scholarly journals Nonorthogonal Multiple Access for Next-Generation Mobile Networks: A Technical Aspect for Research Direction

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Muhammad Hussain ◽  
Haroon Rasheed
Keyword(s):  
Mobile Networks ◽  
Mobile Communications ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Research Direction ◽  
Technical Aspect ◽  
Base Station ◽  
System Capacity ◽  
Rate System ◽  
High Data

5G mobile communications offer several benefits, which include providing extremely low latency, very high data rates, significant improvement in the number of users, and increase in base station capacity and perceived quality of service. This may be achieved at the cost of an increased receiver complexity by nonorthogonal access of users. Nonorthogonal multiple access (NOMA) is one of the capable contenders to achieve the vision of 5G wireless communications. Supporting a higher number of users than available orthogonal resources is the key feather of NOMA. In this article, the basic principle of NOMA has been reviewed and compared with other orthogonal multiple access (OMA). A comprehensive survey is presented in the latest NOMA scheme. The distinguished NOMA schemes design principle features, and recent deployments are discussed. Furthermore, the performance is compared in terms of the bit error rate, system capacity, and energy efficiency. The performance results show that NOMA can achieve the required goals, in terms of the user data rate, system capacity, interference cancellation scheme, and reception complexity.

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 On the performance of non-orthogonal multiple access (NOMA) using FPGA

2020 ◽  
Vol 10 (2) ◽  
pp. 2151
Author(s):  
Mohamad Abdulrahman Ahmed ◽  
Khalid F. Mahmmod ◽  
Mohammed M. Azeez
Keyword(s):  
Gaussian Noise ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Additive White Gaussian Noise ◽  
Base Station ◽  
Rate Performance ◽  
Allocation Mechanism ◽  
Close Match ◽  
Fifth Generation ◽  
Field Programmable

In this paper,  non-orthogonal multiple access (NOMA) is designed and implemented for the fifth generation (5G) of multi-user wireless communication.  Field-programmable gate array (FPGA) is considered for the implementation of this technique for two users. NOMA is applied in downlink phase of the base-station (BS) by applying power allocation mechanism for far and near users, in which one signal contains the superposition of two scaled signals depending on the distance of each user from the BS.  We assume an additive white Gaussian noise (AWGN) channel for each user in the presence of the interference due to the non-orthogonality between the two users’ signals. Therefore, successive-interference cancellation (SIC) is exploited to remove the undesired signal of the other user. The outage probability and the bit-error rate performance are presented over different signal-to-interference-plus-noise ratio (SINR). Furthermore, Monte-Carlo simulations via Matlab are utilized to verify the results obtained by FPGA, which show exact-close match.

scholarly journals No-Regret Matching Game Algorithm for NOMA Based UAV-Assisted NB-IoT Systems

2021 ◽  
Vol 26 (1) ◽  
pp. 79-85
Author(s):  
Samar Shaker Metwaly ◽  
Ahmed. M. Abd El-Haleem ◽  
Osama El-Ghandour
Keyword(s):  
Communication Networks ◽  
Multiple Access ◽  
Learning Algorithm ◽  
Base Station ◽  
Throughput Capacity ◽  
System Capacity ◽  
Wireless Communication Networks ◽  
Total Rate ◽  
Small Base ◽  
Matching Game

NB-IoT is the standardized technology for machine type communication (MTC) in Long Term Evolution (LTE). NB-IoT can achieve IoT requirements nevertheless, it suffers a low rate and capacity. On the other hand, Unmanned aerial vehicles (UAV) and Non-Orthogonal Multiple Access (NOMA) are promising technology used to enhance the throughput, capacity, and coverage of wireless communication networks. In this paper, we propose a heterogeneous network scenario where a UAV small Base Station (UBS) is used to assist the LTE Macro Base Station (MBS) with the help of the Non-Orthogonal Multiple Access technique to solve the NB-IoT throughput and capacity issues. Matching game based no-regret learning algorithm is proposed to optimize the NB-IoT device association and using NOMA pairing at each base station to provide the maximum system total rate and capacity. Simulation results show that our proposed scheme increases the total rate of the system by 60% and the system capacity by at least 80%, compared to NOMA without UAV and the total rate and capacity of the system by 200% and 85% respectively, with OMA scheme.

