Course detail

Theory of Communications

FEKT-MPA-TOCAcad. year: 2021/2022

The course deals with principals, methods and characteristics of communication systems. It focuses on modern digital systems and modulation methods in particular. However, student of the course can also intensify his/her knowledge of analog modulations, their parameters and implementations. The theoretical information obtained at lectures are subsequently verified by computer simulations with models built in the MATLAB-SIMULINK environment. At the same time, student learns lot of technical terms and expands his/her vocabulary for the field of communication technology.

Language of instruction

English

Number of ECTS credits

4

Mode of study

Not applicable.

Offered to foreign students

Of all faculties

Learning outcomes of the course unit

Student, who passed the course, is able:
- to distinguish basic types of binary signals, to compute and draw their spectra and describe principles and characteristics of the most widely used line codes,
- to list individual blocks of the digital communication system and explain their functions,
- to describe additive white Gaussian noise (AWGN) channel model, to define bit error rate, to compute probability of error reception in case of both baseband and passband binary signal transmission affected by AWGN,
- to describe principles, to define parameters and to list characteristics of basic and modern modulation methods,
- to explain the cause of intersymbol interferences (ISI) and Nyquist strategy of zero ISI in sampling moments, to draw and describe impulse responses of both raised cosine and Gaussian shaping filters,
- to describe the principle of channel equalization, to explain operations of adaptive equalizer and decision feedback equalizer,
- to explain the principle and importance of synchronization in the communication system, to explain the purpose of scrambling, to design the block diagram of a simple self-synchronizing scrambler,
- to describe principles of the automatic repeat request (ARQ) and the forward error correction (FEC), to explain the principle of interleaving, to describe methods of block and convolutional interleaving,
- to explain the difference between natural and uniform methods of sampling, the cause of aperture distortion and methods of its suppression,
- to describe principles of the pulse width modulation (PWM), the pulse position modulation (PPM) and the pulse density modulation (PDM),
- to explain the difference between uniform and non-uniform methods of quantization, to compute the power of the quantization noise, to draw the graphs of compressor and expander transfer functions,
- to describe principles and to list basic characteristics of pulse coded modulations (PCM, DPCM, DM, SDM),
- to explain principles of basic methods of signal multiplexing and multiple access,
- to describe and design the orthogonal frequency division multiplex (OFDM), to define its basic parameters and to list its typical characteristics and examples of application,
- to describe basic types of intensity modulations of light used in optoelectronics,
- to define and compute basic quantities used in the information theory (self-information, entropy, redundancy, mutual information, channel capacity), to explain the principle of the trellis coded modulation (TCM).

Prerequisites

Student, who enrolls for the course, should know basic definitions and characteristics of signals and systems with both continuous and discrete time, including their mathematical description and representation in the frequency domain, and also know basic types of probability density and distribution functions and have knowledge of the signal sampling and filtration. It is also assumed that student can compute the derivative and integral of a function, modify equations with logarithms, complex numbers and trigonometric functions, solve linear equations and use the MATLAB software. In general, the bachelor level knowledge from the area of mathematics and physicsl and general English language competence are required.

Co-requisites

Not applicable.

Planned learning activities and teaching methods

Teaching methods comprehend lectures and computer exercises where the theory learned at lectures is explained in details with the aid of MATLAB-SIMULINK models. The Moodle e-learning software is used for the final testing of students’ knowledge.

Assesment methods and criteria linked to learning outcomes

Every student can obtain up to 100 points in total. (Up to 10 points for completed assignments and up to 90 points for final computer quiz.)
Participation in computer exercises is mandatory as well as solution of given assignments.

Course curriculum

Lectures:
1) Signals in communication systems. Basic waveform representations of binary digits. Modulation rate, bit rate.
2) Line codes. Required channel bandwidth. General digital communication system.
3) Noise in communication systems. AWGN channel. Probability of error. Matched filter. Correlation receiver.
4) Amplitude modulation, frequency modulation and phase modulation.
5) Amplitude shift keying, frequency shift keying and phase shift keying.
6) Basic parameters and features of the modulation system, keyings QPSK, O-QPSK, MSK, FFSK, GMSK.
7) Keyings π/4-DQPSK, 8PSK, MQAM, CAP.
8) Effect of the noise in passband. Modulations in optoelectronics.
9) Basic pulse modulations. Digital representation of analog signal. Quantization.
10) Reduction of intersymbol interference (ISI). Synchronization. Scrambling.
11) Methods of error control. Interleaving. Equalization.
12) Multiplexing and multiple access. Spread spectrum systems. Orthogonal frequency-division multiplexing (OFDM).
13) Introduction to the information theory. Channel capacity. Trellis coded modulation (TCM).

