Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

IEEE Transactions on Information Forensics and Security

Secrecy Capacity Enhancement With Distributed Precoding in Multirelay Wiretap Systems

Hang Long, Wei Xiang, Yueying Zhang, Yuanan Liu, Wenbo Wang

Published Nov 27, 2012• 45 citations
Publisher

Abstract

The secrecy capacity of relay communications is investigated in this paper, where an eavesdropper is present. Distributed precoding through multiple relay nodes can be used to enhance the received signal power at the destination node and to mitigate the signal leakage to the eavesdropper, simultaneously. Due to individual power constraints at relay nodes, the distributed precoding scalar at each relay node is equivalent to a distributed precoding angle. An iterative algorithm is proposed to find the suboptimum distributed precoding angles at all the relay nodes, where the channel state information (CSI) sharing overhead among the relay nodes can also be substantially reduced. Each relay node receives the equivalent CSI from its preceding relay node, computes its distributed precoding angle, and updates the equivalent CSI for the next relay node. Compared with the simple decode-and-forward relaying protocol with random distributed precoding, the proposed iterative distributed precoding algorithm is able to further improve on the secrecy capacity of the multirelay wiretap system with an acceptable CSI sharing overhead.

DOI
10.1109/tifs.2012.2229988

Related papers

Distributed precoding in multi-relay wiretap systems with amplify-and-forward

Jing Wang, Xiaoting Wang, Qianghua Guo +2 more

The security of the multi-relay wiretap system with an eavesdropper is investigated in this paper, where the amplify-and-forward (AF) relaying protocol is used. Appropriate distributed precoding design at the relay nodes can be utilized to guarantee the secure communication, which means maximizing the ratio of received signal power at the destination node and the eavesdropper node. In decode-and-forward relaying systems, an iterative algorithm has been proposed to find sub-optimum distributed precoding angles at all the relay nodes [1]. In this paper, this algorithm is extended to be used in AF systems with some modifications. In the algorithm, after receiving the equivalent channel state information (CSI) from the last relay node, the current relay node derives the optimum distributed precoding angle, and updates the equivalent CSI for the next one, so that each relay node shares much less CSI information with each other, compared with the exhaustive search scheme. Numerical and simulation results demonstrate that in the AF protocol system, the iterative algorithm can help achieve considerable secrecy capacity with a little CSI sharing overhead.

International Conference on Communications and Networking in China (ChinaCom)•Aug 1, 2013•1 citation

Enhancing secrecy capacity of multi‐relay wiretap systems with partial channel state information

Hang Long, Wei Xiang, Jing Wang +2 more

Summary Distributed precoding has provento be capable of enhancing the secrecy capacity of the multi‐relay wiretap system. An iterative distributed precoding and channel state information (CSI) sharing scheme can be used to reduce the CSI overhead at each relay node. However, in practical applications, the CSI of each relay node cannot be perfectly known to themselves, especially that of the relay‐eavesdropper channels. Thus, partial CSI for the relay‐eavesdropper links is assumed, and the corresponding distributed precoding and CSI sharing schemes are investigated. Under the assumption that the average value of the relay‐eavesdropper channel is known at each relay node, an extended iterative distributed precoding and CSI sharing scheme is proposed. Simulation results demonstrate that with the increase of the power ratio of the constant part to the random part of the relay‐eavesdropper channels, the proposed scheme with partial CSI performs increasingly close to the one with perfect CSI in secrecy capacity. Copyright © 2014 John Wiley & Sons, Ltd.

International Journal of Communication Systems•Apr 24, 2014•3 citations

Precoder design for AF cooperative systems with multiple wiretapping relays

Chia‐Hao Lee, Li-Chung Lo, Wan-Jen Huang

This paper considers an amplify-and-forward (AF) cooperative system with multiple relays which may eavesdrop on the source signal without authorization. In conventional cooperative system where the relays are assumed trustworthy, the precoding design usually tends to optimize quality of the received signal at the relays. However, the considered system relies on the relays' assistance and requires to prevent source information eavesdropped by the relays. With this regard, we proposed that the destination transmits artificial noise to interfere the signal reception of wiretapping relays. The artificial noise can be fully eliminated at the destination with perfect channel information. We propose a precoder design for the cooperative system that aims to maximize the received SNR at the destination subject to constraining quality of received signal at the relays. It shows through simulation results that the proposed scheme is able to improve the secrecy capacity of the cooperative system with wiretapping relays effectively.

