scholarly journals Cooperative Secure Transmission in MISO-NOMA Networks

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 352
Author(s):  
Yang Chen ◽  
Zhongpei Zhang ◽  
Bingrui Li
Keyword(s):  
Multiple Access ◽  
Transmission Scheme ◽  
Secrecy Rate ◽  
Legitimate User ◽  
Secrecy Outage ◽  
Adaptive Power ◽  
High Level ◽  
Secure Transmission ◽  
Qos Requirement

In this paper, we investigate cooperative secure transmission in non-orthogonal multiple access (NOMA) networks where a source (Alice) intends to transmit confidential messages to one legitimate user with high-level security requirement (LU1), and serve another normal one (LU2) simultaneously. In order to enhance the transmission security, a cooperative jammer (Charlie) is employed to confuse multiple non-colluding eavesdroppers (Eves). Taking both secrecy outage restriction of LU1 and the desired quality of service (QoS) requirement of LU2 into consideration, we propose an adaptive power allocation strategy for maximizing secrecy rate. Numerical results are provided to validate that our proposed scheme significantly outperforms the conventional NOMA secure transmission scheme.

scholarly journals On Secrecy Outage Probability for Downlink NOMA Systems With Relay-Antenna Selection

2021 ◽  
Author(s):  
Shu Xu ◽  
Chen Liu ◽  
Hong Wang ◽  
Mujun Qian ◽  
Wenfeng Sun
Keyword(s):  
Outage Probability ◽  
Multiple Access ◽  
Antenna Selection ◽  
Maximal Ratio Combining ◽  
Selection Combining ◽  
Secrecy Outage Probability ◽  
Channel State ◽  
Secrecy Outage ◽  
Secure Transmission ◽  
Theoretical Results

Abstract Secure transmission is essential for future non-orthogonal multiple access (NOMA) system. This paper investigates relay-antenna selection (RAS) to enhance physical-layer security (PLS) of cooperative NOMA system in the presence of an eavesdropper, where multiple antennas are deployed at the relays, the users, and the eavesdropper. In order to reduce expense on radio frequency (RF) chains, selection combining (SC) is employed at both the relays and the users, whilst the eavesdropper employs either maximal-ratio combining (MRC) or selection combining (SC) to process the received signals. Under the condition that the channel state information (CSI) of the eavesdropping channel is available or unavailable, two e↵ective relay-antenna selection schemes are proposed. Additionally, the closed-form expressions of secrecy outage probability (SOP) are derived for the proposed relay-antenna selection schemes. In order to gain more deep insights on the derived results, the asymptotic performance of the derived SOP is analyzed. In simulations, it is demonstrated that the theoretical results match well with the simulation results and the SOP of the proposed schemes is less than that of the conventional orthogonal multiple access (OMA) scheme obviously.

scholarly journals Improving Physical Layer Security of Cooperative NOMA System with Wireless-Powered Full-Duplex Relaying

Information ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 279
Author(s):  
Yuan Ren ◽  
Yixuan Tan ◽  
Meruyert Makhanbet ◽  
Xuewei Zhang
Keyword(s):  
Physical Layer Security ◽  
Multiple Access ◽  
Physical Layer ◽  
Cooperative Transmission ◽  
Full Duplex ◽  
Artificial Noise ◽  
Transmission Scheme ◽  
Self Energy ◽  
Wireless Energy Harvesting ◽  
Secure Transmission

Non-orthogonal multiple access (NOMA) and wireless energy harvesting are two promising technologies for improving spectral efficiency and energy efficiency, respectively. In this paper, we study the physical layer security of a wireless-powered full-duplex (FD) relay-aided cooperative NOMA system. In particular, the source is wiretapped by an eavesdropper, and the FD relay assists the transmission from the source to a near user and a far user with self-energy recycling. To enhance the security performance of the system, we propose an artificial noise (AN)-aided cooperative transmission scheme, in which the relay emits a jamming signal to confuse the eavesdropper while receiving the signal from the source. For the proposed scheme, the ergodic secrecy sum rate (ESSR) is derived to characterize the secrecy performance and a lower bound of ESSR is obtained. Finally, numerical results verify the accuracy of the theoretical analysis of the proposed AN-aided secure transmission scheme. The superiority of the proposed scheme is also demonstrated since this scheme can achieve better secrecy performance, compared to the conventional cooperative NOMA scheme.

scholarly journals QoS-Oriented Dynamic Power Allocation in NOMA-based Wireless Caching Networks

