Shared hybrid-fiber coax transmission system having increased bandwidth in the upstream and downstream directions

DETAILED DESCRIPTION Briefly, in accordance with a preferred embodiment of the invention, a method is provided for reliable transmission (reduced noise), as well as increased bandwidth in both the upstream and downstream directions in a CATV system.
Pursuant to the invention, information originating at the subscriber premises is digitally modulated via a carrier to a high frequency band (typically 750-1000 MHz) that is allocated to for upstream information transmission.
The modulated signal is then digitally regenerated by at least one repeater.
By the same token, high frequency downstream signals, typically those lying in a frequency band of 500-750 MHz, are also digitally regenerated, allowing this signal band to be used for downstream of signals that would otherwise be degraded by noise.
Each repeater, by its nature, will generate an essentially noise-free output signal for transmission if the signal-to-noise ratio of the signals input to the repeaters is adequate which is usually the case.
From a noise perspective, deploying repeaters in this manner accomplishes the same effect for upstream as reducing the number of HHPS served by each fiber node, without actually reducing the number of HHPS that are served.
Moreover, since the upstream and downstream repeaters operate in a high frequency band, there is sufficient bandwidth for emerging broadband services and high market penetration.
This approach of digitally regenerating the upstream and downstream information and modulating the upstream information via a carrier to a high frequency band is applicable to all-coax cable systems as well as hybrid fiber-coax systems.