Design and simulation of a cooperative communication system based on DCSK/FM-DCSK

Frequency modulated differential chaos shift keying (DCSK/FM-DCSK), a joint modulation and spread spectrum technique, is a promising modulation technique for low-cost and low-complexity wireless transmission applications. The noise performance of DCSK/FM-DCSK is superior to most conventional modulation schemes in multipath-channel environment. Cooperative communication, on the other hand, is receiving increasing attention due to its efficiency in sharing single-antenna mobiles or network nodes with other antennas to achieve combating fading via transmitting diversity. By combining these two aspects of advantages, a novel chaotic communication system is proposed in this paper, aiming to achieve combating multipath and fading effects. Simulation results show that significant performance improvement can be achieved by the proposed system in comparison with non-cooperative systems. It is found that the choice of some key parameters, such as the spread spectrum factor and the relay selective strategy, affect the system performance prominently. It reveals that the combination of the DCSK/FM-DCSK framework with a cooperative strategy is of great practical value for certain wireless communication networks.