2020 ◽  
Author(s):  
Yue Yin ◽  
Miao Liu ◽  
Guan Gui ◽  
Haris Gacanin ◽  
Fumiyuki Adachi
Keyword(s):  
Quality Of Service ◽  
Power Allocation ◽  
Spectral Efficiency ◽  
Multiple Access ◽  
Base Station ◽  
System Efficiency ◽  
Allocation Strategy ◽  
Dynamic Power ◽  
Qos Requirement

<div>Non-orthogonal multiple access (NOMA) based</div><div>wireless caching network (WCN) is considered as one of the most</div><div>promising technologies for next-generation wireless communications</div><div>since it can significantly improve the spectral efficiency.</div><div>In this paper, we propose a quality of service (QoS)-oriented</div><div>dynamic power allocation strategy for NOMA-WCN. In content</div><div>stack phase, the base station sends multiple files to the content</div><div>servers by allocating different powers according to the different</div><div>QoS targets of files, for ensuring that all content servers can</div><div>successfully decode the two most popular files. In content deliver</div><div>phase, the content servers serve two users at the same time</div><div>by allocating the minimum power to the far user according</div><div>to the QoS requirement, and then all the remaining power is</div><div>allocated to the near user. Hence, the proposed power allocation</div><div>scheme is able to increase the hit probability and drop the outage</div><div>probability compared with conventional method. Simulation</div><div>results confirm that the proposed power allocation method can</div><div>significantly improve the caching hit probability and reduce the</div><div>user outage probability. It is also shown that this strategy can</div><div>reduce the user delay time, improve the system efficiency and</div><div>the capacity.</div>

scholarly journals Security performance analysis for power domain NOMA employing in cognitive radio networks

2020 ◽  
Vol 9 (3) ◽  
pp. 1046-1054
Author(s):  
Thi-Anh Hoang ◽  
Chi-Bao Le ◽  
Dinh-Thuan Do
Keyword(s):  
Cognitive Radio ◽  
Multiple Access ◽  
Base Station ◽  
Cognitive Networks ◽  
Secrecy Outage Probability ◽  
Security Threat ◽  
Performance Improvements ◽  
Legitimate User ◽  
Power Domain ◽  
Secrecy Outage

The power domain non-orthogonal multiple access (NOMA) technique introduces one of the fundamental characteristics and it exhibits the possibility of users to decode the messages of the other paired users on the same resources. In cognitive radio inspired NOMA (CR-NOMA), the base station (BS) has to serve untrusted users or users with different security clearance. This phenomenon raises a security threat particularly in such CR-NOMA. This paper develops a tractable analysis framework to evaluate the security performance of cooperative non-orthogonal multiple access (NOMA) in cognitive networks, where relay is able to serve two far NOMA users in the presence of external eavesdropper. In particular, we study the secrecy outage probability in a two-user NOMA system. This situation happens in practical the BS is pairing a legitimate user with another untrusted user. Main reason is that the non-uniform distribution in terms of trusted and untrusted users in the cell. By performing numerical results demonstrate the performance improvements of the proposed NOMA scheme in comparison to that of several situations in terms of different parameters. Furthermore, the security performance of NOMA is shown to verify the derived expressions.

scholarly journals QoS-Oriented Dynamic Power Allocation in NOMA-based Wireless Caching Networks

2020 ◽  
Author(s):  
Yue Yin ◽  
Miao Liu ◽  
Guan Gui ◽  
Haris Gacanin ◽  
Fumiyuki Adachi
Keyword(s):  
Quality Of Service ◽  
Power Allocation ◽  
Spectral Efficiency ◽  
Multiple Access ◽  
Base Station ◽  
System Efficiency ◽  
Allocation Strategy ◽  
Dynamic Power ◽  
Qos Requirement

