College of Communication Engineering, Jilin University, Changchun 130012, China;
College of Geo-Exploration Sciences and Technology, Jilin University, Changchun 130026, China;
College of Communication Engineering, Jilin University, Changchun 130012, China;
College of Communication Engineering, Jilin University, Changchun 130012, China;
chaos detection; bifurcation threshold value; weak signal; phase plane; Lyapunov exponent;