臺灣博碩士論文加值系統

第四代無線通訊的長期演進技術進階版(Long Term Evolution-Advanced, LTE-Advanced)系統裡，上行系統採用擁有低峰均值功率比(Peak to Average Power Ratio, PAPR)特性的單載波分頻多重存取(Single carrier Frequency Division Multiple Access, SC-FDMA)，並使用LTE-Advanced標準裡的載波聚合(Carrier Aggregation, CA)技術來提升傳輸頻寬，以達到更高的傳輸速率。本文將原有SC-FDMA架構中，有預編碼功能的離散傅利葉轉換(Discrete Fourier Transform, DFT)改以離散小波轉換(Discrete Wavelet Transform, DWT)的方式來進行預編碼，藉此來降低位元錯誤率(Bit Error Rate, BER)，此架構被稱作小波轉換之單載波分頻多重存取技術(Wavelet SC-FDMA, W-SC-FDMA)，並以此系統為基礎加上CA技術來改良，使整體傳輸效益更加提升。
然而使用CA技術時，PAPR會隨著聚合的分量載波個數越多而持續上升，因此破壞了SC-FDMA本身帶來的低PAPR優點，故在本論文所使用改良為DWT預編碼之SC-FDMA中使用部分選擇性映射(Partial Selected Mapping, PSLM)的技術來降低PAPR，並假設接收端用來還原訊號的側訊息(Side Information, SI)為完美估測。方法的模擬上，除了原先參考文獻中降低PAPR的方法外，本論文另外提出新的降低PAPR架構，針對DWT所產生的近似組成(Approximation Component)中加入PSLM，以達到降低運算複雜度和PAPR。
在本論文當中，除了會探討常規SC-FDMA與W-SC-FDMA於不同通道模型、不同聚合總頻寬的BER效能模擬，也會針對加入降低PAPR技術後PAPR的效能模擬，並討論結果之間的差異變化與總結。

LTE-Advanced proposed carrier aggregation techniques which utilizes aggregated multiple carriers to increase the bandwidth and achieve high data rate. In practice, LTE-Advanced uplink systems adopt single carrier frequency division multiple access (SC-FDMA) which has a low Peak to Average Power Ratio (PAPR) characteristic. In order to lower the bit error rate, we used the Discrete Wavelet Transform(DWT) to replace conventional Discrete Fourier Transform this precoding operation in SC-FDMA. The system we used which named Wavelet SC-FDMA(W-SC-FDMA). In this thesis, we proposed a new system structure let W-SC-FDMA with Carrier Aggregation.
However, not only the conventional SC-FDMA but also the W-SC-FDMA system’s low PAPR characteristic will lose as the number of aggregated carriers are increasing. Therefore, we adopt the Partial Selected Mapping (PSLM) technique to reduce PAPR and discussed how to design the PSLM in Wavelet Transform structure. PAPR will reduce by multiplying phase factor which represents as the Side Information (SI) at the receiver. The receiver must have received the side information in order to recover the signal’s phase but as the SI were transmitted in system would decrease data rate because of the extra SI data.
To avoid this situation, our structure adopts Physical Uplink Shared Channel (PUSCH), its time slot structure includes reference symbol which can be used for channel estimation. Therefore, we use the reference symbol to substitute the SI to achieve without directly sending SI. And we also use reference symbol’s characteristics to estimate the phase factor and recover the signal’s phase by estimated phase. In this thesis, we chose five kinds of phase estimate methods and discussed in imperfect channel estimation in order to observe what would change in BER. Furthermore, as previous section we mentioned the W-SC-FDMA system, the new system structure with CA and lower PAPR methods; we will simulate the BER performance of new structure in different channel models, equalizers, different aggregation bandwidth and different number of aggregated carriers. Further, we compared the PAPR’s variation in original and new structure.

