Full Duplex Amplifier Ringing Suppression for HFC Networks

The patent applies Active Interference Cancellation (AIC) and Digital Echo Cancellation (EC) to convert harmful interference and echo signals into cancellable components. By capturing reference signals from the other branch and processing them through adaptive filters, the system generates anti-phase signals that cancel the harmful reflections and echoes, transforming the problem of signal interference into a solvable mathematical cancellation task.

The patent introduces ringing suppressors as intermediary components between the amplifier branches. These suppressors include reference signal capture circuits, adaptive filters, and cancellation generators that mediate the interaction between upstream and downstream signals. The intermediaries process reference signals and generate cancellation signals without directly altering the main signal paths, enabling interference removal while preserving full duplex operation.

The patent segments the amplifier into distinct functional branches (upstream and downstream) with separate ringing suppressors for each branch. Each suppressor is further segmented into reference signal capture, adaptive filtering, and cancellation generation components. This modular segmentation allows independent optimization of each component and simplifies the overall design by dividing the complex interference cancellation task into manageable subsystems.

The patent uses reference signals that are copies of the transmitted signals from the other branch. By capturing and processing these reference copies through adaptive filters, the system creates virtual models of the interference paths without requiring direct physical measurement of the harmful signals. This copying approach reduces the need for complex sensing hardware while maintaining effective cancellation capability.