A Physical Layer Covert Transmission Device and Method Based on Constant Envelope Signal

Abstract

The invention relates to a physical layer covert transmission device and method based on a constant envelope signal, belonging to the field of wireless communication. The present invention realizes fast switching of the antenna impedance by embedding an impedance switching device between the constant envelope signal generator and the transmitting antenna, so that the envelope of the original signal is changed by analog keying at the radio frequency transmitting end, so as to achieve The physical layer realizes the purpose of covert transmission; at the same time, the present invention adds interference signals to the covert information and encrypts the transmitted covert information through the form of multiple antennas without affecting the demodulation of the original signal. The invention uses envelope detection, channel estimation and corresponding concealed information decoder to obtain concealed information after removing interference signal at the receiving end, and uses constant envelope signal demodulator to obtain original constant envelope information. The invention has the characteristics of low power consumption, low cost, high concealment and strong anti-intercept ability.

Description

technical field [0001] The invention relates to a physical layer covert transmission device and method based on a constant envelope signal, belonging to the field of wireless communication. Background technique [0002] The wireless communication technologies commonly used in the Internet of Things include Zigbee technology, Wifi technology, Bluetooth (Bluetooth) technology, and LoRa technology. Among them, Zigbee technology, Bluetooth technology, Lora technology, etc. are all constant envelope signals, which encode information by changing the phase or frequency of the transmission signal, and the relevant demodulators only demodulate information by detecting the phase or frequency of the transmission signal. Therefore, these constant-envelope signals lack the detection and utilization of the physical layer signal amplitude. Therefore, for these technologies, the information of the physical layer signal amplitude can be modulated without affecting the demodulation of the ori...

AI Technical Summary

Problems solved by technology

[0003] Existing anti-interception and anti-jamming technologies for various constant envelope signals usually use direct sequence spread spectrum technology, frequency hopping technology, etc. to achieve low sensitivity at the signal level or to perform encryption and decryption at the protocol layer. Earlier, there were many effective countermeasures against these encryption and concealment technologies, so the concealment of these technology-related devices is weak, and it is easy to be identified, stolen or destroyed by interference

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