近几年来,加拿大、美国等一些国家已经或正在建立国内通信和电视广播兼用的低功率卫星系统,以加速国内电视广播事业的发展。尽管这类低功率卫星系统具有投资较省和技术较成熟等一些优点,但从长远来看,它将会带来许多难以解决的问题。所谓的“低功率”和“高功率”,只是一种定性的区别,至今为止,人们还没有明确规定它们的绝对阀值。但在实际应用中,高功 In recent years, some countries such as Canada and the United States have established or are establishing low-power satellite systems that serve both domestic communications and television broadcasting in order to speed up the development of domestic television broadcasting. Although such low-power satellite systems have some advantages such as relatively low-cost investment and relatively mature technologies, it will bring many unsolvable problems in the long run. The so-called “low power” and “high power” are just a qualitative difference, so far, they have not yet clearly defined their absolute threshold. However, in practice, high power