Cognitive Radio Assisted Non-Orthogonal Multiple Access: Outage Performance

2019 ◽  
Author(s):  
Hong-Nhu Nguyen ◽  
Si-Phu Le ◽  
Chi-Bao Le ◽  
Ngoc-Long Nguyen ◽  
Nhat-Tien Nguyen ◽  
...  
Keyword(s):  
Cognitive Radio ◽  
Multiple Access ◽  
Outage Performance

scholarly journals Cognitive Radio-Assisted NOMA Broadcasting for 5G Cellular V2X Communications: Model of Roadside Unit Selection and SWIPT

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1786
Author(s):  
Dinh-Thuan Do ◽  
Anh-Tu Le ◽  
Thi-Anh Hoang ◽  
Byung Moo Lee
Keyword(s):  
Cognitive Radio ◽  
System Performance ◽  
Multiple Access ◽  
Unit Selection ◽  
Performance Simulation ◽  
Selection Scheme ◽  
Outage Performance ◽  
Battery Capacity ◽  
Rf Signals ◽  
Roadside Unit

The outage performance is a significant problem to implement the Cognitive Radio (CR) paradigm in the Vehicle to Everything (V2X) networks. Recently, more interest has focused on Non-Orthogonal Multiple Access (NOMA) in wireless-powered communication. In the conventional CR-enabled V2X-NOMA network, spectrum sensing and limited battery capacity at the Roadside Unit (RSU) may cause serious outage performance. In this study, RSU selection scheme is adopted. This paper presents an interesting model of a system with Simultaneous Wireless Information and Power Transfer (SWIPT) and a CR-enabled V2X-NOMA network. In the downlink, the RSU harvests wireless energy from Radio Frequency (RF) signals and senses the spectrum state at the same time. A CR-enabled V2X-NOMA system performance is presented by deriving exact expressions of outage probability of distant vehicles. In the overlay CR-enabled V2X-NOMA network, the constraints are transmit power and the number of designed RSU that make significant impacts on system performance. Simulation results show that the CR-enabled V2X-NOMA get benefits from energy harvesting and RSU selection scheme.

scholarly journals On Exact Outage and Throughput Performance of Cognitive Radio based Non-Orthogonal Multiple Access Networks With and Without D2D Link

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3314 ◽  
Author(s):  
Dinh-Thuan Do ◽  
Anh-Tu Le ◽  
Chi-Bao Le ◽  
Byung Moo Lee
Keyword(s):  
Cognitive Radio ◽  
Power Allocation ◽  
Multiple Access ◽  
Signal Transmission ◽  
Outage Performance ◽  
System A ◽  
Primary Network ◽  
Secondary Network ◽  
Fixed Power ◽  
Analytical Expressions

In this paper, we investigate the performance of a secondary network in a cognitive radio network employing a non-orthogonal multiple access (NOMA) scheme to form a CR-NOMA system serving many destination users. In the secondary network of our proposed system, a device-to-device (D2D) scheme is deployed to further provide the signal transmission at a close distance of NOMA users in downlink, and such performance is evaluated under the situation of interference reception from the primary network. An outage performance gap exists among these NOMA users since different power allocation factors are assigned to the different destinations. Unlike existing NOMA schemes that consider fixed power allocation factors, which are not optimal in terms of outage performance, our proposed paradigm exhibits optimal outage in the scenario of D2D transmission. In particular, the outage performances in two kinds of schemes in term of existence of D2D link are further achieved. Simulation results validate the analytical expressions, and show the advantage of each scheme in the proposed CR-NOMA system based on outage performance and throughput.

scholarly journals Multiple Access in Cognitive Radio Networks: From Orthogonal and Non-Orthogonal to Rate-Splitting

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Safaa Gamal ◽  
Mohamed Rihan ◽  
Saleh Hussin ◽  
Adel Zaghloul ◽  
A. Abdelaziz Salem
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Multiple Access ◽  
Radio Networks ◽  
Rate Splitting

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.

Outage Performance Analysis for User Cooperative NOMA with Incremental Hybrid Forwarding Protocols

2021 ◽  
Author(s):  
Suyue Li ◽  
Junhuai Liu ◽  
Anhong Wang
Keyword(s):  
Monte Carlo ◽  
Outage Probability ◽  
Multiple Access ◽  
System Throughput ◽  
Closed Form Expression ◽  
Collaborative Communication ◽  
Form Expression ◽  
Outage Performance ◽  
Threshold Rate ◽  
Rate Pair

Abstract Non-orthogonal multiple access (NOMA) collaborative communication is extremely beneficial to the users with poor channel conditions. It is essential to examine the performance of different NOMA users with superior cooperative forwarding protocols. This paper addresses the user cooperative NOMA system where one strong user (U2) assists one weak user (U1) to forward messages, and investigates the outage performance of both users with hybrid decode-and-amplify forwarding (HDAF) protocol. First, we derive the outage probability of U2 and U1 with HDAF. Secondly, we provide the closed-form expression for outage probability of U1 with the incremental hybrid decode-and-amplify forward (IHDAF) protocol at U2, which can further enhance the outage performance of U1 compared with HDAF. Moreover, we also present the system throughput expression and provide deep analysis on the effect of different forwarding protocols. Numerical results and Monte Carlo simulations jointly confirm the correctness of all the analytic derivations. In addition to saving the energy consumption of U2, IHDAF can make U1 achieve superior outage performance to HDAF. However, the system throughput almost overlap for both schemes given a threshold rate pair.

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