Frequency modulated radar signal with combined chaotic sequence based on Bernoulli map

Abstract

Chaotic signal shows amounts of advantages in the application of radar systems for its easy generation and control. The model of combined chaotic maps based on Bernoulli map is proposed in this paper. Then, the chaos based frequency modulated (FM) radar signal is put forward and the frequency spectrum, ambiguity function are also analyzed in theory. In simulation, the phase spaces, Approximate entropy (ApEn) and balance of the combined chaotic maps are investigated, which shows the combined maps sequences have greater performances than the initial sequences. Additionally, the Peak side-lobe level (PSL) and Integrated side-lobe level (ISL) of signal autocorrelation are discussed, and they drop greatly with the combined chaotic maps after frequency modulation. Simulation results also show that the FM signal based on combined chaotic maps has flatter frequency spectrum in the whole frequency band and a thumbtack ambiguity function.