Introduction to the digital broadcasting technologies

In the world, several digital satellite broadcastings have been serviced. Also, some digital terrestrial and cable broadcastings will start soon. In this paper, we will introduce the total image of the digital broadcasting system and mention a little about the broadcasting program production, which has actively employed a variety of digital technologies. Distinctive features of the digitally coded signals are high quality transmission and multi-channel services. To realize these results, high efficiency signal compression and multi-level modulation technologies were developed. Also, some powerful error-correction methods are employed to protect signals from errors added on the way of transmission. We will explain the principles of these basic technologies.