Electromagnetic Interference in RIS-Aided Communications

Physical Layer Security of RIS-Assisted Communications under Electromagnetic Interference

“…3 includes the presence of both direct and indirect channels. For convenience of discussion, we define ρ = P β1 σ 2 EMI as in [4] as the ratio between the signal power and EMI power at each of the RIS elements. Monte Carlo (MC) simulations are provided to double-check the validity of the approximations made throughout the analysis.…”

“…We also assume that the RIS is subject to EMI, which is produced by controllable/uncontrollable sources in the far-field of the RIS. According to [4], the received signals at both B and E can be written as where i ∈ {B, E} indicates either the legitimate or the eavesdropper channels, P is the transmit power at A, x is the transmitted signal with E{|x| 2 } = 1, and n i ∼ CN (0, σ 2 i ) is the additive white Gaussian noise with σ 2 i power. The EMI effect is denoted by the vector ν ∈ C N ×1 , h d,i ∈ C M×1 refers to the direct channel between A-to-B or A-to-E, w ∈ C M×1 denotes the beamforming vector at and g n is the nth row vector of G. In such a setup, the phases φ 1...n and the transmit beamforming vector w are jointly optimized [12] to maximize the received signal-to-noise ratio (SNR) at B.…”

“…These can be dynamically configured to tune the phases and amplitudes of the impinging waves on the RIS, helping to overcome the detrimental effects of the wireless channel [1]. While RISs have a tremendous potential to be a game-changer technology on the verge of 6G, practical impairments related to their implementation and deployment are known to limit their performance; these are the cases of imperfect phase-shift compensation [2], spatial correlation [3] or, very recently, electromagnetic interference (EMI) [4].…”

“…A large body of research has been motivated by the potential of integrating both RIS and PLS to enable secure and intelligent radio environments [7][8][9][10]. However, even though the effect of the EMI present in any wireless environment is known to affect RIS-aided communications [4], its effects in physical layer security have not been analyzed yet. Since EMI can appear from intentional and non-intentional (e.g., natural pollution/radiation) causes [4], it can play a key role in compromising the security of communications.…”

“…However, even though the effect of the EMI present in any wireless environment is known to affect RIS-aided communications [4], its effects in physical layer security have not been analyzed yet. Since EMI can appear from intentional and non-intentional (e.g., natural pollution/radiation) causes [4], it can play a key role in compromising the security of communications. From a PLS perspective, intentional signals can be induced in a cooperative jamming-eavesdropping fashion.…”