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Proceedings ArticleDOI

Performance Analysis of Hybrid NOMA-OMA Scheme for 5G NR System

TL;DR: In this article, a hybrid NOMA-OMA based seamless data transmission over the same 5G NR frame is carried out with help of different numerology factor which indirectly controls the subcarrier spacing, without affecting the conventional OMA based transmission Performance of the proposed method is analyzed in terms of the average bit error rate (BER) and ergodic capacity performance for various modulation schemes.
Abstract: The non-orthogonal multiple access (NOMA) scheme has been considered as a study item in 3rd generation partnership project (3GPP) for its possible use in fifth-generation new radio (5G NR) and beyond In this paper, we explore the available scalable bandwidth feature of 5G NR and propose a hybrid NOMA-OMA scheme based downlink data transmission in 5G NR The hybrid NOMA-OMA based seamless data transmission over the same 5G NR frame is carried out with help of different numerology factor which indirectly controls the subcarrier spacing, without affecting the conventional OMA based transmission Performance of the proposed method in conventional 5G NR system is analyzed in terms of the average bit error rate (BER) and ergodic capacity performance for various modulation schemes The results are illustrated for different µ used in 5G NR specifications Moreover, the obtained results are corroborated with the analytically obtained expressions
Citations
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Proceedings ArticleDOI
01 Sep 2022
TL;DR: In this paper , a Zadoff-Chu sequence based pilot signal assignment scheme was proposed to improve orthogonality between signals with different numerologies and reduce bit error rate (BER) performance.
Abstract: In the fifth-generation mobile communication system (5G) mixed numerology is standardized to meet the requirements of various services. In this paper, mixed numerology signal transmission in which multiple signals with different numerologies is assumed. As a conventional pilot signal, demodulation reference signal (DMRS) in a forth generation mobile communication (4G) is applied. However, under mixed numerology non-orthogonal multiple access (NOMA), DMRS can not realize orthogonality between pilot signals. As a solution, new pilot signal design based on a Zadoff-Chu sequence is proposed. The proposed pilot signal assignment scheme improves orthogonality between signals with different numerologies and, as a result, reduces bit error rate (BER) performance. Numerical results obtained through computer simulation show that the proposed pilot signal assignment scheme improves the performance by about 2.0 dB at a BER of 1$0^{-2}$.
References
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Journal ArticleDOI
TL;DR: NOMA can be expected to efficiently exploit the near-far effect experienced in cellular environments and offer a better tradeoff between system efficiency and user fairness than orthogonal multiple access (OMA), which is widely used in 3.9 and 4G mobile communication systems.
Abstract: SUMMARY This paper presents our investigation of non-orthogonal multiple access (NOMA) as a novel and promising power-domain user multiplexing scheme for future radio access. Based on information theory, we can expect that NOMA with a successive interference canceller (SIC) applied to the receiver side will offer a better tradeoff between system efficiency and user fairness than orthogonal multiple access (OMA), which is widely used in 3.9 and 4G mobile communication systems. This improvement becomes especially significant when the channel conditions among the non-orthogonally multiplexed users are significantly different. Thus, NOMA can be expected to efficiently exploit the near-far effect experienced in cellular environments. In this paper, we describe the basic principle of NOMA in both the downlink and uplink and then present our proposed NOMA scheme for the scenario where the base station is equipped with multiple antennas. Simulation results show the potential system-level

