臺灣博碩士論文加值系統

隨著發展的順利，第五代行動通訊(5G)將在 2020 年在全球推出，有助於物聯網(IoT)應用發展，提供大量所需的基礎設施，迎來一個更智慧更便利的世界。由於較高的頻譜效益以及對多重路徑衰減(multi-path fading)的較強抵抗力，在第五代移動通訊中仍選擇正交分頻多工 (Orthogonal Frequency Division Multiplexing; OFDM)作為波形。然而，作為多載波技術高峰均功率比(Peak-to-Average Power Ratio; PAPR)的問題依舊存在，造成較多的功率消耗或是需要線性度較高的功率放大器。4G 的解決方案如功率回退，單載波分頻多工 (Single Carrier Frequency Division Multiplexing) 將不再滿足物聯網場景需求。本篇論文提出改良式帕波式（Papoulis-Gerchberg）演算法並結合軟性決策輔助，通過該演算法還原來自功率放大器的分線性失真，在發射端不增加任何系統功能方塊的情況下增進系統效能。在本篇模擬中，以 IEEE 802.11ah 標準，PGA 可在五次疊代內有效還原以加入相位失真的改良式固態功率放大器為模型的非線性雜訊。

With the well underway development, 5G (Fifth-Generation mobile networks) networks are expected to launch across the world by 2020. The networks will help rising the Internet of Things (IoT) technology, providing the infrastructure needed to carry huge amounts of data, allowing for a smarter and more connected world.
Due to the high spectrum efficiency and the strong resistance to the multi-path fading, OFDM (Orthogonal Frequency Division Multiplexing) was chosen as the waveform in the 5G (Fifth-Generation mobile networks) mobile communication. However, as a multi-carrier technique the high PAPR (Peak-to-Average Power Ratio) problem still remains. It requires sophisticated PA (Power Amplifier) or the higher power consumption in the system. The current solution in 4G such as IBO (Input Back Off), SC-FDM (Single Carrier Frequency Division Multiplexing) will not satisfied in the IoT scenario.
This paper proposed an improved Papoulis-Gerchberg algorithm (PGA) with soft decision to enhance the performance at the receiver for the nonlinear noise from PA with no additional function block at the transmitter.
In the simulation verification, PGA can effectively restore nonlinear noise from modified SSPA (Solid State Power Amplifiers) with phase distortion within five iterations on the IEEE 802.11ah standard which is a long range and lower power version for Wi-Fi published in 2017.

目錄
誌謝 i
摘要 ii
ABSTRACT iii
圖目錄 vi
表目錄 ix
第壹章 緒論 1
1.1 研究背景與動機 1
1.2 研究目標 2
1.3 本文架構 2
第貳章 文獻探討與背景知識 3
2.1各標準裝置壽命比較 3
2.2 正交分頻多工(OFDM) 4
2.3峰均值功率比 (PAPR) 8
2.4高峰均值功率比解決辦法 9
2.4.1 裁切法(Clipping) 9
2.4.2 壓擴法(Companding) 10
2.4.3 預編碼(Precoding) 11
2.4.4 功率回退法(IBO) 12
2.4.5 預失真法(Digital Predistortion) 13
2.3.6 最大似然法則法(Maximum-Likelihood Detection) 14
2.4 小結 14
第参章 改良式帕波式演算法 15
3.1 帕波式演算法(Papoulis-Gerchberg Algorithm) 15
3.2決策輔助演算法(Decision-aided Reconstruction) 17
3.3 改良式硬性決策帕波氏疊代演算法 18
3.3.1失真訊號初值及更新設定 18
3.3.2改良式硬性決策輔助及低通濾波 19
3.3.3還原步驟以及系統方塊圖 21
3.4 小結 23
第肆章 系統模擬 24
4.1 系統模組 24
4.1.1 IEEE 802.11ah 24
4.1.2改良式固態功率放大器模型 25
4.1.3誤差向量幅度 27
4.2 模擬結果與分析 29
4.2.1 頻譜分析 30
4.2.2 原始演算法之EVM還原效果 30
4.2.3提出演算法之EVM還原效果 33
4.2.3最佳還原位置分析及BER表現比較 35
4.4 小結 39
第陸章 結論 40
參考文獻 41

[1]IMT-2020 (5G) Promotion Group. (Feb. 2015). IMT-2020(5G) PG-WHITE PAPERN 5G CONCEPT. http://www.imt-2020.org.cn/en/docu-ments/download/25.
[2]Y. Wu and Z. Y. William, “Orthogonal frequency division multiplexing: A multi-carrier modulation scheme,” IEEE Trans. Consumer Electronics, vol. 41, no. 3, pp. 392–399, Aug. 1995.
[3]F. H. Raab et al., “Power amplifiers and transmitters for RF and microwave,” IEEE Trans. Microw. Theory Techn., vol. 50, no. 3, pp. 814–826, Mar. 2002.
