Chaotic sequences for spread spectrum: an alternative to PN-sequences

A new class of signature sequences for use in direct sequence spread spectrum (DS/SS) communication systems is proposed. In arriving at these new sequences, the theory of chaos has been used. The correlation properties of these chaotic sequences are similar to random white noise. Their noise-like characteristics are explained. The numbers and lengths of chaotic sequences are not restricted like m-sequences. The performance of chaotic sequences in multiple-access communication is 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 (LPI). A method for generating chaotic sequences suitable for use in DS/SS system has been proposed. In this method, the spreading sequences change from one bit to the next in a very random-like fashion, causing undesired interception to be very difficult.<>