International Symposium on Communications and Information Technologies•Sep 1, 2014•2 citations

Secrecy Enhancement via Cooperative Relays in Multi-Hop Communication Systems

Elham Nosrati, Xianbin Wang, Arash Khabbazibasmenj +1 more

This paper proposes using cooperative relays to improve the ergodic secrecy capacity (ESC) of a multi-hop decode-and-forward (DF) relaying system where communication takes place in the presence of multiple non-colluding eavesdroppers. The proposed scheme is based on a recent approach to generate artificial noise in which transmitter of each hop allocates a portion of its power for generating an intentional interference at the eavesdroppers. Under the assumption that the transmitters can only use limited transmit power, a power allocation strategy has been developed which maximizes the secrecy capacity by optimally distributing the power between the original signal and the artificial noise. Since the optimal solution depends on the channel state information (CSI) of the eavesdroppers, which is difficult to obtain in practice, a sub-optimal solution is also presented in which the CSI of the eavesdroppers is not needed.

IEEE Vehicular Technology Conference•May 1, 2016•3 citations

Precoding and Cooperative Jamming in Multi- Antenna Two-Way Relaying Wiretap Systems Without Eavesdropper’s Channel State Information

Hang Long, Wei Xiang, Yuli Li

This paper studies secrecy communications in a multi-antenna two-way relaying wiretap system. Each source node transmits user and jamming signals with distinct precoding vectors. Based on the assumption that the channel state information relating to the eavesdropper is unknown by the legitimate nodes, new precoding design algorithms are proposed. The jamming signals are designed to ensure that minimum interference is perceived by the other source node. The precoding vectors of the user signals are designed to form two parallel vectors in the equivalent wiretap channel at the eavesdropper. Two algorithms are proposed based upon the zero-forcing and matched-filter schemes, which are dubbed the selective zero-forcing-based precoding (SZFP) and matched-filter-based precoding schemes. Analytical and simulation results are presented to demonstrate that the SZFP algorithm is more applicable when the eavesdropper is equipped with a large number of antennas or the eavesdropper's channels are in good condition.

IEEE Transactions on Information Forensics and Security•Jan 23, 2017•25 citations

Precoding and Destination-Aided Cooperative Jamming in MIMO Untrusted Relay Systems

Luyuan Zhang, Hang Long, Li Qun Huang

In this paper, secrecy communications with cooperative jamming in a two-hop one-way untrusted relay system is studied. Assuming that all nodes are equipped with multiple antennas, new precoding designs are proposed to increase the secrecy capacity. Two situations are considered, namely only designing precoding vector for jamming signal when user signal has been determined, and designing precoding vectors for both user and jamming signals by jointly considering the source node. For each situation, two alignment algorithms are proposed, namely zero-forcing-based (ZF) alignment algorithm and minimum-mean-squared-error-based (MMSE) alignment algorithm. Both algorithms are designed to ensure that the equivalent wiretap channel matrix forms two aligned vectors. The channel vector from the destination node is designed to be aligned with that from the source node, so that the eavesdropping node cannot decode user signals. Analytical and simulation results show that all proposed scheme can achieve secure communication, and the MMSE algorithm performs better than the ZF. In addition, the destination-relay link has greater impact on the secrecy performance than the relay-destination link.

