Research Article
Distributed Precoding in Multi-Relay Wiretap Systems with Amplify-and-Forward
@INPROCEEDINGS{10.1109/ChinaCom.2013.6694635, author={Jing Wang and Xiaoting Wang and Qianghua Guo and Hang Long and Yixian Shen}, title={Distributed Precoding in Multi-Relay Wiretap Systems with Amplify-and-Forward}, proceedings={8th International Conference on Communications and Networking in China}, publisher={IEEE}, proceedings_a={CHINACOM}, year={2013}, month={11}, keywords={security secrecy capacity relay systems precoding}, doi={10.1109/ChinaCom.2013.6694635} }- Jing Wang
Xiaoting Wang
Qianghua Guo
Hang Long
Yixian Shen
Year: 2013
Distributed Precoding in Multi-Relay Wiretap Systems with Amplify-and-Forward
CHINACOM
IEEE
DOI: 10.1109/ChinaCom.2013.6694635
Abstract
The security of the multi-relay wiretap system with an eavesdropper is investigated in this paper, where the amplifyand-forward (AF) relaying protocol is used. Appropriate distributed precoding design at the relay nodes can be utilized to guarantee the secure communication, which means maximizing the ratio of received signal power at the destination node and the eavesdropper node. In decode-and-forward relaying systems, an iterative algorithm has been proposed to find sub-optimum distributed precoding angles at all the relay nodes [1]. In this paper, this algorithm is extended to be used in AF systems with some modifications. In the algorithm, after receiving the equivalent channel state information (CSI) from the last relay node, the current relay node derives the optimum distributed precoding angle, and updates the equivalent CSI for the next one, so that each relay node shares much less CSI information with each other, compared with the exhaustive search scheme. Numerical and simulation results demonstrate that in the AF protocol system, the iterative algorithm can help achieve considerable secrecy capacity with a little CSI sharing overhead.