Physical layer security via maximal ratio combining and relay selection over Rayleigh fading channels

Abstract

In this paper, the impact of both maximal ratio combining (MRC) and relay selection on the physical layer security in wireless communication systems is investigated by analyzing critical issues such as the probability characteristics of the legitimate receiver (Bob) and malicious eavesdropper (Eve)'s end-to-end signal-to-noise ratio (SNR), the secrecy outage probability and the average secrecy channel capacity over Rayleigh fading Channel, etc. Unlike the conventional physical layer security schemes, we assume that Bob receives its data from both the relay and the source via cooperative relay, provided that MRC is employed at the receiver. Particularly, compared to the conventional MRC methods, the proposed method is capable of achieving a higher spatial diversity order by performing relay selection, as validated by performing the theoretical analysis as well as numerical simulation. Furthermore, the closed-form expressions in terms of secrecy outage probability and average secrecy capacity are all consistent with the numerical results. Finally, the proposed scheme may be substantially affected by a number of parameters such as the number of relays, the SNR of links and the ratio of main-to-eavesdropper ratio (MER) λ ME . CitationZhong B, Wu M G, Li T, et al. Physical layer security via maximal ratio combining and relay selection over Rayleigh fading channels. Sci China Inf Sci,

Leakage rate–based untrustworthy relay selection

“…For instance, to achieve 10 −1 IP, the required outage performance are between 10 −3 and 10 −2 , 10 −2 and 10 −1 , and 10 −1 and 10 0 for M is equal to 6, 4, and 2, respectively. These observations are consistent with the analytical derivations, which are (18), (20), (24), (26), and the derived asymptotic expressions. Figure 10 presents the AR performance comparisons of HD and FD strategies in OWR case.…”

“…However, the obtained performance improvements with the FD-based selection strategy is at negligible levels. These observations are consistent with the analytical derivations (18), (20), (22), and derived asymptotic CDF expressions. Figure 4 presents the outage performance of the HRS in OWR mode.…”

“…By using the Taylor series expansion, the exp(x) term can be written as exp(x) = 1 + x for x → 0. 35 By doing this variable change on the OP expressions in (17), (18), (19), (20), (21), and (22), the asymptotic CDF expressions can be obtained. These derivations are omitted in here because of the space limitations.…”

“…This section now focuses on the derivation of the HD-based TWR case. In this regard, starting with (4), (5) and utilizing the strategy in (12), following the procedures as in the appendix B in the work of Ozduran, 26 the final CDF expression can be obtained as in (18). Please note that, because of the space limitations, the CDF derivation details of the HD-based TWR case is presented in the appendix B in the work of Ozduran 26 and omitted here.…”

“…The work of Li et al 17 and its extended version 18 consider that the source communicates with the destination via N available DF-based HD relay terminals. Li et al 17,18 also consider that the information exchange process overhears by a single eavesdropper. In addition, they 17,18 also consider max-min (MM)-based relay selection and maximal ratio combining (MRC) techniques at the destination to improve the PHY security.…”