# AN-Aided Secure Beamforming for ELAA-SWIPT in Mixed Near- and Far-Field

## TL;DR

This paper proposes an artificial noise-aided secure beamforming scheme for large-scale antenna systems supporting simultaneous wireless information and power transfer in mixed near- and far-field environments, enhancing security and energy efficiency.

## Contribution

It introduces a novel hybrid beamforming design and optimization framework for secure SWIPT in mixed near- and far-field scenarios with artificial noise.

## Key findings

- The proposed scheme improves secrecy rates in mixed-field SWIPT systems.
- Artificial noise effectively enhances security against eavesdropping.
- The scheme's performance depends on user visibility regions and angular separation.

## Abstract

This letter investigates secure hybrid beamforming (HB) design for an extremely large-scale antenna array-aided simultaneous wireless information and power transfer (SWIPT) system operating in a mixed near-field (NF)/far-field (FF) environment. A base station (BS) employs HB to transmit information and artificial noise (AN) signals simultaneously to multiple FF information receivers (IRs) and NF energy receivers (ERs). The objective is to maximize the weighted sum secrecy rate for the IRs, considering both Type-I (unable to cancel AN) and Type-II (capable of canceling AN) IRs, subject to minimum energy harvesting requirements at the ERs and a BS transmit power constraint. We formulate optimization problems for both IR types and develop an efficient iterative algorithm based on successive convex approximation. Simulation results validate the proposed scheme and provide crucial insights into the security performance of mixed-field SWIPT systems, highlighting the influence of visibility regions and angular user separation.