Adaptive approach for detection in chaos-based digital communication systems with transmitted-reference

In this paper, a transmission scheme is proposed for chaos-based communication systems, in which chaotic reference signals and information-bearing signals are transmitted in succession. Chaotic reference signals modulated by a binary training sequence are sent periodically. The same chaotic signals are then modulated by the binary data and transmitted. Two types of receivers are proposed and studied. The two receivers attempt to estimate the chaotic reference signal by using an adaptive filter and a simple inverse-and-average method, respectively. The estimated chaotic signal is then used to correlate with the information-bearing signals for determining the received symbols. The performance bounds of these two schemes are also derived. Finally, the bit error rates of the proposed system are simulated and compared with the widely-studied differential chaos-shift-keying system.