Digital communications

COURSE CONTENTS

THEORY

Description:
Course aim is to give the basics of digital signals transmission and to describe the modern digital communication systems. In the theoretical course part the theory of digital signal transmission is presented and the techniques of converting an analog signal to digital as well as the techniques of digital modulation and transmission are analyzed. For the more complete comprehension of all subject from point of view of students, in the laboratorial course part, simulation of basic digital communication systems with the use of suitable simulation parcels is attempted.

Layout:

• Basics of  time and frequency representation of digital signals. The basic principles of signals theory and the basic mathematic background that is used in the study of digital communications systems (Analysis Fourier, probability theory, theory of sampling and coding, linear systems) are given.
• Basic principles of designing digital communication systems. Elements of digital communication systems, factors affecting digital communication systems design and performance, fundamental principles and technological restrictions in the methods of digital data transmission.
• Signaling principles. Baseband signaling, Binary and M-ary signaling. The effect of noise and finite bandwidth are analyzed, and the maximum channel capacity is described.  The problem of intersymbol interference and the use of and Nyquist and are presented too.
• Noise and interference in digital communication systems.
• Sources and consequences of noise and interference effect in digital signal transmission parameters. Ways of confrontation of relative problems.
• Basic techniques of digital modulation. Basic techniques of modulation and representation of signals are analyzed, such as PSK, FSK, ASK, MSK, PAM, QAM, PCM, DPCM, ADPCM, DM, ADM, BPSK, DPSK,  QPSK, BFSK, M-ary systems.  Modulation techniques and coherent and nocoherent demodulation techniques are analyzed. Timing and carrier recovery circuits are presented.
• Rectangular modulation schemes. Vector chart, eye and constellation diagrams, noise effects. Unicode transmission techniques (FDM, OFDM).

LABORATORY

During the series of laboratorial exercises the student:

• Will be familiarized with the use and the planning of suitable simulation parcels (Python, Matlab) for the study of digital communication systems, 
• Will develop algorithms for solution of problems of digital modulation.
• The students will undertake in teams the two or three individuals the study, implementation and presentation of small scale of work that is related to subjects of digital communications.

The laboratories will cover:

• Development of algorithms for solution of Fast Fourier Transformation  (FFT) exercises,
• Development of algorithms for solution of basic types of digital modulation exercises,
• Designing of basic types of digital filters, and
• Designing of digital communications systems with the use of Simulink. 

RECOMMENDED BIBLIOGRAPHY

• J. Proakis, "Digital Communications", 2001, McGraw-Hill, ISBN 0-07-118183-0.
• A. Bateman, "Digital Communications", Addison – Wesley, 1999, ISBN 0-201-34301-0.
• B. Sklar, "Digital Communications: Fundamentals and Applications", 2^nd  Edition, Prentice Hall PTR, 2001, ISBN: 0130847887.
• B.P. Lathi, "Modern Digital and Analog Communications Systems", Oxford University Press; 3rd Edition, 1998, ISBN: 0195110099.
• M. Simon, S. Hinedi, W. Lindsey, "Digital Communication Techniques:  Signal Design and Detection", Prentice Hall, 1994.
• R. Ziemer R. Peterson "Introduction to Digital Communication", 2nd ed. Prentice Hall 2000.
• J. Proakis M. Salehi, "Contemporary Communication Systems Using  Matlab", PWS Publishing Company, 1997, ISBN 0-534-93804-3.
• A. Cavallo, R. Setola, F. Vasta, "Using MATLAB Simuling and Control System Toolbox. A Practical Approach", 1996, Prentice Hall Europe,  ISBN 0-13-261058-2.
• K. Feher, "Wireless Digital Communications. Modulation & Spread Spectrum Applications" Prentice Hall PTR, 1995, ISBN 0-13-098617-8.
• Κ. Sam Shanmugan, "Ψηφιακά και αναλογικά συστήµατα επικοινωνίας", Μετάφραση – Επιµέλεια Κ. Καρούµπαλου, Έκδοση Γ. Πνευµατικού.
• G. Loukrezi, "Subjects of digital communication ", Publications Gutenberg, Athens 1993.
• G. Syrkou, "Digital signal prosessing ", 2nd Edition, Athens 2000.