Anti-eavesdropping double-differential bidirectional relay transmission method

Abstract

The invention discloses an anti-eavesdropping double-differential bidirectional relay transmission method. A relay node broadcasts a known symbol sequence first, a source node estimates the channel energy between the source node and a relay, and an eavesdropping node estimates the channel energy between the eavesdropping nod and the relay; two source nodes respectively carry out double differential modulation, and send modulation signals to the relay, the relay carries out a conjugate operation to received mixed signals and then amplifies and forwards the mixed signals; finally, the source nodes carry out interference self-cancellation to the received signals and decode information of the received signals by means of the estimated local channel energy and the structure designed according to the method, and the eavesdropping node cannot decode the received signals correctly, and therefore the anti-eavesdropping aim is reached. Compared with an existing amplification and forwarding differential bidirectional relay transmission method, the anti-eavesdropping double-differential bidirectional relay transmission method is advantaged in that the transmission safety is achieved, and the source nodes can carry out decoding successfully under the condition of unknown carrier wave frequency offset existing in the system.

Description

technical field [0001] The invention belongs to the technical field of differential transmission and physical layer security of a wireless two-way relay system, and in particular relates to a double differential transmission method for resisting eavesdropping by unauthorized nodes. Background technique [0002] Wireless relay technology is a new technology that utilizes geographically dispersed wireless nodes to achieve space diversity. In order to solve the limitations of the size and power of wireless terminals, wireless relay technology utilizes the broadcast characteristics of wireless channels and the cooperation of idle nodes in the network to form a virtual multi-antenna system to obtain space diversity gain. Compared with the one-way wireless relay system, the two source nodes in the two-way relay system can use the relay to send information to each other at the same time, so it has higher transmission efficiency. Specifically, a two-way relay transmission includes ...

AI Technical Summary

Problems solved by technology

However, the movement of the nodes will cause the Doppler frequency deviation of the carrier, which will cause the channel to change rapidly, so that the basic assumption of the differential scheme cannot be established.

Images