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兵工学报 ›› 2023, Vol. 44 ›› Issue (5): 1521-1528.doi: 10.12382/bgxb.2022.0025

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基于自然对数复合函数近似l0范数的DOA估计

单泽彪1,2,3, 常立民1, 刘小松1,*(), 王宇祥1   

  1. 1 长春理工大学 电子信息工程学院, 吉林 长春 130022
    2 吉林大学 通信工程学院, 吉林 长春 130022
    3 长春气象仪器研究所, 吉林 长春 130102
  • 收稿日期:2022-01-08 上线日期:2022-07-10
  • 通讯作者:
    *邮箱: E-mail:
  • 基金资助:
    国家自然科学基金项目(61571462); 吉林省自然科学基金项目(YDZJ202301ZYTS412)

DOA Estimation Based on Approximate l0 Norm of Natural Logarithm Composite Function

SHAN Zebiao1,2,3, CHANG Limin1, LIU Xiaosong1,*(), WANG Yuxiang1   

  1. 1 School of Electronic and Information Engineering, Changchun University of Science and Technology, Changchun 130022, Jilin, China
    2 College of Communication Engineering, Jilin University, Changchun 130022, Jilin, China
    3 Changchun Meteorological Instrument Research Institute, Changchun 130102, Jilin, China
  • Received:2022-01-08 Online:2022-07-10

摘要:

针对现有基于压缩感知的DOA估计算法收敛速度慢、精度不高等问题,提出一种基于自然对数复合函数近似l0范数的DOA估计算法。新算法采用一种自然对数复合函数来近似l0范数,将求解l0范数问题转化为近似l0范数的最优化问题。采用牛顿迭代法获得自然对数复合函数(即近似l0范数)的迭代表达式,通过内外双层循环的方法获得牛顿迭代的最优解,即通过外层循环控制函数逼近因子σ的大小,内层循环采用最陡梯度法对牛顿迭代表达式进行求解,经有限次迭代即可获得近似l0范数的最优解,进而得到DOA的估计值。通过仿真实验验证新算法的有效性,结果表明新算法在单快拍条件下即可实现DOA有效估计,且与平滑l0范数算法及其改进算法相比具有更快的计算速度和更高的估计精度。

关键词: 波达方向估计, 压缩感知, 近似l0范数, 自然对数复合函数

Abstract:

A DOA estimation algorithm based on a natural logarithm compound function approximating l0 norm is proposed to address the issues of slow convergence and low accuracy of existing compressed-sensing-based DOA estimation algorithms. We transform the problem of solving the l0 norm into an optimization problem of approximating the l0 norm by using a natural logarithm compound function. The Newton iteration method is employed to obtain the iteration expression of the natural logarithm compound function (for approximating l0 norm).The optimal solution of Newton iteration is obtained through inside and outside double-loop iteration, where the outside loop controls the magnitude of function approximation factor σ, and the inside loop solves the Newton iteration expression using the steepest descent method. The optimal solution of the approximate l0 norm is obtained after finite iterations, and the estimated value of DOA can be obtained. Simulation results show that the proposed algorithm achieves effective DOA estimation under the condition of a single snapshot, and outperforms the existing smoothened l0 norm algorithm and its improved algorithms in terms of speed and accuracy.

Key words: DOA estimation, compressed sensing, approximate l0 norm, natural logarithm composite function