Spread spectrum communication method based on chaotic spread spectrum sequence

Abstract

The invention relates to a spread spectrum communication method based on a chaotic spread spectrum sequence. At a transmitting end, target information is converted into a binary sequence serving as a signal source; a length N of a spread spectrum sequence is determined according to information of the signal source and is greater than or equal to that of the signal source; under the conditions that gamma belongs to a set from 1.5 to 2 and x0 belongs to a set from -1 to 1 and is not equal to 0, +0.5 and -0.5, iteration is gradually executed for N times, so that a simulation real value sequence {x1, x2, ..., xi, ..., and xN} with the length of N is obtained; the information of the signal source is subjected to baseband modulation and then binary sequence modulation produced in the step 4, so that a spread spectrum is obtained; at a receiving end, the target information is obtained through relevant demodulation. Compared with the prior art, the spread spectrum sequence produced by the method is uniform in distribution, high in randomness, and the spread spectrum sequence is relatively sensitive to an initial value; a chaotic state can be quickly realized, and the chaos degree is relatively high; and therefore, the security, the reliability and the completeness of the information in a spread spectrum communication process are guaranteed.

Description

technical field [0001] The invention belongs to the technical field of nonlinear spread spectrum communication, and relates to a spread spectrum communication method based on a chaotic spread spectrum sequence. Background technique [0002] In spread spectrum communication, the selection of spread spectrum sequence is very important. Traditional binary pseudo-random (PN) sequences have been gradually replaced by chaotic sequences. The chaotic sequence is generated by a deterministic equation, which is easy to reproduce, and the sequence is extremely sensitive to the chaotic parameters and initial values, and has the statistical characteristics of Gaussian white noise and long-term unpredictability. Therefore, chaotic sequences are widely used in spread spectrum communication systems. Judging from the searched papers, Logistic mapping and improved Logistic mapping are mainly used now. [0003] The main method steps of the improved Logistic mapping are: [0004] Step 1 det...

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Problems solved by technology

However, when the chaotic parameters of this sequence are selected, the full map can only be obtained when γ=2, which leads to a large parameter range, and the generated iterative sequence results will be distributed in a banded area, which is relatively concentrated, which is not conducive to For the randomness requirements of the spreading sequence for secure communication, see figure 1 .

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