An LPI wireless communication system based on chaotic modulation

In this paper, we investigate a phase randomization technique in order to modify the coherence structure of a chaotically modulated signal. Phase randomization is shown to reduce the detectability of cyclostationary features, introduced by the constant chip rate of the chaotically modulated signal. The chaotic modulation scheme is based on the symbolic dynamics of a modified Bernoulli shift map and backward iteration. The receiver estimates the transmitted sequence using the maximum-likelihood (ML) estimation approach. We present a second-order statistical cyclostationary analysis in addition to the resulting bit error-rate (BER) of the modulation. The paper presents the overall feasibility of such a scheme by an analysis of the receiver complexity.