Secrecy rate maximization of RIS-assisted SWIPT systems: A two-timescale beamforming design approach
Secrecy rate maximization of RIS-assisted SWIPT systems: A two-timescale beamforming design approach
Reconfigurable intelligent surfaces (RISs) achieve high passive beamforming gains for signal enhancement or interference nulling by dynamically adjusting their reflection coefficients. Their employment is particularly appealing for improving both the wireless security and the efficiency of radio frequency (RF)-based wireless power transfer. Motivated by this, we conceive and investigate a RIS-assisted secure simultaneous wireless information and power transfer (SWIPT) system designed for information and power transfer from a base station (BS) to an information user (IU) and to multiple energy users (EUs), respectively. Moreover, the EUs are also potential eavesdroppers that may overhear the communication between the BS and IU. We adopt two-timescale transmission for reducing the signal processing complexity as well as channel training overhead, and aim for maximizing the average worstcase secrecy rate achieved by the IU. This is achieved by jointly optimizing the short-term transmit beamforming vectors at the BS (including information and energy beams) as well as the long-term phase shifts at the RIS, under the energy harvesting constraints considered at the EUs and the power constraint at the BS. The stochastic optimization problem formulated is nonconvex with intricately coupled variables, and is non-smooth due to the existence of multiple EUs/eavesdroppers. No standard optimization approach is available for this challenging scenario. To tackle this challenge, we propose a smooth approximation aided stochastic successive convex approximation (SA-SSCA) algorithm. Furthermore, a low-complexity heuristic algorithm is proposed for reducing the computational complexity without unduly eroding the performance. Simulation results show the efficiency of the RIS in securing SWIPT systems. The significant performance gains achieved by our proposed algorithms over the relevant benchmark schemes are also demonstrated.
Array signal processing, Communication system security, Heuristic algorithms, Intelligent reflecting surface, Optimization, Signal processing algorithms, Simultaneous wireless information and power transfer, Wireless communication, passive beamforming, physical layer security, simultaneous wireless information and power transfer, two-timescale
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Zhao, Ming-Min
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Xu, Kaidi
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Cai, Yunlong
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Niu, Yong
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Hanzo, Lajos
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Zhao, Ming-Min
e9f74691-d195-4489-b38b-35e6834c2d0d
Xu, Kaidi
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Cai, Yunlong
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Niu, Yong
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Hanzo, Lajos
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Zhao, Ming-Min, Xu, Kaidi, Cai, Yunlong, Niu, Yong and Hanzo, Lajos
(2022)
Secrecy rate maximization of RIS-assisted SWIPT systems: A two-timescale beamforming design approach.
IEEE Transactions on Wireless Communications, .
(doi:10.1109/TWC.2022.3225969).
Abstract
Reconfigurable intelligent surfaces (RISs) achieve high passive beamforming gains for signal enhancement or interference nulling by dynamically adjusting their reflection coefficients. Their employment is particularly appealing for improving both the wireless security and the efficiency of radio frequency (RF)-based wireless power transfer. Motivated by this, we conceive and investigate a RIS-assisted secure simultaneous wireless information and power transfer (SWIPT) system designed for information and power transfer from a base station (BS) to an information user (IU) and to multiple energy users (EUs), respectively. Moreover, the EUs are also potential eavesdroppers that may overhear the communication between the BS and IU. We adopt two-timescale transmission for reducing the signal processing complexity as well as channel training overhead, and aim for maximizing the average worstcase secrecy rate achieved by the IU. This is achieved by jointly optimizing the short-term transmit beamforming vectors at the BS (including information and energy beams) as well as the long-term phase shifts at the RIS, under the energy harvesting constraints considered at the EUs and the power constraint at the BS. The stochastic optimization problem formulated is nonconvex with intricately coupled variables, and is non-smooth due to the existence of multiple EUs/eavesdroppers. No standard optimization approach is available for this challenging scenario. To tackle this challenge, we propose a smooth approximation aided stochastic successive convex approximation (SA-SSCA) algorithm. Furthermore, a low-complexity heuristic algorithm is proposed for reducing the computational complexity without unduly eroding the performance. Simulation results show the efficiency of the RIS in securing SWIPT systems. The significant performance gains achieved by our proposed algorithms over the relevant benchmark schemes are also demonstrated.
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Secrecy Rate Maximization of RIS-assisted SWIPT Systems A Two-Timescale Beamforming Design Approach
- Accepted Manuscript
Text
Secrecy Rate Maximization of RIS assisted SWIPT Systems A Two Timescale Beamforming Design Approach
- Accepted Manuscript
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Secrecy Rate Maximization of RIS assisted SWIPT Systems A Two Timescale Beamforming Design Approach
- Accepted Manuscript
Text
Secrecy_Rate_Maximization_of_RIS-assisted_SWIPT_Systems_A_Two-Timescale_Beamforming_Design_Approach
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Accepted/In Press date: 26 November 2022
e-pub ahead of print date: 7 December 2022
Additional Information:
The work of M. M. Zhao was supported in part by the National Key R&D
Program of China under Grant 2021YFA1003304, in part by the National
Natural Science Foundation of China under Grant 62001417, and in part by
the Zhejiang Provincial Natural Science Foundation of China under Grant
LQ20F010010. The work of Y. Cai was supported in part by the National Natural Science Foundation of China under Grants 61971376 and 61831004, and
the Zhejiang Provincial Natural Science Foundation for Distinguished Young
Scholars under Grant LR19F010002. L. Hanzo would like to acknowledge the
financial support of the Engineering and Physical Sciences Research Council
projects EP/W016605/1 and EP/P003990/1 (COALESCE) as well as of the
European Research Council’s Advanced Fellow Grant QuantCom (Grant No.
789028).
Keywords:
Array signal processing, Communication system security, Heuristic algorithms, Intelligent reflecting surface, Optimization, Signal processing algorithms, Simultaneous wireless information and power transfer, Wireless communication, passive beamforming, physical layer security, simultaneous wireless information and power transfer, two-timescale
Identifiers
Local EPrints ID: 473138
URI: http://eprints.soton.ac.uk/id/eprint/473138
ISSN: 1536-1276
PURE UUID: d0d49194-1c2e-4de8-9bea-b4301b1b9e7d
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Date deposited: 10 Jan 2023 18:34
Last modified: 18 Mar 2024 02:36
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Contributors
Author:
Ming-Min Zhao
Author:
Kaidi Xu
Author:
Yunlong Cai
Author:
Yong Niu
Author:
Lajos Hanzo
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