B8383 - COMUNICAZIONI WIRELESS LM

Learning outcomes

At the end of the course, the student acquires knowledge of information transmission over wireless radio channels. In particular, the student is able to design and dimension a digital wireless link, understands the problems of digital modulation and demodulation, the effects of multipath propagation, and the corresponding mitigation techniques, including multi-carrier (OFDM) and multi-antenna (MIMO) schemes. In addition, the student gains knowledge of the main issues related to the design of mobile radio systems, including resource management and multi-user interference, with particular reference to terrestrial and satellite fifth-generation (5G) systems.

Course contents

Prerequisites: Knowledge of signal processing, probability theory, estimation and detection theory, fundamentals of information theory and coding, and basic principles of electromagnetic wave propagation and antennas.

Programme:

1. Introduction to wireless communication systems and review topics

1. Course introduction and evolution of telecommunication systems
2. Review: real and complex Gaussian random variables; Rayleigh, exponential, log-normal, and chi-square statistics; elements of matrix algebra; eigenvalue decomposition and singular value decomposition (SVD)
3. Review of decision theory, estimation theory, and machine learning
4. Discrete-time baseband equivalent of bandpass systems: tapped delay line (TDL) model

2. The wireless channel

1. Main characteristics of radio wave propagation as a function of frequency; multipath propagation
2. Statistical characterization of the radio channel; channel selectivity in time and frequency (coherence bandwidth and coherence time)
3. Large-scale fading modeling: path loss and shadowing
4. Small-scale fading modeling: multipath fading
5. Clarke–Jakes narrowband model
6. Statistical models for multi-antenna systems
7. 3GPP radio channel models

3. Transmission over non-selective bandlimited channels

1. Linear modulations: signal constellations and spectral characteristics; signal-to-noise ratio Eb/N0; optimal transmission in AWGN channels
2. Examples of signal constellations and corresponding error probabilities
3. Spectral efficiency and trade-off with energy efficiency; theoretical limits: Shannon capacity and channel coding considerations

4. Transmission over frequency-selective channels

1. Flat fading transmission; link budget under slow and fast fading; outage probability and average error probability
2. Diversity techniques: time, frequency, and spatial diversity
3. Optimal transmission in frequency-selective channels: MLSE receiver
4. Suboptimal equalization techniques: linear equalizers
5. Multi-carrier transmission: OFDM and applications
6. Channel estimation and synchronization
7. Examples of standards: terrestrial and satellite digital television

5. Multi-antenna systems (MIMO)

1. Definitions; MIMO channel capacity and spatial multiplexing; propagation effects (LOS, rich NLOS, keyhole)
2. SIMO systems: maximal ratio combining (MRC)
3. MISO systems with and without channel state information at the transmitter (CSIT): beamforming and Alamouti scheme
4. Optimal MIMO schemes with CSIT (SVD-MIMO); schemes without CSIT: V-BLAST, zero forcing, MMSE, and successive interference cancellation (SIC)
5. Multi-user MIMO and massive MIMO

6. Elements of mobile radio systems

1. Evolution from 1G to 5G; network architectures; frequency reuse (co-channel interference); multiple access techniques; mobility management; main performance metrics (network spectral efficiency and area throughput)
2. Main features of the 5G standard
3. Overview of advanced topics toward 6G: integrated sensing and communications (ISAC), semantic communications, 3D networks, and cell-free systems

 

 

Readings/Bibliography

No specific textbook purchase is required. Lecture slides are available on the Virtuale platform.

Recommended textbooks:

• D. Tse, P. Viswanath, Fundamentals of Wireless Communications, Cambridge University Press, 2005
• R. W. Heath Jr., A. Lozano, Foundations of MIMO Communication, Cambridge University Press, 2018
• A. Goldsmith, Wireless Communications, Cambridge University Press, 2005
• J. G. Proakis, Digital Communications, McGraw-Hill
• J. D. Parsons, The Mobile Radio Propagation Channel, 2nd edition, Wiley
• O. Andrisano, D. Dardari, Lecture Notes on Telecommunication Systems: Design Principles of Mobile Radio Systems, Esculapio, Bologna, 2001

Teaching methods

• Lectures in the classroom
• Problem-solving exercises assigned and discussed during the course

Assessment methods

The exam consists of an oral examination aimed at verifying the knowledge acquired and the achievement of the learning outcomes.

In particular, the assessment evaluates the student’s ability to:

• understand and design a digital wireless communication link, considering the trade-off between complexity, performance, and robustness
• understand the impact of radio propagation on wireless system design
• understand the principles of multi-carrier (OFDM) and multi-antenna (MIMO) systems
• analyze radio resource management techniques and the role of co-channel interference
• interpret the main architectural solutions of cellular networks

The final grade is based on three questions covering the main topics of the course. One of the questions may involve the solution of a short design or analysis problem in wireless communications.

Alternatively, the student may present a project agreed with the instructor, consisting of the development of a Matlab/Python simulation platform, replacing one of the three questions.

Students with learning disabilities (DSA) or temporary/permanent disabilities are invited to contact the relevant University office in advance (https://site.unibo.it/studenti-con-disabilita-e-dsa/it ). Any accommodations will be evaluated and approved by the instructor at least 15 days in advance, in accordance with the course learning objectives.

Teaching tools

• Teaching material: available in electronic format on the University Virtuale platform
• Simulation platform: Matlab/Python

Office hours

See the website of Davide Dardari