Joint Design of Optimal Cooperative Jamming and Power Allocation for Linear Precoding

TL;DR

This paper proposes a joint design of power allocation and cooperative jamming in multiuser broadcast channels to enhance physical layer security, providing optimal and suboptimal solutions with demonstrated effectiveness.

Contribution

It introduces a joint optimization framework for power allocation and cooperative jamming in linear precoding systems, including an optimal solution under specific antenna conditions and a versatile suboptimal algorithm.

Findings

Optimal solution when jammer antennas ≥ total user and eavesdropper antennas

Suboptimal algorithm applicable to all scenarios

Numerical results confirm effectiveness for secure communications

Abstract

Linear precoding and cooperative jamming for multiuser broadcast channel is studied to enhance the physical layer security. We consider the system where multiple independent data streams are transmitted from the base station to multiple legitimate users with the help of a friendly jammer. It is assumed that a normalized linear precoding matrix is given at the base station, whereas the power allocated to each user is to be determined. The problem is to jointly design the power allocation across different users for linear precoding and the cooperative jamming at the friendly jammer. The goal is to maximize a lower bound of the secrecy rate, provided that a minimum communication rate to the users is guaranteed. The optimal solution is obtained when the number of antennas at the friendly jammer is no less than the total number of antennas at the users and eavesdropper. Moreover, a suboptimal algorithm is proposed, which can be applied for all the scenarios. Numerical results demonstrate that the proposed schemes are effective for secure communications.