<div>Non-orthogonal multiple access (NOMA) based</div><div>wireless caching network (WCN) is considered as one of the most</div><div>promising technologies for next-generation wireless communications</div><div>since it can significantly improve the spectral efficiency.</div><div>In this paper, we propose a quality of service (QoS)-oriented</div><div>dynamic power allocation strategy for NOMA-WCN. In content</div><div>stack phase, the base station sends multiple files to the content</div><div>servers by allocating different powers according to the different</div><div>QoS targets of files, for ensuring that all content servers can</div><div>successfully decode the two most popular files. In content deliver</div><div>phase, the content servers serve two users at the same time</div><div>by allocating the minimum power to the far user according</div><div>to the QoS requirement, and then all the remaining power is</div><div>allocated to the near user. Hence, the proposed power allocation</div><div>scheme is able to increase the hit probability and drop the outage</div><div>probability compared with conventional method. Simulation</div><div>results confirm that the proposed power allocation method can</div><div>significantly improve the caching hit probability and reduce the</div><div>user outage probability. It is also shown that this strategy can</div><div>reduce the user delay time, improve the system efficiency and</div><div>the capacity.</div>

scholarly journals Secure On-Off Transmission in UAV Relay-Assisted mmWave Networks

2019 ◽  
Vol 9 (19) ◽  
pp. 4138
Author(s):  
Ruiqian Ma ◽  
Weiwei Yang ◽  
Yu Zhang ◽  
Songqing Wang
Keyword(s):  
Antenna Arrays ◽  
Channel Model ◽  
High Mobility ◽  
Secrecy Outage Probability ◽  
Alignment Error ◽  
The Novel ◽  
Transmission Scheme ◽  
Aerial Vehicle ◽  
Secrecy Outage ◽  
Secure Transmission

This paper investigates secure transmission in unmanned aerial vehicle (UAV) relay-assisted millimeter wave (mmWave) networks, where the selected UAV relay performs secure transmission in both the on-off and non-on-off schemes. Meanwhile, there are multiple eavesdroppers randomly distributed on the ground and attempting to wiretap the transmission. Leveraging the air-to-ground channel model and the tools of stochastic geometry, the novel expressions of transmit probability (TP) and secrecy outage probability (SOP) are derived in both the on-off and non-on-off transmission schemes with perfect beam alignment. The secrecy performance improvement is demonstrated in the on-off transmission scheme, and we find that there exists an optimal altitude of UAV relays to achieve the best TP. In addition, due to the limitations of UAV carriers, such as its low computational capacity and high mobility, the perfect beam alignment is difficult to achieve in the mmWave networks aided by UAV relays, and the effect of beam alignment error on the secrecy performance is investigated in the considered networks. Analyzing the numerical and simulation results, we find that the SOP will not have obvious deterioration when the beam alignment error is relatively small, and the SOP can be improved by using the antennas with a large number of elements. However, in high beam alignment error regime, the antenna arrays with a smaller number of elements will provide the better SOP.

scholarly journals Secure Transmission in mmWave Wiretap Channels: On Sector Guard Zone and Blockages

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 427 ◽  
Author(s):  
Yi Song ◽  
Weiwei Yang ◽  
Zhongwu Xiang ◽  
Yiliang Liu ◽  
Yueming Cai
Keyword(s):  
Outage Probability ◽  
Mobile Networks ◽  
Secure Communication ◽  
Artificial Noise ◽  
Secrecy Outage Probability ◽  
Transmission Scheme ◽  
Secrecy Outage ◽  
Key Enabling Technologies ◽  
Secure Transmission ◽  
Guard Zone

Millimeter-wave (mmWave) communication is one of the key enabling technologies for fifth generation (5G) mobile networks. In this paper, we study the problem of secure communication in a mmWave wiretap network, where directional beamforming and link blockages are taken into account. For the secure transmission in the presence of spatially random eavesdroppers, an adaptive transmission scheme is adopted, for which sector secrecy guard zone and artificial noise (AN) are employed to enhance secrecy performance. When there exists no eavesdroppers within the sector secrecy guard zone, the transmitter only transmits information-bearing signal, and, conversely, AN along with information-bearing signal are transmitted. The closed-form expressions for secrecy outage probability (SOP), connection outage probability (COP) and secrecy throughput are derived under stochastic geometry. Then, we evaluate the effect of the sector secrecy guard zone and AN on the secrecy performance. Our results reveal that the application of the sector secrecy guard zone and AN can significantly improve the security of the system, and blockages also can be utilized to improve secrecy performance. An easy choice of transmit power and power allocation factor is provided for achieving higher secrecy throughput. Furthermore, increasing the density of eavesdroppers not always deteriorates the secrecy performance due to the use of the sector secrecy guard zone and AN.

scholarly journals Energy-Efficient Transmission Based on Direct Links: Toward Secure Cooperative Internet of Things

