDHIR
6. a.Describe in detail about the Standards Organizations for data communication.
(8)
b. State the concept of Data Communication circuits using a basic block diagram.
(8)
BTL 1 Remember
7. Predict the BCS for the following data and CRC generating polynomial. Data
G(x) = x10
+ x9
+ x7+ x
5 + x
3+ x
2 +x
1 + x
0 CRC 16 polynomial, G(x) = x
16 +
x15
+ x2
+ x0 (16)
BTL 2 Understand
8. Write about the generation of PAM and it’s demodulation. (16) BTL 1 Remember
9. Identify the features and purposes of serial interfaces. Describe t h e mechanical,
electrical and functional characteristics of RS 232 interface. (16)
BTL 4 Analyze
10. a.Compare the various Pulse Communication Systems with waveforms. (16) BTL 6 Create
11. Show Vertical redundancy checking and Cyclic redundancy checking under Error
detection with example. (16)
BTL 3 Apply
12.
a.Draw the block diagram of PCM transmitter and receiver and explain. (12)
b.What is ISI? How can it be reduced? (4)
BTL 1 Remember
13.
Point out Error correction schemes. (16) BTL 4 Analyze
14. For a 12bit data string of 101100010010. Determine the number of Hamming bits
required, arbitrarily place the Hamming bits into the data stream, Identify the logic
condition of each Hamming bit. Assume an arbitrary single bit transmission error
and prove that the Hamming code will successfully detect the error. (16)
BTL 2 Understand
UNIT IV - SOURCE AND ERROR CONTROL CODING
Entropy, Source encoding theorem, Shannon fano coding, Huffman coding, mutual information, channel capacity,
channel coding theorem, Error Control Coding, linear block codes, cyclic codes, convolution codes, viterbi decoding algorithm.
PART A
Q.No Questions BT
Level
Competence
1. Identify the entropy of the system for an event that has six possible outcomes with
probabilities 1/2,1/4,1/8,1/16,1/32?
BTL 1 Remember
2. Express prefix coding. BTL 2 Understand
S.MARIRAJAN T.V.SUDHIR
3. Can you identify the hamming distance between the following code words C1=
1000111 and C2 = 0001011.
BTL 4 Analyze
4. How would you organize the formula to show mutual information? BTL 3 Apply
5. What is mutual information and state its properties? BTL 1 Remember
6. State in your own words about the Shannon’s theorem on information capacity of a
channel.
BTL 2 Understand
7. What approach would you use to differentiate lossy source coding from lossless
source coding?
BTL 3 Apply
8. Can you formulate a theory for source coding theorem? BTL 6 Create
9. What is the theme of source coding theorem? BTL 4 Analyze
10. How would you describe the channel capacity of a discrete memory less channel? BTL 1 Remember
11. Illustrate Bandwidth efficiency. BTL 2 Understand
12. Show that if Ci and Cj are two code vectors in the (n,k) linear block code , then their
sum is also a code vector with an example?
BTL 1 Remember
13. Demonstrate the difference between Shannon fano coding from lossy source
coding.
BTL 3 Apply
14. State entropy. BTL 1 Remember
15. What is the main idea of Information rate? BTL 2 Understand
16. Can you explain about the linear block codes? BTL 1 Remember
17. Compile the difference between cyclic codes and convolution codes. BTL 6 Create
18. Evaluate cyclic codes and convolution codes. BTL 5 Evaluate
19. Analyze the function of vertical redundancy checking. BTL 4 Analyze
20. What is your opinion of vertical redundancy checking? BTL 5 Evaluate
PART –B
1. Describe how Viterbi procedure is used for decoding convolution codes. (16) BTL 1 Remember
2. a.Interpret Mutual information and its properties in detail. (8)
b. Show the difference between Source coding theorem and Channel coding theorem
with equations. (8)
BTL 3 Apply
3. Consider a discrete memoryless source with source alphabets S = S0, S1, S2 and
their probabilities P0 = ¼, P1 = ¼ , P2 = ¼ . Generate the entropy of the source H(X)
& H(X2). Also prove that the entropy of the extended source is equal to n times H(X)
i.e., H(X2) = 2*H(X). (16)
BTL 5 Evaluate
S.MARIRAJAN T.V.SUDHIR
4. Show the expression for channel capacity of a continuous channel. Comment on the
trade off between SNR and capacity. (16)
BTL 1 Remember
5. a.Estimate a syndrome calculator for a 7,4 cyclic code generated by the polynomial
G(x) = X3 + X + 1. Identify the syndrome for the received vector 1001101. (8)
b.Predict a cyclic encoder for the same 7,4 cyclic code and obtain the code vector
for the message vector 1100. (8)
BTL 2 Understand
6. Compare the Linear Block Codes and Binary Cyclic Codes in detail. (16) BTL 4 Analyze
7. A source generates five messages m0,m1,m2,m3 and m4 with probabilities
