Abstract:

In order to enhance the anti-interception performance of modulation-hopping technology, a method to design wide-gap chaos modulation hopping pattern based on time of day (TOD) is proposed. According to the deficiency of the cycle extraction algorithm in the balance, an improved algorithm combining the cycle extraction and reshaping operation is presented to design Chaos modulation hopping pattern. The analysis and simulation results verify this method has better properties in balance. Furthermore, in order to perfect the anti-interception property, symmetry algorithm and random shift replace algorithm are introduced to widen the modulation hopping pattern gap. Simulation results prove that symmetry algorithm is applicable for generating the long periodic hopping pattern used in valid data communications, while random shift replace algorithm is proper for the short periodic pattern with the good balance in the range of maximum effective length, and it can be used in the situations of short-cycle emergency communications.

Key words: anti-intercepted communications, modulation hopping, modulation hopping pattern, chaos, wide gap