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"Research of various diversity systems for improveing availability of the Ku-band and L-and satellite communication and broadcasting systems"

“研究各种分集系统，以提高 Ku 波段和 L 波段以及卫星通信和广播系统的可用性”

基本信息

批准号：
13650422
负责人：
HATSUDA Takeshi
金额：
$ 2.62万
依托单位：
Hokkaido Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2004
项目状态：
已结题

项目摘要

The satellite diversity (Sat.D) system and Time-delayed diversity (TDD) system characteristics for Ku-band and L-band satellite communication and broadcasting systems are obtained by using the GPS satellite signals and the Excel software for overcome signal level degradations caused by rain attenuation or shielding satellite signals by urban buildings and trees etc. The following results can be obtained.(1)TDD system characteristics for the L-band mobile satellite systemThe TDD system is constructed by using two radio channels. The first channel (f1) is real-time broadcast signal and the second channel (f2) is delayed-time (τ) broadcast signal. The mobile receiver receives both channels at a certain location, where satellite broadcasting signals are attenuated by buildings, etc. After several minutes, the mobile receiver receives both channels at different locations; as a result, the satellite broadcast signals are not attenuated. In the mobile receiver, the real-time signal and the de … More layed-time signal are combined or switched to a higher quality channel. By the effect of the TDD system, the availability of digital mobile broadcast satellite system can be improved.Experiments are carried out in four main cities in Hokkaido, i.e., Sapporo, Asahikawa, Otaru and Hakodate. The experimental data are processed by data process software. From analyzed results, it becomes clear that the optimum delay-times are about 3-6 minutes for TDD system. By using the TDD system, the satellite visibilities can be improved about twice.(2)Sat.D system characteristics for the L-band mobile satellite systemThe Sat.D system is constructed by using two satellites. The orbital separation angle is defined as θs and both mobile receivers are presented in the same location. The mobile receivers receive signal from both satellites at a certain location, where the signal from one satellite is attenuated by buildings, etc.; however, the signal from the other satellite is not attenuated by buildings, etc. Therefore, satellite visibilities can be improved using the Sat. D system. The experimental data are processed by data process software. By using the Sat.D system, the satellite visibilities can be improved about twice and about 90% satellite visibility can be achieved.(3)Ku-band Sat. D system characteristicsThe Ku-band Sat.D system characteristics are obtained by using a measuring system which is constructed with a spectrum analyzer and processing PC. Maximum numbers of measured satellites are seven. The measured data are processed by PC. Better improvement of rain attenuation can be obtained in winter season, because of narrower cloud distribution. More long term measurement will be necessary for more detail propagation data.(4)Proposal of TDD/Sat.D systemThe TDD/Sat.D system is proposed, and this concept is combination of TDD system and Sat.D system. By using the TDD/Sat. D system, almost perfect visibilities would be achieved. Further studies should be continued for the system design of the TDD/Sat.D system.Above mentioned results are published in the Proc.of the IEEE AP-S (Antenna and Propagation Symposium) or paper of IEICE of Japan, with 37 total paper numbers. Less

针对Ku波段和L波段卫星通信广播系统，利用GPS卫星信号和克服降雨衰减或城市建筑物、树木对卫星信号屏蔽等引起的信号电平下降的Excel软件，得到了卫星分集系统和时延分集系统的系统特性。(1)L频段移动卫星系统的时延分集系统特性。第一频道(F1)是实时广播信号，第二频道(F2)是延迟时间(τ)广播信号。移动接收器在某个位置接收两个频道，其中卫星广播信号被建筑物等衰减。几分钟后，移动接收器在不同位置接收两个频道；因此，卫星广播信号不会衰减。在移动接收器中，实时信号和De…更多的分层时间信号被组合或切换到更高质量的信道。通过TDD系统的实施，提高了数字移动广播卫星系统的可用性，并在北海道的札幌市、旭川市、大田市和函馆市四个主要城市进行了试验。利用数据处理软件对实验数据进行处理。从分析结果可以看出，TDD系统的最佳延迟时间约为3-6分钟。利用时分双星系统，卫星的能见度可以提高一倍左右。(2)L频段移动卫星系统的卫星D系统特点卫星D系统由两颗卫星组成。轨道分离角定义为θS，两个移动接收器出现在同一位置。移动接收器在某个位置接收来自两颗卫星的信号，其中一颗卫星的信号受到建筑物等的衰减；而来自另一颗卫星的信号不受建筑物等的衰减。因此，可以使用卫星来提高卫星的能见度。D系统。利用数据处理软件对实验数据进行处理。利用卫星D系统，卫星能见度可提高一倍左右，卫星能见度可达90%左右。(3)Ku波段卫星。D系统特性利用由频谱分析仪和处理PC机组成的测量系统获得Ku波段卫星D系统特性。测量卫星的最大数量是七颗。测量数据由PC机进行处理。冬季由于云层分布较窄，降雨衰减效果较好。TDD/SIT.D系统的建议TDD/SIT.D系统是TDD系统和SAT.D系统的结合。通过使用TDD/Sat。D系统，可以实现近乎完美的能见度。TDD/SIT.D系统的系统设计还有待进一步研究。上述结果发表在IEEE AP-S(天线与传播研讨会)或日本IEICE的论文上，共37篇。较少