ARIS-RSMA Enhanced ISAC System: Joint Rate Splitting and Beamforming Design
This work addresses fairness bottlenecks in multi-target sensing for ISAC systems, representing an incremental improvement over existing methods.
The paper tackles fairness in multi-target sensing for integrated sensing and communication systems under obstructed line-of-sight by proposing an ARIS-assisted RSMA scheme with optimized beamforming and rate splitting, achieving performance close to sensing-only upper bounds and outperforming baselines like nonorthogonal multiple access and passive RIS.
This letter proposes an active reconfigurable intelligent surface (ARIS) assisted rate-splitting multiple access (RSMA) integrated sensing and communication (ISAC) system to overcome the fairness bottleneck in multi-target sensing under obstructed line-of-sight environments. Beamforming at the transceiver and ARIS, along with rate splitting, are optimized to maximize the minimum multi-target echo signal-to-interference-plus-noise ratio under multi-user rate and power constraints. The intricate non-convex problem is decoupled into three subproblems and solved iteratively by majorization-minimization (MM) and sequential rank-one constraint relaxation (SROCR) algorithms. Simulations show our scheme outperforms nonorthogonal multiple access, space-division multiple access, and passive RIS baselines, approaching sensing-only upper bounds.