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.

scholarly journals Power density of rectangular microstrip patch antenna arrays for 5G indoor base station

2020 ◽  
Vol 19 (3) ◽  
pp. 1367
Author(s):  
Nor Adibah Ibrahim ◽  
Tharek Abd Rahman ◽  
Razali Ngah ◽  
Omar Abd Aziz ◽  
Olakunle Elijah
Keyword(s):  
Power Density ◽  
Antenna Arrays ◽  
Base Station ◽  
Small Cell ◽  
Base Stations ◽  
System Capacity ◽  
High Data ◽  
Communication Devices ◽  
Set Up ◽  
Cell Base

The fifth-generation (5G) network has been broadly investigated by many researchers. The capabilities of 5G include massive system capacity, incredibly high data rates everywhere, very low latency and the most important point is that it is exceptionally low device cost and low energy consumption. A key technology of 5G is the millimeter wave operating at 28 GHz and 38 GHz frequency bands which enable massive MIMO and small cell base station densification. However, there has been public concern associated with human exposure to electromagnetic fields (EMF) from 5G communication devices. Hence, this paper studies the power density of a 5G antenna array that can be used for the indoor base station. The power density is the amount of power or signal strength absorbed by a receiver such as the human body located a distance from the base station. To achieve this, the design of array antennas using CST software at 28 GHz, fabrication and measurement were carried out in an indoor and hallway environment. The measurement processes were set up at IC5G at UTM Kuala Lumpur in which the distance of the transmitter to receiver where 1 m, 4 m, 8 m, and 10 m. In this study, the measured power density is found to be below the set limit by ICNIRP and hence no health implication is feared. Regardless, sufficient act of cautionary has to be applied by those staying close to small cell base stations and more studies are still needed to ensure the safety of use of 5G base stations.

scholarly journals NOMA and OMA-Based Massive MIMO and Clustering Algorithms for Beyond 5G IoT Networks

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Taj Rahman ◽  
Feroz Khan ◽  
Inayat Khan ◽  
Niamat Ullah ◽  
Maha M. Althobaiti ◽  
...  
Keyword(s):  
Computational Complexity ◽  
Interference Cancellation ◽  
Massive Mimo ◽  
Multiple Access ◽  
Clustering Algorithms ◽  
Mobile Network ◽  
Base Station ◽  
Signal Interference ◽  
Global Changes ◽  
Power Requirement

The Internet of Things (IoT) has brought about various global changes, as all devices will be connected. This article examines the latest 5G solutions for enabling a massive cellular network. It further explored the gaps in previously published articles, demonstrating that to deal with the new challenges. The mobile network must use massive multiple input and output (MIMO), nonorthogonal multiple access (NOMA), orthogonal multiple access (OMA), signal interference cancellation (SIC), channel state information (CSI), and clustering. Furthermore, this article has two objectives such as (1) to introduce the cluster base NOMA to reduce the computational complexity by applying SIC on a cluster, which ultimately results in faster communication and (2) to achieve massive connectivity by proposing massive MIMO with NOMA and OMA. The proposed NOMA clustering technique working principle pairs the close user with the far user; thus, it will reduce computational complexity, which was one such big dilemma in the existing articles. This will specifically help those users that are far away from the base station by maintaining the connectivity. Despite NOMA’s extraordinary benefits, one cannot deny the significance of the OMA; hence, the other objective of the proposed work is to introduce OMA with MIMO in small areas where the user is low in number, it is already in use, and quite cheap. The next important aspect of the proposed work is SIC, which helps remove interference and leads to enhancement in network performance. The simulation result has clearly stated that NOMA has gained a higher rate than OMA: current NOMA users’ power requirement (weak signal user 0.06, strong signal user 0.07), spectral efficiency ratio for P-NOMA and C-NOMA (21%, 5%), signal-to-noise ratio OMA, P-NOMA, C-NOMA (28, 40, 55%), and user rate pairs NOMA, OMA (7, 3), C-NOMA, and massive MIMO NOMA SINR (4.0, 2.5).

