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PHYSICAL LAYER MODELS AND TECHNIQUES FOR SOFTWARE RADIO

CODE 90139
ACADEMIC YEAR 2022/2023
CREDITS
  • 5 cfu during the 1st year of 10378 INTERNET AND MULTIMEDIA ENGINEERING(LM-27) - GENOVA
  • SCIENTIFIC DISCIPLINARY SECTOR ING-INF/03
    LANGUAGE English
    TEACHING LOCATION
  • GENOVA
  • SEMESTER 2° Semester
    MODULES This unit is a module of:
    TEACHING MATERIALS AULAWEB

    OVERVIEW

    Physically grounded channel modeling techniques for mobile communications.Effects of Hertzian channels on transmitted radio signals by using  deterministic and probabilistic models for single and multi-user mobile systems. Main modulation techniques for mobile comms. including CDMA and OFDM. Radio systems simulation models, including digital receiver structure and techniques. Software Defined and Cognitive Radio and seminars on advanced spectrum sensing in SDR. 

    AIMS AND CONTENT

    LEARNING OUTCOMES

    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

    AIMS AND LEARNING OUTCOMES

     To acquire knowledge on methods and techniques related to: 

     Mathematical models for radio transmission:

    Basic 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 

    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 

    Software radio architectures;. from software to cognitive radio 

    To acquire capabilities of programming by means of labs using matlab and wireless sw development tools

    TEACHING METHODS

    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. 

     

    SYLLABUS/CONTENT

    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

    RECOMMENDED READING/BIBLIOGRAPHY

    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

    TEACHERS AND EXAM BOARD

    LESSONS

    EXAMS

    EXAM DESCRIPTION

    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

    Students with learning disorders ("disturbi specifici di apprendimento", DSA) will be allowed to use specific modalities and supports that will be determined on a case-by-case basis in agreement with the delegate of the Engineering courses in the Committee for the Inclusion of Students with Disabilities

    ASSESSMENT METHODS

    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 amathematical probabilistic way signal transformations along the transmission and signal processing characteristics of modulation techniques  

    Exam schedule

    Date Time Location Type Notes
    11/01/2023 10:30 GENOVA Orale
    11/01/2023 10:30 GENOVA Scritto
    25/01/2023 10:30 GENOVA Orale
    25/01/2023 10:30 GENOVA Scritto
    08/02/2023 10:30 GENOVA Orale
    08/02/2023 10:30 GENOVA Scritto
    07/06/2023 10:30 GENOVA Orale
    07/06/2023 10:30 GENOVA Scritto
    21/06/2023 10:30 GENOVA Orale
    21/06/2023 10:30 GENOVA Scritto
    12/07/2023 10:30 GENOVA Orale
    12/07/2023 10:30 GENOVA Scritto
    26/07/2023 10:30 GENOVA Orale
    26/07/2023 10:30 GENOVA Scritto
    23/08/2023 10:30 GENOVA Orale
    23/08/2023 10:30 GENOVA Scritto
    13/09/2023 10:30 GENOVA Orale
    13/09/2023 10:30 GENOVA Scritto