Joint Secure Beamforming for Cognitive Radio Networks with Untrusted Secondary Users

TL;DR

This paper proposes a novel frequency-domain artificial noise approach for secure joint beamforming in cognitive radio networks with untrusted secondary users, optimizing resource allocation for secrecy and energy harvesting.

Contribution

It introduces a new artificial noise method and an efficient Lagrange duality-based algorithm for secure beamforming in cognitive radio networks with untrusted users.

Findings

Proposed algorithm outperforms heuristic schemes.

Effective balance between secrecy and energy harvesting.

Enhanced physical-layer security in cognitive radio networks.

Abstract

In this paper, we consider simultaneous wireless information and power transfer (SWIPT) in orthogonal frequency division multiple access (OFDMA) systems with the coexistence of information receivers (IRs) and energy receivers (ERs). The IRs are served with best-effort secrecy data and the ERs harvest energy with minimum required harvested power. To enhance physical-layer security and yet satisfy energy harvesting requirements, we introduce a new frequency-domain artificial noise based approach. We study the optimal resource allocation for the weighted sum secrecy rate maximization via transmit power and subcarrier allocation. The considered problem is non-convex, while we propose an efficient algorithm for solving it based on Lagrange duality method. Simulation results illustrate the effectiveness of the proposed algorithm as compared against other heuristic schemes.