Author/Editorチョドカビーキットヤダ, ピーラメドダ
Chodkaveekityada, Peeramed
Alternative Title大容量衛星通信のための降雨減衰対策技術に関する研究
Note (General)Since the first satellite was launched in the 20^<th> century, satellite communication technology has been undergoing constant improvement and development to support the growing user demand. The use of satellite broadcasting in the 22 GHz band was recently proposed to transmit highcapacity signals, such as Super Hi-Vision TV. According to ITU frequency allocation, such a band is available in Regions 1 (Europe, the Middle East, Russia, and Africa) and 3 (Asia, Australia, and Oceania). Region 3 includes Japan. In these high throughput satellite and future satellite broadcasting system, rain attenuation has a strong effect on satellite communication systems that use frequencies above 10 GHz, including the Ku- and Ka-bands. Several impairment mitigation strategies including site diversity, time diversity, adaptive satellite power control, and modulation or coding control, can be used to reduce the influence of rain attenuation. Each method has unique advantages and disadvantages depending on its services. The above mentioned methods may be based on qualitative proposals or empirical knowledge. It is needed to evaluate above future methods quantitatively in order to realize efficient practical link impairments mitigation. This thesis deals mainly three rain attenuation mitigation methods to maintain satellite link service: time diversity, adaptive satellite power control and site diversity. The evaluations of these methods are done by using measured rainfall rate data all over Japan and Thailand, and measured received level data of satellite signals in Japan and Thailand. Time diversity is shown to likely be the most effective method. The adaptive satellite power control method can be used to improve satellite communication or broadcasting performance in narrow targeted areas. Regarding site diversity method, spatial correlation property of rainfall rate is investigated precisely. It is found that the spatial correlation of rainfall rates has anisotropic characteristics. This is useful to design efficient site diversity design. This thesis also re-considers the theoretical relationships among rainfall rate, attenuation and depolarization due to rain up to 100 GHz using latest rain model such a Gamma distribution raindrop size distribution. Dual polarization wireless communication link is useful to increase link capacity twice as much. However, the above mentioned depolarization effect is expected to play a more significant role in such a dual-polarized link design.
首都大学東京, 2016-09-30, 博士（工学）
Collection (particular)国立国会図書館デジタルコレクション > デジタル化資料 > 博士論文
Date Accepted (W3CDTF)2017-12-04T02:02:48+09:00
Data Provider (Database)国立国会図書館 : 国立国会図書館デジタルコレクション