Ye Shujun, Liu Guanhao, Zhou Yan, Dang Bo
School of Information Science and Technology, Northwest University, Xian, 710127, China.
School of Electronic Engineering, Xian Shiyou University, Xian, 710065, China.
Sci Rep. 2022 Feb 22;12(1):2989. doi: 10.1038/s41598-022-04792-0.
As an emerging technology, the hybrid analog-digital structure has been considered for use in future millimeter-wave communications. Although this structure can reduce the hardware cost and power consumption considerably, the spatial covariance matrix (SCM), as the core of subspace-based direction of arrival (DOA) estimation, cannot be obtained directly. Previously, the beam sweeping algorithm (BSA) has been found effective for reconstructing the spatial covariance matrix and realizing DOA estimation by forming the beams to difference directions. However, it is computationally intractable owing to the high-dimensional matrix operation. To address this problem and improve the DOA estimation performance, this paper applies the nested array to the hybrid analog-digital structure and proposes the enhanced BSA (EBSA) for DOA estimation. By deleting a large number of redundant elements exist in the SCM to be reconstructed, the computational cost can be considerably reduced. Also, the nested array can offer high degrees of freedom. Finally, simulation experiments are conducted to verify the performance of EBSA. The results indicate that the proposed EBSA is better than the state-of-the-art method in terms of estimation accuracy and computational cost.
作为一种新兴技术，混合模拟 - 数字结构已被考虑用于未来的毫米波通信。尽管这种结构可以显著降低硬件成本和功耗，但作为基于子空间的到达方向（DOA）估计核心的空间协方差矩阵（SCM）无法直接获得。此前，已发现波束扫描算法（BSA）对于通过向不同方向形成波束来重建空间协方差矩阵和实现DOA估计是有效的。然而，由于高维矩阵运算，其计算量很大。为了解决这个问题并提高DOA估计性能，本文将嵌套阵列应用于混合模拟 - 数字结构，并提出了用于DOA估计的增强波束扫描算法（EBSA）。通过删除待重建的SCM中存在的大量冗余元素，可以显著降低计算成本。此外，嵌套阵列可以提供高自由度。最后，进行了仿真实验以验证EBSA的性能。结果表明，所提出的EBSA在估计精度和计算成本方面优于现有方法。
