Digital transmission for improved synchronization of analog chaos generators in communications systems.

We present a method for synchronization of chaos generators based on transmission of an analog chaotic waveform in a digital form. Experimental comparisons between digital and analog transmission of chaos from a delayed differential feedback system are performed. Synchronization is demonstrated to be between 18 and 39 dB (or equivalently 63 to 7943 times) better for digital transmission than analog. Coherent chaotic modulation and demodulation is demonstrated in a situation where there is no effective synchronization using analog transmission.

[1]  K. Ikeda,et al.  High-dimensional chaotic behavior in systems with time-delayed feedback , 1987 .

[2]  Polina S. Landa,et al.  Stochastic and Chaotic Oscillations , 1992 .

[3]  Laurent Larger,et al.  Communicating with optical hyperchaos: information encryption and decryption in delayed nonlinear feedback systems. , 2001, Physical review letters.

[4]  Wu Xiaofu,et al.  Design and realization of an FPGA-based generator for chaotic frequency hopping sequences , 2001 .

[5]  Clare D. McGillem,et al.  A chaotic direct-sequence spread-spectrum communication system , 1994, IEEE Trans. Commun..

[6]  Leon O. Chua,et al.  Transmission of Digital signals by Chaotic Synchronization , 1992, Chua's Circuit.

[7]  Ronald N. Bracewell,et al.  The Fourier Transform and Its Applications , 1966 .

[8]  Michael Peter Kennedy,et al.  The role of synchronization in digital communications using chaos. I . Fundamentals of digital communications , 1997 .

[9]  M. P. Kennedy,et al.  Chaotic communications with correlator receivers: theory and performance limits , 2002, Proc. IEEE.

[10]  Luigi Fortuna,et al.  Chaos preservation through continuous chaotic pulse position modulation , 2001, ISCAS 2001. The 2001 IEEE International Symposium on Circuits and Systems (Cat. No.01CH37196).

[11]  Michael Peter Kennedy,et al.  Chaos shift keying : modulation and demodulation of a chaotic carrier using self-sychronizing chua"s circuits , 1993 .

[12]  Laurent Larger,et al.  Communicating with Optical Hyperchaos , 2001 .

[13]  Dorizzi,et al.  Statistics and dimension of chaos in differential delay systems. , 1987, Physical review. A, General physics.

[14]  Laurent Larger,et al.  Dynamics of non-linear feedback systems with short time-delays , 2001 .

[15]  Laurent Larger,et al.  OPTICAL ENCRYPTION SYSTEM USING HYPERCHAOS GENERATED BY AN OPTOELECTRONIC WAVELENGTH OSCILLATOR , 1998 .

[16]  Peter Stavroulakis,et al.  Chaos Applications in Telecommunications , 2005 .

[17]  C. Robilliard,et al.  Enhancing the Security of Delayed Differential Chaotic Systems With Programmable Feedback , 2006, IEEE Transactions on Circuits and Systems II: Express Briefs.

[18]  Cuomo,et al.  Circuit implementation of synchronized chaos with applications to communications. , 1993, Physical review letters.

[19]  Michael Peter Kennedy,et al.  The role of synchronization in digital communications using chaos. II. Chaotic modulation and chaotic synchronization , 1998 .

[20]  J.E. Mazo,et al.  Digital communications , 1985, Proceedings of the IEEE.