Time-Division Multiplexed Optical Covert Communication System Based on Gain-Switched Optical Pulses

Abstract

In optical covert communication systems based on gain-switched distributed feedback semiconductor lasers, the trade-off between the modulation frequency and the spectral imperceptibility limits the bit rate of the secure channel. To improve the system performance in terms of the bit rate and covertness, optical time-division multiplexing is introduced to optical covert communication for the first time. The optical time-division multiplexed covert channel can work under both multiple-user and single-user conditions. The optical time-division multiplexed covert communication system is demonstrated via a system simulation. The results show that the covertness is enhanced by the optical time-division multiplexing in the spectral domain. The receiver sensitivity of the multiple-user condition is lower than the single-user one.