OVERVIEW

A digital communication system conveys information in form of discrite symbols from its source to a destination some distance away. The approach used to face the subject is from a general viewpoint: since all the communication systems have the same basic function of transfering information, the course presents the principles and problems of conveying informarmation in terms of digital messages in electrical form through a noisy channel.

AIMS AND CONTENT

LEARNING OUTCOMES

The course is aimed at providing the bases of digital communications: the baseband and bandpass transmissions will be presented, discussed, and compared. The goal is to give the students an adequate knowledge needed to understand the key elements for designing and developing modern telecommunication systems.

AIMS AND LEARNING OUTCOMES

Attendance, active participation to lectures, and individual study will allow students

- to appreciate the theoretical and actual advantages deriving from the use of digital systems

- to understand the main elements of a digital communication system;

- to know the main baseband transmission systems and to compare the principal parameters affecting their performance;

- to know the main bandpass transmission systems and to compare the principal parameters affecting their performance.

PREREQUISITES

Students are expected to have a reasonable background in signal theory, probability theory, random processes and analog modulations.

TEACHING METHODS

Traditional lectures (50 hours) + about 10 hours of exercises carried out in classroom. Due to the Covid-19 emergency, lectures might be provided by means of Teams platform, if required by the competent authorities.

SYLLABUS/CONTENT

General concepts: analog and digital messages. Scheme of a digital communication system. Digital transmission over baseband channels: PAM. Intersymbol interference: Nyquist criterion. PAM power spectrum. Main line codes and their spectra. PAM optimum receivers.

-  Bit and frame synchronization: basic techniques.

-  Digital transmission over bandpass channels: OOK, ASK, FSK, CPFSK, PSK and their power spectra. Noise equivalent bandwidth. Synthesis of modulators by means of QAM systems.

-  Coherent reception for binary bandpass systems: optimal receivers for OOK, FSK, PRK. Noncoherent OOK, FSK, DPSK receivers: performance (error probability) evaluation. Bandpass M-ary QAM, APK and PSK receivers, performance evaluation. Link budget in digital transmission

RECOMMENDED READING/BIBLIOGRAPHY

A. B. Carlson, P. B. Crilly, J. C. Rutledge, “Communication Systems”, 4th edition,  Mac Graw Hill, 2002

B. Sklar “Digital Communications: Fundamentals and Applications”, Prentice Hall 2001

Handouts by the teacher

TEACHERS AND EXAM BOARD

LESSONS

LESSONS START

II semester (approx. from Feb. 22 to May 27).

For more details, see the timetable edited by the "Scuola Politecnica"

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

Written + oral

ASSESSMENT METHODS

The written exam is devoted to assess whether the students have actually learnt  the spectra estimation, the use of constellation, and the evaluation of link budgets.

The oral exam is aimed at evaluting the synthsis, reasoning, and critical capacities of studens on the topics covered by the lectures.

Exam schedule

FURTHER INFORMATION

None