| 1. |
- Bengtsson, Mats, et al.
(författare)
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CELTIC CP5-026 WINNER+, D1.4 Initial Report on Advanced Multiple Antenna Systems
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This deliverable captures the first set of best innovative concepts identified in the field of Advanced Multiple Antenna Systems for potential inclusion into the WINNER+ system concept. The concepts consist of promising principles or ideas as well as detailed innovative techniques. For each concept, the associated benefits as well as the corresponding requirements on the system architecture and protocols, measurements and signalling, are considered. The document involves two main tracks: development of new advanced antenna schemes in the context of conventional cellular networks, and a study of coordinated multipoint transmission and reception, where multiple network nodes cooperate to enhance system performance.
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| 2. |
- Komulainen, Petri, et al.
(författare)
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CSI acquisition concepts for advanced antenna schemes in the WINNER+ project
- 2010
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Ingår i: Future Network and MobileSummit 2010 Conference Proceedings. - : IIMC International Information Management Corporation. - 9781905824182 ; , s. 5722348-
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Konferensbidrag (refereegranskat)abstract
- This paper summarizes four novel advanced antenna concepts explored in the framework of the WINNER+ project. The concepts are related to multiuser MIMO communication in cellular networks, focusing on the acquisition and application of channel state information (CSI) at the transmitter in time-division-duplex (TDD) mode. The concepts include new ideas for CSI modeling and sounding for the purposes of multiuser precoding, and methods for pilot signal design with the aim to support the estimation of different CSI quantities. Furthermore, a new relaying strategy for terminal-to-terminal communication is described. All the ideas are feasible for adoption into practical upcoming communication systems such as LTE-Advanced, and most of the proposed concepts have only a minor impact on standards.Our study indicates that the CSI at its best is not only about estimating the channel responses between different antenna pairs. What counts is the nature of the intended communication link as well as the form in which CSI is applied.
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| 3. |
- Svensson, Tommy, 1970, et al.
(författare)
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CELTIC CP5-026 WINNER+, D1.9 Final Innovation Report
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This deliverable is the final innovation report from the innovation workpackage in WINNER+. The document describes the latest innovations and their assessment as well as summarizes the innovations developed in the work package during the project. We analyze the suitability of these innovations as technology enablers for improving current systems, in particular IMT Advanced and beyond.
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| 4. |
- Tolli, Antti, et al.
(författare)
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Distributed Coordinated Transmission with Forward-Backward Training for 5G Radio Access
- 2019
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Ingår i: IEEE Communications Magazine. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0163-6804 .- 1558-1896. ; 57:1, s. 58-64
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Tidskriftsartikel (refereegranskat)abstract
- CoMP transmission and reception have been considered in cellular networks for enabling larger coverage, improved rates, and interference mitigation. To harness the gains of coordinated beamforming, fast information exchange over a backhaul connecting the cooperating BSs is required. In practice, the bandwidth and delay limitations of the backhaul may not be able to meet such stringent demands. These impairments motivate the study of cooperative approaches based only on local CSI that require minimal or no information exchange between the BSs. To this end, several distributed approaches are introduced for CB-CoMP. The proposed methods rely on the channel reciprocity and iterative spatially precoded over-the-air pilot signaling. We elaborate how F-B training facilitates distributed CB by allowing BSs and UEs to iteratively optimize their respective transmitters/receivers based on only locally measured CSI. The trade-off due to the overhead from the F-B iterations is discussed. We also consider the challenge of dynamic TDD where the UE-UE channel knowledge cannot be acquired at the BSs by exploiting channel reciprocity. Finally, standardization activities and practical requirements for enabling the proposed F-B training schemes in 5G radio access are discussed.
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| 5. |
- Tölli, Antti, et al.
(författare)
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Multiuser MIMO Systems
- 2011
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Ingår i: Mobile and Wireless Communications for IMT-Advanced and Beyond. - : John Wiley & Sons. - 9781119993216 - 9781119976431 ; , s. 89-120
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Bokkapitel (refereegranskat)abstract
- In Multiple Input Multiple Output (MIMO) communications, multiple antenna elements are employed both in the transmitter and the receiver, in order to obtain increased data rates or improved reliability compared to single-antenna transmission. In cellular systems, the Base Stations (BS) may operate in Single User (SU)-MIMO mode, i.e. to employ point-to-point transmission of data just for one multi-antenna User Equipment at a time. Alternatively, the BS can perform Multiuser (MU)-MIMO transmission, i.e. spatially multiplex data streams intended for different UEs that may be equipped with arbitrary numbers of antenna elements. The use of MU-MIMO mode offers potential system capacity gains especially when the BS employs a large antenna array. This chapter discusses various aspects of MIMO communications, with a special focus on the downlink direction of cellular systems. First, an overview of the fundamentals and existing techniques is given. Then, the MIMO related standards and standardization activities are described. Finally, some recent advances concerning MU-MIMO communications are addressed.
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