一种四进制Duffing混沌数字通信系统

为提高多进制混沌通信系统的性能,解决Duffing混沌系统受混沌同步技术限制的问题,本文设计了基于Duffing振子的四进制混沌数字通信系统.利用二进制Duffing混沌调制方法与正交幅度调制技术（Quadrature Amplitude Modulation, QAM）结合的思想,实现了基于Duffing振子的四进制混沌调制.同时,根据Duffing振子解调信号的原理,文中简化了域分割检测器的结构,并构建了基于同频Duffing振子阵列的混沌信号解调器和基于Duffing振子的四进制混沌数字接收机,完成了基于Duffing振子的四进制混沌数字通信系统的设计.仿真结果表明:基于Duffing振子的四进制混沌信号发射机完成了对基带信号的四进制混沌调制；简化的域分割检测器可自动识别Duffing振子相轨迹,且其结构和算法更易实现；基于Duffing振子的四进制混沌数字接收机完成了四进制Duffing混沌信号的非相干解调,该混沌数字通信系统的误码率等性能优于经典的四进制混沌数字通信系统.本文针对Duffing振子混沌通信技术,改善了基于Duffing振子的四进制混沌数字通信系统的设计方法,为多进制混沌通信系统的构建提供了参考.

A quaternary chaotic digital communication system based on Duffing oscillator

To improve the property of M-ary chaotic communication system and develop the chaotic synchronization technique of Duffing chaotic system, a quaternary chaotic digital communication system using Duffing oscillator is presented in this paper. The binary chaotic modulation method with Duffing oscillator was combined with Quadrature Amplitude Modulation (QAM) to realize quaternary chaotic modulation with Duffing oscillator. Meanwhile, according to the demodulation theory of Duffing oscillator, the zone partition was simplified, and the chaotic signal demodulator based on Duffing oscillators array as well as the quaternary chaotic digital receiver based on Duffing oscillator was constructed, which realized the quaternary chaotic digital communication system design based on Duffing oscillator. Simulation results show that the quaternary chaotic modulation could be achieved by the quaternary chaotic signal transmitter. The simplified zone partition could recognize the phase trajectory of the Duffing oscillator with easier realization of structure and algorithm. The quaternary chaotic digital receiver based on Duffing oscillator could realize noncoherent demodulation of the quaternary Duffing chaotic signal, and results show that the BER property of the chaotic system was better than that of the classical quaternary chaotic systems. Therefore, the quaternary chaotic digital communication system based on Duffing oscillator introduced in this paper simplifies the chaotic modulation method and noncoherent demodulation with Duffing oscillator, which provides reference for the construction of M-ary chaotic communication system.