IEEE/CIC International Conference on Communications in China (ICCC)•Aug 9, 2020•2 citations
The secrecy capacity of relay communications is investigated in this paper, where an eavesdropper is present. Distributed precoding through multiple relay nodes can be used to enhance the received signal power at the destination node and to mitigate the signal leakage to the eavesdropper, simultaneously. Due to individual power constraints at relay nodes, the distributed precoding scalar at each relay node is equivalent to a distributed precoding angle. An iterative algorithm is proposed to find the suboptimum distributed precoding angles at all the relay nodes, where the channel state information (CSI) sharing overhead among the relay nodes can also be substantially reduced. Each relay node receives the equivalent CSI from its preceding relay node, computes its distributed precoding angle, and updates the equivalent CSI for the next relay node. Compared with the simple decode-and-forward relaying protocol with random distributed precoding, the proposed iterative distributed precoding algorithm is able to further improve on the secrecy capacity of the multirelay wiretap system with an acceptable CSI sharing overhead.
The security of the multi-relay wiretap system with an eavesdropper is investigated in this paper, where the amplify-and-forward (AF) relaying protocol is used. Appropriate distributed precoding design at the relay nodes can be utilized to guarantee the secure communication, which means maximizing the ratio of received signal power at the destination node and the eavesdropper node. In decode-and-forward relaying systems, an iterative algorithm has been proposed to find sub-optimum distributed precoding angles at all the relay nodes [1]. In this paper, this algorithm is extended to be used in AF systems with some modifications. In the algorithm, after receiving the equivalent channel state information (CSI) from the last relay node, the current relay node derives the optimum distributed precoding angle, and updates the equivalent CSI for the next one, so that each relay node shares much less CSI information with each other, compared with the exhaustive search scheme. Numerical and simulation results demonstrate that in the AF protocol system, the iterative algorithm can help achieve considerable secrecy capacity with a little CSI sharing overhead.
Summary Distributed precoding has provento be capable of enhancing the secrecy capacity of the multi‐relay wiretap system. An iterative distributed precoding and channel state information (CSI) sharing scheme can be used to reduce the CSI overhead at each relay node. However, in practical applications, the CSI of each relay node cannot be perfectly known to themselves, especially that of the relay‐eavesdropper channels. Thus, partial CSI for the relay‐eavesdropper links is assumed, and the corresponding distributed precoding and CSI sharing schemes are investigated. Under the assumption that the average value of the relay‐eavesdropper channel is known at each relay node, an extended iterative distributed precoding and CSI sharing scheme is proposed. Simulation results demonstrate that with the increase of the power ratio of the constant part to the random part of the relay‐eavesdropper channels, the proposed scheme with partial CSI performs increasingly close to the one with perfect CSI in secrecy capacity. Copyright © 2014 John Wiley & Sons, Ltd.
This paper considers an amplify-and-forward (AF) cooperative system with multiple relays which may eavesdrop on the source signal without authorization. In conventional cooperative system where the relays are assumed trustworthy, the precoding design usually tends to optimize quality of the received signal at the relays. However, the considered system relies on the relays' assistance and requires to prevent source information eavesdropped by the relays. With this regard, we proposed that the destination transmits artificial noise to interfere the signal reception of wiretapping relays. The artificial noise can be fully eliminated at the destination with perfect channel information. We propose a precoder design for the cooperative system that aims to maximize the received SNR at the destination subject to constraining quality of received signal at the relays. It shows through simulation results that the proposed scheme is able to improve the secrecy capacity of the cooperative system with wiretapping relays effectively.
This paper proposes using cooperative relays to improve the ergodic secrecy capacity (ESC) of a multi-hop decode-and-forward (DF) relaying system where communication takes place in the presence of multiple non-colluding eavesdroppers. The proposed scheme is based on a recent approach to generate artificial noise in which transmitter of each hop allocates a portion of its power for generating an intentional interference at the eavesdroppers. Under the assumption that the transmitters can only use limited transmit power, a power allocation strategy has been developed which maximizes the secrecy capacity by optimally distributing the power between the original signal and the artificial noise. Since the optimal solution depends on the channel state information (CSI) of the eavesdroppers, which is difficult to obtain in practice, a sub-optimal solution is also presented in which the CSI of the eavesdroppers is not needed.
This paper studies secrecy communications in a multi-antenna two-way relaying wiretap system. Each source node transmits user and jamming signals with distinct precoding vectors. Based on the assumption that the channel state information relating to the eavesdropper is unknown by the legitimate nodes, new precoding design algorithms are proposed. The jamming signals are designed to ensure that minimum interference is perceived by the other source node. The precoding vectors of the user signals are designed to form two parallel vectors in the equivalent wiretap channel at the eavesdropper. Two algorithms are proposed based upon the zero-forcing and matched-filter schemes, which are dubbed the selective zero-forcing-based precoding (SZFP) and matched-filter-based precoding schemes. Analytical and simulation results are presented to demonstrate that the SZFP algorithm is more applicable when the eavesdropper is equipped with a large number of antennas or the eavesdropper's channels are in good condition.
In this paper, secrecy communications with cooperative jamming in a two-hop one-way untrusted relay system is studied. Assuming that all nodes are equipped with multiple antennas, new precoding designs are proposed to increase the secrecy capacity. Two situations are considered, namely only designing precoding vector for jamming signal when user signal has been determined, and designing precoding vectors for both user and jamming signals by jointly considering the source node. For each situation, two alignment algorithms are proposed, namely zero-forcing-based (ZF) alignment algorithm and minimum-mean-squared-error-based (MMSE) alignment algorithm. Both algorithms are designed to ensure that the equivalent wiretap channel matrix forms two aligned vectors. The channel vector from the destination node is designed to be aligned with that from the source node, so that the eavesdropping node cannot decode user signals. Analytical and simulation results show that all proposed scheme can achieve secure communication, and the MMSE algorithm performs better than the ZF. In addition, the destination-relay link has greater impact on the secrecy performance than the relay-destination link.