[4]E. Morin, M. Maman, R. Guizzetti, and A. Duda, “Comparison of the Device Lifetime in Wireless Networks for the Internet of Things,” IEEE Access, vol. 5, pp. 7097–7114, 2017.
[5]C.-P. Liang, J.-H. Jong, W. Stark, and J. East, “Nonlinear amplifier effects in communications systems,” IEEE Trans. Microw. Theory Tech., vol. 47, pp. 1461–1466, Aug. 1999.
[6]L. Cho et al, “When UUDN meets 5G waveforms: New challenge of signal linearity?,” Int. Conf. on Applied System Innovation (ICASI), Sapporo, Japan, July, 2017.
[7]J. Joung, C. K. Ho, K. Adachi, and S. Sun, “A survey on power-amplifiercentric techniques for spectrum- and energy-efficient wireless communications,” IEEE Commun. Surveys Tuts., vol. 17, no. 1, pp. 315–333, 1st Quart. 2015.
[8]J. Armstrong, “New OFDM peak-to-average power reduction scheme,” Proc. IEEE, VTC2001 Spring, Rhodes, Greece, 2001
[9]S. Kimura, T. Nakamura, M. Saito and M. Okada, “PAR reduction for OFDM signals based on deep Clipping,” 3rd International Symposium on Communications, Control and Signal Processing, pp. 911 - 916, Mar. 2008.
[10]J. Armstrong, “Peak-to-average power reduction for OFDM by repeated clipping and frequency domain filtering,” Electron. Lett., vol. 38, no.5, pp. 246–247, Feb. 2002.
[11]X. Li and L. J. Cimini, Jr., “Effects of clipping and filtering on the performance of OFDM,” IEEE Commun. Lett., vol. 2, no. 5, pp. 131–133, May 1998.
[12]H. Saedi, M. Sharif and F. Marvasti, “Clipping noise cancellation in OFDM systems using oversampled signal reconstruction,” IEEE Commun. Lett., vol. 6, no. 2, pp.73–75, 2002.
[13]H.Chen and M. Haimovish, “Iterative Estimation and Cancellation of Clipping Noise for OFDM Signals,” IEEE Commun. Lett., vol. 7, no. 7, pp. 305–307, July 2003.
[14]N. Bibi and B. Cheetham, “Clipping noise mitigating iterative receivers for ofdm,” IEEE Int. Conf. on Networked Embedded Systems for Every Application, pp. 1–5, 2012.
[15]D. Kim and G. L. Stüber, “Clipping noise mitigation for OFDM by decision-aided reconstruction,” IEEE Commun. Lett., vol. 3, no. 1, pp. 4–6, Jan. 1999.
[16]F. Yang, J. Gao, S. Liu, and J. Song, “Clipping noise elimination for OFDM systems by compressed sensing with partially aware support,” IEEE Trans. Broadcast., vol. 63, no. 1, pp. 103–110, Mar. 2017.
[17]T. Jiang, Y. Yang, and Y. Song, “Exponential companding transform for PAPR reduction in OFDM systems,” IEEE Trans. Broadcast., vol. 51, no. 2, pp. 244–248, June, 2005.
[18]T. Jiang, W. Xiang, P. C. Richardson, D. Qu, and G. Zhu, “On the nonlinear companding transform for reduction inPAPR of MCM signals,” IEEE Trans. Wireless Commun., vol. 6, no. 6, pp. 2017–2021, June 2007.
[19]Y. Rahmatallah, N. Bouaynaya, and S. Mohan, "Bit-error-rate performance of companding transforms for OFDM," IEEE Trans. Veh. Technol., vo1.62, no.8, pp. 4116-4120, Oct. 2013.
[20]S. Mazahir and S. A. Sheikh, “On companding schemes for PAPR reductionin OFDM systems employing higher order QAM,” IEEE Trans. Broadcast., vol. 62, no. 3, pp. 716–726, Jan. 2016.
[21]M. Noune and A. Nix, “Frequency-domain precoding for single carrier frequency-division multiple access,” IEEE Commun., vol. 47, no.6, pp.68–74, May, 2009.
[22]X .Zhu, G. Zhu and T. Jiang, “Reducing the peak-to-average power radio using unitary matrix transformation,” IET Commun., vol. 2, no. 2, pp. 161–171, 2009.
[23]C. Y. Hsu and H. C. Liao, “Generalised precoding method for PAPR reduction with low complexity in OFDM systems,” IET Commun., pp.796-808, May 2018.
[24]L. Cho, H.C. Liao and C. Y. Hsu, “Adjustable PAPR reduction for DFT-s-OFDM via improved General Precoding scheme,” IET Electron. Lett., Vol. 54, no. 14, p. 903 – 905, July, 2018
[25]O. A. Gouba and Y. Louet “Theoretical analysis of the trade-off between efficiency and linearity of the High Power Amplifier in OFDM context,” European Wireless 2012, Poznan, Poland, Apr. 2012.
