Estimation of Nonuniform Invariant Density Chaotic Signals with Applications in Communications*

In this paper we compare two techniques applied to the estimation of discrete-time one-dimensional chaotic orbits: the maximum likelihood estimation and the modified Viterbi algorithm. As the second one performs better, it is used in two digital modulation schemes based on identification of chaos generator maps: the Modified Maximum Likelihood Chaos Shift Keying using one and two maps. Both have better symbol error rate characteristics than non-coherent chaos communication schemes.