SD-Based Low-Complexity Precoder Design for Gaussian MIMO Wiretap Channels

TL;DR

This paper introduces a low-complexity precoder design for Gaussian MIMO wiretap channels that achieves comparable secrecy performance to existing methods but with significantly reduced computational complexity.

Contribution

The paper proposes a simultaneous diagonalization based low-complexity method for optimizing MIMO wiretap channels, improving efficiency over traditional iterative algorithms.

Findings

SDLC scheme achieves similar secrecy rates as existing methods.

The proposed method significantly reduces computational complexity.

Simulation results confirm the effectiveness of the SDLC approach.

Abstract

This paper considers a Gaussian multi-input multi-output (MIMO) multiple access wiretap (MAC-WT) channel, where an eavesdropper (Eve) wants to extract the confidential information of all users. Assuming that both the legitimate receiver and Eve jointly decode their interested messages, we aim to maximize the sum secrecy rate of the system by precoder design. Although this problem could be solved by first using the iterative majorization minimization (MM) based algorithm to get a sequence of convex log-determinant optimization subproblems and then using some general tools, e.g., the interior point method, to deal with each subproblem, this strategy involves quite high computational complexity. Therefore, we propose a simultaneous diagonalization based low-complexity (SDLC) method to maximize the secrecy rate of a simple one-user wiretap channel, and then use this method to iteratively optimize the covariance matrix of each user. Simulation results show that in contrast to the existing approaches, the SDLC scheme achieves similar secrecy performance but requires much lower complexity.