Wired (electrical, optical) communication division
Wired commnication (optical fiber solution)
Optical physical layer
Optical communication system simulation
Optical communication systems that use optical fibers as transmission media have excellent EMC characteristics. We are building a simulator to estimate communication performance considering the vehicle routing (length, connector axial deviation, bending). Applications of various DSP (Digital Signal Processing) such as PAM (Pulse-Amplitude Modulation) and error correction technologies are also possible. We are also conducting designs of customized passive components and optical systems.
![](images/hikari/hikari01.jpg)
Optical transmission system evaluation and standard conformance test
Standards such as automotive optical Ethernet 1000BASE-RH determine the test point (TP) of the electrical domain and the optical domain. In additon, ISO21111-3,-5 describe conformance test items and interconnection test items as well as the methods. ISO21111-4 specifies test methods for optical components with reference to IEC standards. In addition to conducting these tests, our laboratory proposes new test methods(ex IEEE P802.3cz and IEEE P802.3dh) if necessary.
![](images/hikari/hikari02.jpg)
3D Computational Model of Optical Interconnection
At the connection between optical fibers (connectors), there is a possibility of loss of optical power due to changes in the propagation mode caused by axis misalignment and other factors. We have developed a 3D mode coupling equation for fiber-optic connectors in matrix form (Point Radiance Matrix1),2)). This allows us to calculate insertion loss, mode power conversion, near-field-pattern distribution (NFP), and far-field-pattern distribution (FFP), taking into account the 3-D axis shift. The matrix equation can be extended to interconnections between multimode optical devices, provided that the source NFP is known.
![](images/hikari/hikari03_en.png)
1) X. Mao and M. Kagami, “Modeling an MMF Connector via Point Radiance Matrix and its Application in Automotive SI-MMF Connection,”
J. Lightwave Technol., 40, 5698 – 5707, 2022.
2) Xuesong Mao and Manabu Kagami, “Point radiance calculation of GI-MMF and its application in a fiber connection,” Optics Express, vol. 31, No. 1, pp. 163-176 (2023)
Wired communication (copper wire solution)
Electrophysical layer
Test house for automotive Ethernet communication standards (coming soon…)
We are well-equipped for IEEE802.3-based test of automotive Ethernets with copper wire (100BASE-T1, 1000BASE-T1, ...) and various tests conformable to the OPEN Alliance SIG.
![](images/copper/copper01.jpg)
Test house for other automotive communication standards (coming soon…)
Many communication standards have been proposed for the spread of autonomous driving. We will choose the standards in high demand and prepare the related test environment.