Summary
International Symposium on Antennas and Propagation
2010
Session Number:4FD1
Session:
Number:4FD1-2
Improvement of DOA Estimation Accuracy of UWB Signal by Using Sub-Band Processing
Shohei OHAKA, Mitoshi FUJIMOTO, Toshikazu HORI,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
High resolution method for direction of arrival (DOA) estimation using array antenna is studied actively [1]. In almost previous studies, it is assumed that the antenna elements have the same directional patterns. However, it is very difficult to make many antenna elements they have just the same directional patterns. Furthermore, the directional patterns are distorted due to mutual coupling between the antenna elements. The estimation accuracy is decayed if the directional patterns are distorted intensively [2]. Generally, to avoid the effect of directional pattern distortion, antenna characteristics are calibrated before the estimation, however, it is difficult to cancel the effect of distortion when the arrival signal is very wideband because the directional patterns depend on the frequency. In this paper, sub-band technique to decrease the effect of antenna pattern distortion is proposed. And following two methods using sub-band processing are proposed for improving the estimation accuracy: (A) Averaging the estimated DOA in respective sub-bands, (B) Averaging the MUSIC spectrums of respective sub-band. Moreover, effect of correlation between arrival waves is analyzed and discussed when plural waves are arriving. It is shown that method (B) has high tolerance for amplitude and phase distortion of the element pattern.