Non-Orthogonal Multiple Access: Common Myths and Critical Questions
Non-Orthogonal Multiple Access: Common Myths and Critical Questions
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DOI：
10.1109/mwc.2019.1800598
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发表时间：
2019-10-01
影响因子：
12.9
通讯作者：
Poor, H. Vincent
中科院分区：
文献类型：
--
作者：
Vaezi, Mojtaba;Schober, Robert;Poor, H. Vincent
非正交多址（NOMA）在第五代（5G）及以后无线网络的无线电接入技术设计方面受到了极大的关注。NOMA背后的基本概念是在相同的资源块（例如，时隙、子载波、扩频码或空间）中服务多于一个用户。与正交多址（OMA）技术相比，NOMA促进了大规模连接，降低了延迟，提高了用户公平性和频谱效率，并提高了可靠性。虽然NOMA得到了通信界的极大关注，但它也受到了一些广泛的误解，例如“NOMA是基于向信道条件较差的用户分配更高的功率。因此，小区边缘用户在NOMA中接收更多功率，并且由于这种偏向小区用户的功率分配，与OMA相比，在NOMA中小区间干扰更严重。NOMA也会为了频谱效率而牺牲安全性。“上述说法实际上是错误的，本文旨在识别关于NOMA的常见神话，并澄清为什么它们不是真的。我们还提出了对于在5G及以后有效采用NOMA至关重要的关键问题，并确定了NOMA有前途的研究方向，这将需要在未来进行深入研究。
Non-orthogonal multiple access (NOMA) has received tremendous attention for the design of radio access techniques for fifth generation (5G) wireless networks and beyond. The basic concept behind NOMA is to serve more than one user in the same resource block, for example, a time slot, subcarrier, spreading code, or space. With this, NOMA promotes massive connectivity, lowers latency, improves user fairness and spectral efficiency, and increases reliability compared to orthogonal multiple access (OMA) techniques. While NOMA has gained significant attention from the communications community, it has also been subject to several widespread misunderstandings, such as "NOMA is based on allocating higher power to users with worse channel conditions. As such, cell-edge users receive more power in NOMA and due to this biased power allocation toward celledge users inter-cell interference is more severe in NOMA compared to OMA. NOMA also compromises security for spectral efficiency." The above statements are actually false, and this article aims at identifying such common myths about NOMA and clarifying why they are not true. We also pose critical questions that are important for the effective adoption of NOMA in 5G and beyond and identify promising research directions for NOMA, which will require intense investigation in the future.