Proportional-integral feedback demodulation for secure communications

A novel demodulation strategy for secure communications using chaotic signa ls is proposed. The approach fits within the general definition of inverse system masking (ISM) methods. In the transmitter, an information signal is encoded using modulation of a parameter in the chaotic system. In the recei ver, a synchronous chaotic system is augmented with a proportional-integral (PI) feedback demodulator. The integral feedback action induces certain ro bustness capabilities into the demodulation loop. Simulations are presented for a class of Lur'e systems. (C) 2000 Elsevier Science B.V. All rights re served.