Patent ID: 7003028

Claim:
A circuit for adaptively amplifying an input signal, the circuit comprising: an adaptive filter connected to receive the input signal and to amplify a predetermined frequency range of the input signal by an amount based on an amplification control signal input to the adaptive filter to generate an amplified input signal; a comparator connected to receive the amplified input signal from the adaptive filter and a predetermined threshold signal, the comparator outputting a comparison signal based on a comparison of the amplified input signal to the predetermined threshold signal; and a filter adaptation circuit connected to receive the comparison signal and to modify the amplification control signal based on the comparison signal and a known training pattern, wherein the filter adaptation circuit comprises: a first circuit connected to receive the comparison signal, the known training pattern, and a system clock signal, the first circuit converting the comparison signal, the known training pattern, and the system clock signal into a first output signal that is asserted on a falling edge of the known training pattern when the comparison signal indicates that the input signal is above a level of the predetermined threshold signal and a second output signal that is asserted on the falling edge of the known training pattern when the comparison signal indicates that the input signal is below the level of the predetermined threshold signal; and a second circuit connected to receive the first and second output signals and to increase the amplification control signal when the first output signal is asserted and the second output signal is not asserted and to decrease the amplification control signal when the first output signal is not asserted and the second output signal is asserted.