Study of Iterative Detection, Decoding and Channel Estimation for RIS-Aided MIMO Networks

This work proposes an iterative detection, decoding and channel estimation scheme for multiple-antenna systems assisted by multiple reflective intelligent surfaces (RIS). A novel channel estimation technique that exploits low-density parity-check (LDPC) codes and iterative processing is developed to enhance estimation accuracy while reducing the number of required pilot symbols. The key idea is to exploit encoded pilots to improve the iterative process, enabling the use of not only pilot bits but also parity bits from the coded packet to refine channel estimation. Simulations analyze a sub-6 GHz scenario where the channel propagation is not sparse and multiple RIS are deployed, considering both LOS and NLOS conditions. Numerical results show significant performance gains for the proposed scheme and estimator over competing approaches.