Abstract
In order to satisfy higher requirements for data transmission rate and system capacity, millimeter wave (mmWave) with abundant spectrum resources has be exploited and become a research hotspot of the fifth generation (5G) mobile communication systems. However, introducing mmWave technologies into cellular networks also faces many severe challenges, especially the initial user equipment (UE) discovery. In the UE discovery, the narrow-beam directional scanning is often used to search the UE, but it increases the control overhead of the system and brings about a non-negligible search delay. In this paper, we will analyze the average search delay of mmWave systems under two different UE access methods, i.e., the random scanning access method in independent networks and the search method based on UE location in heterogeneous networks. Taking the average search times discovering UEs as a measure and the number of search sectors in beam-space as an optimization parameter, the optimal number of sectors with the maximum capacity is obtained so that the search delay and the capacity can be balanced. The simulation results verify the correctness of the analysis and show that the performance of the user discovery method in heterogeneous networks is better than that of the random scan access method in mmWave independent networks.
Highlights
With the increasing number of intelligent terminals and traffic in cellular mobile communication system [1], people put forward higher requirements for data transmission rate and system capacity
The results showed that the number of user equipment (UE) in the first scan was increased by 19% and the delay was reduced by 84% compared with the current advanced methods. [16] analyzed the directional cell search delay for fixed cellular networks
SIMULATION RESULTS we provide numerical simulations of average search times and capacity based on the analysis in the previous sections
Summary
With the increasing number of intelligent terminals and traffic in cellular mobile communication system [1], people put forward higher requirements for data transmission rate and system capacity. Fan et al.: Delay Analysis and Optimization of Beam Scanning-Based User Discovery in mmWave Systems base station In this processing, the UE first detects the neighboring BSs in the cell search phase and acquires the connection with the network by initiating the random access phase. In mmWave systems, the high path loss characteristics will result in a mismatch between the control range and the data transmission range when the BS and directial transmission are exploited To solve this problem, in the process of UE discovery, BSs need to use BF technology to obtain narrow beams and scan the whole beam space directionally to expand the coverage of mmWave system.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
