Joint Optimization for VLC-MIMO Over-the-Air Computation With Perfect and Imperfect CSI

Abstract

This letter addresses the challenges of spectrum scarcity and co-channel interference in visible light communication (VLC) multiple-input multiple-output (MIMO) systems by introducing over-the-air computation (AirComp) technology. Under VLC-specific transmission constraints, the precoding matrices, aggregation matrix, and DC bias vectors are tightly coupled, which makes the resulting optimization problem highly non-convex. To solve this problem, we propose a Stiefel manifold-based alternating optimization (SMAO) method designed for VLC-MIMO AirComp systems to minimize the aggregation mean squared error (MSE). Simulation results show that the proposed SMAO method achieves a lower aggregation MSE than the baseline methods under both perfect and imperfect channel state information (CSI).