Analog signal transmission system

Analog signal transmission systems, signals vary continuously over time, must be based on linear modulation and linear transfer systems, single side band modulation of modulated signal bandwidth can be the same as the original signal, with its frequency-multiplexed system made up of highly utilized, for bandwidth-constrained metal cables. In the wireless transmission system, in order to overcome the interference and fading, most second modulation of the analog base-band signal using frequency modulation. Sometimes in order to expand capacity, some mega-capacity analogue microwave radio relay systems are also useful for amplitude modulation. Analog transmission system used in early business volume of the telephone network, the disadvantage is that the noise and signal relay system damage has accumulated.