Now 7777 visitors
Today:0 Yesterday:0
Total: 160207 216S 51P 5R
2026-10-22, Week 43
Member Login
TACT Journal Homepage
Call for Paper
Committee
Find My Paper
Author Homepage
Statistics & History
Welcome Message
Paper Procedure
FAQ
Paper Archives
Outstanding Papers
Program & Proceedings
Presentation Platform
Hotel & Travel Info
Photo Gallery
Scheduler Login
Seminar
Archives Login
Sponsors


















Online Q&A Session
Paper Number Author:
Paper Title
Keyword
Q&A Number **Select your question number !!
Questioner eMail:
Question
Answer
by
Author
Save Q&A

* Edit or answer any Q&A by selecting Q&A number Hyper Link below + Write button (Save)
ICACT20210169 Question.1
Questioner: mrobaei.dev@gmail.com    2021-02-08 오후 4:46:35 		ICACT20210169 Answer.1
Answer by Auhor yfujii@kke.co.jp   2021-02-08 오후 4:46:35
Chrome Click!!
Thank you for your presentation. I have two questions. You have mentioned a fast channel estimation is required because the channel varies rapidly. My first question is, what is the order of channel variation (fading) in magnitude (in dB, power) and also time (in seconds, or OFDM subframes, slot)? And my second question is how fast the channel should be estimated (in seconds, OFDM subframes, slots, etc.)? Do you have any recommendations about the channel estimation rate? Thank you in advance for your time. Thank you for your question. We assume mobility in nano-area is less than 10mm per one OFDM frame(10msec) is less than 10mm. With the assumption above, and consider the mmWave's wave length, it is required to estimate fading channel every 10msec. Regarding blockage, the time constraints is much reluxed, such as 0.1sec or longer.
ICACT20210169 Question.2
Questioner: lijingwei10@huawei.com    2021-02-08 오후 4:47:13 		ICACT20210169 Answer.2
Answer by Auhor yfujii@kke.co.jp   2021-02-08 오후 4:47:13
Chrome Click!!
Could you explain the necessity that we pay attention to the nano area? The demand for wireless communication is expected to become more sophisticated in the near future. Within several years, not only massive access nor ultra low latency, but also both of them will be required at the same time for some of the applications. As mentioned in the opening slide, we believe that 'nano area' is one solution to meet that demand. A large number of terminals are accommodated using the wide band of mmWave, and while reducing latency, at the same time, base station redundancy is provided to ensure communication reliability. This is the reason why we focus on the 'nano area.
ICACT20210169 Question.3
Questioner: lijingwei10@huawei.com    2021-02-09 오후 7:00:54 		ICACT20210169 Answer.3
Answer by Auhor yfujii@kke.co.jp   2021-02-09 오후 7:00:54
Chrome Click!!
Thank you for your nice presentation. But I have a question. In this presentation, you show an 8 element linear antenna array, I am wondering if the area antenna will have a better performanc than the linear antenna array? And what is the differenc between the linear attenna array with the area attenna array? We chose linear array antennas not because they are superior to planar array antennas, but simply for the purpose of verifying the accuracy of analog and digital beamforming using array antennas, which are easier to analyze than planar (area?) antennas. We chose the linear array antenna, which is easier to analyze than the planar array antenna. In the next research year, we plan to conduct hybrid beamforming experiments using a 32-element (8x4) planar array antenna.
ICACT20210169 Question.4
Questioner: kawano.masahiro959@mail.kyutech.jp    2021-02-09 오후 7:09:20 		ICACT20210169 Answer.4
Answer by Auhor yfujii@kke.co.jp   2021-02-09 오후 7:09:20
Chrome Click!!
Thank you for your very interesting presentation. My name is Kawano, and I am a student at Kyushu Institute of Technology. I have two questions on page 13 of the slide. In ComRU, it is considered necessary to synchronize the LO of multiple RUs, the transmission start timing, and other clocks. Q1. How do you achieve these synchronizations in your experiments this time? Q2. Do you have any ideas for achieving synchronization when you put this experimental system to practical use? Thank you. Thank you for your questions, Mr. Kawano. Q1 In this experiment, multiple RUs were synchronized using a common LO. Q2 Synchronizing RUs that are physically located far apart is a particularly challenging task in mmWave, and one of the major research topics for the next research year. Even though it is difficult to achieve permanent synchronization without a common LO, we believe that it is possible to synchronize them for a very short time period by making the best use of 5G UL and DL synchronization signals.