Digital television signals are transmitted by converting digital information into electrical signals and adopting certain modulation methods. Commonly used modulation modes include frequency shift keying modulation (FSK), phase shift keying modulation (PSK) and quadrature amplitude modulation (QAM), among which QAM is a more commonly used modulation mode. Digital TV signal transmission methods have broadcast, cable transmission and satellite transmission and other ways, of which cable transmission and satellite transmission signal quality is better, more stable, broadcast transmission is more popular.
Finally, the digital TV signal is converted into a TV signal by the digital receiver, which is displayed on the TV as a high-quality picture.
The specific process is divided into three steps: encoding, transmission and decoding. First, the original signal is digitally compressed and encoded by the encoder, and the compressed signal is QAM modulated by the modulator, and then transmitted to the receiving end through the transmission medium (such as cable TV, satellite, terrestrial digital TV, etc.).
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The digital TV at the receiving end decodes the received signal into the original signal through the decoder, and finally displays it through the display device. The whole transmission process needs to ensure the stability and correctness of the signal to ensure the quality and stability of the digital TV signal.