发表机构
The University of Sydney; University of Technology Sydney; Fudan University（悉尼大学; 悉尼科技大学; 复旦大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出一种利用延迟-多普勒域特性的OFDM信道估计算法，通过紧凑时频关系、线性估计及域间转换细化，实现高精度信道估计，性能优于传统方法。
AI 中文摘要
本文针对正交频分复用（OFDM）系统，提出了一种新颖的信道估计（CE）算法，该算法利用了延迟-多普勒（DD）域信道的独特特性。具体而言，通过仅关注时频（TF）域信道矩阵的非零元素，以紧凑形式推导了时频域输入输出关系（IOR）。基于该紧凑IOR，首先使用线性最小均方误差估计器进行粗略的时频域信道估计。然后，通过酉变换将所得的时频域估计转换到延迟-多普勒域以进行进一步细化。我们揭示了有效的延迟-多普勒域信道矩阵可以视为多个具有不同相移的延迟-多普勒域信道响应的聚合。这使得我们能够设计一种基于阈值的估计方法，以高精度估计延迟-多普勒域信道参数。随后，将估计出的延迟-多普勒域信道参数用于形成时频域信道的细化估计。数值结果表明，在相同导频部署下，所提方法相比传统OFDM信道估计技术能够获得显著的性能增益。
英文摘要
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.
