1. A signal detector for detecting channel data in an input signal, the signal detector comprising: a nonlinear detector to calculate a branch metric associated with an input signal; preprocessor circuitry responsive to the input signal and an output of the nonlinear detector to adapt at least one parameter used to calculate the branch metric; loading circuitry to normalize the at least one parameter by computing a term comprising a function of the at least one parameter and other parameters and an offset term comprising a logarithm of the function, wherein the function includes a comparison operation of the at least one parameter and the other parameters; and output circuitry to provide the normalized at least one parameter to the nonlinear detector.