Synchronization and channel estimation in OFDM systems
1998 (English)Doctoral thesis, comprehensive summary (Other academic)
This thesis addresses synchronization and channel estimation in OFDM communication systems. The joint maximum likliehood estimator of symbol time and carrier frequency offsets for OFDM systems using a cyclic prefix is presented. This estimator exploits the redundancy introduced by the prefix and does not require extra pilot information. Signal models, accounting for pulse shaping, channel dispersion, or slowly changing synchronization errors and the associated maximum likliehood estimators are presented. Tracking synchronization of a multiuser OFDM system, which often has been questioned, is feasible using a scheme incorporating the above estimator concept. Furthermore, this thesis analyzes channel estimators based on the discrete Fourier transform. The symbol error rate of systems employing these estimators may experience an irreducible error floor. A novel channel estimation concept using singular-value decomposition of the channel attenuations is presented. These channel estimators, designed with suitably chosen fixed design parameters, combine low-complexity and high performance.
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 1998. , 158 p.
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544 ; 1998:32
Research subject Signal Processing
IdentifiersURN: urn:nbn:se:ltu:diva-18017Local ID: 664da890-7bc9-11db-8824-000ea68e967bOAI: oai:DiVA.org:ltu-18017DiVA: diva2:991023
Godkänd; 1998; 20061122 (haneit)2016-09-292016-09-29Bibliographically approved