scholarly journals Exploiting non-orthogonal multiple access in device-to-device communication

2021 ◽  
Vol 22 (2) ◽  
pp. 919
Author(s):  
Sang Hoon Lee ◽  
Soo Young Shin
Keyword(s):  
Closed Form ◽  
Interference Cancellation ◽  
Multiple Access ◽  
D2d Communication ◽  
System Capacity ◽  
Time Sharing ◽  
Sum Capacity ◽  
Closed Form Solutions ◽  
Device To Device ◽  
Device To Device Communication

This paper proposes an uplink non-orthogonal multiple access (NOMA) system with device-to-device (D2D) communication, enabling NOMA users to communicate with other users/devices using D2D communication to improve the system capacity. In the NOMA-D2D system, two cellular users communicated with the BS using uplink NOMA, and two cellular users simultaneously communicated with the D2D users using downlink NOMA. Closed-form solutions for the ergodic sum capacity of the proposed system are derived analytically. The analytical results are validated via simulations and they are compared with the results obtained from conventional schemes. The comparison shows that, in scenarios where efficient interference cancellation can be achieved, the proposed NOMA system with the D2D model can achieve higher capacity gains than conventional benchmark schemes. When  dB, NOMA-D2D achieves capacity gains of 192.2% and 157.5% over the conventional OMA and the time-sharing-based NOMA, respectively.

Reconfigurable Antenna Beamforming in Device to Device Communication

2015 ◽  
Vol 740 ◽  
pp. 819-822
Author(s):  
Qing Shen ◽  
Tian Tian Guo ◽  
Yao Zhi Du
Keyword(s):  
Communication System ◽  
Signal Transmission ◽  
Cellular Communication ◽  
D2d Communication ◽  
System Capacity ◽  
Reconfigurable Antenna ◽  
Device To Device ◽  
Device To Device Communication

Device-to-Device (D2D) communication allows user devices in proximity to directly communicate with each other through reusing resources in cellular communication system. D2D improves the system capacity while it also raises some challenges on interference. This paper adopts reconfigurable antenna in D2D communication generating directional signal transmission between D2D pairs which mitigates the interference to other users. The simulations show that such scheme improve the system capacity compared to the traditional one.

A Novel User Grouping Algorithm for Downlink NOMA

2021 ◽  
Author(s):  
Navideh Ghafouri Jeshvaghani ◽  
Naser Movahhedinia ◽  
Mohammad Reza Khayyambashi
Keyword(s):  
Interference Cancellation ◽  
Multiple Access ◽  
Spectrum Efficiency ◽  
System Capacity ◽  
Substantial Impact ◽  
User Grouping ◽  
Radio Access ◽  
Power Domain ◽  
Rate Maximization ◽  
Sum Rate

Abstract Non-orthogonal multiple access (NOMA) is one of the promising radio access techniques for resource allocation improvement in the 5th generation of cellular networks. Compared to orthogonal multiple access techniques (OMA), NOMA offers extra benefits, including greater spectrum efficiency which is provided through multiplexing users in the transmission power domain while using the same spectrum resources non-orthogonally. Even though NOMA uses Successive Interference Cancellation (SIC) to repeal the interference among users, user grouping has shown to have a substantial impact on its performance. This prformance improvement can appear in different parameters such as system capacity, rate, or the power consumption. In this paper, we propose a novel user grouping scheme for sum-rate maximization which increases the sum-rate up to 25 percent in comparison with two authenticated recent works. In addition to being matrix-based and having a polynomial time complexity, the proposed method is also able to cope with users experiencing different channel gains and powers in different sub-bands.

scholarly journals A Power-Domain NOMA Inspired Overlay Spectrum Sharing Scheme

2018 ◽  
Author(s):  
Fazlul Kader
Keyword(s):  
Spectrum Sharing ◽  
Multiple Access ◽  
Spectrum Efficiency ◽  
User Needs ◽  
Sum Capacity ◽  
Closed Form Solutions ◽  
Sharing Scheme ◽  
Power Domain ◽  
Cooperative Spectrum Sharing ◽  
Capacity Gain

