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数字电视信号的传送由PCM传送系统完成。PCM传送媒介分有线和无线两大类。同轴电缆、光导纤维等属有线传输信道;用微波站中继传输、卫星传输等属无线信道。光纤及卫星传输是正在迅速发展的传输方法。 4—1 PCM传送系统的构成 PCM传送系统的构成示于图1。此系统方框图是以基带传输为例,输入的模拟信号先要加以频带限制,以避免产生折叠噪声,然后
Transmission of digital television signals is accomplished by the PCM transmission system. PCM transmission media sub-wire and wireless sub-categories. Coaxial cable, optical fiber is a wired transmission channel; with microwave relay transmission, satellite transmission is a wireless channel. Fiber and satellite transmission is a rapidly evolving method of transmission. 4-1 Structure of PCM Transmission System The structure of the PCM transmission system is shown in FIG. The system block diagram is based on the baseband transmission, for example, the first input analog signal to be band-limited to avoid folding noise, and then