The document is a course file report for the course "Digital Communications" taught in the Electronics and Communication Engineering department. It includes information such as the department vision and mission, program outcomes, course outcomes mapped to program outcomes, syllabus, session plan, lecture plan, assignment questions, sample scripts, course material, question papers, and references. The course covers topics like PCM, digital modulation techniques, baseband transmission, information theory, error control codes, and spread spectrum modulation over 5 units taught across 17 lectures.

1. A
Course File Report
On
“DIGITAL COMMUNICATIONS”
Department Of
Electronics & Communication Engineering
CMR ENGINEERING COLLEGE
(Affiliated to J.N.T.U, HYDERABAD)
KANDLAKOYA (V), MEDCHAL ROAD HYDERABAD-501 401

2. COURSE FILE
Subject: DIGITAL COMMUNICATIONS
Year: III B.Tech II SEM Branch: ECE
S.NO CONTENTS
1. Department vision & mission
2. List of PEOs and POs
3. Mapping of course out comes with POs
4. Syllabus copy
5. Individual time table
6. Session plan
7. Detailed lecture plan
8. Session execution log
9. Assignment Questions
10. Sample assignment script
11. Unit-wise course material
12. Mid exam question papers
13. Sample mid answer script
14. Material collected from Internet/Websites
15. Power point presentations
16. Previous question papers
17.
References (Text books/websites/Journals)

3. 1. Department Vision & Mission:
Vision
To promote excellence in technical education and scientific research in electronics and
communication engineering for the benefit of society.
Mission
 To impart excellent technical education with state of art facilities inculcating values and
lifelong learning attitude.
 To develop core competence in our students imbibing professional ethics and team spirit.
 To encourage research benefiting society through higher learning
2. List of PEOs , POs & PSOs:
Program Educational Objectives:
1. Excel in professional career & higher education in Electronics & Communication
Engineering and allied fields through rigorous quality education.
2. Exhibit professionalism, ethical attitude, communication skills, team work in their
profession and adapt to current trends by engaging in lifelong learning.
3. Solve real life problems relating to Electronics & Communications Engineering for the
benefits of society.
Program Specific Outcomes:
1. Ability to apply concepts of Electronics & Communication Engineering to associated
research areas of electronics, communication, signal processing, VLSI, Embedded systems
2. Ability to design, analyze and simulate a variety of Electronics & Communication
functional elements using hardware and software tools along with analytic skills

4. Program Outcomes:
1
Engineering knowledge: Apply the knowledge of mathematics, science, engineering fundamentals, and
an engineering specialization to the solution of complex engineering problems
2
Problem analysis: Identify, formulate, review research literature, and analyze complex engineering
problems reaching substantiated conclusions using first principles of mathematics, natural sciences, and
engineering sciences.
3
Design/development of solutions: Design solutions for complex engineering problems and design
system components or processes that meet the specified needs with appropriate consideration for the
public health and safety, and the cultural, societal, and environmental considerations.
4
Conduct investigations of complex problems: Use research-based knowledge and research methods
including design of experiments, analysis and interpretation of data, and synthesis of the information to
provide valid conclusions.
5
Modern tool usage: Create, select, and apply appropriate techniques, resources, and modern
engineering and IT tools including prediction and modeling to complex engineering activities with an
understanding of the limitations.
6
The engineer and society: Apply reasoning informed by the contextual knowledge to assess societal,
health, safety, legal and cultural issues and the consequent responsibilities relevant to the professional
engineering practice.
7
Environment and sustainability: Understand the impact of the professional engineering solutions in
societal and environmental contexts, and demonstrate the knowledge of, and need for sustainable
development.
8
Ethics: Apply ethical principles and commit to professional ethics and responsibilities and norms of the
engineering practice.
9
Individual and team work: Function effectively as an individual, and as a member or leader in diverse
teams, and in multidisciplinary settings.
10
Communication: Communicate effectively on complex engineering activities with the engineering
community and with society at large, such as, being able to comprehend and write effective reports and
design documentation, make effective presentations, and give and receive clear instructions.
11
Project management and finance: Demonstrate knowledge and understanding of the engineering and
management principles and apply these to one’s own work, as a member and leader in a team, to manage
projects and in multidisciplinary environments.
12
Life-long learning: Recognize the need for, and have the preparation and ability to engage in
independent and life-long learning in the broadest context of technological change.

