Wideband Interference Suppression for Automotive mmWave CS Radar: From Algorithm-Based to Learning-Based ApproachesWANG Xiaoyan; KOIZUMI Ryoto; UMEHIRA Masahiro; SUN Ran; TAKEDA Shigeki, In recent times, there has been a significant focus on the development of automotive high-resolution 77GHz CS (Chirp Sequence) radar, a technology essential for autonomous driving. However, with the increasing popularity of vehicle-mounted CS radars, the issue of intensive inter-radar wideband interference has emerged as a significant concern, leading to undesirable missed targe detection. To solve this problem, various algorithm and learning based approaches have been proposed for wideband interference suppression. In this study, we begin by conducting extensive simulations to assess the SINR (Signal to Interference plus Noise Ratio) and execution time of these approaches in highly demanding scenarios involving up to 7 interfering radars. Subsequently, to validate these approaches could generalize to real data, we perform comprehensive experiments on inter-radar interference using multiple 77GHz MIMO (Multiple-Input and Multiple-output) CS radars. The collected real-world interference data is then utilized to validate the generalization capacity of these approaches in terms of SINR, missed detection rate, and false detection rate., The Institute of Electronics, Information and Communication Engineers
IEICE Transactions on Communications, 01 Dec. 2024
Stock Monitoring and Localization Systems for FIFO Method Using RFID Based Pressure Sensing Tag and AIDanang Kumara Hadi; Zequn Song; Budi Rahmadya; Ran Sun; Shigeki Takeda, This research introduces real-time monitoring and localizing product stock using the First-In-First-Out (FIFO) method with radio frequency identification (RFID) pressure sensing tags. The proposed FIFO system has RFID pressure sensing tags that detect pressure changes, generate sensor codes, and estimate a stock location. Integrating artificial intelligence (AI) improves location estimation accuracy of up-to-date stock visibility. The ability of RFID pressure sensing tags and AI to detect stock from sensor code data enables more effective asset management, optimizes stock management, reduces product waste, and contributes to better efficiency in product inventory management.
IEEJ Transactions on Electronics, Information and Systems, 01 Sep. 2024
An Auxiliary Antenna and Repeater Node for Reading Arrayed RFID Sensor Tags in Shielded AreasDanang Kumara Hadi; Zequn Song; Shusuke Kobayashi; Ran Sun; Budi Rahmadya; Shigeki Takeda, Collecting temperatures inside shield areas is a technological challenge for RFID sensor tags. This paper proposes a new RFID sensor tag reading technique inside shield areas such as metallic cases. The proposed method consists of an auxiliary antenna and repeater RFID sensor tag. A coaxial cable connects the repeater RFID sensor tag installed inside a shield area to the external auxiliary antenna. An RFID reader identifies multiple RFID sensor tags installed inside the shielded area through the repeater RFID sensor tag exploiting electromagnetic coupling effects. Experimental results using the chassis of a desktop computer validated that the proposed method identified the multiple RFID sensor tags and enabled measuring temperatures inside the metallic shield area.
2nd International Symposium on Information Technology and Digital Innovation: Creative Trends in Sustainable Information Technology Design and Innovation, ISITDI 2024, 2024
Indoor Localization Based on Analyzing Observed Wi-Fi Access Point Logs Using ChatGPTBudi Rahmadya; Yuta Sato; Shigeki Takeda; Ran Sun; Zequn Song; Danang Kumara Hadi, Argent demands regarding indoor real-time localization systems (RTLS) accelerate research and developments on these technologies. Recent advances in Wi-Fi technologies, including Wi-Fi 6 and 7, further facilitate the development of RTLS technologies by utilizing signal processing and artificial intelligence/machine learning (AI/ML) technologies. These research and development activities also accelerate future wireless communication for achieving the integrated sensing and communication (ISAC) concept. The recent developments in Wi-Fi technologies have led to increased numbers of APs for gaining reliable wireless links. Therefore, we observe many APs in workplaces, office environments, and homes. These situations enable exploiting observed Wi-Fi information for localizations. This paper proposed an indoor localization method based on the analyses of surrounding Wi-Fi access points using ChatGPT. The experiments validated that ChatGPT could infer the corresponding room names to given unknown Wi-Fi logs based on analyzing known Wi-Fi logs observed in priori in individual rooms.
