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Multi-user MIMO

About: Multi-user MIMO is a research topic. Over the lifetime, 10265 publications have been published within this topic receiving 227206 citations. The topic is also known as: multi user mimo & MU-MIMO.


Papers
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Proceedings ArticleDOI
09 Jun 2013
TL;DR: Analytically it is shown that pilot contamination can be made to vanish asymptotically in the number of antennas for a certain class of channel fading statistics, and how a coordinated user-to-pilot assignment method can be devised to help fulfill this condition in practical networks.
Abstract: Pilot contamination is known to severely limit the performance of large-scale antenna (“massive MIMO”) systems due to degraded channel estimation. This paper proposes a twofold approach to this problem. First we show analytically that pilot contamination can be made to vanish asymptotically in the number of antennas for a certain class of channel fading statistics. The key lies in setting a suitable condition on the second order statistics for desired and interference signals. Second we show how a coordinated user-to-pilot assignment method can be devised to help fulfill this condition in practical networks. Large gains are illustrated in our simulations for even small antenna array sizes.

75 citations

Patent
12 Jun 2008
TL;DR: In this paper, the authors describe a method, apparatus, and computer program product embodiment to enable an access point in a wireless network to use Orthogonal Frequency-Division Multiple Access (OFDMA) reserve subcarriers of OFDM symbols for transmitting high priority voice data and video data to particular wireless devices, while the access point allocates the remaining available sub-carriers for contention-based access by other wireless devices.
Abstract: Method, apparatus, and computer program product embodiments are disclosed to enable an access point in a wireless network to use Orthogonal Frequency-Division Multiple Access (OFDMA) reserve subcarriers of OFDM symbols for transmitting high priority voice data and video data to particular wireless devices, while the access point allocates the remaining available subcarriers for contention-based access by other wireless devices.

75 citations

Journal ArticleDOI
TL;DR: An overview of these uplink MIMO schemes is presented, along with their impact on reference signals and DL control signaling, and their link performances are compared.
Abstract: The evolution of LTE uplink transmission toward MIMO has recently been agreed in 3GPP, including the support of up to four-layer transmission using precoded spatial multiplexing as well as transmit diversity techniques. In this article, an overview of these uplink MIMO schemes is presented, along with their impact on reference signals and DL control signaling. Receivers suitable for uplink MIMO are presented, and their link performances are compared.

75 citations

Journal ArticleDOI
13 Jun 2008
TL;DR: A low complexity scheduling algorithm which aims to maximize the capacity upper bound is proposed and results show that the proposed scheduling algorithm achieves comparable total throughput as the optimal algorithm with much lower complexity.
Abstract: In multiuser MIMO systems, the base station schedules transmissions to a group of users simultaneously. Since the data transmitted to each user are different, in order to avoid the inter-user interference, a transmit preprocessing technique which decomposes the multiuser MIMO downlink channel into multiple parallel independent single-user MIMO channels can be used. When the number of users is larger than the maximum that the system can support simultaneously, the base station selects a subset of users who have the best instantaneous channel quality to maximize the system throughput. Since the exhaustive search for the optimal user set is computationally prohibitive, a low complexity scheduling algorithm which aims to maximize the capacity upper bound is proposed. Simulation results show that the proposed scheduling algorithm achieves comparable total throughput as the optimal algorithm with much lower complexity.

74 citations

Patent
Young-Han Nam1, Jianzhong Zhang1
29 Oct 2010
TL;DR: In this article, a wireless communication system includes a base station capable of communicating with a plurality of subscriber stations, and the base station can transmit control information and data to a subscriber stations.
Abstract: A wireless communication system includes a base station capable of communicating with a plurality of subscriber stations. The base station can transmit control information and data to a subscriber stations. The base station also can identify a set of RS patterns to be used to communicate with the subscriber station, assign a subset of antenna port numbers within the set of RS patterns to the subscriber stations. The base station can indicate the assigned states in a Downlink Control Information (DCI) format transmitted in a Physical Downlink Control Channel (PDCCH). The base station transmits the data using a subset of antenna ports corresponding to the subset of antenna port numbers. The base station also can map reference signals corresponding to the subset of antenna ports according to at least one RS pattern within the set of RS patterns.

74 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202363
2022122
2021170
2020211
2019234
2018263