| 引用本文: | 危政凯， 郭柏炀， 李志汇， 周青松. 基于稀疏离散余弦变换的快速时延估计[J]. 雷达科学与技术, 2025, 23(6): 635-642.[点击复制] |
| WEI Zhengkai, GUO Baiyang, LI Zhihui, ZHOU Qingsong. Fast Time Delay Estimation Based on Sparse Discrete Cosine Transform[J]. Radar Science and Technology, 2025, 23(6): 635-642.[点击复制] |
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| 摘要: |
| 在复杂的电离层环境中，多径效应对天波超视距雷达探测产生严重干扰，易产生虚假目标。对多径时延参数的快速、准确估计有助于抑制多径干扰、提升雷达探测精度，对超远距离目标探测具有重要意义。针对信号在电离层的传播特性，本文提出了一种能够基于稀疏离散余弦变换的高效多径时延估计算法，实现对接收端信号时延的快速估计。所提方法首先利用多径信号的路径稀疏特性，采用随机置换、加窗滤波、子采样离散余弦变换及哈希映射的方式，并进行迭代统计离散余弦域的峰值特性，进而实现对多径时延的高精度估计。实验表明，相较于傅里叶域的处理方法，所提算法能够有效降低时延估计的平均绝对误差，同时在噪声下具有更强的鲁棒性；相较于离散余弦变换算法，稀疏离散余弦变换算法具有更低的计算复杂度，运行时间大幅缩短。 |
| 关键词: 多径效应 时延估计 稀疏离散余弦变换 哈希映射 |
| DOI：DOI:10.3969/j.issn.1672-2337.2025.06.005 |
| 分类号:TN957.54 |
| 基金项目:国家自然科学基金（No.62301581， 62401600）； 中国博士后科学基金面上项目（No.2023M734313）； 安徽省研究生创新项目；湖南省研究生创新项目 |
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| Fast Time Delay Estimation Based on Sparse Discrete Cosine Transform |
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WEI Zhengkai, GUO Baiyang, LI Zhihui, ZHOU Qingsong
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College of Electronic Engineering, National University of Defense Technology, Hefei 230037, China
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| Abstract: |
| In complex ionospheric environments, the multipath effect causes severe interference to sky-wave over-the-horizon radar detection, easily generating false targets. Rapid and accurate estimation of multipath time-delay parameters is crucial for suppressing multipath interference, improving radar detection accuracy, and is of great significance for ultra-long-range target detection. According to the signal propagation characteristics within the ionosphere, an efficient multipath time-delay estimation algorithm based on sparse discrete cosine transform （SDCT） is proposed in this paper, achieving fast estimation of the time delays in received signals. The method first leverages the path sparsity of multipath signals, employing random permutation, windowed filtering, subsampled discrete cosine transform, and Hash mapping, combined with iterative statistical analysis of peak characteristics in the discrete cosine domain, to achieve high-precision estimation of multipath time delays. Experimental results demonstrate that compared to processing methods in the Fourier domain, the proposed algorithm effectively reduces the mean absolute error （MAE） of time-delay estimation while exhibiting stronger robustness under noisy conditions. Furthermore, compared to the standard discrete cosine transform algorithm, the sparse discrete cosine transform algorithm features lower computational complexity and significantly reduced running time. |
| Key words: multipath effect delay estimation sparse discrete cosine transform Hash mapping |
