Joint CFO, Gridless Channel Estimation and Data Detection for Underwater Acoustic OFDM Systems
Joint CFO, Gridless Channel Estimation and Data Detection for Underwater Acoustic OFDM Systems
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DOI：
10.1109/joe.2022.3162025
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发表时间：
2021-07
影响因子：
4.1
通讯作者：
L. Wan;Jiang Zhu;En Cheng;Zhiwei Xu
中科院分区：
文献类型：
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作者：
L. Wan;Jiang Zhu;En Cheng;Zhiwei Xu
在本文中，我们提出了一种基于无网格变分贝叶斯谱估计（VALSE）的迭代接收机，称为JCCD-VALSE，它可以联合估计载波频偏（CFO）和高分辨率信道，并进行数据解码。基于模块化的观点，以高分辨率、低复杂度的无网格VALSE算法为动力，构建了VALSE模块、CFO估计（CFO测试）模块和解码器模块。模块间交换软信息，逐步提高信道估计和数据解码精度。由于将信道的多径延迟作为连续参数处理，而不是在网格上处理，避免了泄漏效应。此外，该方法是一种更完整的贝叶斯方法，所有的干扰参数，如噪声方差、信道先验分布参数和路径数都是自动估计的。数值模拟和海上试验数据表明，该方法优于现有的基于网格的联合信道和数据解码方法。此外，还验证了包括CFO估计在内的联合处理提供了性能增益。
In this article, we propose an iterative receiver based on gridless variational Bayesian line spectra estimation (VALSE), named JCCD-VALSE, that jointly estimates the carrier frequency offset (CFO), the channel with high resolution and carries out data decoding. Based on a modularized point of view and motivated by the high resolution and low-complexity gridless VALSE algorithm, three modules named the VALSE module, the CFO estimation (CFO est.) module, and the decoder module are built. Soft information is exchanged between the modules to progressively improve the channel estimation and data decoding accuracy. Since the delays of multipath of the channel are treated as continuous parameters instead of on a grid, the leakage effect is avoided. Beside, the proposed approach is a more complete Bayesian approach as all the nuisance parameters, such as the noise variance, the parameters of the prior distribution of the channel, and the number of paths are automatically estimated. Numerical simulations and sea test data are utilized to demonstrate that the proposed approach performs better than the existing grid-based joint channel and data decoding approaches. Furthermore, it is also verified that joint processing, including CFO estimation, provides performance gain.