Novel method to reduce the estimation variance of DCSK

In this paper, we analyze the factors which cause the estimation variance in a DCSK (differential chaos shift keying) telecommunication system implemented with a noise reduction module. There are three main factors in this system: the DCSK signal itself, the additive channel noise and the noise reduction module. To avoid the variance in the DCSK signal and the signal reduction that is caused by additive channel noise, a novel DCSK scheme with a chaotic polyphase sequence (CPS) is presented. Simulation results show that the noise performance of this novel DCSK slightly degrades in contrast with frequency-modulated (FM) DCSK for the estimation variance of the noise reduction scheme. However, this design can be implemented easily.