Mariem Chemingui

—Uplink electromagnetic field (EMF) exposure in direct-to-satellite communication raises concerns about potential health effects due to the high transmit power needed to compensate for path loss over large distances. In this regard, we propose an EMF-aware architecture where multiple Low-Earth orbit (LEO) satellites cooperatively serve each user to reduce uplink EMF exposure while meeting users' data rate requirements. Considering limited resources at the satellites, a proper user-satellite association policy is designed through a tailored many-to-many stable marriage (i.e., Gale-Shapley) algorithm. Then, the optimal power control mechanism at the user terminal (UT) is designed. The proposed algorithm achieves an EMF exposure reduction of one order of magnitude compared to Space single-input single-output (SISO) scheme while maintaining a data rate of 20 [Mbps].

The rollout of the 5G networks has raised some concerns about potential health effects from increased exposure to EMF. To address these concerns, we design a novel EMF-aware architecture for uplink communications. Specifically, we propose an ARIS assisted multi-user MIMO system, where the ARIS features a RIS panel mounted on an UAV, offering a flexible and adaptive solution for reducing uplink EMF exposure. We formulate and solve a new problem to minimize the EMF exposure by optimizing the system parameters, such as transmit beamforming, resource allocation, transmit power, ARIS phase shifts, and ARIS trajectory. Our numerical results demonstrate the effectiveness of EMF-aware transmission scheme over the benchmark methods, achieving EMF reductions of over 30% and 90% compared to the fixed ARIS and non-ARIS schemes, respectively.

—Emerging dual-functional radar communication (RadCom) systems promise to revolutionize wireless systems by enabling radar sensing and communication on a shared platform, thereby enhancing spectral efficiency. However, the high transmit power required for efficient radar operation poses risks by potentially exceeding the electromagnetic field (EMF) exposure limits enforced by the regulations. To address this challenge, we propose an EMF-aware signalling design that enhances RadCom system performance while complying with EMF constraints. Our approach considers exposure levels not only experienced by network users but also in sensitive areas such as schools and hospitals, where the exposure must be further reduced. First, we model the exposure metric for the users and the sectors that encounter sensitive areas. Then, we design the waveform by exploiting the trade-off between radar and communication while satisfying the exposure constraints. We reformulate the problem as a convex optimization program and solve it in closed form using Karush–Kuhn–Tucker (KKT) conditions. The numerical results demonstrate the feasibility of developing a robust RadCom system with low electromagnetic (EM) radiations.