RIS-Assisted D-MIMO for Energy-Efficient 6G Indoor Networks
This work addresses energy efficiency challenges for future 6G indoor network deployments, representing an incremental improvement with specific design insights.
The paper tackles the problem of maximizing energy efficiency in RIS-assisted distributed MIMO systems for 6G indoor networks by proposing an alternating optimization framework that jointly optimizes access point power allocation and RIS phase configurations, achieving clear energy efficiency gains over baselines in simulations with realistic power-consumption models.
We propose an alternating optimization framework for maximizing energy efficiency (EE) in reconfigurable intelligent surface (RIS) assisted distributed MIMO (D-MIMO) systems under both coherent and non-coherent reception modes. The framework jointly optimizes access point (AP) power allocation and RIS phase configurations to improve EE under per-AP power and signal-to-interference-plus-noise ratio (SINR) constraints. Using majorization-minimization for power allocation together with per-element RIS adaptation, the framework achieves tractable optimization of this non-convex problem. Simulation results for indoor deployments with realistic power-consumption models show that the proposed scheme outperforms equal-power and random-scatterer baselines, with clear EE gains. We evaluate the performance of both reception modes and quantify the impact of RIS phase-shift optimization, RIS controller architectures (centralized vs. per-RIS control), and RIS size, providing design insights for practical RIS-assisted D-MIMO deployments in future 6G networks.