Channel Estimation for OFDM via Delay-Doppler Refinement

2026-09-09

AI Summary

本文提出了一种新的OFDM信道估计算法，通过时频域粗估计和延迟-多普勒域精炼来提高估计精度。

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.

Problem

• Channel Estimation
• OFDM
• Delay-Doppler Domain

Innovation

• Delay-Doppler Refinement
• Orthogonal Frequency Division Multiplexing (OFDM)
• Channel Estimation
• Unitary Transformation
• Threshold-based Estimation