Ingress noise cancellation for upstream signals on a cable television system using an antenna to determine local noise

摘要

A cable television system employs noise cancellation in order to reduce radio frequency noise for upstream signals. The noise cancellation can be located at the headend or located at the juncture between the cable distribution system and the subscriber distribution system. The system employing noise cancellation at the headend has an antenna at a central distribution point on the cable system, such as a fiber node. The system employing noise cancellation at the juncture between the cable distribution system and the subscriber distribution system employs a local antenna. The noise received by the antenna is correlated with noise on the line in an adaptive filter for cancelling or reducing the noise on the line.