Patent ID: 7382416

Claim:
A nonlinear process circuit configured to perform a nonlinear transformation of a nonlinear input signal, comprising: a main circuit configured to form the nonlinear input signal into a first nonlinearly-processed signal using a first function which has an approximate linear characteristic divided into a plurality of intervals; and an assistant circuit configured to form the first nonlinearly-processed signal into a second nonlinearly-processed signal using a second function which has an approximate linear characteristic in which each of the intervals is divided into two connected line segments, wherein the main circuit includes a decision circuit configured to determine a particular interval out of the intervals in which the nonlinear input signal falls; a signal-generation circuit configured to form the nonlinear input signal into a plurality of first processed signals for each of the intervals; a plurality of main processing circuits corresponding to respective intervals, each of the main processing circuits configured to multiply the first processed signals inputted into the respective intervals by predetermined coefficients to form second processed signals; and a first addition circuit configured to add the second processed signals resulting from multiplication processes in the respective intervals, the first addition circuit forming the first nonlinearly-processed signal, and the assistant circuit includes an assistant storage circuit configured to store a correction amount to be added to the first function, and the assistant circuit is configured to read the correction amount of a selected interval from the assistant storage circuit, and to form the second function having characteristics in which the correction amount is added to at a midpoint of the selected interval of the first function such that a point at which the correction amount has been added is set as a maximum gain and the correction amount decreases toward start and end points of the selected interval.