Course detail

Theory of Communication

FEKT-LTSDAcad. year: 2016/2017

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 tutorial classes are subsequently verified by laboratory measurements with specially designed instruments and also by computer simulations with models built in the MATLAB-SIMULINK environment.

Language of instruction

Czech

Number of ECTS credits

6

Mode of study

Not applicable.

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 physics are required. It is also recommended to pass the Signal and Systems Analysis (KASS) course before.

Co-requisites

Not applicable.

Planned learning activities and teaching methods

Teaching methods comprehend lectures, computer exercises and laboratory measurements. The MATLAB software is used for computer exercises. Laboratory measurements proceed with the aid of specially prepared electronic instruments, Agilent 33220A generators and Tektronix TDS 2002 scopes. Student have to process five assignments during the course.

Assesment methods and criteria linked to learning outcomes

The final grade depends on total sum of points obtained during the laboratory measurements, computer simulations, professional trainings and written exam of the course. Student can get:
- up to 25 points for five assignments,
- up to 5 points for laboratory measurements,during them student obtain points for correctly measured results and conclusions stated in the given protocol,
- up to 5 points for computer exercises, during them student obtain points for correctly processed tasks,
- up to 65 points for the compulsory exam, which has a written form and only students who passed the laboratory measurements and computer exercises and who submitted all processed assignments are able to take a make-up it. If the examinator has a problem with the evaluation of the written exam, he/she can put supplement oral questions to the student.

Course curriculum

1) Signals in communication systems (continuous, discrete). Basic waveform representation of binary digits. Line codes. Noise in communication systems. Receiving of disturbed signal.
2) Amplitude and frequency modulations and keyings. Phase modulation and keying. Problems of carrier recovery in BPSK demodulator, differential phase shift keying (DPSK).
3) Advanced keying techniques (QPSK, 8PSK, OK-QPSK, MSK, FFSK, GMSK, pi/4-DQPSK, MQAM). Reducing of intersymbol interference (ISI). Synchronization. Scrambling. Methods of error control. Interleaving. Equalizers.
4) Basic pulse modulations (PAM, PWM, PPM). Methods of analog-to-digital conversions (PCM, DPCM, DM, ADM, SDM). Multiplexing and multiple access. Orthogonal frequency division multiplex.
5) Effect of the noise in passband. Modulations in optoelectronics. Introduction to the information theory. Channel capacity. Trellis coded modulation.

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 speed of transmission.

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

All laboratory measurements and computer exercises are compulsory. If the student duly apologize his/her absence, missed exercises and measurements could be repeated in agreement with the teacher. The processing and sending of the all five assignments in time is compulsory too.

Recommended optional programme components

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

DOBEŠ J., ŽALUD V. Moderní radiotechnika. 1. vyd., Praha : BEN, 2006. 768 s. ISBN 80-7300-132-2 (CS)

Recommended reading

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)
PROAKIS J. G. Digital Communications. 4th ed., New York (USA) : McGraw-Hill, 2001. 1002 p. ISBN 0-07-232111-3 (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)

Classification of course in study plans

  • Programme EEKR-ML Master's

    branch ML-TIT , 1. year of study, winter semester, compulsory

  • Programme EEKR-ML1 Master's

    branch ML1-TIT , 1. year of study, winter semester, compulsory

  • Programme EEKR-CZV lifelong learning

    branch ET-CZV , 1. year of study, winter semester, compulsory

Type of course unit

 

Lecture

26 hours, optionally

Teacher / Lecturer

Syllabus

Basic terms of the theory of communication and data transmission.
Communication systems focused on digital modulations. Classification of modulating techniques.
Base-band discrete coded modulations.
Signal formats for digital data representation. Intersymbol interference (ISI) and its reduction.
Digital data filtering. SNR maximization.
Two-stage and more-stage discrete modulations with harmonic carriers.
Geometric representation of modulated signals. Main groups of digital modulations.
BFSK, BPSK, D-BPSK modulations.
MPSK, QPSK, D-QPSK, O-QPSK, pi/4 - QPSK modulations.
CPM (CPFSK, MSK, GMSK) modulation. M-QAM modulations.
Modulating formats with multiple carriers MCM, orthogonal frequency multiplex OFDM.
Techniques of reconstruction of reference carrier and time raster for digital modulations.
Techniques of signal visualization for discrete modulations. Comparison of the individual techniques.

Fundamentals seminar

13 hours, optionally

Teacher / Lecturer

Syllabus

Transmission and modulating rate. Signals and their spectrum.
PCM, DPCM, DM.
Formats of digital signals. Their parameters in the time and frequency domains.
ASK, BFSK, DPSK.
Test (10 points). Shift keying I.
Shift keying II.

Exercise in computer lab

13 hours, compulsory

Teacher / Lecturer

Syllabus

Base-band data transmission.
BPSK.
QPSK.
MSK and GMSK.
Data communication bz means of modem.
Testing and credit hour.

Laboratory exercise

13 hours, compulsory

Teacher / Lecturer

Syllabus

Base-band data transmission.
BPSK.
QPSK.
MSK and GMSK.
Data communication bz means of modem.
Testing and credit hour.