5. 3. List of Cos and mapping of CO’s:
Course Name: DIGITAL COMMUNICATIONS (C321)
Course Outcome (CO)-Program Outcome (PO) Matrix:
Course
Outcomes
(CO) PO1 PO2 PO3 PO4 PO5 PO6 PO7 PO8 PO9 PO10 PO11 PO12
C321.1 2 2 1 - - - - - - 3 - -
C321.2 2 3 2 - 2 - - - - 2 - -
C321.3 2 3 2 - 2 - - - - - - -
C321.4 3 2 3 - 2 - - - - - - -
C321.5 3 2 3 - 2 - - - - 2 - -
Course
Code.CO No
Course Outcomes (CO’s)
At the end of the course student will be able to
C321.1 Explain the concepts of PCM and DM,S/N ratio of PCM and DM.
C321.2 Apply the concepts of different digital modulation techniques.
C321.3
Implement the concepts of eye diagrams, probability of errors for ASK,
PSK, FSK, CROSS TALK.
C321.4
Illustrate about INFORMATION THEORY.
C321.5
Demonstrate the concepts of different error detecting and error correcting
codes like block codes, cyclic codes and convolution codes and spread
spectrum communications.

6. Course Outcome (CO)-Program Specific Outcome (PSO) Matrix:
4.Syllabus Copy
UNIT-I
ELEMENTS OF DIGITAL COMMUNICATION SYSTEMS:Advantages of digital communication
systems, Bandwidth-S/N-tradeoff,Hartley-Shannonlaw,Sampling-theorem
PULSE CODE MODULATION : PCM Generation and Reconstruction, Quantization noise, Non uniform
Quantization and Companding, Differential PCM systems (DPCM),Adaptive DPCM, Delta modulation and
adaptive delta modulation, noise in PCM and DM systems.
UNIT -II
DIGITAL MODULATION TECHNIQUES : Introduction, ASK,ASK Modulator, Coherent ASK Detector,
Non Coherent Detector, FSK,Bandwidth and frequency spectrum of FSK,Non coherent FSK detector,
Coherent FSK detector,FSK detection using PLL,BPSK,Coherent PSK detector,BPSK, Differential PSK
UNIT - III
BASEBAND TRANSMISSION AND OPTIMAL RECEPTION OF DIGITAL SIGNAL
Pulse shaping for optimum transmissions, A Base band signal receiver, Probability of error, optimum receiver,
optimal of coherent reception, signal space representation and probability of error, eye diagrams for
ASK,PSK,FSK, crosstalk.
INFORMATION THEORY : Information and entropy, conditional entropy and redundancy, Shannon Fano
coding, Mutual information, Information loss due to noise , source codings -Huffman code, variable length
coding, source coding to increase average information per bit,Lossy source coding.
UNIT – IV
ERROR CONTROL CODES
LINEAR BLOCK CODES : Matrix description of Linear Block codes, Error detection and error correction
capabilities of Linear block codes
CYCLIC CODES: Algebraic structure, encoding, syndrome calculation, Decoding
CONVOLUTION CODES: Encoding, Decoding using state, tree and trellis diagram, decoding using Viterbi
algorithm, Comparison of error rates in coded and uncoded transmission.
UNIT – V
SPREAD SPECTREUM MODULATION: Use of spread spectrum, Direct sequence spread
spectrum(DSSS),Code division multiple access, Ranging using DSSS,Frequency hopping spread spectrum,PN-
Sequences:Generation and charactereistics,Synchronization in spread spectrumsystem.
Course
Outcomes
(CO’s) PSO1 PSO2
C321.1 1 2
C321.2 3 3
C321.3 2 3
C321.4 3 3
C321.5 3 3

7. 5.Individual Time Table
SUBJECT: DC,AE lab SECTION:III- C&II-A,C NAME: N.Soujanya
6.
7. Session plan
Unit
NO
Title No of
lectures
1 ELEMENTS OF DIGITAL
COMMUNICATION SYSTEMS
17
2 DIGITAL MODULATION
TECHNIQUES
10
3 BASEBAND
TRANSMISSION AND
OPTIMAL RECEPTION OF
DIGITAL SIGNAL
12
4 ERROR CONTROL
CODES
12
Day
&
Time
I II III IV
12.40 -
01.20
V VI VII
09.10 –
10.10
10.10-
11.00
11.00 –
11.50
11.50 –
12.40
01.20 –
02.20
02.20 –
03.10
03.10 –
04.00
MON DC AE lab
TUE DC DC
WED AE lab AE lab
THU AE lab DC
FRI DC
SAT DC

