Physical-Layer Security Improvement with Reconfigurable Intelligent Surfaces for 6G Wireless Communication Systems

Area of Science:

• Wireless communication systems
• Information theory
• Signal processing

Background:

• Reconfigurable intelligent surfaces (RISs) offer flexible and cost-effective signal manipulation for wireless networks.
• RIS-aided techniques are crucial for enhancing data rate and energy efficiency in 6G systems.
• Physical-layer security (PLS) is a critical concern in wireless networks, especially with increasing eavesdropping threats.

Purpose of the Study:

• To propose and evaluate a novel RIS-based channel randomization (RCR) technique.
• To improve the physical-layer security (PLS) of a time-division duplex (TDD) downlink cellular wire-tap network.
• To enhance achievable secrecy rates in 6G wireless communication systems.

Main Methods:

• A novel RIS-based channel randomization (RCR) technique is proposed for a TDD downlink cellular wire-tap network.
• Multiple RISs pseudo-randomly generate reflection matrices for pilot signal duration (PSD) and data transmission duration (DTD).
• The base station (BS) estimates channels using RIS reflection matrices and selects the user equipment (UE) with the best secrecy rate.

Main Results:

• The proposed RCR technique demonstrates superior performance in terms of achievable secrecy rates.
• Channel randomization via RIS effectively enhances physical-layer security against eavesdroppers.
• The technique is particularly relevant for 6G systems utilizing tera-hertz (THz) spectrum bands with line-of-sight (LOS) channels.

Conclusions:

• The RCR technique offers a significant advancement in securing wireless communications.
• RIS technology holds great potential for bolstering physical-layer security in future wireless networks.
• This approach provides a viable solution for enhancing secrecy rates in 6G TDD systems.