Patent ID: 8126099

Claim:
Apparatus for a receive circuit that receives a receive sequence having noise, said apparatus comprising: a noise estimator adapted to receive the receive sequence and to determine an estimated value of the noise present in the receive sequence, said estimated value determined by subtracting a remodulated training sequence from the received sequence; a noise autocorrelation estimator adapted to receive said estimated value, calculate a first autocorrelation function based upon said estimated value, and determine an absolute value of said first autocorrelation function as an autocorrelation estimate; and a filter characteristic selector adapted to receive said autocorrelation estimate from said autocorrelation estimator, to compare said autocorrelation estimate to a threshold autocorrelation value, and to select a filter characteristic for a filter in response to the comparison, wherein said filter characteristic selector is adapted to select a unitary-filter characteristic in which whitening noise is not added upon a determination that said autocorrelation estimate is below said threshold autocorrelation value and adapted to select one non-unitary filter characteristic in which whitening noise is added upon a determination that said autocorrelation estimate is above said threshold autocorrelation value.