卫星通信

ABSTRACT Satellite communication is one of the modern communication techniques.

卫星通信是现代通信技术之一。

In this paper we have described the origin and way of development of pack t satellite communication and pointed out its status and function in the future.

本文综合介绍了分组卫星通信的发展过程，并指出了它在未来通信中的地位和作用。

Satellite communication, as one of the significant modern communication technologies, has made a great deal of progress during the past 30 years.

卫星通信作为重要的现代通信技术之一，也取得了极大的进步。

The modem method has been employed in mobile communication system, satellite communication system.

在移动通信、卫星通信中得到广泛应用。

VSAT is a hotspot in satellite communications arid has been widely used in communications,finance and enterprise network .

VSAT已成为卫星通信领域的热点，广泛的应用于通信、金融等行业。

Therefore, in order to ensure the transmission quality, reliability and economical efficiency, we must master the rainfall attenuation influence of earth station setting areas accurately while the designing the earth-space satellite communication links.

因此，在设计地—空卫星通信线路时，为了保证通信系统传输质量、提高可靠性及经济性，就必须要准确地掌握地面站设置区域的降雨衰减所产生的影响。

The arithmetic operations in Galois field is central in the implementation of Reed-Solomon coders,storage and cryptographic algorithms.Multiplication is the most complicated arithmetic operation in Galois field.

1引言纠错编码技术在卫星通信、移动通信、数据存储、以及加密等领域已广泛应用，其中Reed-Solo-mon码是最重要的、也是研究最多的码类之一，已被多个国际标准采用。

Radio-frequency interference will cause severe degradation on satellite communications link performance,and adaptive nulling antenna is an effective anti-jamming measure for communication satellite.

射频干扰会严重影响卫星通信链路性能，而自适应调零天线是一种有效的卫星抗干扰措施。

A series of ka-band propagation experiments supported by ETS-II ,Olympus, ITALSAT. ACTS . Techniques such as rain fade mitigation, spot beam and shape beam have been developed . the commercial apply of ka-band satelliate will be soon.

Ka波段的试验卫星如ETS-Ⅱ、Olympus、ITALSAT、ACTS等已经证实了ka波段卫星通信的可能性，所采用的信道编码、点波束、数据速率调整等抗雨衰关键技术都已成熟，估计第一颗商用通信卫星将会在数年内投入使用。

Nowadays, the 9th generation Intelsat satellites are providing service in orbit, and satcom has become most successful space technology in economy.

目前，已有第9代Intelsat卫星在轨提供服务。卫星通信成为经济上最为成功的空间技术。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