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一、概述直播卫星(DBS)电视广播具有覆盖面积大、传播距离远、传输质量高等优点,是其他传播方式无法比拟的。因此,DBS电视广播在国外得到迅速发展,成为电子科学发展的一个重要方面。我国幅员辽阔,地形复杂,山区占陆地面积的百分之八十。目前电视覆盖的面积很小,人员覆盖也仅达百分之三十。因此,解决覆盖率问题是我国电视发展的当务之急。解决这个问题的最有效的办法是尽快地发展卫星直播电视。 DBS接收系统如图1所示。从卫星上发射信号(下行频率)传播到地面被接收机所接
I. Overview Direct broadcast satellite (DBS) television broadcasting has the advantages of large coverage area, long distance of transmission and high transmission quality, which is unmatched by other modes of transmission. Therefore, the rapid development of DBS television broadcasting in foreign countries has become an important aspect of the development of electronic science. My country has a vast territory and a complex terrain, with mountainous areas accounting for 80% of the land area. At present, the area covered by the television is very small and its coverage reaches only 30%. Therefore, to solve the problem of coverage is the top priority of China’s television development. The most effective way to solve this problem is to develop satellite live television as soon as possible. DBS receiving system shown in Figure 1. Transmission from the satellite signal (downlink frequency) spread to the ground by the receiver connected