Multi-User MIMO Receiver Processing for Time-Varying Channels
2011 (English)In: Wireless Communications Over Rapidly Time-Varying Channels / [ed] Franz Hlawatsch and Gerald Matz, Elsevier Academic Press , 2011, 337-374 p.Chapter in book (Other academic)
Wireless broadband communications for mobile users at vehicular speed is the cornerstone of future fourth-generation systems. This chapter deals with joint iterative channel estimation and multiuser detection for the uplink of a multicarrier (MC) code division multiple access (CDMA) system. MCCDMA is based on orthogonal frequency division multiplexing (OFDM) and employs spreading sequences in the frequency domain. Several complexity reduction methods are discussed enabling a real-world low-complexity implementation, such as an iterative approximation of the maximum a posteriori (MAP) detector in combination with a reduced-rank model for the time-varying channel. This reduced-rank channel model projects the time-varying channel onto a subspace spanned by band-limited and time-concentrated prolate spheroidal sequences. Two different multiuser detection methods are investigated: First, the Krylov subspace method is used to reduce the complexity of multiuser detection using LMMSE filtering. Second, sphere decoding is investigated and a sphere decoder is developed that exploits the reduced-rank channel model for complexity reduction.
Place, publisher, year, edition, pages
Elsevier Academic Press , 2011. 337-374 p.
IdentifiersURN: urn:nbn:se:kth:diva-46476DOI: 10.1016/B978-0-12-374483-8.00008-XScopusID: 2-s2.0-84882302509ISBN: 978-0-12-374483-8OAI: oai:DiVA.org:kth-46476DiVA: diva2:453754
QC 201111152011-11-032011-11-032014-08-21Bibliographically approved