Artificial-Noise Aided Design for Movable-Antenna Enabled Physical-Layer Service Integration

TL;DR

This paper introduces a novel artificial-noise aided movable-antenna scheme for physical-layer service integration, improving secrecy and multicast reliability through joint antenna positioning and transmit design.

Contribution

It proposes a new joint design framework leveraging movable antennas and artificial noise, with a closed-form AN power allocation and a low-complexity optimization algorithm.

Findings

Significant secrecy performance gains achieved.

Low computational complexity and fast convergence.

Effective for movable-antenna-enabled physical-layer service systems.

Abstract

This paper pioneers a novel scheme for artificial-noise (AN)-aided movable-antenna (MA)-enabled physical-layer service integration (PLSI) to harmonize the simultaneous delivery of multicast and confidential messages. By jointly exploiting the spatial reconfiguration capability of MAs and the interference shaping capability of AN, we aim to enhance secrecy performance while guaranteeing multicast reliability. The joint design of MA positions and transmit variables results in a highly coupled and non-convex optimization problem. To address this, we first provide key insights into the role of spatial degrees of freedom in AN design. We then characterize the AN direction under a structured transmission design and derive a closed-form expression for the AN-to-confidential power allocation ratio, which significantly simplifies the overall design. To solve the resulting problem, we further develop a low-complexity block coordinate ascent (BCA)-based scheme that alternates between transmit design and MA position optimization. Numerical results demonstrate that the proposed scheme achieves significant secrecy performance gains with low computational complexity and fast convergence, highlighting its effectiveness for MA-enabled PLSI systems.