Individual Channel Estimation for Beyond Diagonal Reconfigurable Intelligent Surfaces

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Zhao, Kangchun, Mao, Yijie
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918233687195648
author Zhao, Kangchun
Mao, Yijie
author_facet Zhao, Kangchun
Mao, Yijie
contents Beyond Diagonal Reconfigurable Intelligent Surfaces (BD-RIS) has emerged as a promising evolution of RIS technology. By enabling interconnections between RIS elements, BD-RIS architectures offer greater flexibility in wave manipulation compared to traditional diagonal RIS designs. However, these interconnections introduce new research challenges for channel estimation, making existing approaches developed for conventional diagonal RISs ineffective and significantly increasing pilot overhead. To address these challenges, we propose a novel individual channel estimation framework that separately estimates the BS-RIS channel, which typically remains static over time, and the RIS-user channels, which vary rapidly due to user mobility. Specifically, we develop a full-duplex (FD) approach to estimate the BS-RIS channel by leveraging its inherent sparsity. Following this, the RIS-user channels are estimated using a least squares (LS) approach. Numerical results demonstrate that the proposed framework achieves significantly higher channel estimation accuracy, particularly when the number of RIS elements is large, while substantially reducing pilot overhead compared to conventional cascaded channel estimation methods.
format Preprint
id arxiv_https___arxiv_org_abs_2512_05404
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Individual Channel Estimation for Beyond Diagonal Reconfigurable Intelligent Surfaces
Zhao, Kangchun
Mao, Yijie
Signal Processing
Beyond Diagonal Reconfigurable Intelligent Surfaces (BD-RIS) has emerged as a promising evolution of RIS technology. By enabling interconnections between RIS elements, BD-RIS architectures offer greater flexibility in wave manipulation compared to traditional diagonal RIS designs. However, these interconnections introduce new research challenges for channel estimation, making existing approaches developed for conventional diagonal RISs ineffective and significantly increasing pilot overhead. To address these challenges, we propose a novel individual channel estimation framework that separately estimates the BS-RIS channel, which typically remains static over time, and the RIS-user channels, which vary rapidly due to user mobility. Specifically, we develop a full-duplex (FD) approach to estimate the BS-RIS channel by leveraging its inherent sparsity. Following this, the RIS-user channels are estimated using a least squares (LS) approach. Numerical results demonstrate that the proposed framework achieves significantly higher channel estimation accuracy, particularly when the number of RIS elements is large, while substantially reducing pilot overhead compared to conventional cascaded channel estimation methods.
title Individual Channel Estimation for Beyond Diagonal Reconfigurable Intelligent Surfaces
topic Signal Processing
url https://arxiv.org/abs/2512.05404