Circuiti elettronici analogici L-A

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Transcript of Circuiti elettronici analogici L-A

A WAVELET BASED ALGORITHM FOR FILTERING RADAR/SONAR SIGNALS WITH LOW SIGNAL-TO-NOISE RATIOPresentazione Temi per Tesi di TIROCINIO e LAUREA
•Tirocinio: inserimento nel piano didattico, attività formative di tipologia F (9 crediti).
•Date importanti: Domande di ammissione per la Commissione di Tirocinio del Corso di Studio 30 settembre (novembre) 20 dicembre (febbraio 2009)
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OUTLINEOUTLINE
DEIS University of Bologna
)()(
• Fast Discrete Algorithm (FFT) • FFT: a rotation in function space • New basis functions sines and cosines • Not localized in time
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University of Bologna Italy
f(t) = f1(t) + f2(t) + f3(t)
University of Bologna Italy
DEIS University of Bologna
Wavelet TransformsWavelet Transforms
Continuous WT, ƒ(τ) finite energy c(a,b) is a resemblance index between ƒ(τ) and ψ(τ) located at a position b and scale a representing how closely correlated is the wavelet with a portion of the signal ψ(τ) is localized in frequency and in time
( ) ( ) RbRadt a
bttf a
University of Bologna Italy
1 21 2 , ,( ) sin(2 ) sin(2 ) [ ]n n n nf n f n f nτ π τ π τ α δ δ= + + +
f1= 500Hz f2=1 KHz τ=1/8000 s α=1.5 n1=250 n2=282
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t i tt Ce e e
π απαψ − − = −
Radar Signal: fc=64Mhz, Tr=50us, τ=6us, fcarrier=1Mhz
Tx Tx
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DENOISINGDENOISING
Italy
Problem: Radar/Sonar pulses detection and filtering in presence of strong noise and jamming signals
Solution: using a thresholding procedure performed on coefficients resulting from a Wavelet Transform analysis
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samples 100 200 300 400 500 600 700 800 900 1000
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se ns
or s
samples 100 200 300 400 500 600 700 800 900 1000 1100
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DEIS University of Bologna
DEIS University of Bologna
• Classificazione del tessuto • Feature extraction e feature selection • Classificatori statistici lineari / non lineari
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• Algoritmi per classificazione e decisione
•Necessario studiare il modello di segnale • Statistico / Deterministico • Identificazione componenti
Analisi
Estrazione
Classificazione
Segnale
Componenti
Features
DEIS University of Bologna
Classificatori statistici lineari / non lineari
• Separazione di gruppi di regioni sane e malate nello spazio dei parametri
DEIS University of Bologna
Definition of algorithms
Applications: Biomedical Imaging Enhancement, Tissues properties investigation…
“ If you steal from one author it’s plagiarism, if you steal from many it’s research” W.Mizner
DEIS University of Bologna
Data Data compressioncompression
•Fast Discrete algorithms
• WT renders sparse large classes of functions i.e. few noticeable coefficients many negligible
• Ex. Standard JPEG 2000
DEIS University of Bologna
Research topics: Research topics: Music Signal AnalysisMusic Signal Analysis
Definition of algorithms Hardware implementations on FPGA board, on DSP, or Full Custom Design. Applications: Music Information Retrieval, Sound Synthesis and Analysis…
“ La musique est une mathématique mystérieuse dont les élément partecipent de l’infini” C.Debussy
DEIS University of Bologna
Easy to implement: fast algorithms
Well suited for many applications: such as non-stationary analysis or data compression
DEIS University of Bologna
Italy
“Des chercheurs qui cherchent, on en trouve. Des chercheurs qui trouvent, on en cherche.”
de Gaulle
Professors: Guido Masetti, Nicolò Speciale. (Sistemi Integrati per l’Analisi Spettrale LS)
Post Doc: Luca De Marchi, Marco Messina
PhD Students: Martino Alessandrini, Emanuele Baravelli, Salvatore Caporale, Simona Maggio, Alessandro Palladini, Nicola Testoni.
Contact: [email protected]
Students PublicationsStudents Publications
FPGA Implementation of QCWT Based Algorithm for filtering Low SNR Signals, A.Marcianesi, R.Padovani, N.Speciale, N.Testoni, G. Masetti, 2003. Wavelet-based Algorithms for Speckle Removal from B-Mode Images, S. Caporale, A. Palladini, L. De Marchi, N. Speciale, G. Masetti, 2004. Wavelet-based Deconvolution Algorithms Applied to Ultrasound Images, S. Maggio, N. Testoni, L. De Marchi, N. Speciale, G. Masetti, 2005. RLS Adaptive Filters for Ultrasonics Signal Deconvolution, M. Alessandrini, L. De Marchi, N. Speciale,2007
DEIS University of Bologna
Wavelet Transforms
Analisi di segnale
Research topics: Ultrasounds
Conclusions