scholarly journals Rate-Splitting Multiple Access for Intelligent Reflecting Surface aided Multi-User Communications

2021 ◽  
Author(s):  
Ankur Bansal ◽  
Keshav Singh ◽  
Bruno Clerckx ◽  
Chih-Peng Li ◽  
Mohamed-Slim Alouini
Keyword(s):  
Interference Cancellation ◽  
Multiple Access ◽  
Base Station ◽  
Control Technique ◽  
Decode And Forward ◽  
Cell Edge ◽  
Single Antenna ◽  
Rate Splitting ◽  
Reflecting Surface ◽  
The Impact

Intelligent reflecting surface (IRS) has recently emerged as a promising technology for 6G wireless systems, due to its capability to reconfigure the wireless propagation environment. In this paper, we investigate a Rate-Splitting Multiple Access (RSMA) for IRS-assisted downlink system, where the base station (BS) communicates with single-antenna users with the help of an IRS. RSMA relies on rate-splitting (RS) at the BS and successive interference cancellation (SIC) at the users and provides a generalized multiple access framework. We derive a new architecture called IRS-RS that leverages the interplay between RS and IRS. For performance analysis, we utilize an \textit{on-off control technique} to control the passive beamforming vector of the IRS-RS and derive the closed-form expressions for outage probability of cell-edge users and near users. Moreover, we also analyze the outage behavior of cell-edge users for a sufficiently large number of reflecting elements. Additionally, we also analyze the outage performance of cooperative RS based decode-and-forward (DF)-assisted framework called DF-RS. Through simulation results, it is shown that the proposed framework outperforms the corresponding DF-RS, RS without IRS and IRS-assisted conventional non-orthogonal multiple access (NOMA) schemes. Furthermore, the impact of various system's parameters such as the number of IRS reflecting elements and the number of users on the system performance is revealed.

scholarly journals Provide security for wireless mobile networks with different multiple access Techniques and MANET Network

2018 ◽  
Vol 7 (2.20) ◽  
pp. 57
Author(s):  
E Uma Shankari ◽  
S Rajashekhar Reddy ◽  
P Aditya Sharma ◽  
G Geetha
Keyword(s):  
Mobile Networks ◽  
Mobile Communications ◽  
Multiple Access ◽  
High Speed ◽  
Instant Messaging ◽  
Mobile Client ◽  
Network Problems ◽  
Data Rates ◽  
Additional Costs ◽  
Information Cell

The most recent versatile innovation of new features in mobile technology is needed for advancement of the Internet, for the features of better, quicker access of information. Cell division subscribers pay additional costs for instant messaging, stock quotes, and Furthermore easy internet access on their phones. In order to support such a capable system, we need pervasive, high-speed remote connectivity. Bluetooth and 802.11 are currently existing techniques for providing high speed digital wireless connectivity. The extension of 4G technology gave scope for mobile communications. Mobile is not only a portable talking gadget but also utilized for multiple distinctive purposes.4G offers higher data rates for consistent roaming. That portable mobile client might communicate without any disturbance due to network problems. In this process report we discuss different tests that 4G will facing and also gives the solutions for those problems. We recommend our own method for enhancing QoS On 4G eventually by utilizing both SMIP and SIP. We recommend that by utilizing such plan we might accomplish better QoS throughout that process of handover. 

scholarly journals OVERVIEW OF OPTIMIZATION ALGORITHMS FOR UAVS POSITIONING

2021 ◽  
Vol 20 (4) ◽  
pp. 46-53
Author(s):  
Adrián STOSIL ◽  
◽  
Marcel VOLOŠIN ◽  
Taras MAKSYMYUK ◽  
Gabriel BUGÁR ◽  
...  
Keyword(s):  
Mobile Networks ◽  
Base Station ◽  
Base Stations ◽  
System Capacity ◽  
End User ◽  
Widespread Application ◽  
High Bandwidth ◽  
Time Required ◽  
And Control ◽  
Different Levels

