Encoded Jamming Secure Communication for RIS-Assisted Systems
For secure wireless communication systems, this work addresses the channel-dependent limitation of encoded jamming by introducing RIS, providing both theoretical analysis and practical optimization algorithms.
This paper proposes a joint optimization framework integrating reconfigurable intelligent surfaces (RIS) with encoded jamming (EJ) to maximize secrecy rate in wireless communications, analytically deriving conditions where EJ outperforms Gaussian noise jamming and demonstrating via simulations that RIS-assisted EJ overcomes spatial bottlenecks and outperforms optimized Gaussian noise baselines.
This paper investigates a cooperative jamming (CJ)-aided secure wireless communication system. Conventional CJ schemes transmit Gaussian noise (GN) to improve security, which inherently degrades the legitimate receiver's performance. While encoded jamming (EJ) mitigates this interference, its superiority over GN is highly channel-dependent. To overcome this limitation, we introduce a joint optimization framework integrating a reconfigurable intelligent surface (RIS) with EJ to maximize the secrecy rate. \RED{We first establish the information-theoretic relationship between the EJ and GN schemes, identifying the spatial channel conditions that limit EJ performance. For the multiple-input single-output (MISO) scenario, we analytically derive the ergodic secrecy gap as the number of RIS elements grows large and obtain a positive EJ-over-GN gap under explicit power and channel conditions.} Furthermore, for the general multiple-input multiple-output (MIMO) setup, we develop a low-complexity algorithm based on the weighted minimum mean-square-error (WMMSE) framework to handle the resulting non-smooth max-min structure through a WMMSE-based mode-selection framework. By introducing a parameterized function abstraction, the transmit precoding matrices and the RIS phase shift matrix are jointly optimized via block coordinate descent (BCD). Simulation results support the analysis and show that, under the evaluated settings, RIS-assisted EJ can overcome the identified spatial bottlenecks and outperform the optimized GN baseline.