PHYSICAL LAYER MODELS AND TECHNIQUES FOR SOFTWARE RADIO

PHYSICAL LAYER MODELS AND TECHNIQUES FOR SOFTWARE RADIO

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iten
Ultimo aggiornamento 09/05/2021 11:13
Codice
90139
ANNO ACCADEMICO
2021/2022
CFU
5 cfu al 1° anno di 10378 INTERNET AND MULTIMEDIA ENGINEERING (LM-27) GENOVA
SETTORE SCIENTIFICO DISCIPLINARE
ING-INF/03
LINGUA
Inglese
SEDE
GENOVA (INTERNET AND MULTIMEDIA ENGINEERING)
periodo
2° Semestre
moduli
Questo insegnamento è un modulo di:
materiale didattico

OBIETTIVI E CONTENUTI

OBIETTIVI FORMATIVI

Mathematical models for radio transmission: (20) Radio Channel models; Free space model; Probabilistic rain model; Multipath time-variant general statistical model (Time variant pulse response, First order channel models (Fading (Rayleigh, Rice, Nagakami)); Second order models. Radio transmission system models: Frequency selectivity and temporal fading; Slow and fast fading; Diversity transmission (frequency, time, space); Wideband transmissions as frequency selective channels; Channel models and rake receivers. Wideband Digital radio transmission: systems and techniques (20): Multiple Access techniques overview; Wideband modulations: Spread Spectrum: General concepts, Direct Sequence Spread Spectrum and CDMA, Orthogonal Frequency Division Modulation (OFDM) Software and Cognitive Radio (10) : Software radio architectures;. from software to cognitive radio

OBIETTIVI FORMATIVI (DETTAGLIO) E RISULTATI DI APPRENDIMENTO

La frequenza e la partecipazione attiva alle attività formative proposte (lezioni frontali e attività in laboratorio) e lo studio individuale consentiranno allo studente di

-Conoscere i modelli matematici e simulativi dei canali radio di tipo deterministico e probabilistico per poter descrivere in modo analitico le distorsioni introdtte nella trasmissione di un segnale wireless.  

- Conoscere  le principali tecniche di modulazione multiutente di tipo wideband usate nei sistemi wireless e le relative architetture di trasmettitori e ricevitori 

- Conoscere  i fondamenti dei sistemi software radio 

-Conoscere e acquisire  capacità di uso di strumenti di programmazione e di simulazione su calcolatore di sistemi di  trasmissione di segnali radio ed essere in grado di adattare i parametri dei sistemi stessi a casi di studio di canali i cui modelli matematici siano noti.

- Acquisire la capacità di analizzare, commentare  e descrivere i risultati  di simulazione ottenuti applicando quanto appreso a livello teorico ad esperienze di progettazione

Modalità didattiche

The course is divided in two parts.

Lectures in frontal teaching modality presented together with slides will aim at describing the theroretical concepts and the techniques. Such lectires will cover 40 hours and can be recorded and made available on those channels recommended by Univeristy of Genova.

The second part is done within a laboratory carried on by an expert of the field and will involve application of programs in Matlab and GNU radio framework that correspond to theories and techniqeus shown at lectures. Students will be required to present a short report at the end of each lab experience.

10 Lab experiences are planned and will help students to link theoretical concepts to practical laboratory programming experiences. 

PROGRAMMA/CONTENUTO

 

1 Introduction:

Multiple Access techniques: FDMA, TDMA, FD-TDMA

CDMA. Comparison with FD/TDMA.

2. Wireless channel models

Circuital model for radio links

Free space model.

 Isotropic and directional antennas.

Transmitted Power 3D propagation

Deterministic and statistical channel models.

Additional loss from earth surface propagation, LOS; atmosphere effects

Statistical attenuation channel model: rain and shadowing

Multipath channel model

Equivalent low pass signal representation

time variant pulse response,

Rayleigh, Rice, Nagakami fading models

Second order and first order models.

Fading models; multipath Intensity profile and delay spread, coherence bandwidth.

Time variant channel model: Cross correlation channel model time-frequency spaced.

Doppler power spectrum, Doppler spread and time coherence

Frequency not selective channel model

Spread factor

Frequency selective channels. Tapped delay line model

Rake receiver for frequency selective channels.

 

2. Wideband modulation techniques for wireless channels

Architectures Spread spectrum: features and modulation technique design objectives

Direct sequence Spread spectrum and Frequency Hopping as Spread spectrum techniques

Multiple user interference: Gaussian and not white noise case.

