AbstractsEngineering

Filter Bank Multi-Carrier Modulation

by Frédéric De Poret




Institution: KTH Royal Institute of Technology
Department:
Year: 2015
Keywords: Engineering and Technology; Electrical Engineering, Electronic Engineering, Information Engineering; Other Electrical Engineering, Electronic Engineering, Information Engineering; Teknik och teknologier; Elektroteknik och elektronik; Annan elektroteknik och elektronik; Master of Science in Engineering - Electrical Engineering; Civilingenjörsexamen - Elektroteknik
Record ID: 1371547
Full text PDF: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-168383


Abstract

During the last years, multi-carrier modulations have raised a particular interest due to their high spectral efficiency and the possible assumption of flat frequency fading. The most broadly used multi-carrier modulation is the CP-OFDM. It allows very simple equalizations methods and MIMO transcoders which keep orthogonality between carrier waveforms. However, it does not allow any waveform flexibility and is not fully spectrally efficient. Due to the low waveform flexibility its performance is quite limited in scenarios like the frequency division multiple accesses. In order to improve its performance in this case, it is important to have a multi-carrier modulation with the possibility to have a waveform well localized in time and frequency. Grey analysis shows that the only way to get both full spectral efficiency and waveforms well localized in both time and frequency domain is to give up the orthogonality in the complex field. Using filter bank multi-carrier (FBMC) with Offset-QAM (OQAM) is one combination which achieves this task. In this thesis, we study this modulation, how it is possible to efficiently modulate and demodulate it but also the transcoder (pre-coder, equalizer or both) that can be used when transmitting through multi-tap and MIMO channels. Another modulation, based on FBMC with OQAM, cyclic offset-QAM (COQAM) tries to make a tradeoff between spectral efficiency and simplicity of the equalization and transcoding methods. In this thesis, FBMC based modulation schemes are tested through different scenario: unsynchronized multi-users, unsynchronized uplink, multitaps channels, SIMO, MISO and MIMO channels. COQAM is tested with some of these scenario when it is considered as relevant to test it. ; Under senare år har intresset för multi-carrier modulering ökat på grund av dess höga spektrumeffektivitet under antagandet om slät frekvensfäding. Den vanligaste multicarrier moduleringen i praktiken är CP-OFDM. Denna modulering tillåter användning av enkla equalizeringsmetoder och MIMO transkodare vilket behåller ortogonalitet mellan vågformerna. Däremot tillåter den inte någon flexibilitet i val av vågform och är inte heller helt spektraleffektiv. På grund av inflexibilitet i val av vågform är dess prestanda begränsad under till exempel frekvensmultiplexing (FDMA). För att förbättra prestandan hos CP-OFDM ¨ar det viktigt att ha en modulering med möjlighet att en vågform begränsad i både tid och frekvens. Grey analys visar att det enda sättet att uppnå full spektrumeffektivitet, i kombination med vågformer som är väl begränsade i både tid och frekvens, är att ge upp ortogonaliteten i komplexa fältet. Filter Bank Multi-Carrier (FBMC) med Offset-QAM (OQAM) är ett alternativ som uppnår detta. I den här avhandlingen studeras just denna modulation, hur det är möjligt att göra effektiv modulation och…