Results 141 to 150 of about 789 (166)

SWIPT in Cell-Free Massive MIMO

2018 IEEE Global Communications Conference (GLOBECOM), 2018
In this paper, the performance of simultaneous wireless information and power transfer (SWIPT) for training-based cell-free massive multiple-input multiple-output (MIMO) is investigated. The key idea is to simultaneously transmit information and power via a larger number of spatially-distributed single antenna access points (APs) towards geographically-
Rajan Shrestha, Gayan Amarasuriya
openaire   +1 more source

Full-Duplex Cell-Free Massive MIMO

ICC 2019 - 2019 IEEE International Conference on Communications (ICC), 2019
This work studies a novel full-duplex (FD) cell-free massive multiple-input multiple-output (MIMO) network, where a very large number of multiple-antenna access points (APs) simultaneously serve many single-antenna uplink and downlink users in the same frequency band. The APs operate in the FD mode while the users in the half-duplex (HD) mode.
Tung Thanh Vu, Duy T. Ngo, Hien Quoc Ngo, Tho Le-Ngoc   +3 more
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Cell Free Massive MIMO with Constrained Coverage

Wireless Personal Communications, 2017
As new generations of mobile radio come into service, bandwidth is becoming more and more scarce and systems with very high spectral efficiency become vital. Having a high spectral efficiency, Massive MIMO has shown to be a promising candidate for 5G. Distributing antennas in such systems make them even more spectrally efficient. Cell free Massive MIMO
Mahdi N. Boroujerdi, Aliazam Abbasfar, Mohammad Ghanbari 0001   +2 more
openaire   +1 more source

Power Minimization for Cell-Free Massive MIMO

2019 IEEE International Conference on Consumer Electronics - Taiwan (ICCE-TW), 2019
In this paper, we investigate the total power minimization problem for the downlink cell-free massive multiple- input multiple-output (mMIMO) system, subjecting to the users' quality-of-service (QoS) constraint. Specifically, the total power consists of circuit power, data transmission power, and backhaul power.
Yao Zhang 0016, Haotong Cao, Meng Zhou, Yan Li, Longxiang Yang   +4 more
openaire   +1 more source

FDD-Based Cell-Free Massive MIMO Systems

2018 IEEE 19th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), 2018
Cell-free massive MIMO system is a promising technology of 5G wireless communications that provide a user-centric coverage to the user by the basestation cooperation. Most prior works on the cell-free massive MIMO systems assume the time division duplexing (TDD) systems, although the frequency division duplexing (FDD) systems dominate the current ...
Seungnyun Kim, Byonghyo Shim
openaire   +1 more source

Physical Layer Security in Cell- Free Massive MIMO

2018 IEEE Global Communications Conference (GLOBECOM), 2018
The achievable secrecy rates for a cell-free massive multiple-input multiple-output (MIMO) in the presence of a single-antenna active eavesdropper are derived and compared with that of co-located massive MIMO. The active eavesdropper contaminates the uplink channel estimates at the access points (APs), and the downlink precoders at the APs are ...
Santosh Timilsina, Dhanushka Kudathanthirige, Gayan Amarasuriya   +2 more
openaire   +1 more source

Cell-Free Massive MIMO with Underlay Spectrum-Sharing

ICC 2019 - 2019 IEEE International Conference on Communications (ICC), 2019
In this paper, the coexistence of cell-free massive multiple-input multiple-output (MIMO) and underlay spectrum-sharing is investigated. Thereby, the fundamental performance limits are established to characterize the feasibility of this coexistence. A set of spatially-distributed secondary access points (S-APs), which are underlaid in a primary cell ...
Diluka Loku Galappaththige, Gayan Amarasuriya   +1 more
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Energy efficiency optimization for cell-free massive MIMO

2017 IEEE 18th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), 2017
This paper considers a time-division duplex cell-free massive multiple-input multiple-output downlink with imperfect channel station information and conjugate beamforming scheme. The total energy efficiency is investigated taking into account the hardware power consumption and the backhaul power consumption.
Hien Quoc Ngo, Le-Nam Tran, Trung Quang Duong, Michail Matthaiou, Erik G. Larsson   +4 more
openaire   +1 more source

On the Performance of Multigroup Multicast Cell-Free Massive MIMO

IEEE Communications Letters, 2017
We investigate the performance of a multigroup multicast cell-free massive multiple-input multiple-output system where many access points (APs) multicast signals to many groups of users. A distributed conjugate beamforming with short-term power constraint (STPC) policy is proposed to use at the APs.
Toan X. Doan, Hien Quoc Ngo, Trung Quang Duong, Kamel Tourki   +3 more
openaire   +2 more sources

Internet of Things Based on Cell-Free Massive MIMO

2019 53rd Asilomar Conference on Signals, Systems, and Computers, 2019
We consider Internet of Things (IoT) organized on the principles of Cell-Free Massive MIMO. Since the number of things is very large, orthogonal pilots cannot be assigned to all of them even if the things are stationary. This results in an unavoidable pilot contamination problem, which is severe for IoT since the things are operating at very low ...
Shilpa Rao 0002, Alexei Ashikhmin, Hong Yang 0001   +2 more
openaire   +1 more source