A Composite Pseudorandom Sequence Generated Method Based On Chaotic Theory

A pseudo-random sequence is a sequence that has both random characteristics of random sequences and can be repeatedly generated and reproduced and can be predetermined.It is widely used in the fields of pseudo-code ranging,spread spectrum communication,communication encryption,and radar ranging.With the development of science and technology,obtaining pseudo-random sequences with higher performance has become a research hotspot.Chaos refers to the potential modes existing in the apparent randomness of complex systems.It provides a new way to generate high-performance pseudo-random sequences.Based on the above background,this dissertation mainly studies the characteristics of chaotic pseudo-random sequences generated based on chaos theory.Chaotic pseudo-random sequences have initial value sensitivity,good correlation characteristics and randomness,large number of code families,and are easy to generate and replicate in engineering applications.However,the pseudo-random sequence generated by the basic chaotic map has weak points with low system complexity and poor sequence randomness.Therefore,a new chaotic pseudo-random sequence generated method is proposed in this thesis.The method uses parallel structure combined with basic mapping and other combined type mapping to increase the complexity of the system,this method is called a composite pseudo-random sequence generator.The performance of pseudo-random sequences generated by the composite pseudo-random sequence generator from initial value sensitivity,pseudo-random characteristics and correlation is evaluated.The simulation and experimental results show that the proposed method improves the pseudo-random characteristics of the one-dimensional chaotic sequence and expands the parameter space of the system,which makes the system more confidential.The new chaotic sequence also has better initial value sensitivity and good autocorrelation properties.