Optical fiber transmission of data packets multiplexed with digital audio and video signals

Abstract

Describes a system for transmitting data packets multiplexed with digital audio and NTSC TV signals using optical fibers. Up to 18 channels are allocated for data packets transmitted at a maximum speed of 1.764 Mbps. Digital audio signals are inserted into the horizontal sync period of the NTSC TV signal. In addition to data packet transmission, the digital NTSC TV signal transmission system is used to easily distribute many types of information classified into categories. The proposed system is characterized by: firstly, this system can give a satisfactory picture quality enough to operate it together with video equipment even though the quality of the reproduced pictures is lower than that of normal digital NTSC TV picture codes obtained at a sampling frequency of 4.00/spl times/fsc with a quantizing level of 8 bits. Secondly, NTSC TV picture codes, audio codes, and data packets can satisfactorily be transmitted using inexpensive devices at a transmission rate of as low as 50 Mbps. Thirdly, this system is used for transmitting data packets and audio signal codes which are inserted in the horizontal sync period of the digital NTSC TV signal. Both data packets and audio signal codes can be distributed to the specific receivers specified by device address. A combination of edge-emitting LEDs (ELEDs) and optical fibers enable the transmission system to easily transmit a digital NTSC TV picture signal together with data packets and digital audio codes. A new approach of combining ELEDs and optical fibers to distribute CATV pictures and electronic information via the ISDN is also proposed.