THE PROBLEM OF SPECTRAL EFFICIENCY AND CAPACITY INCREASE IN PERSPECTIVE 6G COMMUNICATION SYSTEMS
Mikhail G. Bakulin, Moscow Technical University of Communications and Informatics, Moscow, Russia, m.g.bakulin@gmail.com
Vitaly B. Kreyndelin, Moscow Technical University of Communications and Informatics, Moscow, Russia, vitkrend@gmail.com
Abstract
The problem of increase of spectral efficiency and increase of the number of users in perspective 6G communication systems is nou in the focus of extensive research all over the world. This problem is being solved in 3G, 4G and 5G systems mainly at the expense of both MIMO technology and orthogonal multiple access (OMA) methods. Orthogonal Frequency Division Multiple Access (OFDMA) and Code Division Multiple Access (CDMA) are such methods. However, since future 6G systems shall meet very high requirements to spectral efficiency, interference immunity and capacity, that orthogonal access OMA cannot already provide required system capacity at given interference immunity and spectral efficiency. Therefore, non-orthogonal methods of multiple access (NOMA) are being considered. If one use claccic correlation reception theory to NOMA signals, then interference immunity of communication system will be not high. NOMA technique require the synthesis of new signals and new reception algorithms, since classic linear correlation reception theory cannot be implemented. Moreover, one needs to find new criteria for such synthesis, those should take into account computational complexity of signal demodulation. It is shown in the article, that general research direction for 6G development is to find quite novel reception algorithms with low computational complexity and search of corresponding novel signals, those can be received via low interference immunity loss with simple algorithms. The requirement to use simple reception algorithms is cased by high requirements to data transmission rate in 6G systems.
Keywords: MIMO technology, orthogonal access, non-orthogonal access, computational complexity, spectral efficiency, capacity, correlation reception.
References
1. Jamil Y. Khan, Mehmet R. Yuce. (2019). Internet of Things (IoT): Systems and Applications. USA, Jenny Stanford Publishing. 350 p.
2. Prokis J. (2000). Digital communications. Edited by D.D.Klovsky. Moscow: Radio and communications. 797 p. (In Russian)
3. Jerry R. Hampton. (2014). Introduction to MIMO Communications, UK, Cambridge University Press. 288 p.
4. Bakulin M.G., Varukina L.A., Kreyndelin V.B. (2014). MIMO technology: principals and algorithms. Moscow: Goryachaya linia – Telecom. 280 p. (In Russian)
5. R1-1809974, “Updated offline summary of performance evaluations for NOMA” ZTE, RAN1#94.
6. Sklyar B. (2003). Digital communications. Theoretical basis and practical implementation, 2-nd edition. Moscow: Izdatelskiy dom “Viliams”. 1104 p.
7. Alamouti S.M. (1998). A Simple Transmit Diversity Technique for Wireless Communications. IEEE Journal on Selected Areas of Communications. Vol. 16. No. 8, October 1998, pp. 1451-1458.
8. Varakin L.E. (1985). Communication systems with pseudo-noise signals. Moscow: Radio I svyaz. 384 p. (In Russian)
9. Zubarev Y.B., Trofimov Y.K., Shloma A.M., Bakulin M.G., Kreyndelin V.B. (2004). New algorithms of signal generation and processing in mobile communication systems. Electrosvyaz. No. 3, pp. 11-13. (In Russian)
10. Tyrtyshnikov E.E. (2007). Matrix analysis and linear algebra. Moscow: Fizmatlit. 480 p. (In Russian)
11. Bakulin M.G., Kreyndelin V.B., Pankratov D.Y. (2018). Technologies in radiocommunication systems on the road to 5G. Moscow: Goryachaya linia – Telecom. 280 p. (In Russian)
12. Bakulin M.G., Kreyndelin V.B., Shloma A.M., Shumov A.P. (2016). OFDM technology. Moscow: Goryachaya linia – Telecom. 360 p. (In Russian)
13. Multiple Access Techniques for 5G Wireless Networks and beyond. Edited by Mojtaba Vaezi, Zhiguo Ding and Vincent Poor. USA: Springer. 2019. 670 p.
14. Ipatov V.P. (1992). Periodic discrete signals with optimal correlation properties. Moscow: Radio I svyaz. 152 p. (In Russian)
15. H.Sari, A.Maatouk, E.Caliskan, M.Assaad, M.Koca, and G.Gui, (2018). On the Foundation of NOMA and its Application to 5G Cellular Networks. Proc., WCNC, April, 2018, Barcelona, Spain.
16. Clazzer, Federico & Munari, Andrea & Liva, Gianluigi & Lazaro, Francisco & Stefanovi?, Ledomir & Popovski, Petar. (2019). From 5G to 6G: Has the Time for Modern Random Access Come? Ýëåêòðîííûé ðåñóðñ: https://arxiv.org/pdf/1903.03063.pdf.
17. Stoica, Razvan-Andrei & Abreu, Giuseppe. (2019). 6G: the Wireless Communications Network for Collaborative and AI Applications. Internet resource: https://arxiv.org/pdf/1904.03413v1.pdf.
18. Bakulin M.G., Kreyndelin V.B., Shumov A.P. (2010). Turboprocessing in communication systems with space-time coding. Radiotechnika I electronika. Vol. 55. No. 2, pp. 206-214. (In Russian)
19. Internet resource: https://nag.ru/articles/article/32077/noma-novaya-tehnologiya-dlya-besprovodnyih-setey.html.
20. Clerckx B., Oestges C. (2013). MIMO Wireless Networks: Channels, Techniques and Standards for Multi-Antenna, Multi-User and Multi-Cell Systems. Second Edition. UK: Elsevier. 733 p.
21. Ben Rejeb T.B.K., Smirnov A.E. (2015). Study of efficiency of signal demodulation methods in systems with large number of antennas. Proceedings of 70-th international conference “Radioelectronic devices and systems for infocommunication technologies – REUS-2015”, devoted to Radio Day. Issue LXX. Moscow: Bris-M, pp. 251-255. (In Russian)
Information about authors:
Mikhail G. Bakulin, Ph.D., Ass.-Prof., Moscow Technical University of Communications and Informatics, Moscow, Russia
Vitaly B. Kreyndelin, Dr. Tech. Sc. Prof. Chief of Department, Moscow Technical University of Communications and Informatics, Moscow, Russia