Synchronization in Chaotic Communication

This paper proposes a Frequency Hopped Spread Spectrum (FHSS) communication system using chaos and its synchronization. The spread spectrum technique of frequency hopping uses pseudorandom number (PN) generator to produce a random sequence of frequencies. A new class of signature sequences for use in Frequency Hopped Spread Spectrum communication systems is proposed. In arriving at these sequences, the theory of chaos has been used. The correlation properties of these chaotic sequences are similar to random white noise. The numbers and lengths of chaotic sequences are not restricted like m sequences. The performances of chaotic sequences in multiple access communication are shown to be similar to that of PN sequences. Furthermore, due to their noise like appearance, chaotic sequences outperform PN sequences in low probability of intercept. In this method the spreading sequences change from one bit to the next in very random like fashion, causing undesired interception to be very difficult. The synchronization of the system is also proposed.