A New Algorithm for Joint Range-DOA-Frequency Estimation of Near-Field Sources
- PDF / 740,127 Bytes
- 7 Pages / 600 x 792 pts Page_size
- 80 Downloads / 213 Views
A New Algorithm for Joint Range-DOA-Frequency Estimation of Near-Field Sources Jian-Feng Chen Key Lab for Radar Signal Processing, Xidian University, Xi’an 710071, China Email: [email protected]
Xiao-Long Zhu Key Lab for Radar Signal Processing, Xidian University, Xi’an 710071, China Department of Automation, Tsinghua University, Beijing 100084, China Email: xlzhu [email protected]
Xian-Da Zhang Department of Automation, Tsinghua University, Beijing 100084, China Email: [email protected] Received 20 December 2002; Revised 29 August 2003; Recommended for Publication by Zhi Ding This paper studies the joint estimation problem of ranges, DOAs, and frequencies of near-field narrowband sources and proposes a new computationally efficient algorithm, which employs a symmetric uniform linear array, uses eigenvalues together with the corresponding eigenvectors of two properly designed matrices to estimate signal parameters, and does not require searching for spectral peak or pairing among parameters. In addition, the proposed algorithm can be applied in arbitrary Gaussian noise environment since it is based on the fourth-order cumulants, which is verified by extensive computer simulations. Keywords and phrases: array signal processing, DOA estimate, range estimate, frequency estimate, fourth-order cumulant.
1.
INTRODUCTION
In array signal processing, there exist many methods to estimate the directions of arrival (DOAs) of far-field sources impinging on an array of sensors [1], such as MUSIC, ESPRIT, and so forth. Most of these methods make an assumption that sources locate relatively far from the array, and thus the wavefronts from the sources can be regarded as plane waves. Based on this assumption, each source location can be characterized by a single DOA [1]. When the source is close to the array, namely, in the near-field case, however, this assumption is no longer valid. The near-field sources must be characterized by spherical wavefronts at the array aperture and need to be localized both in range and in DOA [2, 3, 4]. The near-field situation can occur, for example, in sonar, electronic surveillance, and seismic exploration. To deal with the joint range-DOA estimation problem of near-field sources, many approaches have been presented [2, 3, 4, 5, 6, 7, 8, 9]. The maximum likelihood estimator proposed in [2] has optimal statistical properties, but it needs multidimensional search and is highly nonlinear. Huang and Barkat [3] and Jeffers et al. [4] extended the
conventional one-dimensional (1D) MUSIC method to the two-dimensional (2D) ones for range and DOA estimates. Since 2D MUSIC requires an exhaustive 2D search, their approaches are computationally inefficient. To avoid multidimensional search, Challa and Shamsunder [7] developed a total least squares ESPRIT-like algorithm which applies the fourth-order cumulants to estimate the DOAs and ranges of near-field sources. Nevertheless, it still requires heavy computations to construct a higher-dimensional cumulant matrix in order to obtain the so-
Data Loading...
