Direct Sequence Spread-Spectrum Based Covert Communication Using Random Pulse Width Modulation
Gizem Akcan, Mehmet Emre Çek · 2019
In this study, a covert communication method called as random pulse width modulation (RPWM) is proposed for secure communication where the signals are obtained from the direct noise sequence instead of the pseudo noise (PN) sequence composed by pulse durations. The aim is to develop a spread-spectrum covert communication mimicking statistical properties of white noise by preventing the repetitive structure of auto correlation function observed in the pseudo noise (PN) sequences. For this purpose, random variables are generated having uniform distribution and rectangular pulses are generated whose durations are determined by these random variables. The binary information is determined by using the difference of the mean values as the statistical parameters obtained from the residence times of positive and negative states in the rectangular waveform.