OFDM-Based Chaotic Spread Spectrum Communications with High Bandwidth Efficiency

A novel noncoherent chaotic communication system with low probability interception(LPI) based on orthogonal frequency division multiplexing(OFDM) is proposed in this article. In our OFDM-based chaotic communication system, a special subcarrier is used to send a spreading chaotic signal while the other N - 1 subcarriers are used to send information bearing signals spreaded by the reference chaotic signal. At the receiver, a DCSK similarly differential detector is formed to recover the transmitted information bits without reproduction of the spreading chaotic signal. In particular, we focus on its transmission performance and get approximate analytical expressions of the BER under AWGN based on the Central Limit Theorem(CLT). Simulation results show that our proposed scheme outperforms DCSK under AWGN with high bandwidth efficiency.