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ECOLE SUPÉRIEURE D'ÉLECTRICITÉ Une grande école d'ingénieurs au cœur des sciences de l'information,de l'énergie et des systèmes |
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Journal articles
Large System Analysis of Linear Precoding in MISO Broadcast Channels with Confidential Messages
Abstract : In this paper, we study the performance of regularized channel inversion (RCI) precoding in large MISO broadcast channels with confidential messages (BCC). We obtain a deterministic approximation for the achievable secrecy sum-rate which is almost surely exact as the number of transmit antennas $M$ and the number of users $K$ grow to infinity in a fixed ratio $\beta=K/M$. We derive the optimal regularization parameter $\xi$ and the optimal network load $\beta$ that maximize the per-antenna secrecy sum-rate. We then propose a linear precoder based on RCI and power reduction (RCI-PR) that significantly increases the high-SNR secrecy sum-rate for $1<\beta<2$. Our proposed precoder achieves a per-user secrecy rate which has the same high-SNR scaling factor as both the following upper bounds: (i) the rate of the optimum RCI precoder without secrecy requirements, and (ii) the secrecy capacity of a single-user system without interference. Furthermore, we obtain a deterministic approximation for the secrecy sum-rate achievable by RCI precoding in the presence of channel state information (CSI) error. We also analyze the performance of our proposed RCI-PR precoder with CSI error, and we determine how the error must scale with the SNR in order to maintain a given rate gap to the case with perfect CSI.
https://hal-supelec.archives-ouvertes.fr/hal-00830206
Contributor : Catherine Magnet <>
Submitted on : Tuesday, June 4, 2013 - 3:33:15 PM
Last modification on : Monday, December 14, 2020 - 2:36:02 PM
Contributor : Catherine Magnet <>
Submitted on : Tuesday, June 4, 2013 - 3:33:15 PM
Last modification on : Monday, December 14, 2020 - 2:36:02 PM
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