  In this paper, a multi user Multi-Carrier Differential Chaos Shift Keying
(MC-DCSK) modulation is presented. The system endeavors to provide a good
trade-off between robustness, energy efficiency and high data rate, while still
being simple. In this architecture of MC-DCSK system, for each user, chaotic
reference sequence is transmitted over a predefined subcarrier frequency.
Multiple modulated data streams are transmitted over the remaining subcarriers
allocated for each user. This transmitter structure saves energy and increases
the spectral efficiency of the conventional DCSK system.
