WIRELESS COMMUNICATIONS

Crediti: 
9
Settore scientifico disciplinare: 
TELECOMUNICAZIONI (ING-INF/03)
Anno accademico di offerta: 
2017/2018
Semestre dell'insegnamento: 
Primo Semestre
Lingua di insegnamento: 

INGLESE

Obiettivi formativi

Instruction aim

1) Knowledge and understanding
The course presents the principles of current wireless communication systems, with a rigorous approach and attention to an operational knowledge.

2) Applying knowledge and understanding
Students learn to:
- use the main channel models to analyze and design wireless communication systems
- apply the main diversity, MIMO and resource allocation schemes
- evaluate the performance of wireless communication systems
- select the most suitable solutions in order to meet specifics in terms of performance and cost, also accounting for possible application constraints.

Prerequisiti

Prerequisites

Knowledge of the following subjects is required:
- Probability, random variables and stochastic processes
- Signals, systems and Fourier transform
- Fundamentals of communication systems
- Basics of information theory.

Most of these subjects should be part of a typical first-level university curriculum in Information Engineering. However, the required knowledge can be achieved by passing the following first-year exams:
- Detection and Estimation
- Information Theory.
Students are warmly encouraged to pass these exams before attending the course.

Contenuti dell'insegnamento

Outline

Channel models. Channel capacity. Diversity techniques. Multiple-input multiple-output (MIMO) systems. Resource allocation techniques.

Programma esteso

Detailed outline

1. Channel models (22 h)
1.1 Review of radio propagation (2 h)
1.2 Path loss models (5 h)
Free space
Flat earth
Empirical models
Ray tracing
1.3 Shadowing model (3 h)
Lognormal distribution
Spatial correlation
Outage probability
1.4 Fading models (11 h)
Rayleigh
Rice
Nakagami
Multipath
1.5 MIMO channel models (1 h)

2. Performance of wireless systems (15 h)
2.1 Channel capacity (12 h)
Ergodic capacity with CSIR
Outage capacity
Ergodic capacity with CSIT
Power allocation strategies
High and low SNR regimes
2.2 Average error probability (3 h)
By direct integration
By the moment generating function
Alternate representation of the Gaussian tail function

3. Diversity techniques (13 h)
3.1 Time, frequency and space diversity (1 h)
3.2 Diversity combining (4 h)
Selection combining
Maximal ratio combining
Equal gain combining
3.3 Transmit diversity (2 h)
Maximal ratio transmission with CSIT (beamforming)
Transmit diversity with CSIR (Alamouti scheme)
3.4 Performance analysis of diversity systems (6 h)
Average error probability
Outage probability
Outage capacity
High and low SNR regimes

4. MIMO systems (17 h)
4.1 Singular value decomposition (3 h)
Singular values
Left and right singular vectors
Parallel decomposition of the MIMO channel
4.2 Capacity of the deterministic MIMO channel (5 h)
Capacity with CSIT
Water filling in the channel eigenmodes
Degrees of freedom and spatial multiplexing gain
Capacity with CSIR
4.3 Capacity of the fading MIMO channel (3 h)
Capacity achieving distribution with CSIR
High and low SNR regimes
MIMO outage capacity
4.4 Realistic MIMO systems (6 h)
MIMO diversity and beamforming
Diversity-multiplexing tradeoff
Overview of space-time codes and examples
Overview of multiuser MIMO

5. Introduction to OFDM (5 h)
5.1 Realization of OFDM (4 h)
Direct-form
DFT-form
Cyclic-prefixed
5.2 Resource allocation (1 h)
Single-carrier systems
OFDM systems

Bibliografia

Reference textbooks

Textbook:
A. Goldsmith, Wireless communications, Cambridge University Press, 2005.

Other useful books:
- D. Tse, P. Viswanath, Fundamentals of wireless communications, Cambridge University Press, 2005.
- A. Paulraj, R. Nabar, D. Gore, Introduction to space-time wireless communications, Cambridge Univ. Press, 2003.
- R. E. Ziemer, R. L. Peterson, Digital communications, 2nd edition, Prentice Hall, 2001.

Metodi didattici

Instruction methods

The course is organized in lectures, exercise and laboratory sessions. Homework assignments complement classroom activity.

A tentative schedule in terms of lecture hours might be:
Lectures 56
Exercise sessions 10
Laboratory sessions 6
TOTAL HOURS 72

Effective learning requires the following necessary steps:
- attend actively all the class, exercise and laboratory sessions
- active attendance requires that all the topics of each lecture or session are studied and understood with sufficient depth in order to be able to interact and ask questions during the next lectures
- solve the assigned exercise homework well before the scheduled session in order to fully appreciate the solution offered by the instructor
- complete and submit in due time all the homework to be graded, including exercise and laboratory items
- perform all the homework by yourself; it is allowed to have preliminary discussions with peers, but they must stop before you start working (copying from any source is not allowed, including peers, textbooks and the web: it will cause severe discipline to all the involved parties).

All the above steps are strictly necessary and none can be neglected to achieve a satisfactory preparation and pass the examination.

Modalità verifica apprendimento

Evaluation methods

Evaluation comprehensively based on:
- Level of active participation to classroom lectures, exercise and laboratory sessions (5%)
- Periodically assigned projects (10%)
- Midterm written exam (35%)
- Final exam including written and oral tests (50%).

Remedial evaluation (discouraged option):
Comprehensively based on written exam and oral exam, provided the laboratory activity requirements have been satisfactorily fulfilled during the course.

Altre informazioni

Other issues

The course relies upon a specific web site.