Why does mobile communication use DSB modulation instead of VSB modulation technology?

Modulation technology is a technology that converts baseband signals into transmission signals. In order to ensure the communication effect and overcome the problems in long-distance signal transmission, it is necessary to transfer the signal spectrum to high-frequency channel for transmission through modulation.

Baseband signal is the original electrical signal, which generally refers to the basic signal waveform and the corresponding electrical pulse in digital communication. In wireless telemetry and remote control system and radio technology, modulation is to control the parameters (amplitude, frequency and phase) of high-frequency carrier with baseband signal, so that these parameters change with baseband signal.

Extended data:

1. The high-frequency electric oscillation modulated by the modulation signal is called modulation wave or modulation signal. The modulated signal is transmitted to the receiving end through the channel, and is recovered to the original baseband signal after demodulation at the receiving end. Demodulation is the inverse transformation of modulation and the process of extracting modulation signal from modulated wave.

2. According to the transmission characteristics, modulation methods can be divided into linear modulation and nonlinear modulation. Generalized linear modulation refers to the mutual tuning of modulation parameters in modulated waves.

Modulation process of linear variation of signal.

3. Digital modulation technology can be divided into linear modulation mode and constant envelope modulation mode, and linear modulation mode can be divided into spectrum efficiency and power efficiency. In the mobile communication system, due to the serious fading phenomenon, the required "signal-to-noise ratio" is relatively high.

4. The ultimate goal of modulation technology is to make the modulated signal have strong anti-interference ability, and at the same time, it has less interference to adjacent channel signals, convenient demodulation and easy integration.

References:

Sogou encyclopedia-modulation technology