Patent ID: 7986756

Claim:
An apparatus comprising: at least one processor configured to filter a sequence of input values with an infinite impulse response (IIR) filter having at least one coefficient to obtain a sequence of output values, and to derive a sequence of predicted values based on the sequence of input values, to determine prediction errors between a sequence of predicted values and the sequence of input values, to filter the determined prediction errors, to calculate a partial derivative term based on the determined prediction errors and filtered determined prediction errors, and to update the at least one coefficient based on the partial derivative term; and a memory coupled to the at least one processor, wherein the sequence of input samples is a noisy estimate of a sequence of actual values, and wherein the at least one processor is configured to estimate variation of the sequence of actual samples based on the sequence of input values, and to determine the at least one coefficient based on the estimated variation of the sequence of actual samples.