scholarly journals Joint Relay Selection and Power Allocation for the Physical Layer Security of Two-Way Cooperative Relaying Networks

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Lei Pan ◽  
Zan Li ◽  
Zhengyuan Wang ◽  
Fenggan Zhang

In this paper, we investigate the physical layer security of cooperative two-way relay transmission systems using the amplify-and-forward (AF) protocol in the presence of an eavesdropper. A joint relay selection (RS) and power allocation (PA) scheme is proposed to protect the source-destination transmission against the eavesdropper. However, due to the high computational complexity, it is difficult to obtain the optimal solution for the system secrecy rate. Fortunately, an approximate optimal solution by using the particle swarm optimization (PSO) algorithm is derived. In the simulations, we use random relay selection with optimal power allocation (RRS-OPA) and equal power allocation with optimal relay selection (EPA-ORS) as benchmark schemes to verify the effectiveness of the proposed method. The simulation results show that the proposed method outperforms both RRS-OPA and EPA-ORS and significantly improves the system performance with low complexity.

2020 ◽  
Vol 10 (2) ◽  
pp. 9-17
Author(s):  
Tuan Nhu Nguyen

Abstract— To secure communication from the sender to the receiver in wireless networks, cryptographic algorithms are usually used to encrypt data at the upper layers of a multi-tiered transmission model. Another emerging trend in the security of data transmitted over wireless networks is the physical layer security based on beamforming and interference fading  communication technology and not using cryptographic algorithms. This trend has attracted increasing concerns from both academia and industry. This paper addresses how physical layer security can protect secret data compare with the traditional cryptographic encryption and which is the better cooperative relaying scheme with the state of the art approached methods in wireless relaying beamforming network.Tóm tắt— Việc bảo mật truyền thông vô tuyến từ nơi gửi đến nơi nhận thường sử dụng các thuật toán mật mã để mã hoá dữ liệu tại các tầng phía trên trong mô hình phân lớp. Một xu hướng khác đang được quan tâm rộng rãi là bảo mật tầng vật lý dựa trên kỹ thuật truyền tin beamforming và kỹ thuật tương tác fading kênh chủ động. Xu hướng này hiện đang được thu hút cả trong giới công nghiệp và nghiên cứu. Đóng góp của bài báo này là làm rõ khả năng bảo mật tầng vật lý và so sách chúng với phương pháp bảo mật dùng kỹ thuật mật mã truyền thống. Bài báo cũng so sánh hai kỹ thuật chuyển tiếp được sử dụng chính trong bảo mật tầng vật lý cho mạng vô tuyến chuyển tiếp là Amplify-and-Forward và Decode-and-Forward.


Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2942
Author(s):  
Jialun Li ◽  
Shuai Chang ◽  
Xiaomei Fu ◽  
Liang Zhang ◽  
Yishan Su ◽  
...  

Cooperative relaying is an effective technology to improve the capacity of physical-layer security, in which the relay helps forward the received signal to the destination. In this paper, a cooperative compressive sensing and amplify-and-forward (CCS-AF) scheme, which combines the compressive sensing theory and amplify-and-forward strategy, is proposed to increase the secrecy capacity. To optimize the secrecy performance, a coalition formation algorithm based on coalitional game theory of optimal relay selection is proposed to maximize the secrecy capacity. Different to maximizing the individual utility based on the traditional pareto order, the max-coalition order rule is newly defined to guide the coalitional formation. Simulation results indicate that with the proposed algorithm, part of the relays could form a coalition to forward the information and the proposed algorithm could significantly improve the secrecy capacity of cooperative multi-relay networks.


