Delay-Doppler Domain Estimation of Doubly Selective Channels for Single-Carrier Systems

作者：Cheng Shen, Jinhong Yuan, Yixuan Xie, Hai Lin, Zhi Ding · 发表于：IEEE Transactions on Wireless Communications · 年份：2025 · DOI：10.1109/twc.2025.3582426 · 被引用次数：2 · 研究领域：Advanced Wireless Communication Techniques、Wireless Communication Networks Research、Satellite Communication Systems

This paper introduces a novel method to estimate doubly selective channels for single-carrier (SC) communication systems in high-mobility environments. We propose a transmission frame structure featuring adaptive pilot insertions tailored to the Doppler spread, and an adaptive threshold-based channel estimation method that leverages the delay-Doppler (DD) domain channel characteristics. To mitigate the peak-to-average power ratio (PAPR) and reduce pilot overhead, we further generalize the frame structure from single-pilot scheme to multiple-pilot scheme and propose the design criteria for the pilot. By employing zero correlation zone (ZCZ) sequences with ZCZ sizes equal to or greater than the normalized maximum Doppler shift of the channel, we show that the multiple-pilot scheme effectively enhances estimation accuracy without inducing significant PAPR and pilot overhead increment. For both schemes, we also derive the asymptotically optimal thresholds for DD channel tap detection to minimize mean square error (MSE) of the estimation. Moreover, the closed-form approximation of Cramer-Rao Lower Bound for the channel estimation error is also derived, serving as a performance benchmark. Comparative analysis demonstrates that our proposed method significantly outperforms conventional interpolation techniques in estimating doubly selective fading channels, thereby illustrating its efficacy and practical utility in SC systems.