Patent ID: 7653369

Claim:
A wireless communications receiver comprising: a memory configured to store offset values corresponding to respective gain settings; a gain controller configured to continuously select one of the gain settings based on amplitude of a received signal; an amplifier configured to amplify the signal based on the selected gain setting; and an offset estimator configured to determine an updated offset value as a function of both a time-average value of the signal and a previously-stored offset value and use the updated offset value to correct a DC offset of the received signal, said previously stored offset value being an offset value that was stored in the memory at a time prior to the gain controller switching to the currently-selected gain setting from a previously-selected gain setting; wherein the previously-stored offset value is stored in a data structure that is indexed by a plurality of gain settings, wherein exactly one record in the data structure is present for each gain setting of the gain controller, wherein the offset estimator selects the previously-stored offset for updating by matching the gain setting selected by the gain controller with a record in the data structure having a matching index; wherein the previously-stored offset value is replaced with the updated offset value in the memory in order to more closely approximate an actual DC offset caused by the currently- selected gain setting.