Covert communication methods, computer devices, and readable storage media utilizing linear spread spectrum modulation of nonlinear chirped spread spectrum amplitude.

Abstract

This application relates to a covert communication method, computer device, and readable storage medium utilizing linear spread spectrum modulation of nonlinear chirped spread spectrum amplitude. The method includes nonlinear spread spectrum LoRa communication between a transmitter and a receiver via a legitimate channel. The covert communication method comprises: at the transmitter, performing covert chirped modulation of the legitimate channel amplitude based on a linear chirped spread spectrum modulation method to form a covert channel carrying covert information; embedding the covert channel into the legitimate channel to obtain a transmission signal containing both legitimate and covert information; at the receiver, receiving the transmission signal through a legitimate receiver and demodulating it using legitimate nonlinear chirped modulation to obtain legitimate information; and at the receiver, receiving the transmission signal through a covert receiver, processing it with covert chirped information, and then performing covert chirped demodulation based on a linear chirped spread spectrum modulation method to obtain the covert information. This application embeds covert information into a legitimate nonlinear spread spectrum LoRa channel, improving the parallel transmission capacity of covert information.

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