Exploiting multi-radio cooperation in heterogeneous wireless networks for absolute security against eavesdropping

In this paper, we consider a heterogeneous wireless communication scenario, which is comprised of a source (S) and a destination (D) in the presence of an eavesdropper (E), each equipped with multiple heterogeneous radio access interfaces. In order to enhance the transmission security against eavesdropping, we propose a multi-radio cooperation (MRC) scheme, where the multiple radio interfaces at S are simultaneously utilized to transmit a source signal to D along with a weight design. For the convenience of performance comparisons, the conventional multi-radio switch (MRS) scheme is also considered as a benchmark scheme, in which only the single “best” radio interface is selected at S to transmit the source signal. We evaluate the secrecy capacity and intercept probability (IP) of conventional MRS and proposed MRC schemes over Rayleigh fading channels. It is proved that the proposed MRC scheme can achieve an absolute security with zero IP, which is further validated through Monte-Carlo simulations. Numerical results show that the proposed MRC scheme performs better than conventional MRS scheme in terms of their secrecy capacity and IP.