Research Of Chaotic Synchronization Technology And DCSK Communications System

Chaos is a determinate and similarly random process generated by nonlinearsystem. A chaotic sequence is a non-periodic and irregular process, which is notconvergent but has a bound, and is sensitive to its initial values. For all these specialproperties, chaos has a bright prospect in the fields of spread spectrum communication,secure communication and multiple access communication, etc. With the deepeningresearch on chaotic theories, synchronization of chaotic sequences has become a keytechnical issue in the field of chaotic communication.In combination with the specific application, the article firstly gives a presentationof the latest research with respect to chaotic communication technology. Then it makesa study on the basic chaotic theories including properties of the chaotic sequences,generation methods of chaotic sequences as well as several common chaotic sequencemaps. The primary properties of the chaotic sequences are analyzed and simulated, suchas the properties of balance, autocorrelation, cross-correlation, phase, and powerspectrum, etc.Several synchronization technologies of chaotic sequences are also studied andsimulated in MATLAB, including PC synchronization, active-passive synchronization,adaptive synchronization and the observer-based chaotic synchronization. The articlefurtherly designs a chaotic communication scheme based on noise-induced chaoticsynchronization. The feasibilities of this scheme are then analyzed and verified.Differential Chaos Shift Keying communication system needs no synchronization.It is one of the crucial technologys for chaotic communication. This papersystematically and thoroughly discusses the principle of DCSK communication system,which is simulated in MATLAB afterwards. Based on DCSK communicationtechnology, the SIMO-DCSK and MIMO-DCSK communication schemes are designedby introducing spatial diversity technology. These schemes uses multiple antennas bothin the transmitter and receiver to obtain the space diversity gain for the transmittedinformation signal. It greatly improves the data transmission rate of the system withoutwidening the signal bandwidth. It is shown that the SIMO-DCSK and MIMO-DCSKcommunication schemes obtain obvious space diversity gain than the traditional DCSK communication system under Gauss white noise channel, and, therefore, the bit errorrate performance is greatly improved.