Secure Rate-Splitting for MIMO Broadcast Channel with Imperfect CSIT and a Jammer

TL;DR

This paper proposes a secure rate-splitting strategy for a two-user MIMO broadcast channel with imperfect CSIT and a jammer, demonstrating its optimal sum-secure degrees-of-freedom and superiority over zero-forcing.

Contribution

It introduces a novel secure rate-splitting method with joint nulling and aligning, optimizing security and sum-SDoF in MIMO broadcast channels with a jammer.

Findings

Sum-secure degrees-of-freedom achieved are optimal.

Secure rate-splitting outperforms zero-forcing in this scenario.

The proposed method effectively ensures message security with joint nulling and aligning.

Abstract

In this paper, we investigate the secure rate-splitting for the two-user multiple-input multiple-output (MIMO) broadcast channel with imperfect channel state information at the transmitter (CSIT) and a multiple-antenna jammer, where each receiver has an equal number of antennas and the jammer has perfect channel state information (CSI). Specifically, we design a secure rate-splitting multiple-access strategy, where the security of split private and common messages is ensured by precoder design with joint nulling and aligning the leakage information, regarding different antenna configurations. Moreover, we show that the sum-secure degrees-of-freedom (SDoF) achieved by secure rate-splitting is optimal and outperforms that by conventional zero-forcing. Therefore, we reveal the sum-SDoF of the two-user MIMO broadcast channel with imperfect CSIT and a jammer, and validate the superiority of rate-splitting for the security purpose in this scenario with emphasis of MIMO.