A chaotic SS code generating method and its application to a DS-UWB system

The presently existing methods for generating chaotic binary sequence under finite precision are first studied in this paper, the short cyclic behavior of chaotic sequences is analyzed in detail. At the same time, a chaotic similar function is defined for presenting the cyclic characteristics of the sequences. Based on these efforts, an improved method with scrambling control for generating chaotic binary sequences is proposed. To quantitatively describe the improvement of periodic performance of the sequences, an orthogonal estimator is then defined. Some simulating experiments are also given in this paper. We also apply the short chaotic binary sequence, which is generated by our proposed method, to a multiuser DS-UWB system as a SS code, and compare the application performance with that of the conventional Kasami code. All the results in this paper demonstrate that our proposed method can effectively increase the period of the short chaotic binary code, and more evidently improve the performance of the DS-UWB system.