An improved multiple access scheme for chaos-based digital communications using adaptive receivers

In this paper, a multiple access technique is proposed for chaos-based communication systems in which chaotic reference signals are transmitted together with the information-bearing signals. Chaotic reference signals modulated by a binary training sequence are sent periodically. The same chaotic signals are then modulated by binary data and transmitted. To achieve multiple access, different chaotic signals and training sequences are assigned to different users. At each receiver, an adaptive filter is employed to perform the demodulation based on the user´s pre-assigned training sequence. The bit error rates of the proposed scheme are simulated and compared.