Artificial Noise Aided Secrecy Information and Power Transfer in OFDMA Systems

TL;DR

This paper introduces a novel artificial noise aided transmission strategy for OFDMA systems to simultaneously enhance secrecy and energy harvesting, with efficient algorithms for optimal resource allocation.

Contribution

It proposes a new frequency domain artificial noise method and develops optimal and suboptimal algorithms for secure resource allocation in SWIPT OFDMA systems.

Findings

Proposed algorithms outperform heuristic schemes.

Effective secrecy and energy harvesting balance achieved.

Algorithms show promising simulation results.

Abstract

In this paper, we study 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 the physical layer security for IRs and yet satisfy energy harvesting requirements for ERs, we propose a new frequency domain artificial noise (AN) aided transmission strategy. With the new strategy, we study the optimal resource allocation for the weighted sum secrecy rate maximization for IRs by power and subcarrier allocation at the transmitter. The studied problem is shown to be a mixed integer programming problem and thus non-convex, while we propose an efficient algorithm for solving it based on the Lagrange duality method. To further reduce the computational complexity, we also propose a suboptimal algorithm of lower complexity. The simulation results illustrate the effectiveness of proposed algorithms as compared against other heuristic schemes.