Theoretical Research On Multi-Carrier Correlated Delay Shift Keying Technology In Chaotic Communication System

Chaos Shift Keying is one of the rapidly developing technologies in the field of wireless communication.Chaos Shift Keying has strong anti-interference and security,which makes it a research hotspot.Correlation Delay Shift Keying(CDSK)system,as one of the typical systems in Chaos Shift Keying,has good transmission performance and security performance.But the CDSK system has two disadvantages.First,the error performance of the CDSK system is poor,because the CDSK system uses an adder to replace the switch structure in the Correlation Delay Shift Keying(DCSK)system,resulting in intra-signal interference during signal demodulation.Second,the information transmission rate of the CDSK system is low.Based on the problem of poor error rate and low information transmission rate of the CDSK system,the thesis will study from the perspective of information transmission rate and error performance.The research work of the thesis starts from the following aspects:1.Aiming at the problems of poor error performance and low information transmission rate of CDSK system,an Orthogonal Multi-Carrier Correlation Delay Shift Keying(OMC-CDSK)system suitable for wireless environment is studied.The OMC-CDSK system uses the sum of the chaotic signal and its delayed signal as a reference signal,and the chaotic signal and its delayed signal are respectively added as the information-bearing signal after modulating the information signal.Reference signals and information-bearing signals are transmitted using multi-carrier technology.In this thesis,the bit error rate formula of OMC-CDSK system under Additive White Gaussian Noise(AWGN)channel is derived,and the formula is theoretically and experimentally simulated.The experimental results show that the results of theoretical simulation and experimental simulation are basically the same.OMC-CDSK system effectively improves the information transmission rate and bit error performance of CDSK system.2.In order to further improve the error performance of the OMC-CDSK system,the thesis uses noise reduction technology to improve the OMC-CDSK system,and studies a Phase Quadrature Multi-Carrier Noise Reduction Chaos Delay Shift Keying(PQMC-NRCDSK)system.The PQMC-NRCDSK system uses the duplicated chaotic signal instead of the chaotic signal in the OMC-CDSK system,and uses Multiple Input Multiple Output(MIMO)technology in the system to suppress channel fading.In the thesis,the bit error rate formula of PQMC-NRCDSK system under AWGN channel and Rayleigh channel is derived,and the formula is theoretically and experimentally simulated.The experimental results show that the results of theoretical simulation and experimental simulation are consistent,and the system effectively solves the problem of low error performance of OMC-CDSK system.3.In order to improve the information transmission rate of the PQMC-NRCDSK system,the thesis studies a Phase Quadrature Multi-Carrier Improved Noise Reduction Correlation Delay Shift Keying(PQMC-INRCDSK)system.The reference signal of the PQMC-INRCDSK system is the same as the PQMC-NRCDSK system,but the chaotic signal is not copied when the information carries the signal.Multiple Input Multiple Output(MIMO)technology is used in the system to suppress channel fading.In the thesis,the bit error rate formula of the system under AWGN channel and Rayleigh channel is derived,and the formula is theoretically and experimentally simulated.The experimental results show that the theoretical and experimental simulation results are basically the same,and the system improves the information transmission rate of the PQMC-NRCDSK system.