Procjena kanala u frekvencijskoj domeni u komunikacijskim mrežama koje koriste OFMD

doctoral thesis

• Title (english): Frequency domain channel estimation in OFMD based communication networks
• Author: Mario Bogdanović
• Mentor: Alen Bažant (mentor)
• Committee member: Alen Bažant (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Telecommunications); Zagreb
• Defense date and country: 2016, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering; Telecommunications and Informatics
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

Procjena kanala jedan je od najvažnijih problema u prijenosnim sustavima baziranim na OFDM-u (PLC, bežični sustavi) zbog negativnog utjecaja prigušenja na prijenos signala i interferencije signala s okolnim šumom. Primarna hipoteza rada je da se pravilnom kombinacijom češljastog i blokovskog tipa procjene kanala metodom najmanjih kvadrata (LS metoda) pomoću pilotskih simbola poboljša učinkovitost LS metode procjene kanala u mrežama koje koriste prijenosnu tehniku OFDM u smislu smanjenja količine pogrešno prenesenih podataka te smanjenja ukupne korištene prijenosne snage. U radu je opisano razvijanje nove LS metode procjene kanala za mreže koje koriste prijenosnu tehniku OFDM te određivanje optimalne snage pilotskih podnosioca predložene metode. U sklopu navedenog, kako bi evaluirali razvijenu metodu, provedena je simulacijska usporedba predložene metode s postojećom LS metodom u smislu poboljšanja/pogoršanja kvalitete prijenosa podataka, računalne složenosti, uštede energije te uvjeta prilagođavanja. Dobivenim simulacijskim rezultatima pokazano je poboljšanje učinkovitosti predložene LS metode u smislu poboljšane kvalitete prijenosa podataka te uštedu emitirane snage pilotskih simbola (pa tako i ukupne snage) u odnosu na postojeće LS metode.

Abstract (english)

Channel estimation is one of the most important issues in the transmission systems based on Orthogonal Frequency Division Multiplexing (OFDM) scheme. The primary hypothesis was that the proper combination of comb and block-type of pilot symbol insertion can improve efficiency of Least Squares (LS) channel estimation method using the pilot symbols on networks using OFDM transmission technique. The expected improvement, in the way of the efficiency, was the reducing of amount of incorrectly transmitted data, and reduced pilot symbol power and the total used transmission power. This thesis gives a detailed presentation of new proposed LS channel estimation method in OFDM based communication networks and optimal power distribution on pilot subcarriers in the proposed LS, frequency based, channel estimation method. Within this, to evaluate the developed method, the simulation comparison of the proposed method with the existing LS method in terms of improving/worsening of the quality of data transfer, computing complexity, energy savings, and the conditions of adjustment is made. Obtained simulation results shown improving the efficiency of the proposed LS methods in terms of improved quality of data transmission and save the transmitted power of pilot symbols (and thus total power) compared to existing LS methods.

• Keywords: OFDM; procjena prijenosnog kanala; procjena metodom najmanjih kvadrata; optimalna snaga podnosioca
• Keywords (english): Orthogonal Frequency Division Multiplexing (OFDM); channel estimation; Least Squares estimation; pilot subcarrier power allocation
• Language: croatian
• URN:NBN: urn:nbn:hr:168:034619
• Study programme: Title: Electrical Engineering and Computing; Study programme type: university; Study level: postgraduate; Academic / professional title: Doktor znanosti elektrotehnike i računarstva (Doktor znanosti elektrotehnike i računarstva)
• Type of resource: Text
• Extent: 98 str. ; 30 cm.
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-04-12 13:19:14