Patent ID: 8433274

Claim:
An apparatus for amplifying and filtering a signal in the baseband portion of a receiver, comprising: a series of stages including at least two amplification stages, where each amplification stage is one of (a) a variable gain amplifier (VGA) stage or (b) a Combination stage that combines the VGA stage and a filter stage in one stage, wherein the series of stages is configured as one of: two or more variable gain amplifier (VGA) stages and a filter stage located between the two or more VGA stages; two or more Combination stages; a Combination stage and a VGA stage; or a Combination stage, a VGA stage, and a filter stage located between the Combination stage and the VGA stage; and a Gain Control Unit that varies gain assignment in the amplification stages according to measured signal strength by distributing a total amount of gain among the amplification stages; where the Gain Control Unit is configured to produce the gain assignment based on an estimate of a desired component of the signal and an estimate of an undesired component of the signal; where the Gain Control Unit is configured to estimate one of: the power of the desired component of the signal and the power of the undesired component of the signal by comparing a predicted power of the signal after the signal has been amplified and filtered with a measured power of the signal after the signal has been amplified and filtered; where the predicted power of the signal is determined by measuring a power of the signal before the signal is amplified and filtered and applying a function of the amplification applied in the amplification and filtering to the measured power of the signal before the signal is amplified and filtered, where the function estimates the power of the signal after the signal is amplified and filtered based on the power of the signal before the signal is amplified and filtered and based on the amount of amplification applied to the signal in the amplification and filtering; and where the difference between the predicted power and the measured power of the signal after the signal is amplified and filtered represents the power of the undesired signal component; and where the difference between the measured signal power after the signal is amplified and filtered and the power of the estimated undesired signal component represents the power of the desired signal component.