Modulation significance of DSB amplitude modulation

DSB-AM means double sideband amplitude modulation, which is almost the simplest and most basic of all modulation technologies. Specifically, the modulation signal is used to control the amplitude of high-frequency carrier (sine wave), so that the modulated DSB- AM wave carries the information of the modulation signal, and then the modulation signal is recovered after demodulation at the receiving end. This is a basic flow of carrier communication.

The reason why carrier is needed to complete communication is because the modulated signal is often low frequency, such as audio. If it is transmitted directly by air or cable, the attenuation and interference will be great and will not spread far. High-frequency radio waves have good transmission performance (such as wireless mode), and after modulation, the whole channel can transmit multiple signals through FDM frequency division multiplexing.