QAM Access System

1. Quaternary Amplitude Modulation (QAM) can be used over fibers by modulating RF Subcarriers (SCM). This provides a bandwidth-efficient channel, with the advantage over TDM that cheap CATV electronics can be used to demultiplex channels.
2. This example investigates the degradation caused by adjacent-channel carriers when the subcarriers are passed over a fiber channel.
3. VPItransmissionMaker™ Cable Access provides ready made sources, demonstrations and instrumentation for modeling access systems using digital and analog systems.