| 摘要 |
<p>Method and system for transmitting data in lines of a video signal. The data is packetized (12), provided with a clock-run-in sequence (13) and quadrature amplitude-modulated (14), using a carrier (fc) which is located in the middle of the video bandwidth. The modulated data signal is then inserted (15) in selected video lines. In the preferred embodiment, QAM-16 is used so that data can be transmitted in the vertical blanking interval of a television signal at a higher bit rate (approximately 16 Mbit/s) than conventional teletext (6.9 Mb/s). Optionally, QAM-64 or even QAM-256 may be used to obtain a bit rate of approximately 24 or 32 Mbit/s, respectively.</p> |
