Photonic-Assisted Spread Spectrum Communication Transceiver System Based on DDMZM

Direct Sequence Spread Spectrum (DSSS) systems are practical and dominant among covert communication systems. However, limited digital computation resources and bandwidths of electrical devices prevent the further enhancement in the signal stealth. Here we demonstrated a photonic-assisted spread spectrum communication system. The spreading and decoding processes are achieved in the optical domain by multiplying the signal and the corresponding spread sequence via DDMZMs. Performance of the proposed system (e.g. Gain and Bit Error Rate) is analyzed and optimized based on simulations and experiments. The spreading gain of this system reaches 50 dB with the spread spectrum bandwidth of 8 GHz. When the SNR of incident spread spectrum signal is -26 dB, the BER reaches 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> with the spreading gain of 50 dB. The comprehensive theoretical and experimental analysis on the proposed scheme will facilitate the application of the photonic-assisted spread spectrum system, meanwhile the elegant and simple scheme make it viable for future photonic integration.