Intelligent Reflecting Surface-Assisted Over-the-Air Computation for Backscatter Sensor Networks

For achieving efficient data aggregation and energy supply in Internet of Things, this paper investigates the optimal design for an intelligent reflecting surface (IRS)-aided backscatter sensor network with over-the-air computation (AirComp). To ensure accuracy aggregation, presents a mean-squared error (MSE) minimization problem via jointly optimizing normalization factor, power splitting ratios devices (BDs), phase shifts IRS. Inspired by block coordinate descent technique, we propose alternating optimization method to solve formulated non-convex problem. Specifically, derive factor closed-form expressions, exploit variable substitution technique semi-definite relaxation address shift subproblem. Simulation results demonstrate significant MSE reduction achieved proposed method, comparison other benchmark methods.