2nd International Symposium on Information Technology and Digital Innovation: Creative Trends in Sustainable Information Technology Design and Innovation, ISITDI 2024, 2024
Experimental Evaluations on Learning-based Inter-radar Wideband Interference Mitigation MethodKoizumi Ryoto; Wang Xiaoyan; Umehira Masahiro; Sun Ran; Takeda Shigeki, In recent years, high-resolution 77GHz band automotive radar, which is indispensable for autonomous driving, has been extensively investigated. In the future, as vehicle-mounted CS (chirp sequence) radars become more and more popular, intensive inter-radar wideband interference will become a serious problem, which results in undesired miss detection of targets. To address this problem, learning-based wideband interference mitigation method has been proposed, and its feasibility has been validated by simulations. In this paper, firstly we evaluated the tradeoff between interference mitigation performance and model training time of the learning-based interference mitigation method in a simulation environment. Secondly, we conducted extensive inter-radar interference experiments by using multiple 77GHz MIMO (Multiple-Input and Multiple-output) CS radars and collected real-world interference data. Finally, we compared the performance of learning-based interference mitigation method with existing algorithm-based methods by real experimental data in terms of SINR (signal to interference plus noise ratio) and MAPE (mean absolute percentage error)., The Institute of Electronics, Information and Communication Engineers
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Jan. 2024,
[Reviewed] A Stray Read Suppression Method in UHF passive RFID Systems Utilizing a Metal PlateArai Hoshihiko; Takeda Shigeki; Sun Run, Radio frequency identification (RFID) systems enable us to achieve highly efficient inventory management and inspection work. However, if an RFID reader increases its transmission power to read densely arranged RFID tags in a cardboard box, stray reads of the RFID tags occur. These unwanted reads degrade the overall inventory performance. This letter proposes a reliable reading method for densely arranged RFID tags while suppressing stray reads., The Institute of Electrical Engineers of Japan
IEEJ Transactions on Electronics, Information and Systems, 01 Aug. 2023,
[Reviewed] River-water-level Monitoring with 24GHz FMCW RadarSun Ran; Takeda Shigeki; Kuwahara Yuji; Kobayashi Kaoru, This paper proposed a process of river-water-level monitoring using a 24 GHz FMCW (Frequency modulated continuous wave) radar. To improve its monitoring accuracy, the use of detected river velocities and the quartile-range limitation method excludes the outliers of calculated distances to water. The experiments at an actual river validated the effectiveness of the proposed process., The Institute of Electrical Engineers of Japan
IEEJ Transactions on Electronics, Information and Systems, 01 Aug. 2023,
[Reviewed] RNN-based Interference Suppression Method for CS radar: Simulation and Experimental Evaluations
Ryoto Koizumi; Xiaoyan Wang; Masahiro Umehira; Shigeki Takeda and Ran Sun
Proc. of the International Conference on Artificial Intelligence in Information and Communication (ICAIIC 2023), Feb. 2023, [Reviewed]
A Higher Angular Resolution Millimeter-Wave Automotive Radar Utilizing an Antenna Element Space Pseudo Peak Suppression
K. Suzuki; Y. Owada; R. Sun; S. Takeda; M. Umehira; H. Kuroda
Joint Indo-Japanese Smart City Workshop 2022., Mar. 2022, [Reviewed]
A Higher Angular Resolution Millimeter-Wave Automotive Radar Utilizing an Antenna Element Space Pseudo Peak Suppression to Identify Obstacles on a Road
Y. Owada; K. Suzuki; R. Sun; S. Takeda; M. Umehira; H. Kuroda