摘要 I
ABSTRACT II
致謝 III
目錄 IV
圖目錄 VI
表目錄 VIII
第1章 序論 1
1.1 研究動機與目的 1
1.2 論文架構 3
第2章 相關理論介紹與文獻回顧 4
2.1 長期演進技術進階版 4
2.1.1 單載波分頻多重存取 4
2.1.2 載波聚合 8
2.1.3 上行載波聚合架構 9
2.1.4 長期演進技術進階版通道模型 10
2.2 小波與多解析度處理 13
2.2.1 多解析度展開 14
2.2.2 縮放信號 14
2.2.3 小波信號 17
2.3 一維空間之小波轉換 21
2.3.1 小波級數展開 21
2.3.2 離散小波轉換 21
2.3.3 快速小波轉換 22
2.4 峰均值功率比 24
2.4.1 降低峰均值功率比方法介紹 25
2.4.2 降低載波聚合下的峰均值功率比方法介紹 26
2.5 不直接傳送側訊息之相位估測法 28
2.5.1 不直接傳送側訊息之相位估測的方法一 30
2.5.2 不直接傳送側訊息之相位估測的方法一修正型 31
2.5.3 不直接傳送側訊息之相位估測的方法二(b) 32
2.5.4 不直接傳送側訊息之相位估測的方法二修正型二 33
2.5.5 不直接傳送側訊息之相位估測的方法三 34
第3章 提出的系統架構 36
3.1 不完美通道估測與完美通道估測比較 36
3.2 小波轉換之單載波分頻多重存取技術與載波聚合系統 38
3.3 降低PAPR技術於小波轉換之單載波分頻多重存取與載波聚合系統 40
第4章 模擬結果與討論 43
4.1 不直接傳送側訊息方法於完美與不完美通道估測之BER效能 43
4.1.1 在AWGN通道之BER效能 44
4.1.2 在EPA通道之BER效能 46
4.1.3 在EVA通道之BER效能 48
4.2 W-SC-FDMA與SC-FDMA系統BER效能 51
4.3 W-SC-FDMA與SC-FDMA於載波聚合系統上之BER效能 53
4.3.1 聚合相同總頻寬於不同分量載波數之BER效能 55
4.3.2 聚合不同總頻寬於不同分量載波數之BER效能 57
4.4 W-SC-FDMA於載波聚合系統加入降低PAPR技術之PAPR效能 59
第5章 結論與未來研究方向 62
參考文獻 64

[1] Evolved Universal Terrestrial Radio Access (E-UTRA); Carrier Aggregation; Base Station (BS) radio transmission and reception, 3GPP TR 36.808, Jan, 2015.
[2] M. A. A. El-Hamed, M. I. Dessouky, F. Shawki, M. K. Ibrahim, S. El-Rabaie, and F. E. A. El-Samie, "C35. Wavelet-based SC-FDMA system," in 2012 29th National Radio Science Conference (NRSC), 2012, pp. 447-460.
[3] P. Yen and H. Minn, "Low complexity PAPR reduction methods for carrier-aggregated MIMO OFDMA and SC-FDMA systems," EURASIP Journal on Wireless Communications and Networking, vol. 2012, no. 1, pp. 1-13, 2012.
[4] S. H. Han and J. H. Lee, "An overview of peak-to-average power ratio reduction techniques for multicarrier transmission," IEEE wireless communications, vol. 12, no. 2, pp. 56-65, 2005.
[5] A. Ghosh, R. Ratasuk, B. Mondal, N. Mangalvedhe, and T. Thomas, "LTE-advanced: next-generation wireless broadband technology [Invited Paper]," IEEE Wireless Communications, vol. 17, no. 3, pp. 10-22, 2010.
[6] H. G. Myung and D. J. Goodman, Single Carrier FDMA : A New Air Interface for Long Term Evolution (Wireless Communications and Mobile Computing). Wiley, 2008.
[7] F. Pancaldi and G. M. Vitetta, "Block channel equalization in the frequency domain," IEEE Transactions on Communications, vol. 53, no. 3, pp. 463-471, 2005.
[8] Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation, 3GPP TS 36.211, Jul, 2015.
[9] M. Baker, S. Sesia, and I. Toufik, "LTE-The UMTS Long Term Evolution From Theory to Practice," ed: Chichester: John Wiley & Sons Ltd, 2011.
[10] R. Ratasuk, D. Tolli, and A. Ghosh, "Carrier Aggregation in LTE-Advanced," in 2010 IEEE 71st Vehicular Technology Conference, 2010, pp. 1-5.
[11] Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio transmission and reception, 3GPP TS 36.101, Nov, 2014.
[12] Evolved Universal Terrestrial Radio Access (E-UTRA); Base Station (BS) radio transmission and reception, 3GPP TS 36.104, Feb, 2015.
