Multi-Task Learning-Based Channel Estimation for RIS Assisted Multi-User Communication Systems

In this letter, we propose a multi-task learning (MTL)-based joint channel estimation scheme for reconfigurable intelligent surface (RIS) assisted millimeter-wave communication system, where the direct channel (DC) and cascaded channel (CC) are estimated at the same coherence time by learning the feature of shared pilots. Since the dimension of CC is much larger than the DC, we design a learnable ...