Joint Design of Receive Beamforming and RIS Configuration for Over-the-Air Computation

This work addresses the minimization of mean-squared error (MSE) in an over-the-air system aided by reconfigurable intelligent surfaces (RIS). By jointly optimizing the receive beamforming vector at the base station and the reflection coefficients of the RIS, we aim to improve the accuracy of signal aggregation under device power constraints. We depart from conventional uniform-forcing methods by introducing a misalignment-allowed optimization (Miso) framework that improves performance. Simulations show the proposed algorithms reduce MSE significantly compared to prior methods.