关键词: 混沌, Logistic序列, 相关性, 扩频通信

Abstract: Chaotic sequence, as a spreading code in spread spectrum systems, has the characteristics of rich sequences and good confidentiality. The autocorrelation of traditional two-dimensional maps has great defects, with its high sidelobes and nonzero means. To solve those problems, this paper proposes an improved symmetrical two-dimensional Logistic map with two levels based on phase space reconstruction, which greatly optimizes the correlation property. The simulation results prove that the algorithm mentioned in this paper is effective. Furthermore, the power spectral density, maximum Lyapunov exponent and the cross-correlation are analyzed, which show that the new method is consistent with the requirements of spread spectrum sequences.

Key words: chaotic, Logistic sequence, correlation, spread spectrum communication