Paper Info
Title
Cooperative LBT Design and Effective Capacity Analysis for 5G NR Ultra Dense Networks in Unlicensed Spectrum
Abstract
With the rapidly increasing demand of data traffic in fifth-generation (5G) wireless systems, various sophisticated techniques have been developed to cope with the demand. New radio-unlicensed (NR-U) technology is one of the most promising techniques to address the exponential growth of data traffic. At the same time, NR base stations are densely deployed in 5G. Therefore, large numbers of NR-U base stations attempt to access the unlicensed spectrum. Although listen before talk (LBT) with random backoff can guarantee fairness, it can also increase the collision probability. For the IEEE 802.11 Wi-Fi networks, a contention-based random access protocol is adopted, which cannot guarantee the Quality of Service (QoS). To overcome these problems, a new LBT protocol, referred to as cooperative LBT, is designed, in which zero forcing (ZF) precoding is applied to suppress the multi-user interference. Based on the new LBT protocol, a (N + 3)-state semi-Markovian model is established to characterize the effective capacity of NR-U in unlicensed bands, where N is the number of NR-U base stations. An expression for the effective capacity is obtained, which is a function of QoS, instantaneous transmit rate, the number of Wi-Fi nodes, and NR-U base stations. The influences of the finite backhaul and transmit power on the effective capacity are also analyzed in this paper. The simulation results show that the usage of cooperative communication can reduce the collision probabilities from 0.4928 to 0.1632 and increase the effective capacities by 220.04%. The cooperative LBT protocol has a more compelling advantage for 5G NR ultradense deployment scenarios.
Year
DOI
Venue
2019
10.1109/ACCESS.2019.2910582
IEEE ACCESS
Keywords
Field
DocType
Effective capacity,new radio-unlicensed (NR-U),cooperative network,quality of service (QoS),listen before talk (LBT)
Base station,Transmitter power output,Spectrum management,Backhaul (telecommunications),Computer science,Computer network,Quality of service,Interference (wave propagation),Precoding,Distributed computing,Random access
Journal
Volume
ISSN
Citations 
7
2169-3536
0
PageRank 
References 
Authors
0.34
0
7
Name
Order
Citations
PageRank
Hengguo Song100.34
Qimei Cui264279.84
Yu Gu3294.32
Gordon L. Stüber41150101.86
Yong Li52972218.82
Zesong Fei669986.33
Chongtao Guo77311.11