Receiver Gain Control for Changing Channel Conditions

The patent implements dynamic gain adjustment by introducing a digital automatic gain control circuit that continuously monitors signal quality metrics (such as eye diagram quality or signal-to-noise ratio) and adjusts the digital gain parameter in real-time during data mode operation. This transforms the static gain setting into a dynamic control system that adapts to changing channel conditions, resolving the contradiction between maintaining initial signal quality and adapting to new conditions.

The patent employs a feedback mechanism where the digital automatic gain control circuit receives feedback information about the quality of the received signal (through eye diagram analysis or other quality metrics) and uses this feedback to adjust the digital gain parameter accordingly. This closed-loop control system ensures that signal quality is maintained even when channel conditions change, effectively resolving the contradiction between initial optimization and ongoing adaptability.

The patent introduces a digital automatic gain control circuit as an intermediary component that sits between the existing PGA and the signal processing pipeline. This intermediary component handles the dynamic gain adjustment function, allowing the rest of the system to remain relatively simple while still achieving adaptive signal quality maintenance. The digital controller acts as a mediator that processes quality metrics and generates appropriate gain adjustment commands.

The patent replaces or supplements the traditional analog PGA-based gain control with a digital gain control mechanism implemented through digital signal processing. By using digital techniques (such as digital filtering and digital gain adjustment) instead of purely analog mechanisms, the system achieves dynamic adaptability with reduced hardware complexity and improved precision. The digital domain allows for more flexible and programmable control with fewer physical components.