  Reconfigurable Intelligent Surface (RIS) is one of the key technologies for
the upcoming 6th Generation (6G) communications, which can improve the signal
strength at the receivers by adding artificial propagation paths. In the
context of Downlink (DL) Multi-User Multiple-Input Multiple-Output (MU-MIMO)
communications, designing an appropriate Beamforming (BF) scheme to take full
advantage of this reconfigured propagation environment and improve the network
capacity is a major challenge. Due to the spatial dimension provided by MIMO
systems, independent data streams can be transmitted to multiple users
simultaneously on the same radio resources. It is important to note that
serving the same subset of users over a period of time may lead to undesired
areas where the average Electromagnetic Field Exposure (EMFE) exceeds
regulatory limits. To address this challenge, in this paper, we propose a Dual
Gradient Descent (Dual-GD)-based Electromagnetic Field (EMF)-aware MU-MIMO BF
scheme that aims to optimize the overall capacity under EMFE constraints in
RIS-aided 6G cellular networks.
