数字卫星地球站的系统设计和传输链路计算

卫星传输是广播电视节目主要传输手段之一．卫星地球站由模拟传输转为数字传输，其优势更加明显．以国家广播电影电视总局批准建设项目——浙江省广播电视数字卫星地球站为背景，运用视音频编码技术、数字传输技术和卫星通信技术，对数字卫星站系统功能和系统要求作了详细的阐述，对数字电视编码调制、卫星上行射频和音频切换监视等分系统的设计和构成作了具体介绍，并根据卫星上下行链路计算对卫星租用带宽、上行功率、天线接收系统品质因素等技术参数进行了分析和评价．该项目于2004年获国家广电总局科技创新三等奖，说明设计思路和链路计算方法是合理的.

The system design and link calculation in digital satellite broadcast earth station

The satellite transmission is one of the main means for broadcast transmission.The advantages are more obvious when the satellite broadcast earth station is changed from analog transmission to digital transmission.In this paper,the research work is based on a construction project approved by The State Administration of Radio,Film &TV,P.R.China.The audio and video coding technology,digital transmission technology and satellite communication technology used in this paper are introduced.The system functions and requirements of digital satellite broadcast earth station are discussed in detailed.Digital audio and video coding system,Satellite uplink RF system and audio or video switching and monitoring system are described too.According to calculation of program transmission unlink and downlink,the leased satellite band-width,unlink power,receiving antenna quality factor and other technical parameters are analyzed and evaluated.Zhejiang digital satellite broadcast earth station won the third rank scientific and technological innovation award in 2004.The design and link calculation methods are proved to be reasonable and reliable.