8. 5 SPREAD SPECTREUM
MODULATION:
6
7. Detailed lecture plan
S.no Jntu Syllabus Sub topics No. Of
lectures
Required
Suggested
Books
(Eg. T1,
T2,R5)
1. UNIT-I
Elements of digital
communication
systems
&
Pulse Code
Modulation
1.Advantages of digital
communication systems
L1 T1,R4
2.Bandwidth-S/ntradeoff L2 T1
3.HartleyShannonslaw L3 T1
4.PCM Generation and
Reconstruction
L4 T1
5.Quantization noise L5,L6 T1,T2
6.Non uniform
Quantization and
Companding
L7,L8,L9 T1,T2,R1,R4
8.Delta modulation and
adaptive delta modulation
L10,L11,L1
2,L13,L14 T1
9.Noise in PCM and DM
systems.
L15,L16,L1
7
T1
Total
Classes:-17
2. UNIT-II
Digital Modulation
Techniques
1.Introduction, ASK,ASK
Modulato
L18 T1,T1,R1,R2R3
,R4
2.Coherent ASK
Detector, Non Coherent
Detector
L19,L20
T1,T1,R1,R2R3
,R4
3.FSK,Bandwidth and
frequency spectrumof
FSK
L21,L22
T1,T1,R1,R2R3
,R4
4.Non coherent FSK
detector, Coherent FSK
detector
L23,L24
T1,T1,R1,R2R3
,R4
5.FSK
detectionusingPLLBPSK,
Coherent PSK detector
L25
T1,T1,R1,R2R3
,R4

9. 6.BPSK, Differential
PSK
L26,L27
T1,T1,R1,R2R3
,R4
Total
classes:10
3. UNIT-III
Base band
transmission and
optimal reception of a
digital signal &
Information Theory
1.Pulse shaping for
optimum transmissions
L28
T1
2.A Base band signal
receiver
L29,L30
T1
3.Probability of error,
optimum receiver
L31,L32
T1
4.Optimal of coherent,
signal space
representation and
probability of error
L33,L34
T1
3.Shannon Fano coding L39,L40 T1,T2,R1
4.Mutual information L41,L42 T1,T2,R1
5.Information loss due to
noise
L43
T1,T2,R1
6.Source codings-
Huffman code 7.variable
length coding
L44,L45,L4
6 T1,T2,R1
8.Source coding to
increase average
information per bit,
L47
T1,T2,R1
9.Lossy source coding L48
T1,T2,R1
Total
Classes:12
4. UNIT-IV
Error control codes
1.Linear Block
codes
2.Cyclic codes
3.Convolutional codes
1.Introduction L49
T1,T2
2.Matrix description of
Linear Block codes
L50,L51
T1,T2
3.Error detection and
error correction
capabilities of Linear
block codes
L52,L53
T1,T2
4.Algebraic structure,
encoding
L54,L55
T1,T2
5.Syndrome calculation, L56,L57 T1,T2
6.Decoding L58 T1,T2
7.Encoding, Decoding
using state Diagram
8.Tree and Trellis
Diagram
L59,L60
T1,T2
9.Decoding using Viterbi
algorithm
L61
T1,T2
10.Comparison of error
rates in coded and
uncoded transmission
L62
T1,T2
Total
Classes:12
5. UNIT-V 1.Use of spread spectrum L63 T1,T2
2.Direct sequence spread
spectrum(DSSS)
L64
T1,T2

10. Spread Spectrum
Communication
3.Code division multiple
access,Ranging using
DSSS
L65
T1,T2
4.Frequency hopping
spread spectrum
L66
T1,T2
5.PN-
Sequences:Generation,
L67
T1,T2
6.Charactereistics,Synchr
onization in spread
spectrumsystems
L68
T1,T2
Total
Classes:6
8. Session execution log
S.No Syllabus Scheduled
completed date
Completed date Remarks
1 I-UNIT 26-12-19 7-1-19 COMPLETED
2 I1-UNIT 27-1-19 29-1-19 COMPLETED
3 I11-UNIT 10-2-19 11-2-19 COMPLETED
4 IV-UNIT 1-3-19 2-3-19 COMPLETED
5 V-UNIT 20-3-19 23-3-19 COMPLETED

