Patent ID: 6321073
Filing Date: 2001-11-20
Classification: H03G,H04B

Abstract:
An automatic gain control apparatus for a radiotelephone receiver comprising:memory containing data representing a transfer function of the radio telephone receiver;a gain estimation circuit, operatively coupled to the memory, that estimates input power and determines a required gain for an input signal based on a non-linear portion of the data representing the transfer function; anda DC offset compensation circuit operatively coupled to the gain estimation circuit, the DC offset compensation circuit comprising:a circuit for calculating a mean value of the signal having an in-phase (I) component and a quadrature (Q) component;an in-phase DC compensation circuit for calculating a DC offset error for the I component;a quadrature DC compensation circuit for calculating a DC offset error for the Q component, wherein the DC offset error for the I component and the DC offset error for the Q component are subtracted from the mean value of the signal; anda first analog to digital converter coupled to the circuit for calculating a mean value of the signal, wherein the first analog to digital converter receives the I component and produces a first digital I component containing 8 bits and a second digital I component containing 4 bits and wherein the 4 bits are a subset of the 8 bits.