The present invention employs a mapping function in order to apply a known distortion to an input signal. The mapping function of the present invention is defined by: y=A1*sin(arcsin(x))+A2*cos(2*arcsin(x))+A3*sin(3*arcsin(x))+A4*cos(4*arcsi n(x))+ . . . An*sin(n*arcsin(x))+A(n+1)*cos((n+1)*arcsin(x)), where x is the input signal, y is the output signal, A is the amplitude of the harmonic level for a given harmonic, 1 being the fundamental, n is an odd number and (n+1) represents the highest harmonic of interest.