Patent ID: 8126094

Claim:
A method for managing automatic gain control in quadrature signal paths of a radio-frequency subsystem of a wireless communication system, the method comprising: determining a first signal strength at an input to a channel select filter in a digital receiver path and a second signal strength at an output of the channel select filter; comparing the first and second signal strengths to detect when a blocker is present in the quadrature signal paths of a receiver, and when the blocker is present, forwarding a blocker presence signal to an analog control branch of an automatic gain control circuit; generating an analog control signal in the analog control branch of an automatic gain control circuit in response to the blocker presence signal, the analog control signal configured to adjust at least one controllable gain element in an analog receiver path to prevent saturation of an analog-to-digital converter in the digital receiver path of the radio-frequency subsystem in response to presence of the blocker; determining a difference between the second signal strength at the output of the channel select filter and a reference signal power; and applying the difference between the second signal strength and the reference signal power to the automatic gain control circuit, the automatic gain control circuit having a loop filter coupled to the analog control branch and a digital control branch, the digital control branch generating a digital control word configured to adjust a scaler coupled to the channel select filter.