A generalized modulation law for generating constant-envelope signals via frequency modulation

摘要

In this paper we generalize the calculus of the power density spectrum (PDS) of a constant-envelope spread-spectrum (CE-SS) signal obtained by means of a frequency modulation (FM) using a random pulse amplitude modulated (PAM) signal as the modulation law made by a generic pulse function. We choose two possible profile of such pulses aiming to approximate those generated by the analog circuit implementing the chaotic map and we present both analytical and numerical results that show how the pulse shape affect the PDS shape of the modulated signal.