Channel equalization for synchronization of Ikeda maps

Many communication systems based on the synchronism of chaotic systems have been proposed as an alternative spread spectrum modulation that improves the level of privacy in data transmission. However, due to the lack of robustness of chaos synchronization, even minor channel imperfections are enough to hinder communication. In this paper, we propose an adaptive equalization scheme to recover a binary sequence modulated by a chaotic signal, which in turn is generated by Ikeda maps. The proposed scheme employs the normalized least-mean-squares (NLMS) algorithm with a modification to enable chaotic synchronization even when the communication channel is not ideal. Simulation results show that the modified NLMS can successfully equalize the channel in different scenarios.