Kooperativna automatska klasifikacija signala po tipu modulacije korišćenjem mreže senzora
Cooperative Automatic Modulation Classification by Using Multiple Sensors
Author
Marković, Goran
Mentor
Dukić, MiroslavCommittee members
Ivaniš, Predrag
Marković, Goran

Erić, Miljko
Drajić, Dejan

Metadata
Show full item recordAbstract
U okviru disertacije razmatran je problem kooperativne automatske klasifikacije
signala po tipu primenjene modulacije (Automatic Modulation Classification, AMC)
koja se ostvaruje korišćenjem mreže prostorno distribuiranih senzora. Pri tome, izvršena
je detaljna analiza postojećih rešenja sa stanovišta mogućnosti njihove primene u
realnim uslovima rada koje definišu: nekooperativna priroda izvođenja AMC postupka,
različiti prostorni raspored senzora, i realno propagaciono okruženje koje karakterše
pojava fedinga usled višestruke propagacije. Sprovedenom numeričkom analizom
utvrđeno je da se primenom ranije predloženih (postojećih) rešenja za kooperativnu
AMC sa centralizovanom fuzijom odluka ili distribuiranim procesiranjem ne može
ostvariti uspešna klasifikacija za najveći broj analiziranih realnih scenarija primene.
Na osnovu uočenih nedostataka postojećih rešenja, koja ispoljavaju izuzetno veliku
osetljivost na problem neusklađenosti referentnih vrednosti koje se koriste u procesu
fu...zije, predložen je alternativni koncept fuzije podataka. U ovom novom konceptu,
umesto donošenja nezavisnih lokalnih odluka u senzorima mreže, i njihovog naknadnog
kombinovanja, za potrebe fuzije koriste se vrednosti onih veličina na osnovu kojih se
obavlja AMC, odnosno donose odluke u procesu klasifikacije. Na osnovu predloženog
koncepta fuzije podataka definisan je određen broj novih metoda fuzije, pri čemu je kao
osnov za razvoj ovih rešenja izabran AMC postupak na osnovu kumulanata četvrtog
reda. Sprovođenjem numeričke analize, putem sveobuhvatnog procesa Monte-Carlo
simulacija, pokazano je da se putem primene ovde predloženih metoda fuzije ostvaruju
znatno bolje AMC performanse u poređenju sa postojećim rešenjima, i to kako za
idealizovane scenarije primene tako i za ovde posebno razmatrane realne scenarije
primene kooperativne AMC. Pri tome, najveći dobici ostvareni su u slučaju radio kanala
u kojima se javlja frekvencijski-selektivan feding, dok su najlošiji rezultati dobijeni u
slučaju radio kanala sa ravnim fedingom.
Iz tog razloga, predložen je postupak združene korekcije kumulanata na nivou
mreže, na osnovu koga su značajno poboljšanje performanse za realne scenarije primene
kooperativne AMC. Osim toga, u cilju smanjivanja problema neusklađenosti referentnih
veličina predložen je originalni postupak dvostepene hibridne fuzije, u kome se u prvom...
The main subject of the study portrayed in this thesis, was the proper formulation
of the cooperative automatic modulation classification (AMC) solutions by using the
spatially dispersed and networked sensors. A detailed analysis of the so far proposed
solutions was conducted in order to evaluate their performances under the realistic
application conditions defined with: the inherent uncooperativeness of the AMC
process, different spatial distributions of sensors, and realistic propagation conditions
characterized by the multipath fading channels. Through the comprehensive numerical
analysis, it is shown that by applying the previously proposed centralized decision
fusion and distributed processing under the conditions of here analyzed realistic
application scenarios only a very low AMC performance can be achieved.
Based on the detected deficiencies of the existing solutions for the cooperative
AMC, which exhibit extremely high sensitivity to the problem of mismatched reference
values ...that are used in decision fusion process, we have formulated a new alternative
data fusion concept. In this new concept, instead of making the individual decisions at
the each sensor and performing their combination, we apply the data fusion on the very
features (cumulants) that are used in the classification process. In line with this new
proposed data fusion concept, several new fusion methods are proposed by using the
AMC algorithm based on the fourth-order cumulant. By further numerical analysis
through the comprehensive Monte-Carlo trials, it was proven that here proposed
cooperative AMC solutions greatly outperform the existing ones for the idealized and
also for here considered realistic application scenarios. Thereby, the highest AMC
performance gains were achieved for the frequency-selective fading channels, while the
worst result were obtained for the flat fading channels.
Therefore, additional joint cumulant estimation correction method was proposed,
and it is proven that significant AMC performance enhancements are achieved by
applying this solution in the realistic application scenarios. Also, in order to suppress
the negative effects of using mismatched references, that is found in practice, a novel
hybrid two-stage fusion (HyTSF) was proposed, with the data fusion applied in the first
and the decision fusion in the second step of the proposed procedure. Through the...
Faculty:
Универзитет у Београду, Електротехнички факултетDate:
08-04-2014Projects:
- Advanced Techniques for Efficient Use of Spectrum in Wireless Systems (RS-32028)
- Research and development of robust transmission systems for corporative networks (RS-32037)