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaohui Shang ◽  
Aijun Liu ◽  
Yida Wang ◽  
Qing Xie ◽  
Yong Wang
Keyword(s):  
Energy Efficiency ◽  
Internet Of Things ◽  
Energy Efficient ◽  
Secrecy Outage Probability ◽  
Transmission Scheme ◽  
Practical Applications ◽  
Multiple Sensors ◽  
Secrecy Outage ◽  
Secure Transmission ◽  
Efficient Transmission

In this paper, the secure uplink transmission scenario in Internet of Things (IoT) applications is investigated, where one of multiple sensors communicates with the controller aided by the cooperative relay. Firstly, by considering the direct link, an energy-efficient transmission scheme (EET) is proposed, which can be suitable for the resource-constrained devices and applications in IoT communication. Moreover, the secrecy outage probability (SOP) and secure energy efficiency (SEE) of different transmission strategies are derived, which contributes to the design of energy-efficient secure transmission. Finally, simulation results demonstrate that EET outperforms other transmission protocols in terms of SEE in most situations. To improve the secrecy performance and energy efficiency of the IoT deployment, EET can be adopted as an effective additional strategy in practical applications.

Heart Rate Recovery Changes during Competition Period in High-Level Basketball Players

2018 ◽  
Vol 1 (80) ◽  
Author(s):  
Audrius Gocentas ◽  
Anatoli Landõr ◽  
Aleksandras Kriščiūnas
Keyword(s):  
Heart Rate ◽  
Heart Rate Recovery ◽  
Team Sports ◽  
Basketball Players ◽  
Coeffi Cients ◽  
Competition Period ◽  
Monitoring Training ◽  
Intense Training ◽  
High Level

Research background and hypothesis. Replete schedule of competitions and intense training are features of contemporary team sports. Athletes, especially the most involved ones, may not have enough time to recover. As a consequence, aggregated fatigue can manifest in some undesirable form and affect athlete’s performance and health.Research aim. The aim of this study was to evaluate the changes in heart rate recovery (HRR) and investigate possible relations with sport-specifi c measures of effi cacy in professional basketball players during competition season.Research methods. Eight male high-level basketball players (mean ± SD, body mass, 97.3 ± 11.33 kg; height 2.02 ± 0.067 m, and age 23 ± 3.12 years) were investigated. The same basketball specifi c exercise was replicated several times from September till April during the practice sessions in order to assess the personal trends of HRR. Heart rate monitoring was performed using POLAR TEAM SYSTEM. Investigated athletes were ranked retrospectively according to the total amount of minutes played and the coeffi cients of effi cacy. Research results. There were signifi cant differences in the trends of HRR between the investigated players. The most effective players showed decreasing trends of HRR in all cases of ranking.Discussion and conclusions. Research fi ndings have shown that the quality of heart rate recovery differs between basketball players of the same team and could be associated with sport-specifi c effi cacy and competition playing time.Keywords: adaptation, autonomic control, monitoring training.

About Innovative Content of Subject-Oriented Pedagogical Education

2019 ◽  
Vol 28 (10) ◽  
pp. 106-117
Author(s):  
R. M. Asadullin
Keyword(s):  
Teacher Education ◽  
Teacher Training ◽  
Educational Process ◽  
Professional Activity ◽  
Subject Knowledge ◽  
Technological Structure ◽  
State Pedagogical ◽  
High Level ◽  
Competencies Development

The continuous modernization of the education system makes the problems of the quality of teacher training increasingly relevant. Moreover, the measures taken to improve the system of teacher education are largely confined to the introduction of new organizational and managerial mechanisms and practically do not affect the internal content and technological structure of the teacher training process.Modern pedagogical universities are constantly looking for innovative models of training teachers that will be able to solve non-standard social and professional tasks. However, recent studies in this area do not fully take into account the nature of pedagogical activity and conditions of its formation. Thus, the need arises for a special study of the processes and means of updating the content and technologies of teacher training in order to control the level of students’ professional competencies development, as required by educational and professional standards. This means the creation of a special educational system in a pedagogical university, which can provide a harmonious and synchronous mastering by future specialists of both subject knowledge and methods of pedagogical activity.The article provides a theoretical study aimed at identifying key patterns of designing a new content for teacher education, the basis of which is the formation of a future teacher as a subject of his own professional activity. The author describes the experience of using a subject-oriented model of education, implemented at Bashkir State Pedagogical University n.a. M. Akmulla. The effectiveness of this model is confirmed by the high level of students’ mastery of designing methods and constructing the educational process, as well as their positive experience in the implementation of educational activities.

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