Non-Orthogonal Multiple Access

2019 ◽  
Author(s):  
Sanjeev Gurugopinath
Keyword(s):  
Interference Cancellation ◽  
Communication Systems ◽  
Multiple Access ◽  
Future Research ◽  
Superposition Coding ◽  
Fifth Generation ◽  
Power Domain ◽  
Code Domain ◽  
5G Communication ◽  
Code Division Multiple

Non-orthogonal multiple access (NOMA) has been recently proposed as a technique to increase the network throughput and to support massive connectivity, which are major requirements in the fifth generation (5G) communication systems. The NOMA can be realized through two different approaches, namely, in (a) power-domain, and (b) code-domain. In the power-domain NOMA (PD-NOMA), multiple users are assigned different power levels – based on their individual channel quality information – over the same orthogonal resources. The functionality of PD-NOMA comprises of two main techniques, namely, superposition coding at the transmitter and successive interference cancellation (SIC) at the receiver. An efficient implementation of SIC would facilitate to remove interference across the users. The SIC is carried out at users with the best channel conditions and is performed in descending order of the channel. On the other hand, in the code-domain NOMA (CD-NOMA), multiplexing is carried out using low-density spreading sequences for each user, similar to the code division multiple access (CDMA) technology. In this article, we provide an introduction to NOMA and present the details on the working principle of NOMA systems. Later, we discuss the different types of NOMA schemes under PD- and CD-domains, and investigate the related applications in the context of 5G communication systems. Additionally, we discuss the integration of NOMA with other technologies related to 5G such as cognitive radio and massive MIMO, and discuss some future research challenges.

scholarly journals LARGE-SCALE MIMO MC-CDMA SYSTEM USING COMBINED MULTIPLE BEAMFORMING AND SPATIAL MULTIPLEXING

2018 ◽  
Vol 56 (1) ◽  
pp. 102 ◽  
Author(s):  
Nguyen Huu Trung ◽  
Doan Thanh Binh
Keyword(s):  
System Performance ◽  
Code Division Multiple Access ◽  
Communication Systems ◽  
Multiple Access ◽  
Large Scale ◽  
Spatial Multiplexing ◽  
Propagation Loss ◽  
Fifth Generation ◽  
Simulation Results ◽  
Code Division Multiple

This paper proposes a novel Large-scale (massive) Multi-input Multi-output Multi-carrier Code division multiple access (LS MIMO MC-CDMA) model and application to Fifth-Generation Mobile Communication Systems (5G). This system uses combined cylindrical array antenna multiple beamforming architecture with spatial multiplexing. The model is optimized by Min-Max criteria in order to minimize side lobes and maximize compression of propagation loss. The Monte Carlo simulation results unify with the analytical solution for system performance.

scholarly journals Effects of Power Allocation and User Mobility on Non-Orthogonal Multiple Access Using Successive Interference Cancellation

ELKHA ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Khoirun Niamah ◽  
Solichah Larasati ◽  
Raudhatul Jannah
Keyword(s):  
Power Allocation ◽  
High Power ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Successive Interference Cancellation ◽  
Channel Gain ◽  
User Mobility ◽  
Power Domain ◽  
Code Domain

This research based on simulation to show impact of the power allocation on Non-Orthogonal Multiple Access (NOMA) using Successive Interference Cancellation (SIC). NOMA used superposition code (SC) on the transmitter and SIC on the receiver. NOMA has two categories power domain (PD) and code domain (CD). This research based on PD-NOMA simulated for downlink. The number of users who use the same recourse block are divided into two conditions: user with apply SIC and without SIC base on the value of channel gain from each user. Applying SC on the transmitter and SIC on the receiver will cancel of interference. Novelties of this research are the best performance of power allocation and user mobility based on parameter BER and SNR. Allocation of the power transmit based on value of channel gain every user, where user with value of channel gain is low will be allocated high power transmit, and otherwise. The best result performance of BER vs SNR used ratio power transmit 0.45 dB:0.55 dB, BER  get value SNR for 17 dB and  18 dB. The best performance SNR for mobility of user with speed    = 40 km/h value SNR 18 dB for BER . This research has proposed to show impact of power transmit and interference in performance NOMA.

scholarly journals MULTIPLE ACCESS TECHNIQUES FOR 5G NETWORKS

2020 ◽  
Vol 5 (2) ◽  
pp. 305-314
Author(s):  
Mrs. Rinkoo Bhatia
Keyword(s):  
Multiple Access ◽  
Heterogeneous Traffic ◽  
5G Networks ◽  
Comprehensive Overview ◽  
Fifth Generation ◽  
Power Domain ◽  
Different Types ◽  
Code Domain ◽  
Multiple Access Schemes ◽  
Multiple Domains

Fifth generation (5G) wireless networks face various challenges in order to support largescale heterogeneous traffic and users, therefore new modulation and multiple access (MA) schemes are being developed to meet the changing demands. As this research space is ever increasing, it becomes more important to analyze the various approaches, therefore, in this article we present a comprehensive overview of the most promising Multiple Access schemes for 5G networks. Our article focuses on various types of non-orthogonal multiple access (NOMA) techniques. Specifically, we first introduce different types of modulation schemes, potential for OMA. We then pay close attention to various types of NOMA candidates, including power-domain NOMA, code-domain NOMA, and NOMA multiplexing in multiple domains. From this exploration, we can identify the opportunities and challenges that will have the most significant impacts on modulation and MA designs for 5G networks.

