Research on Spectrum Sharing with Aircraft Radio Altimeters and Co-/Adjacent Frequency-using Systems
Aircraft radio altimeters (operating at frequencies between 4.2 and 4.4 GHz) are avionics that use radio waves to measure the distance between aircraft and the ground. They are used as input parameters for aircraft control systems, throughout a range of flight phases as well as landing, including for airborne collision avoidance systems and wing control.
However, various systems have been operated in recent years in adjacent and identical frequency bands. Adjacent bands are allocated to 5G mobile systems in countries worldwide, including Japan, where mobile phone operators operate 5G mobile systems between 3.6 and 4.1 GHz and 4.5 and 4.6 GHz. In addition and within the same frequency band, a Wireless Avionics Intra-Communication (WAIC) system is being developed as an international standard. As these systems did not exist when the technical standards for radio altimeters were established, electromagnetic interference (EMI) to radio altimeters may occur.
The main purposes of the research project include to clarify conditions under which EMI occurs, such as frequency and power level. We also aim to realize EMI estimation technology for radio altimeters using large-scale electromagnetic field numerical analysis. We will also contribute to international standardization activities for next-generation radio altimeters and provide information to aviation regulators, radio regulators, aircraft operators and telecommunications operators.
- Interference estimation technology using large-scale electromagnetic field numerical analysis
- Clarification of the EMI occurrence condition, such as frequency and power level
- Contribute to international standardization activities for next-generation radio altimeters and provide information to aviation regulators, Radio regulators, aircraft operators and telecommunications operators