Receiving RISs: Enabling Channel Estimation and Autonomous Configuration

Wed, 01 Apr 2026 00:00:00 +0000

Key Contributions

Proposes a semi-passive RIS architecture with RF chains that enables active channel estimation via tunable absorption phase profiles, eliminating the need for external pilot injection.
Introduces a channel estimation protocol exploiting beamspace sparsity and low-rank structure of extremely large MIMO channels, solved efficiently via ADMM.
Demonstrates how RIS-side channel estimates can be leveraged to autonomously optimize phase-quantized reflection coefficients, enabling self-configuring RIS operation.