| 摘要 |
A method and a device for transmitting data over an analog television channel, and particularly for compatibly introducing digital television, as well as promoting the development of the 16/9 picture aspect ratio. The method comprises providing time resources in analog television signals, inserting additional signals therein and retrieving and decoding them when the signals are received. For this purpose, the 4/3 aspect ratio may be reduced to the 16/9 aspect ratio using black bands consisting of video-free lines that free over 5.5-7.45 MHz during the band broadcast time. The method uses the high spectral efficiency of digital modulations to transmit rates of 4.6-6.3 Mbits/s which are sufficient to transmit, alongside the analog programme, one or more digital television programmes with rates varying from 1.5 to 4.5 Mbits/s, depending on quality. A smooth transition to fully digital television may thus be achieved. |