518 citations

Journal ArticleDOI
TL;DR: For the first time in the literature, an exact closed-form bit error rate (BER) expressions under SIC error for downlink NOMA over Rayleigh fading channels are derived and validated by simulations.
Abstract: Non-orthogonal multiple access (NOMA) is a strong candidate for next generation radio access networks due to its ability of serving multiple users using the same time and frequency resources. Therefore, researchers in academia and industry have been recently investigating the error performances and capacity of NOMA schemes. The main drawback of NOMA techniques is the interference among users due to the its non-orthogonal access nature, that is usually solved by interference cancellation techniques such as successive interference cancellation (SIC) at the receivers. On the other hand, the interference among users may not be completely eliminated in the SIC process due to the erroneous decisions in the receivers usually caused by channels. In this study, for the first time in the literature, the authors derive an exact closed-form bit error rate (BER) expressions under SIC error for downlink NOMA over Rayleigh fading channels. Besides, they derive one-degree integral form exact BER expressions and closed-form approximate expressions for uplink NOMA. Then, the derived expressions are validated by simulations. The numerical results are depicted to reveal the effects of error during SIC process on the performance for various cases such as power allocation for downlink and channel quality difference for uplink.

197 citations

Posted Content
TL;DR: This work provides a comprehensive overview of the state-of-the-art in power-domain multiplexing aided NOMA, with a focus on the theoretical N OMA principles, multiple antenna aided NomA design, on the interplay between NOM a and cooperative transmission, onthe resource control of NOMa, onThe co-existence of Noma with other emerging potential 5G techniques and on the comparison with other NOMC variants.
Abstract: Driven by the rapid escalation of the wireless capacity requirements imposed by advanced multimedia applications (e.g., ultra-high-definition video, virtual reality etc.), as well as the dramatically increasing demand for user access required for the Internet of Things (IoT), the fifth generation (5G) networks face challenges in terms of supporting large-scale heterogeneous data traffic. Non-orthogonal multiple access (NOMA), which has been recently proposed for the 3rd generation partnership projects long-term evolution advanced (3GPP-LTE-A), constitutes a promising technology of addressing the above-mentioned challenges in 5G networks by accommodating several users within the same orthogonal resource block. By doing so, significant bandwidth efficiency enhancement can be attained over conventional orthogonal multiple access (OMA) techniques. This motivated numerous researchers to dedicate substantial research contributions to this field. In this context, we provide a comprehensive overview of the state-of-the-art in power-domain multiplexing aided NOMA, with a focus on the theoretical NOMA principles, multiple antenna aided NOMA design, on the interplay between NOMA and cooperative transmission, on the resource control of NOMA, on the co-existence of NOMA with other emerging potential 5G techniques and on the comparison with other NOMA variants. We highlight the main advantages of power-domain multiplexing NOMA compared to other existing NOMA techniques. We summarize the challenges of existing research contributions of NOMA and provide potential solutions. Finally, we offer some design guidelines for NOMA systems and identify promising research opportunities for the future.

137 citations

Proceedings ArticleDOI
02 Jul 2016
TL;DR: This paper gives an overview on the principle of NOMA and recent investigations, and several issues for implementing NomA in real systems are presented.
Abstract: Recently, non-orthogonal multiple access (NOMA) has gained more attention as a candidate multiple access scheme for future radio access. A major reason for this is that NOMA has the potential to achieve a more favorable tradeoff between system efficiency and user fairness than orthogonal multiple access (OMA), which is adopted in the 4th generation mobile communication systems such as LTE and LTE-Advanced. In this paper, we focus on downlink cellular systems. This paper gives an overview on the principle of NOMA and recent investigations. Several issues for implementing NOMA in real systems are also presented.

22 citations

Journal ArticleDOI
TL;DR: This letter proposes a novel orthogonal frequency division multiplexing (OFDM) with index modulation (IM)-based NOMA scheme, called OFDM-IM N OMA, for future multi-user communication systems.
Abstract: Non-orthogonal multiple access (NOMA) is envisioned as an efficient candidate for future communication systems. This letter proposes a novel orthogonal frequency division multiplexing (OFDM) with index modulation (IM)-based NOMA scheme, called OFDM-IM NOMA, for future multi-user communication systems. Inspired by IM and classical NOMA-OFDM, users utilize flexibility by adjusting power allocation factors and subcarrier activation ratios. Our new scheme allows different service users to share available resources as in classical NOMA, more efficiently. It is shown that OFDM-IM NOMA reliably supports a high and low data rate user at the same resources by adjusting their subcarrier activation ratios.

16 citations