Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Near-Field Source Localization by Using Focusing Technique | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID461517 9 pages doi 2008 461517 Research Article Near-Field Source Localization by Using Focusing Technique Hongyang He Yide Wang and Joseph Saillard Ecole Polytechnique de I Universite de Nantes Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique IREENA Rue Christian Pauc BP 50609 44306 Nantes Cedex 3 France Correspondence should be addressed to Hongyang He Received 2 June 2008 Revised 30 September 2008 Accepted 7 November 2008 Recommended by M. Greco We discuss two fast algorithms to localize multiple sources in near field. The symmetry-based method proposed by Zhi and Chia 2007 is first improved by implementing a search-free procedure for the reduction of computation cost. We present then a focusing-based method which does not require symmetric array configuration. By using focusing technique the near-field signal model is transformed into a model possessing the same structure as in the far-field situation which allows the bearing estimation with the well-studied far-field methods. With the estimated bearing the range estimation of each source is consequently obtained by using 1D MUSIC method without parameter pairing. The performance of the improved symmetry-based method and the proposed focusing-based method is compared by Monte Carlo simulations and with Crammer-Rao bound as well. Unlike other near-field algorithms these two approaches require neither high-computation cost nor high-order statistics. Copyright 2008 Hongyang He et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION In the last two decades subspace-based methods for estimating the directions of arrival DOA of far-field sources impinging on an array of .