11. 9. Assignment Questions
MID-1 ASSIGNMENT QUESTIONS
SET-1:
1. A) State and discuss the Shannon Hartley theorem.(CO1)
B) With neat diagram explain about sampling and quantization in detail in digital
communications.
2. A) Draw the block diagram of QPSK System & explain its working. (CO2)
B) Explain the operation of differentially encoded PSK System.
3. A) Derive the expression for bandwidth and spectrum of FSK? (CO2)
B) Explain FSK detection using Phase locked loop and non coherent methods?
4. A) Sketch the waveform of FSK for the input binary sequence 1100100010. (CO1)
B) Explain in detail the need for non uniform quantization in digital communication.
SET-2:
1. Derive an expression for SNR of a PCM encoder using uniform quantizer when the input
Signal is uniformly distributed. (CO1)
2. a) A TV Signal with a Bandwidth of 4.2MHZ is transmitted using Binary PCM. The no. of
Representation level is 512.calculate: 1) Code word length 2) final bit rate 3)
Transmission bandwidth(CO1)
b) Explain the working principle of DPCM?
3. a)Assume the bit data d(t)=10110 to be transmitted using DPSK transmitter & draw the
output waveforms?(CO2)
b) State and prove sampling theorem in time domain?
4. a) List out the advantages of Pass band transmission over base band transmission (CO2)
b) Draw the signal space representation for ASK, BFSK, BPSK and QPSK.(CO2)
SET-3:
1. A) What is in delta modulation? Explain the difference between granular & slope over Load
noise. (CO1)
B) What is companding? Explain how companding improves the SNR of a PCM
System. (CO1)

12. 2. a)Derive an expression for signal to quantization noise power ratio for delta modulation?(CO1)
b) State and prove sampling theorem in time domain?(CO1)
3. a) Comparison among ASK, PSK AND FSK? (CO2)
b) What are the advantages of digital communication system?
4. a) Compare the performance of PCM and DM systems.( (CO1)
b) Differentiate between coherent and non coherent digital modulation systems. (CO2)
DIGITAL COMMUNICATIONS –II MID ASSIGNMENT PAPER
SET-1
1Q) a) The generator matrix for a (6,3) block code is given by G= 111;100
101; 010
110; 001
Find the code vectors?
b) For a (7,4) cyclic code the generator polynomial is given as G(P)= + find the code
vectors in systematic form?(CO5)
2Q) a) Design a syndrome calculator for a (7,4) Hamming code generated by the generator
polynomial G(P)= +P . If the received code vector Y=0110001. And also verify the output
by using the formula method.
b) Explain Code division multiple access Technique.(CO5)
3Q) If the given sequences are 100, 111, 101
i). Sketch convolution encoder configuration
ii).Construct state diagram, Tree diagram and also decode the output from the Tree diagram if
the input sequence is 101100.
b). What are the various spread spectrum techniques, write the advantages of spread spectrum
techniques?(CO5)

13. 4Q) a)For a discrete memory less source with the symbols s1,s2,s3,s4,s5 and their probability of
occurrences are 0.4,0.2,0.2,0.1,0.1 find the efficiency of the code by using Shannon-fano
coding?
b) Prove that I(X;Y)=H(X)-H(X/Y)?(CO4)
SET-2
1Q)a) Define i)Entropy ii)Mutual information iii) conditional Entropy iv)Joint Entropy?
b) For a discrete memory less source with the symbols s1,s2,s3,s4,s5 and their probability of
occurrences are 0.4,0.2,0.2,0.1,0.1 find the efficiency of the code by using Huffman
coding?(CO4)
2Q) a).The parity check matrix of a (7, 4 )Hamming code is as under H=
Calculate syndrome and single bit error. For the received code vector Y=0110110.Then
calculate error correction using syndrome vector?
b) Explain the principle of direct sequence Spread spectrum (DSSS)? (CO5)
3Q) If the given sequences are 100, 111, 101
i). Sketch convolution encoder configuration
ii).Construct state diagram, Trellis diagram and Tree diagram and also decode the output from
the Tree diagram if the input sequence is 101100.
b). Explain about slow frequency hopping and fast frequency hopping? (CO5)

14. 4Q) a) The generator matrix for a (6,3) block code is given by G= 111;100
101; 010
110; 001
Find the code vectors?
b) For a (7,4) cyclic code the generator polynomial is given as G(P)= + find the code
vectors in non-systematic form?(CO5)
SET-3
1Q) a)For a discrete memory less source with the symbols s1,s2,s3,s4,s5 and their probability of
occurrences are 0.4,0.2,0.2,0.1,0.1 find the efficiency of the code by using Shannon-fano coding
b) Prove that I(X;Y)=H(X)-H(X/Y)?(CO4)
2Q)a) Design a syndrome calculator for a (7,4) Hamming code generated by the generator
polynomial G(P)= +P . If the received code vector Y=0110001. And also verify the output
by using the formula method.
b) Explain Code division multiple access Technique?(CO5)
3Q) If the given sequences are 100, 111, 101
i). Sketch convolutional encoder configuration
ii).Construct state diagram, Tree diagram and also decode the output from the Tree diagram if
the input sequence is 101100.
b). Explain about PN sequence generation and their characteristics?(CO5)
4Q) a) The generator matrix for a (6,3) block code is given by G= 111;100
101; 010
110; 001
Find the code vectors?

