Destination Assisted Secret Wireless Communication With Cooperative Helpers

This letter investigates a novel two-stage cooperative scheme to secure the communication system with one source, one destination and multiple helpers. Herein, the source mixes the confidential messages with the interferences transmitted by the helpers and destination. Since the helpers and destination serve to suppress interferences, the destination can acquire an interference-free signal, however the eavesdropper is still confused. This scheme can achieve positive secrecy rate even when the eavesdropper´s channel is much better than the legitimate link, and only requires local channel state information (CSI) and a few parameters of the main link. An efficient sub-optimal algorithm for the majorization of system parameters is proposed to avoid global search and the practical case without eavesdropper´s CSI is also considered. Simulation results demonstrate the effectiveness of the proposed scheme and algorithm.