JRC REVIEW No.76 2025 Technical Reports｜JRC（Japan Radio Co.,Ltd.）

JRC has been conducting research and development of a C-band dual-polarization phased array weather radar as a new system to improve the accuracy of forecasting linear precipitation bands and typhoons, which have become social issues in recent years. The radar system under development employs a technology that forms a "comb-shaped beam," which is different from existing phased array radars, and aims to achieve both the high-precision observation provided by existing parabolic dual-polarization radars and the high-speed observation provided by phased array radars. To verify the performance of this radar in actual meteorological observation, JRC has developed a small-scale version of the experimental model and installed it in Namerikawa City, Toyama Prefecture. In the future, JRC will continue to evaluate the observation data to clarify the effectiveness of the C-band dual-polarization phased array weather radar and to aim for practical application.

Takayuki Kohama
Tatsuya Katsumoto
Shigeharu Shimamura
Makoto Shigeta
Toshinori Kudo

JRC has developed a compact 5G system for local 5G with excellent functional expandability and flexibility. The signal processing server of the developed 5G system uses a 32-core 4th generation Intel® Xeon® scalable processor, achieving an effective throughput of 700 Mbps in the downlink (DL, hereafter) and 60 Mbps in the uplink (UL, hereafter) with the synchronous TDD (Time Division Duplex) pattern used in Japan, and enabling processing for simultaneous connection of up to 128 terminals. In addition, this system has a unique function of realizing Wi-Fi authentication by a SIM issued with a JRC telecommunications number（44004）, enabling roaming between 5G and Wi-Fi. To date, JRC has installed the system at Nagano City Mashima Sports Arena (Nagano City, Nagano Prefecture; White Ring, hereafter), Science Village in Itoshima (Itoshima City, Fukuoka Prefecture), and Nisshinbo Brake Asahi Test Course (Asahi City, Chiba Prefecture), and verified the degree of improvement in functional expandability and transmission speed (effective throughput) at each facility and confirmed the contribution that the system makes to the business of each facility.

Kenji Terada
Yasushi Tabei
Kenji Inoue
Yuki Horikawa
Sadayuki Katsumata

JRC has developed a group communication application (application, hereafter) that can be used with smartphones and PCs in conjunction with our in-house-made portable LTE base station system for public safety (LTEBox) and local 5G systems. This application employs a control algorithm "resistant to instantaneous loss of connection." When a call is disconnected due to unstable radio wave propagation, the application reconnects the communication line after radio wave strength recovers and automatically restores the original call status, eliminating the need to call back and greatly improving convenience for field workers, and the automatic control of video quality enables highly reliable voice and video calls. In addition, advanced priority control is enabled in conjunction with the communication quality of service (QoS) of our LTE/5G system, ensuring reliable transmission of voice and video images even in harsh communication environments on-site. To respond flexibly to user requests and market trends regarding these, JRC has introduced agile methods and developed an application that achieves high reliability in communication. JRC has also evaluated the reliability of the transmission of audio and video data, and achieved high reliability in the transmission of both audio and video data.

Kunimitsu Arai
Daichi Kanai
Takahisa Nakano
Sadayuki Katsumata

Non-contact vital sensing using radar faces technical challenges in detecting minute movements on the body surface, such as signal separation to separate "signals indicating heart rate" from "signals indicating breathing and body movement" and removing disturbances. In response to these challenges, JRC has achieved some success with a sensing system we developed in the past, as reported in a previous report. However, the problem remained that the heart rate measurement results were unstable compared to the respiratory rate measurement results. JRC has developed a new original filtering method based on the difference in the speed change between breathing and heartbeat, taking advantage of our many years of experience developing non-contact vital sensing systems using radar. By applying this method to a non-contact vital sensing system, JRC has successfully improved the accuracy and stability of breathing and heart rate measurements. (175 subjects, 97 % degree of agreement).

Yuto Todoroki
Shinya Yonezawa
Kengo Tsushima

Aiming to contribute to improving agricultural productivity, JRC has developed an image analysis technology to estimate with high accuracy the growth condition of crops in farming fields from satellite observation images. This technology is featured by the application of three image processing methods: “feature extraction,” “multiple image composition,” and “image calibration” to images to compensate for the effects of the atmosphere and other factors that have a significant impact on the analysis of satellite observation images. To evaluate the usefulness of this technology, the accuracy of estimating the number of wheat stems per unit area and the location of lodging occurrence in farm fields of winter wheat cultivar “Kitahonami” was verified. It was confirmed that both could be estimated with high accuracy. Applying this technology to crop cultivation management will make it possible to grasp the growth conditions of crops in more detail than before. It is expected to improve agricultural productivity by optimizing fertilizer and pesticide amounts based on growth conditions.

