Combining Dirty-Paper Coding and Artificial Noise for Secrecy Bo Wang1, Pengcheng Mu1, Chao Wang1, Weile Zhang1, Hui-Ming Wang1, and Bobin Yao2 1School of Electron. & Inform. Eng., Xi’an Jiaotong University, Xi’an, China, 710049 2School of Electron. & Control Eng., Chang’an University, Xi’an, China, 710064

Outline Introduction System model Problem formulation Transmission scheme Optimization algorithm Simulation results Conclusions 2018/7/23 IEEE ICASSP 2016

Introduction Physical layer security Shannon’49 Wiretap channel Wyner’75 CsiszarKorner-TIT’78 Secrecy capacity Secrecy rate & wiretap code Alice Eve Bob X Y Z 2018/7/23 IEEE ICASSP 2016

Introduction Multi-antenna techniques Beamforming KhistiWornell-TIT’10 Artificial noise (AN) GoelNegi-TWC’08 LiMa-TSP’13 Intrinsic secrecy in multiuser networks 2018/7/23 IEEE ICASSP 2016

System model M-user wiretap broadcast channel An N-antenna transmitter Alice M single-antenna legitimate receivers Bob-m A single-antenna passive eavesdropper Eve large-scale fading 2018/7/23 IEEE ICASSP 2016

System model Broadcasting Secrecy capacity & dirty-paper coding (DPC) EkremUlukus-TIT’11 & BagherikaramMotahariKhandani-TIT’13 2018/7/23 IEEE ICASSP 2016

System model ? Secrecy outage Secrecy outage probability (SOP) 2018/7/23 IEEE ICASSP 2016

normal communication rate of Bob-m Problem formulation Secrecy rate maximization secrecy rate of Bob-1 normal communication rate of Bob-m SOP of Bob-1 power budget 2018/7/23 IEEE ICASSP 2016

Transmission scheme Zero-forcing dirty-paper coding (ZF-DPC) 2018/7/23 IEEE ICASSP 2016

Transmission scheme Hybrid secure transmission scheme 2018/7/23 IEEE ICASSP 2016

Transmission scheme Simplified optimization problem 2018/7/23 IEEE ICASSP 2016

Optimization algorithm Simplified SOP Introduce 2018/7/23 IEEE ICASSP 2016

Optimization algorithm Decomposition (fix ) 2018/7/23 IEEE ICASSP 2016

Optimization algorithm Solution to the inner problem optimal power allocation among 2018/7/23 IEEE ICASSP 2016

Optimization algorithm Solution to the outer problem convex quasi-concave The global optimum can be found ! 2018/7/23 IEEE ICASSP 2016

Simulation results Comparison with the traditional AN scheme 2018/7/23 IEEE ICASSP 2016

Conclusions DPC enables a simple and accurate characterization of the intrinsic secrecy in a multiuser broadcast channel. The proposed hybrid secure transmission scheme supports the secure transmission for one user and the normal transmission for some other users simultaneously. The achievable secrecy rate can be close to that of the traditional AN scheme. 2018/7/23 IEEE ICASSP 2016

THANK YOU Bo Wang School of Electronic and Information Engineering, Xi’an Jiaotong University antaeusas@stu.xjtu.edu.cn