Non-orthogonal multiple access (NOMA) and cooperative spectrum sharing (CSS) are integrated into this work to enhance both spectrum efficiency and utilization. An overlay spectrum sharing is proposed by exploiting NOMA in coordinated direct and relay transmission (CDRT) (termed as CSS-NOMA-CDRT). In CSS-NOMA-CDRT, a primary strong NOMA user is directly served by primary transmitter (PT), whereas a primary NOMA weak user needs the assistance of a relay to communicate with PT. Instead of using a dedicated relay, a secondary transmitter (ST) acts as a relay to forward the primary symbol to NOMA weak user and ST transmits own symbol to its receiver at the same time. The performance of the proposed CSS-NOMA-CDRT is evaluated along with closed-form solutions, in terms of ergodic sum capacity and outage probability. Through the analytical and Monte Carlo simulation results, it is demonstrated that CSS-NOMA-CDRT can obtain remarkable capacity gain as compared to the conventional NOMA-based CDRT.

scholarly journals Enhanced Integrated Satellite-Terrestrial NOMA with Cooperative Device-to-Device Communication

Telecom ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 126-149
Author(s):  
Michail Karavolos ◽  
Nikolaos Nomikos ◽  
Demosthenes Vouyioukas
Keyword(s):  
Wireless Networks ◽  
Spectral Efficiency ◽  
Multiple Access ◽  
D2d Communication ◽  
Efficiency Gains ◽  
Satellite Link ◽  
User Pairing ◽  
Device To Device ◽  
Channel Conditions ◽  
Sum Rate

The currently deployed terrestrial wireless networks experience difficulties while coping with the massive connectivity demands of coexisting users and devices. The addition of satellite segments has been proposed as a viable way of providing improved coverage and capacity, leading to the formation of integrated satellite-terrestrial networks. In such topologies, non-orthogonal multiple access (NOMA) can further enhance the efficient use of wireless resources by simultaneously serving multiple users. In this paper, an integrated satellite-terrestrial NOMA network is studied where cooperation between ground users is allowed, following the device-to-device (D2D) paradigm. More specifically, the proposed satellite NOMA cooperative (SANOCO) D2D scheme optimally selects pairs of users, by considering the channel conditions of the satellite and the terrestrial D2D links. In SANOCO-D2D users are served through NOMA in the satellite link, and then, if the weak user fails to decode its signal, terrestrial D2D communication is activated to maintain the total sum rate of the system. Comparisons with conventional orthogonal multiple access (OMA) and an alternative NOMA optimal user pairing scheme show that significant sum rate and spectral efficiency gains can be harvested through SANOCO-D2D under varying channel conditions and terrestrial D2D bandwidth.

scholarly journals Exact Bit Error-Rate Analysis of Two-User NOMA Using QAM with Arbitrary Modulation Orders

2020 ◽  
Author(s):  
Arafat Al-Dweik ◽  
Tasneem Assaf ◽  
Mohamed El Moursi ◽  
Hatem Zein El din ◽  
Mohammad Al-Jarrah
Keyword(s):  
Closed Form ◽  
Power Allocation ◽  
General Expression ◽  
Bit Error Rate ◽  
Error Rate ◽  
Amplitude Modulation ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Rate Analysis ◽  
Multiuser Detector

This work considers the exact bit error rate (BER) analysis of a two-user non-orthogonal multiple access (NOMA) system using quadrature amplitude modulation (QAM). Unlike existing work, no constraints on the modulation order of the QAM symbols for any user. Closed-form expressions are derived for the BER of joint multiuser detector (JMuD), which is demonstrated that it is equivalent to the successive interference cancellation (SIC) receiver. Moreover, a general expression is derived for the relation between the power allocation factors for the two users, which depends on the modulation order for each user.

scholarly journals PEP Analysis of AF Relay NOMA Systems Employing Order Statistics of Cascaded Channels

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 695 ◽  
Author(s):  
Suyue Li ◽  
Anhong Wang ◽  
Jie Liang
Keyword(s):  
Closed Form ◽  
Order Statistics ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Series Representation ◽  
Modified Bessel Function ◽  
Error Performance ◽  
System Parameters ◽  
Cascaded Channels