Multiple user receiver for CDMA over wireless channels: MAP and maximum likelihood receiver

Multiple user interference in CDMA systems: MUI approximation as Gaussian and white noise

Multiuser DS CDMA detectors: optimal and Viterbi detector

Suboptimal multiuser detectors for DS-CDMA: conventional, Decorrelating and MMSE receivers

DS CDMA Kasami sequences

Coarse acquisition methods: Matched filter correlator, Sequential search, RASE

Tracking: DLL, Tau Dither loop

OFDM overview and signal description. Multiple carriers and orthogonality

OFDM: bandwidth and OFDM analog transmitter scheme

OFDM digital modulator and demodulator using DFT Digital spreading for DS SS; PN Gold sequences

               OFDM: Guard interval for multipath channels OFDM performances in white noise: Equalization

OFDM:, differential modulation, interleaving, effects of frequency and phase eroors

OFDM synchronization. phase and time disalignments

 

3. Software Defined Radio

History of Radio;

SDR definition.

From software capable to cognitive radio

SDR: Base station and terminal architecture

ADC and DAC, Down and upconverters, Processors for SDR

 Software Communications Architecture

 Super Heterodyne, Direct conversion Bandpass Sampling

 

4. Laboratory experiences          

Introduction to Matlab for Physical layer radio models

AM modulation using GNU radio environment

Multipath Channel model

Spectrum sensing for Cognitive Radio

Direct sequence Spread spectrum

CDMA over wireless channels

OFDM signal and transmitter

OFDM in multipath environments

Presentation of possible thesis topics

TESTI/BIBLIOGRAFIA

Slides of all lectures will be made available on Aulaweb. Recording of lessons if available will be also provided.

Books and research papers that can help the student to integrate concepts described during frontal activity are here provided and can be integrated during the year.  

G. L. Stuber, Principles of Mobile Communication, Kluwer Academic Publishers, New York, 1996

T. Rappaport, “Wireless Communications: Principles and Practice, 2nd Edition”, Prentice Hall, USA, 2001

J.G.Proakis, “Communication Systems Engineering, 2nd Edition”, Prentice Hall, New Jersey, 2001

Cognitive Radio, Software Defined Radio, and Adaptive Wireless Systems, Ed.,Hüseyin Arslan, Springer, Netherlands, 2007

DOCENTI E COMMISSIONI

LEZIONI

Modalità didattiche

The course is divided in two parts.

Lectures in frontal teaching modality presented together with slides will aim at describing the theroretical concepts and the techniques. Such lectires will cover 40 hours and can be recorded and made available on those channels recommended by Univeristy of Genova.

The second part is done within a laboratory carried on by an expert of the field and will involve application of programs in Matlab and GNU radio framework that correspond to theories and techniqeus shown at lectures. Students will be required to present a short report at the end of each lab experience.

10 Lab experiences are planned and will help students to link theoretical concepts to practical laboratory programming experiences. 

ESAMI

Modalità d'esame

The exam for this module is oral. 

In case of remote exam is necessary or mandatory exam will be oral and done by using Teams platform.

Otherwise, exam will be in presence  In that case, upon request, the oral exam can be divided in two parts: a written pre-assessment based on a set of questions to be answered in one hour followed by a oral discussion.

The written part can be substituted by a lab on line exercise in sessions immediately after the end of the course lessons. 

The oral discussion will cover all the course program. A first set of questions   will be oriented to evaluate knowledge and capabilities of the student on modeling and choosing parameters for a wireless channels for a generic wireless transmission system. The second part of the exam will assess wideband modulation techniques and characteristics of Software Defined Radio architectures. 

Official exam dates are provided by course calendar.   In addition, it is possible to schedule additional exams on per-appointment basis, depending on a number of interested students and professor's availability.

In both cases (official and unofficial exam dates), if you wish to attend an exam, please send an e-mail to: 
- Carlo.Regazzoni@unige.it

at least one week before the exam.

Modalità di accertamento

 Exam aims at assessing the following aspects about acquired student's knowldge and capabilities: 

Level of Knowledge acquired with respect to theories and methods presented in course lectures

Level of Capabilities when selecting appropriate parameters and comparing alternative choices for different wireless channel models and modulation techniques 

  Knowledge and capabilities will not be centered on mnemoninc listing of concepts, methods  and formulas, but on the capability to describe also in a mathematical probabilistic way signal transformations along the transmission and signal processing characteristics of modulation techniques