Computer excercises:
1) MATLAB, HDB3 encoder, AWGN channel model.
2) Matched filter and correlation receiver.
3) Basic keying techniques (ASK, FSK, PSK).
4) Principle of quadrature modulations (QPSK, 16QAM).
5) Pulse modulations (DM, ADM, SDM, PCM).
6) Spread-spectrum techniques.

Work placements

Not applicable.

Aims

Give basic information about signals, methods, principles and parameters of communication systems, especially the digital systems, and also about negative effects on the bit error rate of transmission. To acquaint students with English terminology, lexicon, and specificity of English technical texts in the area of modern communication technologies using the set of lectures focused on the explanation of their principles.

Specification of controlled education, way of implementation and compensation for absences

Student has to do all computer exercises and pass the final computer quiz. Solution of given assignments is mandatory.

Recommended optional programme components

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

PROAKIS, J. G. Digital Communications. 4th ed., New York (USA) : McGraw-Hill, 2001. 1002 p. ISBN 0-07-232111-3 (EN)
HAYKIN, S.; MOHER, M. Introduction to Analog & Digital Communications. 2nd ed., New Jersey (USA) : John Wiley & Sons, 2007. 515 p. ISBN 0-471-43222-9 (EN)

Recommended reading

SKLAR, B. Digital Communications. 2nd ed. Upper Saddle River (USA) : Prentice Hall, 2003. 1080 p. ISBN 0-13-084788-7 (EN)
XIONG, F. Digital Modulation Techniques. 1st ed. Norwood (USA) : Artech House, 2000. 653 p. ISBN 0-89006-970-0 (EN)
HSU, H. P. Schaum's Outline of Theory and Problems of Analog and Digital Communications. 2nd ed., New York (USA) : McGraw-Hill, 2003. 331 p. ISBN 0-07-140228-4 (EN)
GITLIN, R. D.; HAYES, J. F.; WEINSTEIN, S. B. Data Communications Principles. New York (USA) : Plenum Press, 1992. 733 p. ISBN 0-306-43777-5 (EN)

Classification of course in study plans

  • Programme MPC-TIT Master's, any year of study, summer semester, elective
  • Programme MPC-MEL Master's, any year of study, summer semester, elective
  • Programme MPA-CAN Master's, 1. year of study, summer semester, compulsory
  • Programme MPAD-CAN Master's, 1. year of study, summer semester, compulsory
  • Programme MPAJ-TEC Master's, 1. year of study, summer semester, compulsory-optional

Type of course unit

 

Lecture

26 hours, optionally

Teacher / Lecturer

Syllabus

1. Introduction to the theory of signals.
2. Line codes.
3. Effect of the noise in baseband communication.
4. Modulations with harmonic carrier wave (AM, FM, PM).
5. Basic keying techniques (ASK, FSK, PSK).
6. Advanced keying techniques - part I (QPSK, O-QPSK, MSK, FFSK, GMSK).
7. Advanced keying techniques - part II (pi/4-DQPSK, 8PSK, MQAM, CAP).
8. Intersymbol interference and equalization of communication channel.
9. Pulse modulations - part I (PAM, PWM, PPM).
10. Pulse modulations - part II (PCM, DPCM, DM, ADM, SDM).
11. Multiplexing and multiple access.
12. Effect of the noise in bandpass communication and modulations in optoelectronic.
13. Introduction to the information theory and coding.

Exercise in computer lab

12 hours, compulsory

Teacher / Lecturer

Syllabus

1. AWGN channel.
2. Matched filter and correlation receiver.
3. Basic keying techniques (ASK, FSK, PSK).
4. Principle of quadrature modulations (QPSK, 16QAM).
5. Pulse modulations (DM, ADM, SDM, PCM).
6. Spread-spectrum techniques.