RIS-assisted Scheduling for High-Speed Railway Secure Communications

TL;DR

This paper introduces a RIS-assisted scheduling scheme for high-speed railway communications that enhances security and QoS by optimizing beamforming and phase shifts, outperforming existing methods.

Contribution

It proposes a novel RIS-assisted scheduling approach that jointly optimizes beamforming and phase shifts to improve task completion and security in high-speed railway wireless systems.

Findings

Outperforms baseline schemes in task completion rate.

Enhances system secrecy capacity.

Improves QoS in high-speed railway communications.

Abstract

With the rapid development of high-speed railway systems and railway wireless communication, the application of ultra-wideband millimeter wave band is an inevitable trend. However, the millimeter wave channel has large propagation loss and is easy to be blocked. Moreover, there are many problems such as eavesdropping between the base station (BS) and the train. As an emerging technology, reconfigurable intelligent surface (RIS) can achieve the effect of passive beamforming by controlling the propagation of the incident electromagnetic wave in the desired direction.We propose a RIS-assisted scheduling scheme for scheduling interrupted transmission and improving quality of service (QoS).In the propsed scheme, an RIS is deployed between the BS and multiple mobile relays (MRs). By jointly optimizing the beamforming vector and the discrete phase shift of the RIS, the constructive interference between direct link signals and indirect link signals can be achieved, and the channel capacity of eavesdroppers is guaranteed to be within a controllable range. Finally, the purpose of maximizing the number of successfully scheduled tasks and satisfying their QoS requirements can be practically realized. Extensive simulations demonstrate that the proposed scheme has superior performance regarding the number of completed tasks and the system secrecy capacity over four baseline schemes in literature.