The widespread deployment of analogue optical fibre links started in the late 1980s with their incorporation as fibre trunk lines into coaxial cable-based CATV networks, particularly in North America. These coaxial cable television networks provide the multichannel amplitude modulated-vestigial sideband (AM-VSB) modulation over the frequency range from 50 to 88 MHz and from 120 to 550 MHz, whilst the band from 88 to 120 MHz is reserved for frequency modulated (FM) radio broadcast. Vestigial sideband amplitude modulation was employed within the CATV networks as it exhibited the good low-frequency baseband characteristics of double-sideband amplitude modulation whilst conserving bandwidth, and hence it has been widely utilised for the electrical transmission of TV and similar analogue signals.
Analogue intensity modulation for optical-fibre video transmission, Page 1 of 2
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