Author(s):  
Xin Song ◽  
MingLei Zhang ◽  
WenMIn Liu ◽  
ShengBao Wang

Abstract—To minimize total transmit power in a system while guaranteeing the outage probability at the same time in a cooperative system, we propose and analyse two threshold-based hybrid relay selection and power allocation schemes for a three-node cooperative relaying system. They are designated as: the hybrid amplify-direct-forward relaying (HADF) and incremental hybrid decode-direct-forward relaying (IHDDF) schemes. In the HADF scheme, a specific outage probability threshold is derived to determine that the system chooses to optimize power allocation of its source and relay in amplify-and-forward (AF) mode or optimize the power of its source in direct-transmit (DT) mode without a relay. In IHDDF, according to the outage probability threshold, the system chooses to optimize its power in turn with incremental decode-and-forward opportunistic relaying (IDFO) mode or DT mode. Closed-form expressions of the total transmit power of the proposed HADF and IHDDF schemes are derived. The proposed schemes have low computational complexity and system cost. Theoretical analysis and simulation results show that the HADF scheme outperforms the AF and DT schemes, and the total transmission power of the IHDDF scheme is reduced significantly compared with the IDFO and DT schemes. Compared with the HADF scheme, the IHDDF scheme has a better total transmit power in special channel condition.Keywords—power allocation, three-node cooperative relaying system, amplify-and-forward, incremental decode-and-forward opportunistic relaying.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1439
Author(s):  
Janghyuk Youn ◽  
Woong Son ◽  
Bang Chul Jung

Recently, reconfigurable intelligent surfaces (RISs) have received much interest from both academia and industry due to their flexibility and cost-effectiveness in adjusting the phase and amplitude of wireless signals with low-cost passive reflecting elements. In particular, many RIS-aided techniques have been proposed to improve both data rate and energy efficiency for 6G wireless communication systems. In this paper, we propose a novel RIS-based channel randomization (RCR) technique for improving physical-layer security (PLS) for a time-division duplex (TDD) downlink cellular wire-tap network which consists of a single base station (BS) with multiple antennas, multiple legitimate pieces of user equipment (UE), multiple eavesdroppers (EVEs), and multiple RISs. We assume that only a line-of-sight (LOS) channel exists among the BS, the RISs, and the UE due to propagation characteristics of tera-hertz (THz) spectrum bands that may be used in 6G wireless communication systems. In the proposed technique, each RIS first pseudo-randomly generates multiple reflection matrices and utilizes them for both pilot signal duration (PSD) in uplink and data transmission duration (DTD) in downlink. Then, the BS estimates wireless channels of UE with reflection matrices of all RISs and selects the UE that has the best secrecy rate for each reflection matrix generated. It is shown herein that the proposed technique outperforms the conventional techniques in terms of achievable secrecy rates.


Symmetry ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 5
Author(s):  
Pengfei Hou ◽  
Jianping Gong ◽  
Jumin Zhao

In this paper, we proposed a scheme that Injects artificial noise from the tag end (IANT) to enhance the physical layer security of the ambient backscatter communication (ABC) system. The difference between the ABC system and the traditional radio frequency identification system is whether it uses the radio frequency (RF) signals in the environment to supply energy and modulation information for passive tags. In the IANT scheme, we select the best tag to communicate with the reader according to the channel quality between tags and reader, and at the same time select another tag to generate artificial noise that affects the receiving effect of the eavesdropper. This paper uses the method of generating noise copies in the reader to reduce the interference of artificial noise on the signal received by the reader. The simulation results show that with the increase in channel quality between tags and reader and the increase in the number of tags, the proposed IANT scheme is significantly superior to the contrast scheme in terms of system achievable secrecy rate, effectively enhancing the physical layer security of the ABC system.


2014 ◽  
Vol 513-517 ◽  
pp. 3423-3428
Author(s):  
Zhi Kang Zhou ◽  
Qi Zhu

In this paper, an amplify-and-forward (AF) multi-relay network is considered. In order to minimize the system outage probability, a new power allocation and multi-relay selection algorithm is proposed under total power constraint and each node power constraint. In the proposed algorithm, the ideal of ordering is adopted, which leads to the remarkable decrease of the computation complexity together with simple power reallocation. Simulation results show that the proposed multi-relay selection algorithm performs close to the optimal scheme with optimal power allocation and exhaustive search (OPA-ES) but with much lower complexity.


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