Abstract

A hybrid multichannel AM-vestigial-sideband (AM-VSB)/quadrature-amplitude-modulation (QAM) subcarrier-multiplexed fiber-optic system is a promising technique for delivering compressed digital video signals together with the existing analog CATV signals.^1–5 The use of a hybrid AM-VSB/ QAM modulation scheme in a hybrid fiber/coaxial distribution network is a subject of intense interest in the telecommunications and CATV industries. The CATV channels are usually in the 50–500-MHz band, whereas the QAM channels are placed in the 500-MHz-1-GHz band. The required modulation index of QAM channels is about one-tenth of the AM-VSB channels for error-free transmission. Therefore, the QAM channels contribute little to the overall load on the laser.

© 1995 Optical Society of America