Patent ID: 7734266

Claim:
An adaptive radio frequency receiver, comprising: a variable gain circuit configured to generate a gain controlled signal from a radio frequency (RF) input signal in response to control signals; a mixer configured to mix a local oscillator (LO) signal with the gain controlled signal and generate an intermediate frequency (IF) signal; an analog-to-digital-converter configured to generate a digital output signal based on the IF signal; and a controller configured to generate control signals based on the digital output signal, for controlling a gain of the variable gain circuit over a range of input signal levels; wherein the controller generates control signals to adjust the gain of the variable gain circuit based on minimizing the effective received total channel power; wherein the controller is configured to determine the effective received total channel power at a nominal gain, at a slightly increased gain and at a slightly decreased gain, and then adjust the nominal gain to a gain corresponding to the lowest power; and wherein the controller is further configured to: obtain a PchanH value representing the power in the channel with Rx Gain, increased by a increment, wherein Rx Gain represents the actual receiver gain being optimized; obtain a PchanC value representing the power in the channel at nominal Rx Gain; obtain a PchanL value representing the power in the channel with Rx Gain decreased by a decrement; if PchanL<PchanC, and Rx Gain>Gainmin, then generate control signals to decrease Rx Gain, Gainmin represents a minimum gain; if PchanL<PchanC, and Rx Gain≦Gainmin, then generate control signals to maintain Rx Gain; if PchanL≧PchanC, and PchanH≧PchanC, then generate control signals to maintain Rx Gain; if PchanL≧PchanC, PchanH<PchanC and Rx Gain<Gainmax, then generate control signals to increase Rx Gain, wherein Gainmax represents a maximum gain; and if PchanL≧PchanC, PchanH<PchanC and Rx Gain≧Gainmax, then generate control signals to maintain Rx Gain.