Non Orthogonal Multiple Access: Basic Concepts and Misconceptions

2019 ◽  
Vol 7 (1) ◽  
pp. 1-4
Author(s):  
Syed Rizwan Hassan ◽  
Noman Shabbir ◽  
Arooj Unbreen ◽  
Ateeq Ur Rehman ◽  
Ahmad Iqbal
Keyword(s):  
Mobile Communication ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Successive Interference Cancellation ◽  
Receiver Side ◽  
Superposition Coding ◽  
Radio Access ◽  
Power Domain ◽  
Basic Concepts

Non Orthogonal Multiple Access (NOMA) is fundamentally different from the Orthogonal Multiple Access (OMA) techniques as in NOMA the user make access to channel by using the same frequency and in the same time. In NOMA the multiplexing is performed in power domain by using superposition coding at the transmitter and receiver side uses Successive Interference Cancellation (SIC) to separate the transmitted signals that are multiplexed in power domain. This technique is a possible candidate for future radio access so this is a hot topic in research. Being a different method from OMA that is implemented in all previous mobile communication generations several misconceptions have been developed about this technique. This paper give an overview about NOMA based system and also analyze the major misconceptions about this technique and also explain the concepts to resolve these mistaken beliefs.

scholarly journals Evaluation of 5G Key Technique: Non-Orthogonal Multiple Access

2019 ◽  
Vol 8 (2S8) ◽  
pp. 1314-1316
Keyword(s):  
Power Allocation ◽  
Spectral Efficiency ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Quality Data ◽  
Data Service ◽  
Front Edge ◽  
Power Domain ◽  
Channel Interference ◽  
Code Domain

Non-orthogonal multiple access has been put forward as a key technique for 5G. It can provide power-domain and code-domain multiplexing and enables to satisfy the data demand. Its capacity and spectral efficiency are investigated-ed and analyzed. In comparison to the conventional orthogonal multiple access, the existing dominant non-orthogonal multiple access can provide a higher quality data service for multiple users when the transmitted signals are empowered by the power allocation technique and the received signals are decoded by the channel interference cancellation scheme. In this study, NOMA is found to be a front-edge technology the 5G communications.

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.

Uplink Power-Domain Non-Orthogonal Multiple Access (NOMA)

2020 ◽  
Vol 12 (4) ◽  
pp. 65-73
Author(s):  
Faeik T. Al Rabee ◽  
Richard D. Gitlin
Keyword(s):  
Channel Estimation ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Signal To Noise Ratio ◽  
Estimation Error ◽  
Channel Estimation Error ◽  
Estimation Errors ◽  
Channel Estimation Errors ◽  
Fifth Generation ◽  
Power Domain

Non-orthogonal multiple access (NOMA) has been proposed as a promising multiple access (MA) technique in order to meet the requirements for fifth generation (5G) communications and to enhance the performance in internet of things (IoT) networks by enabling massive connectivity, high throughput, and low latency. This paper investigates the bit error rate (BER) performance of two-user uplink power-domain NOMA with a successive interference cancellation (SIC) receiver and taking into account channel estimation errors. The analysis considers two scenarios: perfect (ideal) channel estimation and a channel with estimation errors for various modulations schemes, BPSK, QPSK, and 16-QAM. The simulation results show that, as expected, increasing of the modulation level increases the SIC receiver BER. For example, at a signal-to-noise ratio (SNR) of 5 dB for perfect channel estimation and QPSK modulation, the user that is detected first has a BER of 0.005 compared to 0.14 for the user that is detected with the aid of the SIC receiver. Similarly, the BER of QPSK, assuming 0.25 channel estimation error of user 1, is equal to 0.06 at SNR = 15 dB compared to 0.017 for perfect estimation.

scholarly journals Mitigation of Imperfect Successive Interference Cancellation and Wavelet-Based Nonorthogonal Multiple Access in the 5G Multiuser Downlink Network

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Muneeb Ahmad ◽  
Sobia Baig ◽  
Hafiz Muhammad Asif ◽  
Kaamran Raahemifar
Keyword(s):  
Wavelet Transform ◽  
Interference Cancellation ◽  
Communication Systems ◽  
Multiple Access ◽  
Industrial Revolution ◽  
Symbol Error Rate ◽  
Base Station ◽  
Successive Interference Cancellation ◽  
Signal Pulse ◽  
Power Domain

The fourth Industrial Revolution is expected to lead to an era of technological innovation and digitization that would require connectivity by the users, anywhere and anytime. The fifth generation of wireless communication systems and the technologies therein are being explored to cater to high connectivity needs that encompass high data rates, very low latencies, energy-efficient systems, etc. A multiuser environment is anticipated that would require multiple access techniques, such as Nonorthogonal Multiple Access (NOMA). The user data in the power domain NOMA is superimposed, at the transmitter base station, which is in turn subjected to Successive Interference Cancellation at the user end. In the multiuser downlink, the desired user’s signal is subjected to imperfect SIC due to incomplete cancellation of the undesired user’s signal. Pulse-shaping of NOMA symbols using wavelet transform is proposed to mitigate the multiuser interference due to imperfect SIC. Closed-form symbol error rate (SER) expression is derived for the wavelet NOMA system for a three-user scenario. Analytical results show that wavelet transform pulse-shaped NOMA performs better compared to Fourier transform pulse-shaped NOMA symbols in mitigating SIC and thereby minimize the residual error due to imperfect SIC.

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