The Scheme based on Partial Channel State Information for the Physical Layer Security

The physical layer security technology is an effective way to reduce information leakage in a wireless communication system. In this paper, we study the physical-layer security of one-way wiretap channel which contains a source-destination pair, an eavesdropper and multiple cooperating relay nodes. What's more, in this channel, there exists direct link between the source and the destination (eavesdropper) and lacks he eavesdropper's channel state information (ECSI). To address its physical-layer security, we proposed a scheme which combines amplify-and-forward (AF)-based relay beamforming and cooperation jamming (CJ) technology. We aim at minimizing the power available for transmitting desired information in relays and optimizing the relay weights under the scenario of limiting the signal to ratio at the destination to a given range, which can be solved by convex optimization techniques. After that, we prove that the optimization results are unique and globally optimum. And the numerical results show that the proposed design can effectively enhance secure transmission rate.