The spectral coefficients of the response of nonlinear systems to asymptotically almost periodic inputs

It is known that time-invariant systems having approximately finite memory and satisfying some often-satisfied continuity constraints map asymptotically almost periodic inputs into asymptotically almost periodic outputs with the module of the output a subset of the module of the input. Systems described by Volterra integral equations of the second kind that meet the circle criterion and satisfy some additional constraints fall into this class. In this paper we present an analytical basis for numerically evaluating the spectral coefficients of the output of such systems when the input is asymptotically almost periodic.