Effects of Channel Correlation on Outage Secrecy Capacity (Preprint)

Jinxiao Zhu, Osamu Takahashi, Xiaohong Jiang +2 more

Jinxiao Zhu, Xiaohong Jiang, Osamu Takahashi +1 more

We consider the transmission of confidential data over a wireless quasi-static fading wiretap channel when the main and eavesdropper channels are correlated there. Under the assumption that before transmission the transmitter only knows the channel state information (CSI) of the main channel but has no idea about the CSI of the eavesdropper channel, we derive the asymptotic outage probability and also asymptotic outage secrecy capacity as the transmission power goes to infinity, which cover the corresponding results when the main and eavesdropper channels are independent as special cases. Based on the theoretical results, the effects of channel correlation on the asymptotic outage probability and asymptotic outage secrecy capacity are explored. Remarkably, our results reveal that the correlation between the main and eavesdropper channels has a significant impact on both the asymptotic outage probability and asymptotic outage secrecy capacity and that such an impact can be helpful or harmful depending on the relative channel condition between the main and eavesdropper channels.

M. Z. I. Sarkar, Tharmalingam Ratnarajah

In this correspondence, we consider a confidential communication through slow non-selective correlated Rayleigh fading channel, where a single antenna transmitter communicates at a pre-decided constant rate with a legitimate receiver in the presence of an eavesdropper. Both the legitimate receiver and eavesdropper are equipped with multiple antennas and employ maximal ratio combining (MRC) reception scheme. With the presence of channel diversity, we find the closed-form expressions for the probability of non-zero secrecy capacity and the outage probability of secrecy capacity in terms of channel parameters such as correlation coefficient and the ratio of main and eavesdropper channel gains that will be called average channel gain ratio (CGR). The analysis of secure outage performance with the MRC diversity scheme tells how the channel diversity enhances the secrecy capacity. We quantify the effect of antenna correlation on the probability of positive secrecy capacity and the secure outage probability. We also investigate how the target secrecy rate influences the effect of antenna correlation on the secure outage probability. Moreover, as a result of obtaining the closed-form expressions for the probability of positive secrecy capacity and the outage probability, it is insightful to see how the channel parameters affect the secure outage performance of the correlated channels.

Thang Van Nguyen, Hyundong Shin

Zhang Jiuning, Xuanli Wu, Xu Zhicong +3 more

Physical layer security is an important method to improve the secrecy performance of wireless communication systems. In this paper, we analyze the effect of employing channel correlation to improve security performance in multiple-input multiple-output (MIMO) scenario with antenna selection (AS) scheme. We first derive the analytical expressions of average secrecy capacity (ASC) and secrecy outage probability (SOP) by the first order Marcum Q function. Then, the asymptotic expressions of ASC and SOP in two specific scenarios are further derived. The correctness of analytical and asymptotic expressions is verified by Monte Carlo simulations. The conclusions suggest that the analytical expressions of ASC and SOP are related to the product of transmitting and receiving antennas; increasing the number of antennas is beneficial to ASC and SOP. Besides, when the target rate is set at a low level, strong channel correlation is bad for ASC, but is beneficial to SOP.

Pham Ngoc SON, Hyung Yun Kong