航空学报 > 2012, Vol. 33 Issue (8): 1498-1507

基于自适应步长选择的周期格型线搜索估计

叶浩欢, 柳征, 姜文利   

  1. 国防科学技术大学 电子科学与工程学院, 湖南 长沙 410073
  • 收稿日期:2011-11-18 修回日期:2012-01-11 出版日期:2012-08-25 发布日期:2012-08-23
  • 通讯作者: 柳征 E-mail:nudtlz@163.com
  • 基金资助:
    国家自然科学基金(61002026)

Period Estimation via Lattice Line Search with Adaptive Step-size Selection

YE Haohuan, LIU Zheng, JIANG Wenli   

  1. College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073,China
  • Received:2011-11-18 Revised:2012-01-11 Online:2012-08-25 Published:2012-08-23
  • Supported by:
    National Natural Science Foundation of China (61002026)

摘要: 稀疏、含噪观测条件下周期点过程的周期估计是一个经典的信号处理问题。针对该问题,提出了一种格型线搜索(LLS)算法,该算法通过数值方式搜索似然函数的最大值,但其性能取决于人为预先选取的搜索步长。推导了一个步长计算公式,并利用该公式改进了LLS算法。改进的LLS算法能够自适应选择搜索步长,其达到的克拉美-罗界(CRLB)的信噪比(SNR)门限与最大似然估计(MLE)算法一致,但计算复杂度比后者低一个多的数量级。性能分析与仿真实验表明,所提算法比已有算法能更好地实现估计精度与复杂度的折中。

关键词: 周期估计, 周期点过程, 格型, 搜索步长, 脉冲重复周期

Abstract: A lattice line search (LLS) algorithm is employed to estimate the period of a periodic point process when the observations are sparse and noisy. However, the algorithm involves a numerical search for the maximum of the likelihood function which is previously identified, and the chosen step-size affects estimation performance. This paper focuses on the issue of step-size determination, for which a formula is developed. By using that formula, the LLS algorithm is modified to be able to adaptively determine a suitable step-size from the observation data. Compared with the maximum likelihood estimator (MLE), the modified algorithm can attain the Cramer-Rao lower bound (CRLB) at the same signal-to-noise ratio (SNR) threshold, but its computational complexity is lower by more than one order. Performance analysis and simulations show that the proposed estimator can achieve a better tradeoff between estimation accuracy and computational complexity than do the existing estimators.

Key words: period estimation, periodic point process, lattice, step-size, pulse repetition interval

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