By Qun Shi and RobertS. Burroughs, Panasonic Technologies, Inc.
It is highly likely that a hybrid analog/digital system will be the format for future Cable transmission systems. The motivation, for using hybrid systems, is to maximize the tuning compatibility with existing consumer electronic devices, and such a mixed system may provide excellent digital video pictures, while still maintaining the quality of conventional analog (AM) signals. However, our research results have shown that in such mixed systems the digital signals may suffer a significant performance degradation due to the nonlinear, especially the clipping, operation of the laser transmitter when mixed signals are transmitted by a fiber optic link.
Careful considerations should be given to available trade-offs in such hybrid system designs and realizations.