Sinteza sustava s minimalnim izobličenjem vremenskog odziva

doctoral thesis

• Title (english): Synthesis of systems with minimum distortion of time-domain response
• Author: Goran Molnar
• Mentor: Mladen Vučić (mentor)
• Committee member: Branko Jeren (predsjednik povjerenstva)
• Committee member: Nino Stojković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2010-03-29, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

U sintezi sustava od kojih se traže mala izobličenja vremenskog odziva, zahtjevi mogu biti dani u frekvencijskoj ili u vremenskoj domeni. Pristup u frekvencijskoj domeni je uobičajen jer su postupci u toj domeni jednostavniji. S druge strane, bolji rezultati mogu se očekivati sintezom u vremenskoj domeni. U tom slučaju, potrebno je odabrati odgovarajući model pobudnog signala. Zahtjevi na sustav obično su dani unutar određenog frekvencijskog podruèja. Stoga je u disertaciji predložen model frekvencijski ograničene pobude temeljene na sinc pulsu nulte faze. Ovaj puls jednoliko pobuđuje sve komponente sustava unutar zadanog frekvencijskog područja. Korištenjem odziva na sinc puls, definirane su nove mjere izobličenja temeljene na simetriji valnog oblika, te maksimumu odziva. Optimiranjem ovih mjera dobivene su nove klase sustava koji osiguravaju minimalno izoblièenje vremenskog odziva. Sinteza takvih sustava ilustrirana je na primjerima korektora niskopropusnih i pojasnopropusnih filtara, sustava s konstantnim kašnjenjem, te Hilbertovih transformatora. Nadalje, u sklopu sinteze u vremenskoj domeni razmatrani su i sustavi sa zadanim impulsnim odzivom. Opisana je učinkovita i robusna metoda za njihovo projektiranje. Metoda koristi iterativan postupak koji se temelji na optimizaciji linearne funkcije nad prostorom ogranièenim stošcima drugog reda. Metoda je primijenjena u sintezi valićnih filtara.

Abstract (english)

In the design of systems with minimum time-domain distortion, requirements can be specified in the frequency or in the time domain. The frequency domain approach is common since the design procedures are simpler. On the other hand, better results are expected using the time-domain synthesis. In that case, an appropriate model of system's input signal should be chosen. The requirements set on the system are usually given within some finite band of interest. In this thesis, the frequency-selective model of the input signal is proposed. The model is based on the zero-phase sinc pulse. This pulse uniformly excites the system at all frequencies within the prescribed band. By using the response to sinc pulse, new measures of time-domain distortion are defined, which are based on the symmetry and on the maximum of the response. These measures are suitable for optimization based design, which is used to obtain new classes of systems ensuring minimum distortion of time-domain response. Several design examples are given, including the design of lowpass and bandpass equalizers, constant-delay systems, and Hilbert transformers. Furthermore, the time-domain synthesis of systems having a desired impulse response is also considered. An efficient and robust method for the design of such systems is described. The method involves the iterative procedure based on the second-order cone programming. The features of the method are illustrated through the design of wavelet filters.

• Keywords: sinc puls; odziv na sinc puls; simetrija odziva; maksimum odziva; mjera izobličenja; impulsni odziv; optimizacija; Hilbertov transformator; filtar; korektor
• Keywords (english): sinc pulse; response to sinc pulse; symmetry of time-domain response; maximum of time-domain response; measure of time-domain distortion; impulse response; optimization; Hilbert transformer; filter; equalizer
• Language: croatian
• URN:NBN: urn:nbn:hr:168:206188
• Promotion: 2010
• Study programme: Title: Doctoral study programme "Electrical Engineering and Computing"; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, po-dručje tehničkih znanosti (doktor/doktorica znanosti, po-dručje tehničkih znanosti)
• Type of resource: Text
• Extent: 100 str. : graf. prikazi
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-03-19 09:59:07