scholarly journals Passive Beamforming and Trajectory Optimization for Reconfigurable Intelligent Surface-Assisted UAV Secure Communication

2021 ◽  
Vol 13 (21) ◽  
pp. 4286
Author(s):  
Dawei Wang ◽  
Yang Zhao ◽  
Yixin He ◽  
Xiao Tang ◽  
Lixin Li ◽  
...  
Keyword(s):  
Phase Shift ◽  
Trajectory Optimization ◽  
Secure Communication ◽  
Transmission Rate ◽  
Spectrum Efficiency ◽  
Trajectory Design ◽  
Secrecy Rate ◽  
Fifth Generation ◽  
Communication Scheme ◽  
Secure Transmission

Unmanned aerial vehicle (UAV) and reconfigurable intelligent surface (RIS) methods are promising techniques for improving the energy and spectrum efficiency of Fifth Generation/Beyond Fifth Generation (5G/B5G) networks. In order to take advantage of both techniques, we propose an RIS-assisted UAV secure communication scheme, where an UAV is equipped with RIS to facilitate secure transmission. To maximize the average secrecy rate, we jointly optimize the beamforming power, reflect phase shift, and UAV’s trajectory. For this non-convex problem, we decompose it into the power beamforming problem, the phase shift optimization problem, and the UAV’s trajectory design problem, and proposed an efficient iterative algorithm to solve the problem. The numerical results verify the superiority of the proposed scheme that can improve the average secure transmission rate by about 20% compared to that of Eavesdropping elimination methods.

scholarly journals Robust Secure Beamforming Design for Cooperative Cognitive Radio Nonorthogonal Multiple Access Networks

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Quanzhong Li ◽  
Sai Zhao
Keyword(s):  
Cognitive Radio ◽  
Secure Communication ◽  
Multiple Access ◽  
Spectrum Efficiency ◽  
Maximization Problem ◽  
Artificial Noise ◽  
Practical Case ◽  
Secrecy Rate ◽  
Worst Case ◽  
Rank One

By the integration of cooperative cognitive radio (CR) and nonorthogonal multiple access (NOMA), cooperative CR NOMA networks can improve the spectrum efficiency of wireless networks significantly. Due to the openness and exposure of wireless signals, secure communication is an important issue for cooperative CR NOMA networks. In this paper, we investigate the physical layer security design for cooperative CR NOMA networks. Our objective is to achieve maximum secrecy rate of the secondary user by designing optimal beamformers and artificial noise covariance matrix at the multiantenna secondary transmitter under the quality-of-service at the primary user and the transmit power constraint at the secondary transmitter. We consider the practical case that the channel state information (CSI) of the eavesdropper is imperfect, and we model the imperfect CSI by the worst-case model. We show that the robust secrecy rate maximization problem can be transformed to a series of semidefinite programmings based on S-procedure and rank-one relaxation. We also propose an effective method to recover the optimal rank-one solution. Simulations are provided to show the effectiveness of our proposed robust secure algorithm with comparison to the nonrobust secure design and traditional orthogonal multiple access schemes.

scholarly journals Key Technologies in Massive MIMO

2018 ◽  
Vol 17 ◽  
pp. 01017
Author(s):  
Qiang Hu ◽  
Meixiang Zhang ◽  
Renzheng Gao
Keyword(s):  
Massive Mimo ◽  
Transmission Rate ◽  
New Technology ◽  
Rapid Development ◽  
Research Direction ◽  
Spectrum Efficiency ◽  
Data Traffic ◽  
Wireless Data ◽  
Fifth Generation ◽  
Mimo Technology

The explosive growth of wireless data traffic in the future fifth generation mobile communication system (5G) has led researchers to develop new disruptive technologies. As an extension of traditional MIMO technology, massive MIMO can greatly improve the throughput rate and energy efficiency, and can effectively improve the link reliability and data transmission rate, which is an important research direction of 5G wireless communication. Massive MIMO technology is nearly three years to get a new technology of rapid development and it through a lot of increasing the number of antenna communication, using very duplex communication mode, make the system spectrum efficiency to an unprecedented height.

scholarly journals Novel Chaos Secure Communication System Based on Walsh Code

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Gang Zhang ◽  
Niting Cui ◽  
Tianqi Zhang
Keyword(s):  
Secure Communication ◽  
Transmission Rate ◽  
Multiple Input Multiple Output ◽  
Walsh Code ◽  
Bit Error Ratio ◽  
Shift Keying ◽  
Input Multiple Output ◽  
Communication Scheme ◽  
Chaos Shift Keying ◽  
Differential Chaos Shift Keying

A multiuser communication scheme which is a hybrid of Walsh code with DCSK and CDSK is proposed to improve low data transmission rate of Differential Chaos Shift Keying (DCSK), poor bit error ratio (BER) performance of Correlation Delay Shift Keying (CDSK), and disadvantage of orthogonality in traditional multiuser DCSK. It not only overcomes the disadvantages of DCSK and CDSK, but also has better performance than CDSK and higher transmission data rate than DCSK. It has been proved that the novel multiuser CDSK-DCSK has better properties than traditional Multiple Input Multiple Output-Differential Chaos Shift Keying (MIMO-DCSK) and Modified-Differential Chaos Shift Keying (M-DCSK). Also the multiuser interference is greatly suppressed due to the orthogonality of Walsh code.

