Receive combining vs. multistream multiplexing in multiuser MIMO systems
2011 (English)In: Communication Technologies Workshop (Swe-CTW), 2011 IEEE Swedish, IEEE Communications Society, 2011, 103-108 p.Conference paper (Refereed)
In single-user transmission, the receive antennas should preferably be used to enable multiplexing. The situation is different under multiuser transmission, where only the number of transmit antennas limits the multiplexing gain. The system therefore has the choice between sending one stream per scheduled user (i.e., combining receive antennas for diversity) or selecting a smaller number of users and multiplex multiple streams to each of them. This tradeoff is investigated herein, based on zero-forcing (with receive antenna combining) and block-diagonalization precoding which represents the two extremes. Based on asymptotic analysis and numerical examples, the unexpected conclusion is that each user only should receive one stream and use its antennas to achieve a receive combining gain. This is explained by zero-forcing having a stronger resilience towards spatial correlation and larger benefit from multiuser diversity. This fundamental result has positive implications for the design of multiuser systems as it reduces the hardware constraints at the user devices.
Place, publisher, year, edition, pages
IEEE Communications Society, 2011. 103-108 p.
IdentifiersURN: urn:nbn:se:kth:diva-52851DOI: 10.1109/Swe-CTW.2011.6082475ScopusID: 2-s2.0-83755169708ISBN: 978-1-4577-1877-9OAI: oai:DiVA.org:kth-52851DiVA: diva2:467955
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QC 201112212011-12-212011-12-202011-12-21Bibliographically approved