| Free Space Optics (FSO) is a kind of bidirectional broadband wireless communication technology that can directly transmit data, voice, and video et al. It uses the infrared laser as the carrier and the atmosphere as the media. Since FSO has the advantage of flexibility as RF communication, and the advantages of great capacity, good concealing and high reliability as fiber communication, as a new broadband wireless communications technology, it has become middle/short-range solutions in broadband applications. For FSO, APT is a key technology to establish and maintain the communication link.Due to the notable influence of atmospheric effect and the objects’ relative motion, the Acquisition, Pointing and Tracking (APT) technique based on the traditional mechanical methods such as stepping motor or galvanometer cannot meet the demand of the mobile especially the fast mobile Free-space-optical Communication (FSO). Aiming at the location problem of mobile FSO, this project researches the beam forming theory and method based on optical smart antenna, and explores the new approach of APT at conditions of objects moving. For this purpose, the influence of communication distance and object speed on smart beam forming has been analyzed, and an optical smart antenna model has been presented. To improve the antenna’s efficiency, an equidistant (or not equidistant) and fundamental (or sparse) array element distribution method has been researched. Under different moving speed, communication scope and the divergence angle, the array element distribution method and the rotational speed of antenna has also been presented and analyzed. All the theories and methods in this project have the advantage of improving the quality and flexibility of laser communication under all kinds of complex movement conditions. Also, they have vital significance to real-time accurate APT technique of mobile FSO system. |
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