The precise error performance analysis is challenging for non-orthogonal multiple access (NOMA) systems due to nonlinear successive interference cancellation (SIC) processing among NOMA users. In this paper, the pairwise error probability (PEP) performance of different users is investigated for relay NOMA simultaneous wireless information and power transfer (SWIPT) systems. By employing the order statistics theory, we obtain the ordered probability density function of the cascaded channel through Source-to-Relay-to-User links. Then we derive the analytical closed-form PEP expressions for NOMA users. To obtain the approximate closed-form PEP, we explore the finite series representation of the power of the modified Bessel function to replace the integrand terms. Monte Carlo simulation results show that the approximate analytical PEP of each user is basically in agreement with the simulated PEP. Furthermore, on the basis of the closed-form PEP, the influence of relevant system parameters on the error performance is examined via numerical simulations, which manifests that the choice of power allocation coefficients should be balanced between the users’ channel conditions and the demanded quality of service.

scholarly journals A coordinated non-orthogonal multiple access strategy for integrated terrestrial-satellite networks

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248173
Author(s):  
Qiang He ◽  
Zheng Xiang ◽  
Peng Ren
Keyword(s):  
Outage Probability ◽  
Multiple Access ◽  
Estimation Method ◽  
Relay Node ◽  
Satellite Networks ◽  
System Capacity ◽  
Future Research ◽  
Channel State ◽  
Sum Capacity ◽  
Future Research Directions

In this paper, we investigate the outage probability and ergodic sum capacity of the downlink of the integrated satellite-terrestrial networks (ISTN) with a cooperative non-orthogonal multiple access (CNOMA) scheme, in which a user with better channel condition acts as a relay node and forwards information to the other users. In this paper, a pilot-based channel estimation method is considered which can verify the performance of this scheme with the imperfect channel state information. In this model, all these users are equipped with multi-antennas, and all of them are both in the coverage of a same beam of the satellite. Specifically, the exact analytical expression for the outage probability and ergodic sum capacity of the system is derived. The result shows that this coordinated non-orthogonal multiple access (CNOMA) scheme performs better than that of OMA (TDMA) in this model. Finally, the future research directions are given to further enhance the system capacity.

scholarly journals Outage Performance of Relay-Assisted Single- and Dual-Stage NOMA Over Power Line Communications

2021 ◽  
Author(s):  
ROOPESH RAMESH ◽  
Sanjeev Gurugopinath ◽  
sami muhaidat
Keyword(s):  
Closed Form ◽  
Communication Systems ◽  
Multiple Access ◽  
Optimization Problems ◽  
Power Line ◽  
Closed Form Solutions ◽  
Power Line Communications ◽  
Optimal Power ◽  
Dual Stage ◽  
Outage Probabilities

<p>In this paper, we analyze the performance of relay-assisted, single-stage (SS) non-orthogonal multiple access (NOMA) and dual-stage (DS) NOMA power line communication systems. Specifically, derive closed form expressions for the outage probabilities of the SS NOMA and DS NOMA schemes. Subsequently, we formulate optimization problems and obtain closed-form solutions for the optimal power allocation coefficients of the SS NOMA and DS NOMA scheme, such that the probability of overall outage is minimized. The accuracy of our analysis and the tightness of the approximations employed are validated through Monte Carlo simulations and numerical techniques. Moreover, we show that the DS NOMA scheme outperforms the SS NOMA scheme, in terms of the overall outage probability.</p>

scholarly journals Physical Layer Security Requirements and Solutions for Device to Device Communication

2020 ◽  
Vol 9 (3) ◽  
pp. 3011-3013
Keyword(s):  
Physical Layer Security ◽  
Mobile Station ◽  
Physical Layer ◽  
Base Station ◽  
D2d Communication ◽  
Security Requirements ◽  
Security And Privacy ◽  
5G Network ◽  
Device To Device ◽  
Device To Device Communication

Device-to-Device (D2D) communication is used for cellular networks. D2d communication is the direct communication from one mobile station to other mobile station, without the involvement of the base station. By using the device to device communication lesser delay is possible. By using d2d communication along with 5G network improves the bit rate. 5G network provides the communication with more data rate and lesser delay. Security and privacy are very important for communication. In this paper security and privacy requirements of device to device communication and physical layer privacy solutions are discussed.

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