Research On Chaotic Digital Modulation System Based On DCSK

Chaos is a class of random behavior that is expressed by deterministic nonlinear systems under certain conditions.Chaotic signals have characteristics such as noise,aperiodic,wide spectrum and good Correlation.Compared with the traditional pseudo-random code,chaotic sequence complexity is relatively high,and the chaotic signal generation is easier than pseudo-random code,which makes the chaotic signal has the excellent characteristics needed for secure communication and spread spectrum communication,and better prospects.Compared with the traditional communication,the chaotic communication uses the non-periodic chaotic signal as the carrier to modulate the information.Chaos Shift Keying(CSK)is a research area,which is more focused on chaotic digital communication.Among them,Differential Chaos Shift Keying(DCSK)adopts noncoherent demodulation to avoid chaotic carrier synchronization problem,which is easier to achieve in the actual situation,making it into one of the key technologies in the field of chaotic digital modulation.In this paper,the chaotic digital communication technology has been studied,and the research status of chaotic communication technology is introduced.The basic theory of chaos and the popular chaos digital modulation method are studied.In particular,the principle and realization method of DCSK technology are deeply studied systematically,and the theoretical calculation and the simulation analysis are carried out.We propose the Double Channel DCSK communication scheme(DC-DCSK)because of DCSK's shortcomings in the transmission rate,bit error rate,and data security.This communication scheme improves the modulator and the demodulator based on DCSK.The data transmission rate of the system is improved,and the simulation results show that the bit error rate performance of the original DCSK system is also improved obviously.A high-speed OFDM-DCSK system is designed to further improve the system bit rate and signal energy utilization rate,which is inspired by the Orthogonal Frequency Division Multiplexing DCSK(OFDM-DCSK)scheme.And the theoretical analysis and simulation verification are carried out.