0.55,0.15,0.15,0.10 and 0.05 respectively. The successive messages emitted by the
source are statistically independent. Identify the code words for the messages and
efficiency using Shannon Fano Algorithm. (16)
BTL 1 Remember
8. a.Estimate the capacity of a standard 4kHz telephone channel with a 32 dB signal to
noise ratio. (8)
b.A System has a bandwidth of 4kHz and the signal to noise ratio 28 dB at the input
to the receiver. Evaluate information carrying capacity, capacity of the channel if its
bandwidth is doubled, while the transmitted signal power remains constant. (8)
BTL 6 Create
9. a.Write the Huffman code for a discrete memoryless source with probability
statistics 0.1,0.1,0.2,0.2,0.4. (8)
b.Describe the concept of Channel coding theorem. (8)
BTL 1 Remember
10. The parity check matrix of a particular (7,4) linear block code is given by
[𝐻] = [1 1 1 0 1 0 01 1 0 1 0 1 01 0 1 1 0 0 1
]
(i)Point out Generator matrix and List of all the code vectors (8)
(ii)Identify the minimum distance between code and vector? (8)
BTL 4
Analyze
11. Report Error Control Codes and its applications in detail. (16) BTL 3 Apply
12. Give main idea of Source Coding Theorem? Explain it with suitable examples. (16) BTL 2 Understand
13. Analyze the functioning of convolution codes with example. (16) BTL 4 Analyze
14. Illustrate Entropy Techniques and its properties in detail. (16) BTL 2 Understand
UNIT V - MULTI-USER RADIO COMMUNICATION
Advanced Mobile Phone System (AMPS) - Global System for Mobile Communications (GSM) - Code division
multiple access (CDMA) – Cellular Concept and Frequency Reuse - Channel Assignment and Hand - Overview of Multiple Access Schemes - Satellite Communication - Bluetooth.
PART A
S.MARIRAJAN T.V.SUDHIR
Q.No
Questions
BT
Level
Competence
1. What is near far effect in a CDMA system? BTL 1 Remember
2. What is your opinion of look angles of a satellite? BTL 5 Evaluate
3. State in your own words about TDMA & CDMA. BTL 2 Understand
4. Identify the various handovers carried out in GSM. BTL 1 Remember
5. Classify multiplexing and multiple access. BTL 3 Apply
6. Write about the Bluetooth technology. BTL 1 Remember
7. What conclusions can you give by footprint? BTL 4 Analyze
8. Explain chip code in CDMA system? BTL 2 Understand
9. List the functions of a MODEM. BTL 1 Remember
10. Infer the meaning GSM. BTL 4 Analyze
11. State the term frequency reuse factor in a cellular communication system. BTL 1 Remember
12. Can you predict the applications of satellite communication? BTL 6 Create
13. Give main idea of handoff. BTL 2 Understand
14. Why did hexagons employed to model coverage areas of mobile communication? BTL 1 Remember
15. Illustrate about orthogonal code. BTL 3 Apply
16. How would you compare FDMA & TDMA? BTL 2 Understand
17. Tell the basic components of a satellite earth station subsystem. BTL 5 Evaluate
18. Interpret the frequency hopping. BTL 3 Apply
19. Summarize the function of a transponder. BTL 6 Create
20. Point out Kepler’s three laws of planetary motions. BTL 4 Analyze
PART-B
1. Draw the architecture of GSM system and explain the function of each block. (16) BTL 1 Remember
2. a.Point out Direct Broadcast Satellite. (8) BTL 4 Analyze
S.MARIRAJAN T.V.SUDHIR
b.List the functionality of Bluetooth. (8)
3. Illustrate TDMA in wireless communication systems and it’s uses. (16) BTL 2 Understand
4. Describe the concept of cellular topology and cell fundamentals with examples. (16) BTL 1 Remember
5. Elaborate on the difference betweens GSM & CDMA. (16) BTL 6 Create
6. Write notes on multiple access techniques and it’s types. (16) BTL 1 Remember
7. Interpret the need for multiple access techniques. Draw the block diagram of a
TDMA system and explain. Produce its advantages and disadvantages over FDMA
technique. (16)
BTL 3 Apply
8. Outline the operation of a satellite communication system with a block diagram. (16) BTL 1 Remember
9. Analyze the Satellite frequency plans and frequency allocations in detail. (16) BTL 4 Analyze
10. a. Report the channel assignment strategies. (8)
b. Show the concept of Handoff in cellular communication. (8)
BTL 3 Apply
11. Discuss in detail about Cellular concept and Frequency reuse. (16) BTL 2 Understand
12. Examine the Satellite Access and Satellite Earth Station in detail. (16) BTL 4 Analyze
13. a . Explain the operation of CDMA multiplexing system. (10)
b. Identify the advantages of CDMA over TDMA multiple access schemes. (6)
BTL 2 Understand
14. Summarize in detail Advanced Mobile Phone Systems (AMPS). (16) BTL 5 Evaluate