隨著行動通訊系統的快速發展，如今已提出了相當多嶄新的傳輸技術，其中，通用濾波多載波系統(Universal-Filtered Multi-carrier,UFMC)與正交分頻多工系統(OFDM)的系統架構相似，該系統將輸入的子載波分成多個子頻帶，然後在每個子頻帶上進行濾波，這種做法可以降低頻譜的旁波瓣位準(sidelobe level)，進而避免OFDM系統的高旁波瓣位準所引起的載波間干擾(ICI)，並可以減少循環字首(Cyclic Prefix)的消耗。因此，針對5G複雜的傳輸環境時，UFMC傳輸技術可視為有力的候選。然而UFMC系統作為一種多載波傳輸技術，受到了高峰均值功率比(PAPR)的影響，因此，已經有許多降低PAPR技術被提出，本篇論文中也提出了將預編碼與降低PAPR技術結合，並將該技術應用於UFMC系統上，然後分析其PAPR以及誤碼率(BER)。
非正交多址(NOMA)被認為是有前途的5G多址技術，NOMA允許來自不同用戶的信號重疊，從而提供更高效的傳輸。本篇論文中介紹了非正交多址應用於通用濾波多載波系統(NOMA-UFMC)，然而NOMA-UFMC與UFMC相同，有著高PAPR的缺點，因此，本篇論文將其與提出的降低PAPR技術進行結合並分析。在模擬結果中，提出的方法可以有較低的PAPR並且在BER上可以維持相近的效能。

With the rapid development of the 5th Generation wireless systems (5G), more and more new transmission technologies have been proposed. Among them, the Universal- Filtered Multi-Carrier System (UFMC) and the Orthogonal Frequency Division Multiplexing System (OFDM) have similar system architectures. The system divides the input sub-carrier into multiple sub-bands, and then performs filtering on each sub-band. This approach can reduce the sidelobe level of the spectrum, thereby avoiding the high sidelobe level of the OFDM system which may cause inter-carrier interference (ICI). And it can reduce the consumption of cyclic prefix (Cyclic Prefix). Therefore, UFMC transmission technology can be regarded as a strong candidate for the complex transmission environment of 5G. However, as a multi-carrier transmission technology, the UFMC system is affected by the peak-to-average power ratio (PAPR). Therefore, many PAPR reduction techniques have been proposed. This paper also proposes to combine precoding and PAPR reduction techniques, apply them to the UFMC system, and then analyze its PAPR and bit error rate (BER).
Non-orthogonal multiple access (NOMA) is considered a promising 5G multiple access technology. NOMA allows signals from different users to overlap to provide more efficient transmission. This paper introduces the application of non-orthogonal multiple access to the universal filtered multi-carrier system (NOMA-UFMC). However, NOMA-UFMC also has the disadvantage of high PAPR. Therefore, this paper combines it with the proposed reduced PAPR technology and analysis it. In the simulation results, the proposed method can have lower PAPR and maintain similar BER.

[1] F. Schaich and T. Wild, ''Waveform contenders for 5G -2014; OFDM vs.FBMC vs. UFMC'', in 2014 6th International Symposium on Communications,Control and Signal Processing (ISCCSP), pp. 457-460, May 2014,
[2] V. Vakilian and T. Wild and F. Schaich and S. ten Brink and J. F. Frigon,''Universal-ltered multi-carrier technique for wireless systems beyond LTE",in 2013 IEEE Globecom Workshops (GC Wkshps), pp. 223-228, Dec 2013,
[3] B. Farhang-Boroujeny, "OFDM Versus Filter Bank Multicarrier," IEEE Signal Processing Magazine, vol. 28, no. 3, pp. 92-112, 2011.
[4] F. Schaich and T. Wild, "Waveform contenders for 5G — OFDM vs. FBMC vs. UFMC," in 2014 6th International Symposium on Communications, Control and Signal Processing (ISCCSP), 2014, pp. 457-460
[5] A. F. Almutairi, M. Al-Gharabally, and A. Krishna, "Performance Analysis of Hybrid Peak to Average Power Ratio Reduction Techniques in 5G UFMC Systems," IEEE Access, vol. 7, pp. 80651-80660, 2019.
[6] M. B. Mabrouk, M. Chafii, Y. Louet, and F. Bader, "A Precoding-based PAPR Reduction Technique for UF-OFDM and Filtered-OFDM Modulations in 5G Systems," in European Wireless 2017; 23th European Wireless Conference, 2017, pp. 1-6.
[7] 3GPP-TS-36.104, "LTE;Evolved Universal Terrestrial Radio Access (E-UTRA);User Equipment (UE) radio transmission and reception (3GPP TS 36.101 version 14.3.0 Release 14)," 2017.
[8] BAUML, R., FISCHER, R , and HUBER, J.: 'Reducing the peak-toaveragepower ratio of multicarrier modulation by selected mapping', Electron. Lett., 1996, 32, (22), pp. 2056-2057
[9] S. A. Fathy, M. Ibrahim, S. El-Agooz and H. El-Hennawy, "Low-Complexity SLM PAPR Reduction Approach for UFMC Systems," in IEEE Access, vol. 8, pp. 68021-68029, 2020, doi: 10.1109/ACCESS.2020.2982646.
[10] M. Wu, J. Dang, Z. Zhang, and L. Wu, "An Advanced Receiver for Universal Filtered Multicarrier," IEEE Transactions on Vehicular Technology, vol. 67, no. 8, pp. 7779-7783, 2018.
[11] M. N. Tipán, J. Cáceres, M. N. Jiménez, I. N. Cano and G. Arévalo, "Comparison of clipping techniques for PAPR reduction in UFMC systems," 2017 IEEE 9th Latin-American Conference on Communications (LATINCOM), 2017, pp. 1-4, doi: 10.1109/LATINCOM.2017.8240171.
[12] A. F. Almutairi, M. Al-Gharabally and A. Krishna, "Performance Analysis of Hybrid Peak to Average Power Ratio Reduction Techniques in 5G UFMC Systems," in IEEE Access, vol. 7, pp. 80651-80660, 2019, doi: 10.1109/ACCESS.2019.2916937.
[13] Y. Saito and Y. Kishiyama and A. Benjebbour and T. Nakamura and A. Li and K. Higuchi, Non-Orthogonal Multiple Access (NOMA) for Cellular Fu-ture Radio Access, 2013 IEEE 77th Vehicular Technology Conference (VTC Spring), pp. 1-5, June 2013
[14] M. B. Mabrouk, M. Chafii, Y. Louet, and F. Bader, "A Precoding-based PAPR Reduction Technique for UF-OFDM and Filtered-OFDM Modulations in 5G Systems," in European Wireless 2017; 23th European Wireless Conference, 2017, pp. 1-6.
[15] N. Michailow et al., "Generalized Frequency Division Multiplexing for 5th Generation Cellular Networks," IEEE Transactions on Communications, vol. 62, no. 9, pp. 3045-3061, 2014.