English  |  正體中文  |  简体中文  |  Items with full text/Total items : 28611/40649
Visitors : 630366      Online Users : 91
RC Version 4.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Adv. Search
LoginUploadHelpAboutAdminister

Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/10102

Title: 針對近場訊號源之適應性陣列研究
The Study of Adaptive Array for Near-Field Signal Sources
Authors: 張麗娜
Contributors: NTOU:Department of Merchant Marine
國立臺灣海洋大學:商船學系
Keywords: 指向向量;信號子空間;Toeplitz結構
Steering vector;Signal subspace;Toeplitz structure
指向向量;信號子空間;適應性天線;電腦模擬;消除干擾
Steering vector,Signal subspace;Adaptive antenna;Computer simulation;Suppress interference;Toeplitz structure
Date: 1995-08
Issue Date: 2011-06-28T07:28:14Z
Publisher: 行政院國家科學委員會
Abstract: 摘要:適應性天線陣列在正確知道所欲接收信號之方向向量時,可有效且自動地將干擾消除。但通常我們都假設訊號源位於遠場,即視陣列元所接收的訊號為平面波,然而,當訊號源與陣列之距離有限時,則實際訊號為球面波。因此遠場訊號源之假設造成了指向向量有誤差存在。此指向誤差將使適應性天線陣列將所欲接收之信號誤以為是干擾而予以濾除。為了減緩近場效應所造成陣列效能的衰減,本研究首先以特徵空間為基礎之波束形成法校正有誤差之指向向量,探討其效能受近場訊號源之影響並與傳統波束形成法做一比較。接著,我們以重建遠場訊號源自相關矩陣所具有之Toeplitz結構來設計波束形成器之權重,並以電腦模擬驗證其效能。最後我們提出子陣列之結構來結合信號原有特徵空間之性質及自相關矩陣Toeplitz結構之特性來減緩天線陣列因近場訊號源所造成之效能衰減。
Abstract:Adaptive antennas can suppress the interference efficiently, when the direction vector of the desired signal (steering vector) is correctly set. However, for an imperfect steering vector, the adaptive antenna array tends to suppress not only the interference but also the desired signal. Various kinds of error may exist in the steering vector, for example, error caused by the assumption that the signal source is at the far-field range, while in general, it is not. To alleviate the performance degradation caused by the finite-distance signal source, we first apply the eigenspace-based beamformer to correct the far-field steering vector and analyze its performance. Then, we develop an adaptive array based on the reconstructive Toeplitz structure of the correlation matrix and examine its performance by computer simulations. Finally, we propose a partial adaptive array which combines the eigenspace-based beamformer and the adaptive array with weights computed by the reconstructive Toeplitz structure of correlation matrix.
Relation: NSC85-2213-E019-001
URI: http://ntour.ntou.edu.tw/ir/handle/987654321/10102
Appears in Collections:[商船學系] 研究計畫

Files in This Item:

File Description SizeFormat
index.html0KbHTML94View/Open


All items in NTOUR are protected by copyright, with all rights reserved.

 


著作權政策宣告: 本網站之內容為國立臺灣海洋大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用,請合理使用本網站之內容,以尊重著作權人之權益。
網站維護: 海大圖資處 圖書系統組
DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback