Secure Full Duplex OFDM Wireless Communication Based on Phase Relay between the Legitimate Nodes

Yong Guo, Lijie Zhang
2020 IET Communications  
This study proposes a scheme to realise secure orthogonal frequency-division multiplexing (OFDM) wireless communication between two full duplex nodes-node A and node B. If node A wants to send secret messages to node B, node A and node B transmit the training signal to each other to acquire channel state information (CSI) in the first time frame. Node A acquires the phases of the received signal from node B (no need to decode). In the second time frame, node A then sends secret messages to node
more » ... B with the phases of the modulated signal being added to the random phases of the signal from node B in the previous time frame, i.e node A relaying the phases of the signal from node B. Node B can recover the secret messages from node A, but eavesdroppers cannot because they do not know the CSI of the main channel. The secrecy capacity is irrelevant to the CSI of the eavesdropper channel, which is a big advantage over other schemes. The scheme can guarantee secrecy capacity to be positive in all circumstances and work well for single-input single-output systems. A computation efficient algorithm is presented to optimally allocate power over sub-carriers for secrecy capacity maximisation.
doi:10.1049/iet-com.2019.0916 fatcat:vdaldxudujeo7azbpflue46sia