Home > Publications > Manuscripts > Ergodic Secret-Key Agreement over Spatially Correlated Multiple-Antenna Channels with Public Discussion
Publications

Ergodic Secret-Key Agreement over Spatially Correlated Multiple-Antenna Channels with Public Discussion

Bibliography:

Marwen Zorgui, Zouheir Rezki, Basel Alomair, Eduard A. Jorswieck, and Mohamed-Slim Alouini, Ergodic Secret-Key Agreement over Spatially Correlated Multiple-Antenna Channels with Public Discussionsubmitted to IEEE Transactions on Signal Processing.

Authors:

Marwen Zorgui, Zouheir Rezki, Basel Alomair, Eduard A. Jorswieck, and Mohamed-Slim Alouini

Keywords:

Secret-key agreement, MIMO systems, optimal signaling, correlation, beamforming, high power regime, energy efficiency

Year:

2015

Abstract:

We consider secret-key agreement with public discussion over multiple-input multiple-output (MIMO) Rayleigh fast-fading channels under correlated environment. We assume that transmit, legitimate receiver and eavesdropper antennas are correlated. The legitimate receiver and the eavesdropper are assumed to have perfect channel knowledge while the transmitter has only knowledge of the correlation matrices. First, we derive the expression of the secret-key capacity under the considered setup. We prove that the optimal transmit strategy achieving the secret-key capacity consists in transmitting independent Gaussian signals along the eingenvectors of the transmit correlation matrix. The powers allocated to each channel mode are determined as the solution to a numerical optimization problem. A necessary and sufficient condition for beamforming (i.e., transmitting along the strongest channel mode) to be capacity-achieving is derived. Moreover, we analyze the impact of correlation matrices on the system performance. Finally, we study the system’s performance in the two extreme power regimes. In the high-power regime, we provide closed-form expressions of the gain/loss due to correlation. In the low signal-to-noise ratio (SNR) regime, we investigate the energy efficiency of the system by determining the minimum energy required for sharing a secret-key bit and the wideband slope while highlighting the impact of correlation matrices.​ 

 

ISSN:

2015