Hokkaido University Research Profiles

Information and Communication

A method to evaluate radio wave propagation characteristics of in-vehicle wireless access services by large-scale electromagnetic field analysis

Toward optimal design of wireless environments

We have conducted research in various fields where radio waves are applied, including the evaluation of complex and special propagation environments in airplanes and passenger railroad cars, internal exposure of the human body to radio waves, electromagnetic interference evaluation and mechanism estimation regarding body medical devices implanted in the body, and evaluation of electromagnetic field leakage in wireless power supply devices for electric vehicles.

Content of research

The radio propagation environment inside a vehicle is a special environment that differs from the conventional propagation model due to multiple reflections caused by the surrounding metal and the presence of fixtures and passengers inside. It is therefore necessary to evaluate the characteristics of radio wave propagation, including the effects of absorption and scattering of radio waves by the bodies of passengers, to estimate the quality of the wireless connection under actual operational conditions. However, it is difficult to evaluate the propagation characteristics by actual measurement or simple numerical analysis (e.g., ray tracing). This study addresses modeling of the propagation environment in vehicles, which has been difficult in the past, and realizes a simulation method in a very large analysis space by using a supercomputer.

Potential for social implementation

  • ・We have developed a new method to evaluate the propagation characteristics of wireless communication systems in office and passenger transportation environments. It is expected to apply these results to the optimal design (as well as safety evaluation) of wireless communication environments, such as MIMO and multiple bandwidths, which will become more and more complex in the future

Appealing points to industry and local governments

It is expected to progress as a promising method to achieve the visualization of radio wave propagation in computer space, and to be applied to the use of radio waves and electromagnetic fields in general. Detailed measurements of radio wave propagation characteristics in environments filled with many human bodies, such as large offices, are practically impossible, and computer simulations will have to be used in the future. This research will be a pioneer for this purpose.