Joint Resource Allocation and Beamforming Design for Secure Short Packet Communication in RIS-Aided MISO Systems: Invited Paper

In this work, we consider the physical-layer security problem in multi-user secure reconfigurable intelligent surface (RIS) aided multiple input single output (MISO) short packet communication systems. To enhance the secrecy transmission rate, a novel Riemannian conjugate gradient (RCG) based joint optimization algorithm is proposed for blocklength, beamforming, and RIS phase shift optimization, while subject to resource limitation, unit norm, and unit modulus constraints. More specifically, we first derive the closed-form expression of blocklength and convert the original problem to a more manageable form, which only involves beamforming and RIS phase design. To address the unit norm and unit modulus constraints, the RCG algorithm is utilized for beamforming and RIS phase shift joint optimization. Numerical results demonstrate that our proposed algorithm outperformance the baseline scheme.