Channel Estimation for OFDM via Delay-Doppler Refinement
Abstract
In this paper, we propose a novel channel estimation (CE) algorithm for orthogonal frequency division multiplexing (OFDM) systems that exploits the unique characteristics of the delay-Doppler (DD) domain channel. Specifically, the time-frequency (TF) domain input-output relationship (IOR) is derived in a compact form by focusing solely on the non-zero elements of the TF domain channel matrix. Based on this compact IOR, a coarse TF domain CE is first performed using a linear minimum mean square error estimator. Then, the resultant TF domain estimates are transformed to the DD domain through a unitary transformation for further refinement. We reveal that the effective DD domain channel matrix can be viewed as an aggregation of multiple DD domain channel responses with different phase shifts. This allows us to devise a threshold-based estimation for DD domain channel parameters with high accuracy. The estimated DD domain channel parameters are then applied to form a refined estimate of TF domain channel. Our numerical results demonstrate that the proposed method can achieve substantial performance gains over conventional OFDM channel estimation techniques under the same pilot deployment.
Related
- Neural Network-Based Delay-Doppler-Assisted Channel Estimation for OFDM
- Delay-Doppler Domain Channel Estimation: What if Sparsity is Unknown?
- Model-Order-Adaptive Channel Estimation for AFDM Systems with Fractional Delay and Doppler
- Two-Stage Refinement Sparse Channel Estimation for Reconfigurable Intelligent Metasurface Antenna (RIMSA) Massive MIMO
- On Diagonalizable Delay-Doppler Channels and Their Diagonalizing Waveforms
BibTeX
@misc{nie2026channel,
title = {{Channel Estimation for OFDM via Delay-Doppler Refinement}},
author = {Mingcheng Nie and Hao Chang and Xiaoqi Zhang and Junkai Liu and Wibowo Hardjawana and Branka Vucetic and Yonghui Li},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.09782},
eprint = {2609.09782},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.09782},
}
RIS
TY - UNPB
TI - Channel Estimation for OFDM via Delay-Doppler Refinement
AU - Mingcheng Nie
AU - Hao Chang
AU - Xiaoqi Zhang
AU - Junkai Liu
AU - Wibowo Hardjawana
AU - Branka Vucetic
AU - Yonghui Li
PY - 2026
DA - 2026/09/09
PB - arXiv
DO - 10.48550/arxiv.2609.09782
UR - https://arxiv.org/abs/2609.09782
AB - In this paper, we propose a novel channel estimation (CE) algorithm for orthogonal frequency division multiplexing (OFDM) systems that exploits the unique characteristics of the delay-Doppler (DD) domain channel. Specifically, the time-frequency (TF) domain input-output relationship (IOR) is derived in a compact form by focusing solely on the non-zero elements of the TF domain channel matrix. Based on this compact IOR, a coarse TF domain CE is first performed using a linear minimum mean square error estimator. Then, the resultant TF domain estimates are transformed to the DD domain through a unitary transformation for further refinement. We reveal that the effective DD domain channel matrix can be viewed as an aggregation of multiple DD domain channel responses with different phase shifts. This allows us to devise a threshold-based estimation for DD domain channel parameters with high accuracy. The estimated DD domain channel parameters are then applied to form a refined estimate of TF domain channel. Our numerical results demonstrate that the proposed method can achieve substantial performance gains over conventional OFDM channel estimation techniques under the same pilot deployment.
ER -