Design of demodulator for the chaotic modulation communication system

Chaotic modulation has recently been proposed for spread spectrum (SS) and code division multiple access (CDMA) communication. It embeds the signal of transmission in the bifurcating parameter of a chaotic dynamical system, and uses the wide-band output of the chaotic system as the transmitted signal. Here we consider the demodulation of this communication scheme using an adaptive filter. Not only can an adaptive filter reduce the effect of channel noise, but it also estimates the bifurcating parameter (i.e., the signal of transmission) sequentially which is required in a communication system. Three kinds of adaptive filters: the least mean square (LMS) algorithm, the recursive least square (RLS) technique and the Kalman filter, are considered here. It is found that the demodulators based on these adaptive filters outperform the standard inversion approach used in the literature.