[13] Feasibility study for Further Advancements for E-UTRA (LTE-Advanced), 3GPP TR 36.912, Sep, 2015.
[14] T. S. Rappaport, Wireless Communications: Principles and Practice (2nd Edition). Prentice Hall, Jan. 2002.
[15] S. Adegbite, B. G. Stewart, and S. G. McMeekin, "Least Squares Interpolation Methods for LTE System Channel Estimation over Extended ITU Channels," International Journal of Information and Electronics Engineering, vol. 3, no. 4, July, 2013.
[16] S. Mallet, A Wavelet Tour of Signal Processing, 3rd ed., Third Edition:The Sparse Way, 3rd ed. Academic Press, 3 ed., 2008.
[17] R. C. Gonzalez and R. E. Woods, Digital Image Processing, 3rd ed. (Digital Image Processing). Pearson, 2007.
[18] L. Chun Lin, A tutorial of the Wavelet Transform. Taiwan: NTU EE, Feb 23, 2010.
[19] F. S. Al-kamali, M. I. Dessouky, B. M. Sallam, F. Shawki, and F. E. A. El-samie, "Transceiver scheme for single-carrier frequency division multiple access implementing the wavelet transform and peak-to-average-power ratio reduction methods," IET Communications, vol. 4, no. 1, pp. 69-79, 2010.
[20] F. E. A. El-Samie, F. S. Al-kamali, A. Y. Al-nahari, and M. I. Dessouky, SC-FDMA for Mobile Communications. CRC Press, 2014.
[21] S. H. Müller and J. B. Huber, "OFDM with reduced peak-to-average power ratio by optimum combination of partial transmit sequences," 1997.
[22] B. Robert, F. Robert, and B. Johannes, "Reducing the peak-to-average power ratio of multicarrier modulation by selected mapping," Electron. lett, vol. 32, pp. 2056-2057, 1996.
[23] L. Kewen and X. Ning, "PAPR reduction of uplink for carrier aggregation in LTE-Advanced," in The 2nd International Conference on Information Science and Engineering, 2010, pp. 2224-2226: IEEE.
[24] J. Armstrong, "Peak-to-average power reduction for OFDM by repeated clipping and frequency domain filtering," Electronics Letters, vol. 38, no. 5, pp. 246-247, 2002.
[25] Y. C. Yeah, "Study of phase detection techniques without directly sending side infomation in LTE-A uplink systems," EE, NTUST, Taiwan, Taipei, 2016.
[26] L. Wang, G. Wu, L. Dan, and Y. Xiao, "A Time-Domain PTS without Side Information in SC-FDMA Systems," in 2011 7th International Conference on Wireless Communications, Networking and Mobile Computing, 2011, pp. 1-4.
[27] S.-C. Huang, J.-C. Lin, and K.-P. Chou, "Novel channel estimation techniques on SC-FDMA uplink transmission," in Vehicular Technology Conference (VTC 2010-Spring), 2010 IEEE 71st, 2010, pp. 1-5: IEEE.
[28] H. Arslan, "Channel estimation for wireless OFDM systems," IEEE Surveys and Tutorials, vol. 9, no. 2, pp. 18-48, 2007.
[29] S. Galli, H. Koga, and N. Kodama, "Advanced signal processing for PLCs: Wavelet-OFDM," in 2008 IEEE International Symposium on Power Line Communications and Its Applications, 2008, pp. 187-192.
[30] S. Baig, Fazal-ur-Rehman, and M. J. Mughal, "Performance Comparison of DFT, Discrete Wavelet Packet and Wavelet Transforms, in an OFDM Transceiver for Multipath Fading Channel," in 2005 Pakistan Section Multitopic Conference, 2005, pp. 1-6.
[31] N. Kumar and Ishu, "BER Analysis in Wavelet Based SC-FDMA for LTE Uplink Transmission," in 2015 Fifth International Conference on Advanced Computing & Communication Technologies, 2015, pp. 437-440.
[32] Ishu and N. Kumar, "PAPR reduction in Wavelet based SC-FDMA using PTS scheme for LTE uplink transmission," in 2014 International Conference on Advances in Computing, Communications and Informatics (ICACCI), 2014, pp. 1810-1814.
[33] R. Jain, "Channel Models A Tutorial.," WiMAX Forum AATG, Feb. 2007.