Objectives of the course

The course aims at presenting and describing modern satellite-based communication and positioning systems. Specifically, the first part of the course focuses on key topics and elements that are common to both types of system, such as the propagation of electromagnetic waves in the atmosphere, analog and digital modulation techniques, the link budget. The second part of the course is devoted to different satellite communication systems, whose architecture and key features (e.g. data rate, bit error rate, coding schemes, multiple access schemes) are presented. The last part of the course deals specifically with Global Navigation Satellite Systems (GNSSs), such as the American GPS and the European Galileo, by introducing the basic principles of radio-positioning, the system architectures, the ranging signals, the receiver architectures, and the main applications.
 

Contents

The topics of the course are:

• Atmospheric electromagnetic wave propagation: ionospheric propagation (physical description of the ionosphere and constitutive equations, total reflection, depolarization, attenuation, delay); tropospheric propagation (ray bending effects, scintillations and multipath, attenuation due to gases, clouds and effects due to rain, models for rain attenuation, depolarization due to rain and ice crystals).
• Noise in positioning and communication systems: thermal noise, shot noise, noise due to dissipative elements, antenna noise temperature, Low Noise Amplifier, overall noise of a receiver.
• Modulation techniques: analog modulation (amplitude modulation and associated transmitter block scheme, frequency modulation and associated transmitter block scheme); digital modulation (ASK, PSK, FSK, advanced modulation schemes, bit error rate, bit energy/noise spectral density ratio and its relationship with the bit error rate, Shannon theorem, some elements on information coding).
• Receivers: the heterodyne receiver; brief description of SDR and of AM and FM demodulators.
• Space systems: the link budget; different architectures and mission profiles for satellite positioning and communication systems
• Satellite communication systems: satellite-based communication systems, broadcast (one-way) and telecommunication (two-way) architectures; data relay systems; GEO, MEO, LEO systems.
• Satellite-based localization and positioning: position estimation techniques based on time of arrival, positioning algorithms, uncertainty and error sources, error correction models, system architectures of modern GNSSs (e.g. GPS and Galileo), space segment (satellite architecture, orbits) and ground segment (monitoring stations, information for system correction/maintenance), augmentation systems, applications of GNSSs.

Books

Electromagnetic wave propagation

• C. Riva, G. G. Gentili, Handbook of Electromagnetics, Maggioli Editore (also the Italian version is available --> C. Riva, G. G. Gentili, Appunti di campi elettromagnetici, Maggioli Editore)
• J.A. Richards, Radiowave propagation. An introduction for the non specialists, Springer
• A. Paraboni, M. D’Amico, Radiopropagazione, McGraw-Hill

Global Navigation Satellite Systems

• E.D. Kaplan, C.J. Hegarty, Understanding GPS: Principles And Applications (second edition), Editore: Artech House
• J.-M. Zogg, GPS - Essentials of Satellite Navigation, Editore: u-blox https://zogg-jm.ch/Dateien/GPS_Compendium(GPS-X-02007).pdf

Didactic material

Exams (with solution)

28^th of January 2022

14^th of February 2022

27^th of June 2022

21^st of July 2022

25^th of January 2023

14^th of February 2023

27^th of June 2023

24^th of July 2023

12^th of September 2023

16^th of January 2024

6^th of February 2024