Some Aspects Regarding Frequency Analysis of Nonlinear Systems

Abstract – The Volterra model for nonlinear systems has develloped an identity of its one. We concentrate in this paper of some aspects regarding the characterization of the Volterra system in the frequency domain. Both types of filters are considered: analogues and discretized filters. The applications of the second order kernel transform are widely investigated in bouth cases. Finnaly we derive and analyze the input-output power transfer relationship. Two situations are considered: in the first one the input signal has Gaussian statistics, in the second one there is a little knowledge about the input statistics or the input is non-Gaussian. It is also noted that the ordinary coherence functions cannot be used in explaining the input-output power transfer relationship of a quadratic system excitated by a non-gaussian input signal