Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

A New Transmit Antenna Selection Technique for Physical Layer Security with Strong Eavesdropping

Gonzalo J. Anaya-López, J. Carlos Ruiz-Sicilia, F. Javier López-Martínez

TL;DR

It is shown that the conventional TAS criterion based on the legitimate channel state information (CSI) is not recommended when the average signal-to-noise ratio for the illegitimate user becomes comparable to that of the legitimate user.

Abstract

We propose a new transmit antenna selection (TAS) technique that can be beneficial for physical layer security purposes. Specifically, we show that the conventional TAS criterion based on the legitimate channel state information (CSI) is not recommended when the average signal-to-noise ratio for the illegitimate user becomes comparable or superior to that of the legitimate user. We illustrate that an eavesdropper's based antenna selection technique outperforms conventional TAS, without explicit knowledge of the eavesdropper's instantaneous CSI. Analytical expressions and simulation results to support this comparison are given, showing how this new TAS scheme is a better choice in scenarios with a strong eavesdropper.

A New Transmit Antenna Selection Technique for Physical Layer Security with Strong Eavesdropping

TL;DR

It is shown that the conventional TAS criterion based on the legitimate channel state information (CSI) is not recommended when the average signal-to-noise ratio for the illegitimate user becomes comparable to that of the legitimate user.

Abstract

We propose a new transmit antenna selection (TAS) technique that can be beneficial for physical layer security purposes. Specifically, we show that the conventional TAS criterion based on the legitimate channel state information (CSI) is not recommended when the average signal-to-noise ratio for the illegitimate user becomes comparable or superior to that of the legitimate user. We illustrate that an eavesdropper's based antenna selection technique outperforms conventional TAS, without explicit knowledge of the eavesdropper's instantaneous CSI. Analytical expressions and simulation results to support this comparison are given, showing how this new TAS scheme is a better choice in scenarios with a strong eavesdropper.

Paper Structure

This paper contains 8 sections, 19 equations, 4 figures.

Table of Contents

  1. Introduction
  2. System Model
  3. Optimal TAS
  4. Bob-based TAS
  5. E-TAS
  6. Physical Layer Security
  7. Numerical Results
  8. Conclusion

Figures (4)

  • Figure 1: System model under consideration. The DL transmission of the message $z_{\rm B}$ by the BS (Alice) takes place through the transmit antenna $k$, which is selected according to some TAS criterion.
  • Figure 2: Average secrecy capacity $(\overline C_{\rm S})$ as a function of $\overline\gamma_{\rm B}$ for the schemes O-TAS, B-TAS and E-TAS with $\overline\gamma_{\rm E_0}=10$ dB. The cases with $M=\{2,8\}$ antennas are represented with dash-dotted and solid lines, respectively. Markers correspond to MC simulations.
  • Figure 3: Average secrecy capacity $(\overline C_{\rm S})$ as a function of $\overline\gamma_{\rm E}$ for the schemes O-TAS, B-TAS and E-TAS with $\overline\gamma_{\rm B_0}=10$ dB. The cases with $M=\{2,8\}$ antennas are represented with dash-dotted and solid lines, respectively. Markers correspond to MC simulations.
  • Figure 4: Normalized average secrecy capacity $(\overline C_{\rm S}/\overline C_{\rm S}^{\rm O-TAS})$ as a function of $\overline\gamma_{\rm E_0}/\overline\gamma_{\rm B_0}$, for different values of $\overline\gamma_{\rm B_0}=\{10,20,30\}$ dB. These correspond to the solid, dashed and dash-dotted lines in the figure, respectively, with $M=8$. Markers correspond to MC simulations. The crossing SNR value is identified with a solid black marker for each pair of curves.