FUNDAMENTALS OF TELECOMMUNICATIONS

The educational objectives of the Fundamentals of Telecommunications course are as follows:

1. Knowledge and understanding: the student will learn the basic knowledge of analog and digital techniques for the remote transmission of information and the fundamentals of telecommunication networks, in particular the architecture and network protocols;

2. Applying knowledge and understanding: the knowledge of an applicative nature, acquired through the exercises and the laboratory, will concern the ability to design and configure telecommunications systems starting from a knowledge and understanding of all the techniques that characterize the different phases of signal processing and information management between source and destination; the student will acquire problem solving and teamwork skills.

3. Making judgments: the teaching will stimulate autonomy of judgment and evaluation of the conditions in which to apply the techniques and tools for the design of the physical level that characterizes a telecommunications system;

4. Communication skills: the teaching is based on the use of a language specific to the studies relating to telecommunication techniques and systems which will become the basis of the communication activity set up by the student;

5. Learning skills: learning skills will be stimulated by critical knowledge of the topics covered in the teaching, made possible by attendance at lectures, laboratory activities and the study of reference texts.

The course, which consists of 79 hours of teaching, exercises and laboratory, is delivered in co-teaching (6 + 3 CFU). 

The teachers are also available for online reception meetings, by appointment.

Should teaching be carried out in mixed mode or remotely, it may be necessary to introduce changes with respect to previous statements, in line with the programme planned and outlined in the syllabus.

 

The course in general does not require compulsory attendance, but it is strongly recommended for passing the exam. The laboratory or other skills are mandatory for at least 70% of attendance.

1. Introduction (3 h): course organization, the history of telecommunications (°), general description of a communication system, analog and digital sources, classification of signals and services, transducers. Definitions of bit rate, SNR, BER, SER. Performance parameters of a communication system. Audio frequencies, thresholds of hearing and pain, loss of hearing sensitivity (°).
2. Communication channels (3+3 h) (*): ideal, perfect, linear and time-invariant (LTI), linear and time-varying (LTV). Channel bandwidth. Equalization. Nonlinear channels: harmonic distortion and intermodulation noise, effects and solutions. Noisy channels. AWGN noise and interference. The radio channel and electromagnetic waves. Free-space attenuation and Friis transmission formula. Effects of the medium and atmospheric phenomena on propagation (°). The multipath phenomenon (°). Exercises.
3. Noisy two-port networks (2+4 h): Noisy two-port networks: equivalent noise bandwidth, noise temperature and noise figure. Resistive two-ports (°). Friis formula for cascaded two-ports. Antenna and system temperature. Exercises.
4. The digital telephone signal (5+4 h): Characteristics of the speech signal. Review of sampling (°). Uniform quantization: decision and reconstruction levels; step size, quantization noise and SNR. Nonuniform quantization. PCM coding, A-law and μ-law companding. Speech coding methods. Differential coding DPCM (°). Linear predictive vocoder. Voice Activity Detection (VAD). ITU-T and ETSI speech-compression standards. Frequency-division multiplexing (FDM) and hierarchies in PSTN telephony. Time-division multiplexing (TDM) and hierarchies in ISDN telephony. Exercises.
5. Information theory (4+6 h): Measure of information and entropy. Discrete sources and examples. Source coding: code properties, codeword length, coding efficiency, block coding, Gray codes, Shannon–Fano, Huffman. Exercises.
6. Channel coding (2 h): Objectives and error types. Block codes. Code rate. Encoding/decoding delay. Hamming space and distance. Linear and systematic codes and generator matrix. Spectral efficiency. Repetition and parity-check codes. Interleaver: technique, delay and corrective capability (°).
7. Line coding (3 h): Main binary line codes. Clock recovery. Eye diagram (°). Multilevel coding. Channel capacity and the Shannon–Hartley theorem. Transmission and regeneration of PCM signals over noisy channels (°).
8. Digital baseband transmission (3 h): Binary and M-ary PAM baseband systems. ISI (intersymbol interference). Error probability. Impulse-carrier transmissions.
9. Passband digital modulation and transmission (8 h): Amplitude modulation and demodulation: DSB, SSB, AM and VSB. Recovery of the demodulation carrier. Phase and frequency offset. Balanced and switching DSB modulator (°). Angle modulation: PM and FM (°). Comparison of modulation techniques: power, bandwidth, SNR, complexity. Coherent binary ASK, PSK, FSK: carrier parameters, signals, error probability, optimal filter. Performance comparison: power, bandwidth, BER, complexity. Critical issues and application contexts. M-ary multidimensional modulations: signals, constellations, advantages, coherent QPSK demodulation (°). Hybrid modulations: APSK and QAM. Multicarrier modulation: OFDM.

(°) Topic included only in the full program.          

(*) The second number refers to the hours spent on exercises or other activities

Contribution of the course to the 2030 Agenda for Sustainable Development

The knowledge acquired will support sustainable development in the following areas: Good Health and Well-Being; Quality Education; Decent Work and Economic Growth; Industry, Innovation and Infrastructure; Climate Action; Life Below Water; Life on Land, in line with the 2030 Agenda’s Sustainable Development Goals (SDGs) 3, 4, 8, 9, 13, 14, and 15.

[1] Teacher's slides and notes (available on Studium)

[2] K. Sam, Shanmugam “Digital and Analog Communication Systems”, John Wiley & Sons (a specific reference to the paragraph is given on Studium).

The student may choose between the following two assessment types:

Assessment Type 1 (for those who take and pass the midterm):

• Midterm test with 2 exercises in 90 minutes on the first 5 parts of the syllabus; pass threshold set at 50% correct; validity 1 year

• Term paper (groups of 3–4 people, submission by May) – validity 1 year

• Oral exam with 2 questions on a reduced syllabus (i.e., excluding the topics marked with °).

Assessment Type 2 (for those who do not take or do not pass the midterm):

• Term paper (groups of 3–4 people, submission by May) – validity 1 year

• Written exam (1 exercise in 45 minutes on the first 5 parts of the syllabus); pass threshold set at 50% correct; validity 1 exam session

• Oral exam with 3 questions on the full syllabus

In both assessment types, one of the oral-exam questions concerns the part of the course corresponding to the 3 CFU taught by Prof. Raftopoulos. In addition, a correct completion rate between 50% and 70% will result in a reduction of up to 3 points (out of 30) from the overall grade..

To ensure equal opportunities and in compliance with current laws, interested students may request a personal interview in order to plan any compensatory and/or dispensatory measures based on educational objectives and specific needs. Students can also contact the CInAP (Centro per l’integrazione Attiva e Partecipata - Servizi per le Disabilità e/o i DSA) referring teacher within their department.

Learning assessment may also be carried out on line, should the conditions require it.

The questions cover all topics covered in class. In any case, several completed exercises and a list of possible questions for the oral exam are shared on Studium.