1 Improving Physical-Layer Security in Wireless Communications….pdf

1 Improving Physical-Layer Security in Wireless Communications Using Diversity Techniques Yulong Zou, Senior Member, IEEE, Jia Zhu, Xianbin Wang, Senior Member, IEEE, and Victor C.M. Leung, Fellow, IEEE 4 1 0 2 y a M Abstract 5 Due to the broadcast nature of radio propagation, the wireless transmission can be readily over- 1 heard by unauthorized users for interception purposes and is thus highly vulnerable to eavesdropping ] T attacks. To this end, physical-layer security is emerging as a promising paradigm to protect the wireless I s. communications against eavesdropping attacks by exploiting the physical characteristics of wireless c [ channels. This article is focused on the investigation of diversity techniques to improve the physical- 1 layer security, differing from the conventional artificial noise generation and beamforming techniques v 5 which typically consume additional power for generating artificial noise and exhibit high implementation 2 complexity for beamformer design. We present several diversity approaches to improve the wireless 7 3 physical-layer security, including the multiple-input multiple-output (MIMO), multiuser diversity, and . 5 0 cooperative diversity. To illustrate the security improvement through diversity, we propose a case study of 4 exploiting cooperative relays to assist the signal transmission from source to destination while defending 1 : against eavesdropping attacks