scholarly journals A Secure Communication Scheme Based on Equivalent Interference Channel Assisted by Physical Layer Secret Keys

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xiaoyan Hu ◽  
Liang Jin ◽  
Kaizhi Huang ◽  
Keming Ma ◽  
Changcheng Song ◽  
...  
Keyword(s):  
Channel Coding ◽  
Secure Communication ◽  
Channel Model ◽  
Transmission Rate ◽  
Estimation Error ◽  
Physical Layer ◽  
Superior Performance ◽  
Channel Estimation Error ◽  
Interference Channel ◽  
Communication Scheme

Due to the channel estimation error, most of the physical layer secret key generation schemes need information reconciliation to correct error key bits, resulting in reduced efficiency. To solve the problem, this work proposes a novel secure communication scheme based on a equivalent interference channel. Different keys generated from imperfect channel state information are directly applied to signal scrambling and descrambling, which is equivalent to the process of a signal passing through an interference channel. Legitimate communication parties can reduce interference with the help of similar keys and channel coding without sending additional signals, while the eavesdropper channel is deteriorated due to the spatial decorrelation. For this kind of schemes, we first establish a discrete memoryless broadcast channel model to derive the expressions of bit error rate (BER), channel capacity, and security capacity for performance analysis. Simulation results verify the derivations that the proposed scheme achieves secure communication with a correlated eavesdropping channel and has a higher upper bound of transmission rate. Furthermore, we design a new metric to evaluate the efficiency and the result shows that the proposed scheme has superior performance on error reconciliation efficiency, despite its slight increase in BER.

scholarly journals The Secure Transmission of Videos Using the Karhunen-Loéve (K-L) Decomposition and the Synchronization of the Unified Chaotic System with the Hyperchaotic Chen System

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
N. Smaoui ◽  
M. Zribi ◽  
T. Elmokadem
Keyword(s):  
Chaotic System ◽  
Secure Communication ◽  
Sliding Mode ◽  
Gray Scale ◽  
Chen System ◽  
Unified Chaotic System ◽  
Master System ◽  
Communication Scheme ◽  
To Come ◽  
Secure Transmission

A unique secure communication scheme that can be used for the transmission of gray-scale and color videos is presented in this paper. The proposed scheme is developed by using the Karhunen-Loéve (K-L) decomposition and the synchronization of the unified chaotic system with the hyperchaotic Chen system. First, the gray-scale or color video is represented by a set of N frames. In order to reduce the data, the K-L decomposition is used to come up with data coefficients and eigenfunctions that optimally obtain the crux of the N frames. Using only the most energetic eigenfunctions to approximate the original frames results in computational savings. The data coefficients corresponding to the most energetic eigenfunctions are encrypted and transmitted using a master system composed of a combination of the unified chaotic system and the hyperchaotic Chen system. At the receiver end, these coefficients are recovered and a controller of the sliding mode type is utilized forcing the master and slave systems to synchronize. Simulation results illustrate how the proposed control law is able to synchronize the master and the slave systems. In addition, a demonstration of the recovery of the original frames using the decrypted data coefficients along with the eigenfunctions of the frame is provided. The presented simulations indicate that the proposed scheme results in an excellent performance.

scholarly journals Trajectory planning in UAV emergency networks with potential underlaying D2D communication based on K-means

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Shuo Zhang ◽  
Shuo Shi ◽  
Tianming Feng ◽  
Xuemai Gu
Keyword(s):  
Trajectory Planning ◽  
Trajectory Optimization ◽  
Communication Systems ◽  
Complete Coverage ◽  
Wireless System ◽  
Fifth Generation ◽  
Emergency Communications ◽  
Trajectory Length ◽  
Post Disaster ◽  
Joint Evaluation

AbstractAt present, unmanned aerial vehicles (UAVs) have been widely used in communication systems, and the fifth-generation wireless system (5G) has further promoted the vigorous development of them. The trajectory planning of UAV is an important factor that affects the timeliness and completion of missions, especially in scenarios such as emergency communications and post-disaster rescue. In this paper, we consider an emergency communication network where a UAV aims to achieve complete coverage of potential underlaying device-to-device (D2D) users. Trajectory planning issues are grouped into clustering and supplementary phases for optimization. Aiming at trajectory length and sum throughput, two trajectory planning algorithms based on K-means are proposed, respectively. In addition, in order to balance sum throughput with trajectory length, we present a joint evaluation index. Then relying on this index, a third trajectory optimization algorithm is further proposed. Simulation results show the validity of the proposed algorithms which have advantages over the well-known benchmark scheme in terms of trajectory length and sum throughput.

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