Mobile broadband networks can provide a reliable and flexible communication channel. User requirements can come with different levels of specificity. The widespread application of unmanned aerial vehicles (UAVs, commonly known as a drones) introduces possibilities of use in modern upcoming mobile networks; for example, 5G and 6G, to achieve and support various use cases from low latency to high bandwidth scenarios. For reliable command and control communication, mobile networks can provide flexible differentiated QoS matching the needed reliability, latency and throughput. Many end user equipment connected to the same base station can overload the system and may cause the network to be unavailable. Also, in case the fixed infrastructure is partially decommissioned, destroyed or the network is congested and the system capacity is not sufficient, it is appropriate to use autonomous drones as mobile base stations to ensure well signal coverage of the affected area. The aim of this work is to overview of optimization algorithm developed to provide the best drones’ locations. We compared the techniques of minimization of the number of drones needed to cover users located in a given area with respect to the time required to calculate the optimal positions of the drones.

Design of novel approach for emerging power-domain superposition coding (SC)-using hybrid NOMA-OFDM for 5G communications

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Y.K. Shobha ◽  
H.G. Rangaraju
Keyword(s):  
Interference Cancellation ◽  
Multiple Access ◽  
Mimo System ◽  
Minimum Mean Square Error ◽  
Research Work ◽  
Base Station ◽  
Superposition Coding ◽  
Content Type ◽  
Minimum Mean Squared Error ◽  
Power Domain

PurposeThe suggested work examines the latest developments such as the techniques employed for allocation of power, browser techniques, modern analysis and bandwidth efficiency of nonorthogonal multiple accesses (NOMA) in the network of 5G. Furthermore, the proposed work also illustrates the performance of NOMA when it is combined with various techniques of wireless communication namely network coding, multiple-input multiple-output (MIMO), space-time coding, collective communications, as well as many more. In the case of the MIMO system, the proposed research work specifically deals with a less complex recursive linear minimum mean square error (LMMSE) multiuser detector along with NOMA (MIMO-NOMA); here the multiple-antenna base station (BS) and multiple single-antenna users interact with each other instantaneously. Although LMMSE is a linear detector with a low intricacy, it performs poorly in multiuser identification because of the incompatibility between LMMSE identification and multiuser decoding. Thus, to obtain a desirable iterative identification rate, the proposed research work presents matching constraints among the decoders and identifiers of MIMO-NOMA.Design/methodology/approachTo improve the performance in 5G technologies as well as in cellular communication, the NOMA technique is employed and contemplated as one of the best methodologies for accessing radio. The above-stated technique offers several advantages such as enhanced spectrum performance in contrast to the high-capacity orthogonal multiple access (OMA) approach that is also known as orthogonal frequency division multiple access (OFDMA). Code and power domain are some of the categories of the NOMA technique. The suggested research work mainly concentrates on the technique of NOMA, which is based on the power domain. This approach correspondingly makes use of superposition coding (SC) as well as successive interference cancellation (SIC) at source and recipient. For the fifth-generation applications, the network-level, as well as user-experienced data rate prerequisites, are successfully illustrated by various researchers.FindingsThe suggested combined methodology such as MIMO-NOMA demonstrates a synchronized iterative LMMSE system that can accomplish the optimized efficiency of symmetric MIMO NOMA with several users. To transmit the information from sender to the receiver, hybrid methodologies are confined to 2 × 2 as well as 4 × 4 antenna arrays, and thereby parameters such as PAPR, BER, SNR are analyzed and efficiency for various modulation strategies such as BPSK and QAMj (j should vary from 8,16,32,64) are computed.Originality/valueThe proposed hybrid MIMO-NOMA methodologies are synchronized in terms of iterative process for optimization of LMMSE that can accomplish the optimized efficiency of symmetric for several users under different noisy conditions. From the obtained simulated results, it is found, there are 18%, 23% 16%, and 8% improvement in terms of Bit Error Rate (BER), Least Minimum Mean Squared Error (LMMSE), Peak to Average Power Ratio (PAPR), and capacity of channel respectively for Binary Phase Shift Key (BPSK) and Quadrature Amplitude Modulation (QAM) modulation techniques.

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