Statistical Analysis of the Actual RF Exposure From Massive MIMO Base Stations Serving Moving User Equipment

Abstract

When performing a radio frequency (RF) electromagnetic field (EMF) exposure assessment of a base station as described in the international standard IEC 62232, the actual maximum approach provides an assessment method based on the actual exposure level, in particular for massive MIMO base stations. Computational modeling can be used to estimate a range of applicable power reduction factors. To date, research studies have generally focused on the channel modeling of actual RF EMF exposure assuming that the attached user equipment (UE) is static. However, in real operational conditions, a UE can be moving and triggering multiple beam changes or beam adaptations. This study provides a computational model applicable to moving UEs and investigates the impact on range of applicable power reduction factors compared to modelling studies using static UEs. The results show that -1.5 dB to -3.5 dB lower power reduction factor can be considered with moving UEs compared to static UEs.

Keywords

• 5G
• actual maximum approach
• antenna array
• beamforming
• EMF exposure
• massive MIMO