In this paper, we introduce a novel Multi-Layered Irregular Reconfigurable Intelligent Surface (MLI-RIS) architecture designed to enhance the performance of future 6G wireless communication systems. Unlike traditional regular RIS designs, which suffer from high overhead and inefficiency in dynamic channels, the proposed MLI-RIS disperses elements irregularly across multiple layers, leveraging spatial degrees of freedom to optimize system capacity and signal strength.

Our optimization framework focuses on maximizing key performance metrics such as Weighted Sum Rate (WSR), Rate-Energy Product (REP), and Energy-Constrained Rate (ECR). To achieve this, we decouple the MLI-RIS topology design from precoding and phase optimization, employing advanced techniques like Modified Tabu-Hybrid Sophisticated Neighbor Search-Simulated Annealing (MT-HSNS-SA) and Neighborhood Exploration and Refinement-Cross Entropy (NR-CE) with Iterative Water Filling (IWF) for efficient optimization. Through extensive simulations, we demonstrate that the proposed MLI-RIS architecture significantly outperforms conventional multi-layer regular RIS setups, substantially improving energy and spectral efficiency.

Our findings underscore the transformative potential of the MLI-RIS architecture, positioning it as a key enabler in the evolution of future wireless communication paradigms, with notable applications in improving the energy and capacity efficiency of 6G networks.

Multi-Layer Irregular RIS aided communication system

Original link:https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10706103