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Spatial Separation of Closely-Located Users in Measured Massive MIMO Channels

Flordelis, Jose LU ; Gao, Xiang LU ; Dahman, Ghassan LU ; Rusek, Fredrik LU ; Edfors, Ove LU and Tufvesson, Fredrik LU (2016) In IEEE Transactions on Wireless Communications
Abstract (Swedish)
We investigate the ability of massive multiple-input
multiple-output (MIMO) systems to spatially separate signals sent
to users located close to each other in line-of-sight (LOS) prop-
agation conditions. The analysis is based on fully-synchronous
channel measurements of 9 single-antenna users conducted in
both indoor and outdoor environments at 2.6 GHz. The users are
confined to a small area and communicate concurrently with a
128-antenna base station (BS). We examine the channel condition
number, achievable sum rates and number of simultaneously
served users in various setups and for various numbers of an-
tennas and precoding schemes. Our results indicate that massive
MIMO with 128 antennas... (More)
We investigate the ability of massive multiple-input
multiple-output (MIMO) systems to spatially separate signals sent
to users located close to each other in line-of-sight (LOS) prop-
agation conditions. The analysis is based on fully-synchronous
channel measurements of 9 single-antenna users conducted in
both indoor and outdoor environments at 2.6 GHz. The users are
confined to a small area and communicate concurrently with a
128-antenna base station (BS). We examine the channel condition
number, achievable sum rates and number of simultaneously
served users in various setups and for various numbers of an-
tennas and precoding schemes. Our results indicate that massive
MIMO with 128 antennas and zero forcing (ZF) precoding can
simultaneously serve all 9 users with low transmit power values,
and with low sum rate losses relative to optimal dirty-paper
coding (DPC). This leads us to conclude that users can be spatially
separated with massive MIMO, also in tricky scenarios such
as the one studied here. However, our results do not support
the use of maximum ratio transmission (MRT) precoding for
spatial multiplexing of users in the scenarios considered. We
also study the physical propagation mechanisms that facilitate
spatial separation of users, and the role of antenna polarization
at the BS. Our findings are relevant to the design of future 5G
communication systems. (Less)
Abstract
We investigate the ability of massive multiple-input multiple-output (MIMO) systems to spatially separate signals sent to users located close to each other in line-of-sight (LOS) propagation conditions. The analysis is based on fully-synchronous channel measurements of 9 single-antenna users conducted in both indoor and outdoor environments at 2.6 GHz. The users are confined to a small area and communicate concurrently with a 128-antenna base station (BS). We examine the channel condition number, achievable sum rates and number of simultaneously served users in various setups and for various numbers of antennas and precoding schemes. Our results indicate that massive MIMO with 128 antennas and zero forcing (ZF) precoding can simultaneously... (More)
We investigate the ability of massive multiple-input multiple-output (MIMO) systems to spatially separate signals sent to users located close to each other in line-of-sight (LOS) propagation conditions. The analysis is based on fully-synchronous channel measurements of 9 single-antenna users conducted in both indoor and outdoor environments at 2.6 GHz. The users are confined to a small area and communicate concurrently with a 128-antenna base station (BS). We examine the channel condition number, achievable sum rates and number of simultaneously served users in various setups and for various numbers of antennas and precoding schemes. Our results indicate that massive MIMO with 128 antennas and zero forcing (ZF) precoding can simultaneously serve all 9 users with low transmit power values, and with low sum rate losses relative to optimal dirty-paper coding (DPC). This leads us to conclude that users can be spatially separated with massive MIMO, also in tricky scenarios such as the one studied here. However, our results do not support the use of maximum ratio transmission (MRT) precoding for spatial multiplexing of users in the scenarios considered. We also study the physical propagation mechanisms that facilitate spatial separation of users, and the role of antenna polarization at the BS. Our findings are relevant to the design of future 5G communication systems. (Less)
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IEEE Transactions on Wireless Communications
publisher
IEEE--Institute of Electrical and Electronics Engineers Inc.
ISSN
1536-1276
language
English
LU publication?
yes
id
7078f547-10fc-4f0f-a196-42faefe8bd29
date added to LUP
2016-08-22 14:45:16
date last changed
2016-08-24 10:43:21
@article{7078f547-10fc-4f0f-a196-42faefe8bd29,
  abstract     = {We investigate the ability of massive multiple-input multiple-output (MIMO) systems to spatially separate signals sent to users located close to each other in line-of-sight (LOS) propagation conditions. The analysis is based on fully-synchronous channel measurements of 9 single-antenna users conducted in both indoor and outdoor environments at 2.6 GHz. The users are confined to a small area and communicate concurrently with a 128-antenna base station (BS). We examine the channel condition number, achievable sum rates and number of simultaneously served users in various setups and for various numbers of antennas and precoding schemes. Our results indicate that massive MIMO with 128 antennas and zero forcing (ZF) precoding can simultaneously serve all 9 users  with low transmit power values, and with low sum rate losses relative to optimal dirty-paper coding (DPC). This leads us to conclude that users can be spatially separated with massive MIMO, also in tricky scenarios such as the one studied here. However, our results do not support the use of maximum ratio transmission (MRT) precoding for spatial multiplexing of users in the scenarios considered. We also study the physical propagation mechanisms that facilitate spatial separation of users, and the role of antenna polarization at the BS. Our findings are relevant to the design of future 5G communication systems.},
  author       = {Flordelis, Jose and Gao, Xiang and Dahman, Ghassan and Rusek, Fredrik and Edfors, Ove and Tufvesson, Fredrik},
  issn         = {1536-1276},
  language     = {eng},
  month        = {06},
  publisher    = {IEEE--Institute of Electrical and Electronics Engineers Inc.},
  series       = {IEEE Transactions on Wireless Communications},
  title        = {Spatial Separation of Closely-Located Users in Measured Massive MIMO Channels},
  year         = {2016},
}