[26]R. Baxley and G. T. Zhou, “Power savings analysis of peak-to-average power ratio in OFDM,” IEEE Trans. Consum. Electron., vol. 50, no. 3, pp. 792–798, Oct. 2004.
[27]W. J. Kim, S. P. Stapleton, J. H. Kim, and C. Edelman, “Digital predistortion linearizes wireless power amplifiers,” IEEE Microw. Mag., vol. 6, no. 3, pp. 54–61, Sep. 2005.
[28]M. R. Beikmirza, A. Mohammadi and R. Mirzavand, "Power amplifier linearisation using digital predistortion and multi-port techniques," IET Science, Measurement & Technology, vol. 10, no. 5, pp. 467-476, July, 2016.
[29]J. Tellado, L. M. C. Hoo, and J. M. Cioffi, “Maximum-likelihood detection of nonlinearly distorted multicarrier symbols by iterative decoding,” IEEE Trans. Commun, vol. 51, no. 2, pp. 218–228, Feb. 2003.
[30]J. Guerreiro, R. Dinis, and P. Montezuma, “Optimum and sub-optimum receivers for OFDM signals with strong nonlinear distortion effects,” IEEE Trans. Commun., vol. 61, no. 9, pp. 3830–3840, Sep. 2013.
[31]H. Ochiai, “Performance of optimal and suboptimal detection for uncoded OFDM system with deliberate clipping and filtering,” in Proc. of the Global Telecommunications Conf., 2003. GLOBECOM ’03, San Francisco, CA, USA, pp.1618–1622, Dec. 2003.
[32]D. Papailiopoulos and G. Karystinos, “Near ml detection of nonlinearly distorted ofdm signals,” in the 41th Asilomar Conf. on Signals, Systems and Computers, pp. 1756–1760, Nov. 2007.
[33]R. W. Gerchberg, “Super resolution through error energy reduction,” Opt. Acta, vol. 21, no. 9, pp. 709-720, 1974.
[34]A. Papoulis, “A new algorithm in spectral analysis and band-limited extrapolation,” IEEE Trans. Circuits, Syst., vol. 22, no. 9, pp. 735-742, Sept. 1975.
[35]L. Cho et al, “The Convergence Analysis of Extended Papoulis-Gerchberg Algorithm on AWGN-Smeared Signals,” IEEE Int. Conf. on Applied System Innovation, Chiba, Tokyo, Japan, Apr. 2018.
[36]C.-H. Ting, The Mitigation of HPA’s Nonlinear Effect on OFDM Signals via Papoulis-Gerchberg Algorithm, M.S. thesis, graduate institute of Commun. Eng., Tatung University, Taipei, Taiwan, 2017.
[37]P. Ferreira, “Interpolation and the discrete Papoulis-Gerchberg algorithm,” IEEE Trans. Signal Process., vol. 42, pp. 2596-2606, Oct.1994.
[38]IEEE Standard for Information technology-Telecommunications and information exchange between systems - Local and metropolitan area networks--Specific requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 2: Sub 1 GHz License Exempt Operation, IEEE Std 802.11ah, 2016.
[39]M. Honkanen and S. G. Haggman, “New aspects on nonlinear power amplifier modeling in radio communication system simulations,” Proc. IEEE Int. Symp. Pers., Indoor Mobile Radio Commun. (PIMRC), vol. 3., pp. 844–848, Sep. 1997.
[40]P. Baneli, G. Baruffa and S. Cacopardi,“Effects of HPA Nonlinearity on Frequency Multiplexed OFDM Signals,” IEEE Trans. Broadcast., vol. 47,no. 2, pp.123-136, June , 2001,.
[41]E. Costa and S. Pupolin, “M-QAM-OFDM System Performance in the Presence of a Nonlinear Power Amplifier and Phase Noise,” IEEE Trans. Commun., vol. 50, no. 3 pp. 462–72., Mar. 2002
[42]C. Dudak and N. D. Kahyaoglu,“A Descriptive Study on AM-AM and AM-PM Conversion Phenomena Through EVM-SNR Relation,” IEEE Topical Conf. on Power Amplifiers for Wireless and Radio Applications (PAWR), April, 2012.
[43]P. O. Fisher and S. F. Al-Sarawi, “Analog RF predistorter simulation using well-known behavioral models,” IEEE 10th Conf. on Industrial Electronics and Applications (ICIEA), Nov, 2015.
[44]P. O. Fisher and S. F. AI-Sarawi, "Improving the Accuracy of SSPA Device Behavioral Modeling," Int. Conf. on Information and Communication Technology Research (ICTRC), Abu Dhabi, May 2015.
[45]L. Cho et al, “Green OFDM for IoT: Minimizing IBO Subject to a Spectral Mask,” IEEE Int. Conf. on Applied System Innovation, Chiba, Tokyo, Japan, Apr. 2018.