Multi-dimensional Parameter Estimation in RIS-aided MU-MIMO-OFDM Channels

TL;DR

This paper introduces a novel dual-structure and multi-dimensional transformation algorithm for channel estimation in RIS-aided MU-MIMO-OFDM systems, significantly improving accuracy and reducing complexity.

Contribution

It proposes a new DS-MDT algorithm that exploits dual-structure features and multi-dimensional transformations for enhanced channel estimation in RIS-assisted systems.

Findings

Reduces NMSE by up to 10 dB

Maintains lower complexity than existing methods

Improves CE performance for weak channel conditions

Abstract

We address the channel estimation (CE) problem in reconfigurable intelligent surface (RIS) aided orthogonal frequency-division multiplexing (OFDM) systems by proposing a dual-structure and multi-dimensional transformations (DS-MDT) algorithm.The proposed approach leverages the dual-structure features of the channel parameters to assist users experiencing weaker channel conditions, thereby enhancing CE performance. Moreover, given that the channel parameters are distributed across multiple dimensions of the received tensor, the proposed algorithm employs multi-dimensional transformations to isolate and extract distinct parameters. The numerical results demonstrate the proposed algorithm reduces the normalized mean square error (NMSE) by up to 10 dB while maintaining lower complexity compared to state-of-the-art methods.