Next Article in Journal
On Some Initial and Initial Boundary Value Problems for Linear and Nonlinear Boussinesq Models
Previous Article in Journal
Hierarchical Open-Set Object Detection in Unseen Data
Open AccessArticle

Access Control and Pilot Allocation for Machine-Type Communications in Crowded Massive MIMO Systems

1
Department of Information and Communication System, Inje University, 197, Inje-ro, Gimhae-si, Gyeongsangnam-do 50834, Korea
2
Department of Electrical and Computer Engineering, One Shields Avenue, Kemper Hall, University of California, Davis, CA 95616, USA
3
High Safety Core Technology Research Center, Inje University, 197, Inje-ro, Gimhae-si, Gyeongsangnam-do 50834, Korea
4
Department of Electronic, Telecommunications, Mechanical Automotive Engineering, Inje University, 197, Inje-ro, Gimhae-si, Gyeongsangnam-do 50834, Korea
*
Author to whom correspondence should be addressed.
Symmetry 2019, 11(10), 1272; https://doi.org/10.3390/sym11101272
Received: 6 September 2019 / Revised: 30 September 2019 / Accepted: 4 October 2019 / Published: 11 October 2019
Massive machine-type communication (mMTC) in 5G New Radio (5G-NR) or the Internet of Things (IoT) is a network of physical devices such as vehicles, smart meters, sensors, and smart appliances, which can communicate and interact in real time without human intervention. In IoT systems, the number of networked devices is expected to be in the tens of billions, while radio resources remain scarce. To connect the massive number of devices with limited bandwidth, it is crucial to develop new access solutions that can improve resource efficiency and reduce control overhead as well as access delay. The key idea is controlling the number of arrival devices that want to access the system, and then allowing only the strongest device (that has the largest channel gain and each device is able to check whether it is the strongest device) be able to transit to BS. In this paper, we consider a random access problem in massive MIMO context for the collision resolution, in which the access class barring (ACB) factor is dynamically adjusted in each time slot to maximize access success rate for the strongest-user collision resolution (SUCRe) protocol. We propose the dynamic ACB scheme to find optimal ACB factor in the next time slot and then apply SUCRe protocol to achieve a good performance. This method is called dynamic access class barring combined strongest-user collision resolution (DACB-SUCR). In addition, we investigate two different ACB schemes that consist of the fixed ACB and the traffic-aware ACB to compare with the proposed dynamic ACB. Analysis and simulation results demonstrate that, compared with SUCRe protocol, the proposed DACB-SUCR method can remarkably reduce pilot collision, and increase access success rate. It is also shown that the dynamic ACB gives better performance than the fixed ACB and the traffic-aware ACB. View Full-Text
Keywords: access class barring; IoT; mMTC; massive MIMO; pilot allocation; access control access class barring; IoT; mMTC; massive MIMO; pilot allocation; access control
Show Figures

Figure 1

MDPI and ACS Style

Vo, T.-H.; Ding, Z.; Pham, Q.-V.; Hwang, W.-J. Access Control and Pilot Allocation for Machine-Type Communications in Crowded Massive MIMO Systems. Symmetry 2019, 11, 1272.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop