Novel multiple access scheme for CDSK chaotic communication system

A novel code division multiple access scheme for correlation delay shift keying (CDMA-CDSK) chaotic communication system is proposed. In each user's system transmitter, the chaotic signal generated by different chaotic signal source is adopted as a reference signal. Reference signal is modulated by the sent data after a variable delay. Sum of the modulated signal and the reference signal is multiplied by the respective spreading codes to achieve multiple access communication. In each user receiver, the received signal is multiplied by the same respective spreading codes, and then takes a differential demodulation. The CDMA-CDSK chaotic communication system bit error rate (BER) in additive white Gaussian noise channel is analyzed theoretically. The results show that when spreading codes have the ideal orthogonality, the CDMA-CDSK system not only can eliminate the multiple access interference from different users very well, but also has a certain inhibition to the noise of the channel, and the multiple access system has good BER performance. © 2012 Binary Information Press.