FIBEROPTIC DIGITAL VIDEO MULTIPLEXING USING OPTICAL CDMA

The use of laser pulsing in the form of code-division multiple access (CDMA) to multiplex a set of digital video signals over a fiber networ k is proposed. The laser pulsing is used to generate unique code seque nce addresses which identify each source, and the video data are modul ated on these sequences. Digital encoding using pulse position modulat ion (PPM) is proposed, having advantages that permit efficient integra tion of optical and electronic processing. Data recovery is achieved b y optical correlation for sequence recognition, followed by standard e lectronic PPM decoding. The relation between key system parameters of the encoding, decoding, and optics is derived, and indicates that comp ressed video rates between 5-20 Mb/s/channel, with 25-50 channels, is possible with relatively standard hardware. Experimental breadboard re sults being carried out at USC on this system are reported, and indica te the feasibility of the CDMA concept for fiber multiplexing.