Yasumasa Koiso
Tatsuki Hori
Takuma Todoroki
Hiroki Shimoda

A GNSS compass is equipment that installs multiple GNSS antennas on the ship, determines the ship's heading from the bow heading and the relative position of each antenna, and supplies the ship's heading information to external devices such as radar and ECDIS, and is required to have high heading accuracy. A recent problem surrounding GNSS positioning is interference (spoofing/jamming). A GNSS receiver that receives intentional interference not only has difficulty positioning but also induces the output of incorrect position and time information. Since this instance hinders the normal operation of ships and leads to accidents such as groundings, anti-interference measures are essential. To solve this problem, JRC has developed a new GNSS compass JLR-41, which achieves the same heading detection accuracy as the existing high-accuracy model JLR-31 while keeping the external dimensions to approximately 50 % (similar to the existing model JLR-21) compared to the existing high-accuracy model and is also capable of detecting interference.

Yuji Kora
Yasuhide Nagaoka
Tetsu Kato
Shinji Oda

JRC has developed a new multiplex radio equipment, the “JUK-1000 Series (equipment, hereafter)”, which features faster data transmission speeds in multiplex radio communication networks and an expanded range of supportable interfaces. This equipment realizes the conversion of multiplex radio communication lines to IP (Internet Protocol), and aims to improve the flexibility of wireless communication system design by expanding the supportable interfaces and to improve the maintainability of the equipment. This equipment employs "Cross Polarization Interference Canceller (XPIC)" and "IP data transmission in a co-channel system" as key technologies supporting improved transmission capacity.

Masahiro Yasukawa
Hideo Ono
Hideo Morita
Takayuki Katsube
Yasuyuki Kato

Global Navigation Satellite System (GNSS), which are increasingly introduced as auxiliary equipment installed in railway vehicles to determine the vehicle's position, are systems that measure the current position by receiving radio waves transmitted from multiple positioning satellites. Therefore, positioning accuracy is degraded in locations where reception of GNSS signals transmitted from satellites is unstable, and positioning is impossible inside tunnels or underground, where GNSS signals are completely blocked. Vehicle positioning must maintain accuracy even in locations along the operating section where GNSS signals are completely blocked. JRC Mobility has evaluated the possibility of applying vehicle positioning technology that uses sensors other than GNSS (angular velocity sensors, acceleration sensors, and millimeterwave speedometer) and developed a railway vehicle positioning algorithm that enables seamless and highly accurate positioning by automatically selecting sensors according to the GNSS positioning conditions for each positioning environment, even in location where GNSS positioning is unstable or impossible.

JRC Mobility Inc.
Kento Nakagawa
Hisashi Sato
Kotaro Takahashi

In response to the high demand for radio equipment in the public safety and utility fields, JRC has developed single band radio equipment that supports a single frequency band and is supplying it to the North American market. However, there has been a growing demand in the market to replace existing models which has been more than 10 years since its development, and there has also been a desire to support functions that enhance convenience such as Bluetooth and Wi-Fi. In response to this growing demand, JRC has developed new single band radio equipment with Bluetooth and Wi-Fi functions to increase its added value while keeping its price and size at the same level as existing models. JRC has improved convenience by equipping our newly developed single band radio equipment with a multi-operation function and reduced power consumption during operation by reviewing the circuit configuration.

JRC Mobility Inc.
Satoshi Hasebe

As the labor shortage due to the decline in the working population has become a social issue, NJRC is working to solve this issue through our smart factory business. Recently, in response to the high demand for autonomy of "work involving handling wire harnesses" in the smart factory business field, NJRC has constructed autonomous soldering equipment for wire harnesses (this equipment, hereafter) by applying our strength in mechatronics technology. The underlying technologies of this equipment are "robot vision technology," "wire harness positioning technology," and "wire harness forming technology." Applying these technologies to the equipment has enabled autonomous soldering work of wire harnesses, which has been difficult in the past.

Nagano Japan Radio Co., Ltd.
Takumi Yamada

JRC REVIEW No.76 2025 Technical Reports