The Research Of Chaos M-ary Modulation And Demodulation Method Based On Chaotic Oscillator

Chaotic signals have been applied in communications due to their broadband characteristics, unpredictable properties as well as orthogonal features. However, the recent researches of chaos mainly focus on the binary systems, the information transmission rate of which is low, while the researches of M-ary chaotic communication system are not in-depth and extensive enough. To change the situation and effectly improve the information transmission rate, a novel chaos M-ary modulation and demodulation method based on chaos oscillator is proposed in this paper.Firstly, it describes the principle of chaos M-ary modulation method based on phase plane partition of chaos oscillator, introduces the way to choose the best chaos cscilltator, analyzes the factor that influences the region distribution of the phase trajectory as well as how to achieve the mapping from M-ary information to phase trajectory region. Secondly, it studies the realization algorithm of Hamilton Map as well as the method to drive the Hamilton Map by M-ary information to get chaotic baseband signals. Then it discusses the chaos M-ary demodulation method base on ZPD (zone partition divider) method. Finally, it studies the way to construct M-ary communication system based on chaos M-ary modulation and demodulation method, and evaluates the effect of this method in communications. Simulation results show that:under the condition that the occupied bandwidth and the information rate are equal, the anti-noise performance of the communication system based on chaos M-ary modulation and demodulation method can achieve the theoretical limit of the ideal incoherent OOK receiver.