Joint Indo-Japanese Smart City Workshop 2022, Mar. 2022, [Reviewed]
A Link Analysis Based Device-Free Localization Method of RFID Tags Using a Tiny Drone having a Wound-Wire for Shadowing Propagation Paths
B. Rahmadya; S. Takeda; R. Sun
Joint Indo-Japanese Smart City Workshop 2022, Mar. 2022, [Reviewed]
RFID Tag Antenna Design for Books and Document Management Applications Considering the Surrounding Paper
R. Miyajima; B. Rahmadya; S. Takeda; R. Sun
Joint Indo-Japanese Smart City Workshop 2022, Mar. 2022, [Reviewed]
A Stray Reads Suppression Method of UHF Passive RFID tags Utilizing the Image Theory
H. Arai; S. Takeda; R. Sun
Joint Indo-Japanese Smart City Workshop 2022, Mar. 2022, [Reviewed]
A Battery-Less RFID-Based Wireless Vibration and Physical-Shock Sensing System Using Edge Processing for Long-Term Measurements
Z. Song; R. Sun; B. Rahmadya; S. Takeda
2021 31st International Telecommunication Networks and Applications Conference (ITNAC), Nov. 2021, [Reviewed]
M字形誘電体アレー構造による広帯域移相器
孫冉; 武田茂樹; 鹿子嶋憲一, Lead
電気学会論文誌C, Aug. 2021, [Reviewed]
A UHF RFID Based Battery-Less Walking Detection Sensor Tag
Z. Song; S. Takeda and R. Sun
Joint Indo-Japanese Smart City Workshop 2021, Mar. 2021, [Reviewed]
Virtually Extended Array Antennas with an Overlearning Supression for Automotive mm-Wave radars
J. Sakai; K. Suzuki; J. Zheng; R. Sun; S. Takeda and M. Umehira
Joint Indo-Japanese Smart City Workshop 2021, Mar. 2021, [Reviewed]
Proposal of Antenna Element Space Interference Cancelling Radar
R. Sun; J. Sakai; K. Suzuki; J. Zheng; S. Takeda and M. Umehira, Lead
Joint Indo-Japanese Smart City Workshop 2021, Mar. 2021, [Reviewed]
A framework to determine secure distances for either drones or robots based inventory management systems
B. Rahmadya; R. Sun; S. Takeda; K. Kagoshima; and M. Umehira, IEEE
IEEE Access, Sep. 2020, [Reviewed]
Optimization of Frame Synchronization System for Optical Wireless Hybrid PPM-OOK Frame Communication
Tomohiro Kiguchi; Ran Sun; Hiromasa Habuchi; Yusuke Kozawa, RISP
Proceedings of RISP International Workshop on Nonlinear Circuits, Communications and Signal Processing 2020 (NCSP2020), 21 Feb. 2020, [Reviewed]
Enhancement of Optical Wireless Punctured Turbo Code System in Strong Turbulence Channel
Ran Sun; Hiromasa Habuchi; Yusuke Kozawa, RISP
Proceedings of RISP International Workshop on Nonlinear Circuits, Communications and Signal Processing 2020 (NCSP2020), 21 Feb. 2020, [Reviewed]
Proposal of Optical Wireless Turbo Coded System with Hybrid PPM-OOK Signaling
Ran Sun; Hiromasa Habuchi; Yusuke Kozawa, IEEE
Proceedings of IEEE 2018 12th International Conference on Signal Processing and Communication Systems (ICSPCS), Dec. 2018, [Reviewed]
BER Performance Impaired by Transmission Time Offset Between Users in Optical Wireless CSK/ACDMA System Using DMPOMs
Takashi Tokunaga; Hiromasa Habuchi; Yusuke Kozawa; Ran Sun, IEEE
Proceedings of IEEE 7th Global Conference of Consumer Electronics, 12 Oct. 2018, [Reviewed]
Error Correcting Codes in Underwater RGB-LED Parallel Communication: Turbo or LDPC?
Ran Sun; Hiromasa Habuchi; Yusuke Kozawa, RISP
Proceedings of the RISP International Workshop on Nonlinear Circuits, Communication and Signal Processing, 06 Mar. 2018, [Reviewed]
Enhancement of RGB Parallel Turbo-code System with UTPA in Optical Partial Erasure Channel
Ran Sun; Hiromasa Habuchi; Yusuke Kozawa, IEEE
Proceeding of 13th 2016 IEEE Vehicular Technology Society Asia Pacific Wireless Communications Symposium (APWCS2016), 26 Aug. 2016, [Reviewed]
Novel Parallel Optical Turbo-code Communication System using RGB LEDs for Partial Erasure Channel
Ran Sun; Hiromasa Habuchi; Yusuke Kozawa
The 31st International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2016), 13 Jul. 2016, [Reviewed]