15. b) For a (7,4) cyclic code the generator polynomial is given as G(P)= + find the code
vectors in non-systematic form?(CO5)
10. Sample assignment Script
(Attached separately)
11. Unit wise course material
(Attached separately)
12. Mid exam Question Papers
MID 1
1. A) What is in delta modulation? Explain the difference between granular & slope over Load
noise. (CO1)
B) What is companding? Explain how companding improves the SNR of a PCM
System. (CO1)
2. a)Derive an expression for signal to quantization noise power ratio for delta modulation?(CO1)
b) What are the advantages of digital communication system? (CO1)
3. Comparison among ASK, PSK AND FSK? (CO2)
4. a) Compare the performance of PCM and DM systems.( (CO1)
b) Differentiate between coherent and non coherent digital modulation systems. (CO2)

16. MID 2
1Q)a) Define i)Entropy ii)Mutual information iii) conditional Entropy iv)Joint Entropy?
b) For a discrete memory less source with the symbols s1,s2,s3,s4,s5 and their probability of
occurrences are 0.4,0.2,0.2,0.1,0.1 find the efficiency of the code by using Huffman
coding?(CO4)
2Q) a).The parity check matrix of a (7, 4 )Hamming code is as under H=
Calculate syndrome and single bit error. For the received code vector Y=0110110.Then
calculate error correction using syndrome vector?
b) Explain the principle of direct sequence Spread spectrum (DSSS)? (CO5)
3Q) If the given sequences are 100, 111, 101
i). Sketch convolution encoder configuration
ii).Construct state diagram, Trellis diagram and Tree diagram and also decode the output from
the Tree diagram if the input sequence is 101100.
b). Explain about slow frequency hopping and fast frequency hopping? (CO5)
4Q) a) The generator matrix for a (6,3) block code is given by G= 111;100
101; 010
110; 001
Find the code vectors?
b) For a (7,4) cyclic code the generator polynomial is given as G(P)= + find the code
vectors in non-systematic form?(CO5)

17. 13. Sample mid answer script
(Attached separately)
14. Material collected from internet/websites
(Attached separately)
15. Power Point Presentations (PPTs)
dc ppt.zip
16. Previous Question Papers
dc question papers.zip
17.Text Books/Websites/URLs/ e-Resources
TEXT BOOKS
T1. Principles of Communication Systems – H. Taub and D. Schilling,Gautam Saha,3rd
Edition,McGraw-Hill,2008
T2. Digital and Analog Communication Systems - Sam Shanmugam, John Wiley, 2005.
REFERENCE BOOKS
R1. Digital Communications – John G.Proakis, Masoud salehi-5th Edition,
Mc Graw-Hill,2008.
R2. Digital communications - Simon Haykin, John Wiley, 2005.

18. R3. Digital communications-Ian A.Glover, Peter M.Grant, 2nd Edition, Pearson
Edu.,2008.
R4. Communication Systems – B.P.Lathi, BS Publication, 2006.
Websites/URLs/ e-Resources
1. http://www.nptel.iitm.ac.in/video.php?subjectId=117105085
2. http://as.wiley.com/WileyCDA/WileyTitle/productCd-EHEP000391.html
3. http://www.handbook.unsw.edu.au/undergraduate/courses/2013/MATH3901.html
4. http://www.gobookee.net/probability-and-stochastic-processes-yates-solution-manual/
5. http://freepdfdb.com/pdf/probability-theory-and-stochastic-processes-peebles
6. http://www.uq.edu.au/study/course.html?course_code=STAT4403
7. http://www.maths.unsw.edu.au/courses/math5846-introduction-probability-and-stochastic-
processes
8. http://en.wikipedia.org/wiki/Stochastic_process
9. http://www.math.niu.edu/~rusin/known-math/index/60-XX.html
10. https://studyat.anu.edu.au/courses/ENGN8538;details.html