GSVD-Based Precoding in MIMO Systems With Integrated Services

TL;DR

This paper proposes a GSVD-based precoding scheme for MIMO broadcast channels with integrated multicast and confidential services, optimizing subchannel and power allocation to maximize secrecy rate while ensuring multicast quality.

Contribution

It introduces a novel GSVD-based precoding method combined with a DC algorithm for joint subchannel and power allocation in secure MIMO broadcast channels.

Findings

The proposed scheme improves secrecy rates in MIMO systems.

Joint optimization enhances multicast service quality.

Numerical results validate the effectiveness of the approach.

Abstract

This letter considers a two-receiver multiple-input multiple-output (MIMO) Gaussian broadcast channel model with integrated services. Specifically, we combine two sorts of service messages, and serve them simultaneously: one multicast message intended for both receivers and one confidential message intended for only one receiver. The confidential message is kept perfectly secure from the unauthorized receiver. Due to the coupling of service messages, it is intractable to seek capacity-achieving transmit covariance matrices. Accordingly, we propose a suboptimal precoding scheme based on the generalized singular value decomposition (GSVD). The GSVD produces several virtual orthogonal subchannels between the transmitter and the receivers. Subchannel allocation and power allocation between multicast message and confidential message are jointly optimized to maximize the secrecy rate in this letter, subject to the quality of multicast service (QoMS) constraints. Since this problem is inherently complex, a difference-of-concave (DC) algorithm, together with an exhaustive search, is exploited to handle the power allocation and subchannel allocation, respectively. Numerical results are presented to illustrate the efficacy of our proposed strategies.