On Actual Maximum Exposure From 5G Multicolumn Radio Base Station Antennas for Electromagnetic Field Compliance Assessment
Journal article, 2021

The traditional approach of radio frequency electromagnetic field exposure compliance assessment is highly conservative when applied to radio base station antennas implementing dynamic beamforming. In this article, an analytical model based on the queuing theory with a hyperexponential service distribution time is developed to assess the time-averaged actual maximum downlink exposure of 5G multicolumn radio base station antennas by taking into account the effects of beam scanning over time in free space. Using the measured antenna radiation patterns, the 5G downlink antenna precoding codebook, and assuming a conservative user equipment distribution, the ratio of the actual maximum exposure to the theoretical maximum exposure with 100% traffic load and 75% time-division duplex downlink duty cycle is found to be less than 0.5 and 0.3 for four-transmitter and eight-transmitter radio base station antennas, respectively. These results show that assuming constant peak power transmission in a fixed direction leads to an overestimate of downlink exposure also from conventional antennas characterized by only a few transmitters in addition to massive multi-input multi-output products.

Base stations

Transmitting antennas

5G

Antenna theory

Antenna radiation patterns

beamforming

electromagnetic field exposure

Massive MIMO

Array signal processing

base station antenna

Precoding

Author

Bo Xu

Ericsson

Davide Colombi

Ericsson

Christer Tornevik

Ericsson

Fatemeh Ghasemifard

Ericsson

Jiajia Chen

Chalmers, Electrical Engineering, Communication and Antenna Systems, Optical Networks

IEEE Transactions on Electromagnetic Compatibility

0018-9375 (ISSN)

Vol. In Press

Subject Categories

Telecommunications

Communication Systems

DOI

10.1109/TEMC.2021.3090107

More information

Latest update

8/3/2021 7