Impact of non-orthogonal training on performance of downlink base station cooperative transmission
Författare
Summary, in English
Base station (BS) cooperative transmission is a promising technique to improve spectral efficiency of cellular systems, using which the channels become asymmetric in average gain. In this paper, we study the impact of the asymmetric channel gains on the performance of coherent cooperative transmission systems, when minimum mean square error (MMSE) and least square (LS) channel estimators are applied for jointly estimating the channel state information (CSI) under non-orthogonal training. We first derive an upper bound of rate loss caused by both channel estimation errors and CSI delay. We then analyze the mean square errors of the MMSE and LS estimators under both orthogonal and non-orthogonal training, which finally reveals the impact of different kinds of training on the precoding performance. It is shown that non-orthogonal training for the users in different cells leads to minor performance degradation for the MMSE channel estimator assisted downlink precoding. The performance degradation induced by channel estimation errors
is almost independent of the user’s location. By contrast, the performance loss caused by CSI delay is more
severe for users located at the cell center than that for users located at the cell edge. Our analysis is verified
via simulation results.
is almost independent of the user’s location. By contrast, the performance loss caused by CSI delay is more
severe for users located at the cell center than that for users located at the cell edge. Our analysis is verified
via simulation results.
Avdelning/ar
Publiceringsår
2011
Språk
Engelska
Sidor
4633-4639
Publikation/Tidskrift/Serie
IEEE Transactions on Vehicular Technology
Volym
60
Issue
9
Fulltext
- Available as PDF - 335 kB
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Dokumenttyp
Artikel i tidskrift
Förlag
IEEE - Institute of Electrical and Electronics Engineers Inc.
Ämne
- Electrical Engineering, Electronic Engineering, Information Engineering
Status
Published
Forskningsgrupp
- Electromagnetic theory
- Radio Systems
ISBN/ISSN/Övrigt
- ISSN: 1939-9359