| 摘要 |
The return path for a signal in a cable system uses a portion of the 50-750 MHz frequency band to send signals from each set-top box therein to a receiver at the feeder line end. A band stop filter is placed in each auxiliary feeder line to prevent the return signal from set-top boxes being received by more than one feeder line end. The feeder line end also has a receiver and high to low frequency converter that retransmits the signals in the low portion (5-50 MHz of the frequency spectrum) to the headend. High pass filters are placed at taps going into homes to prevent low frequency noise from home devices, home wiring and drop wiring from entering the feeder lines. This system eliminates virtually all ingress noise picked up by the collection of set-top boxes, home wiring and drop wiring from entering the cable system.
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