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研究生:張家維
研究生(外文):Chang, Chia-Wei
論文名稱:ICIAwareK-BestMIMODetectionforFastFadingChannel
論文名稱(外文):用於快速變化通道中和正交分頻多工系統載波間互相干擾相關的K-Best球體解碼器
指導教授:吳仁銘
指導教授(外文):Wu, Jen-Ming
學位類別:碩士
校院名稱:國立清華大學
系所名稱:電機工程學系
學門:工程學門
學類:電資工程學類
論文種類:學術論文
畢業學年度:98
語文別:英文
論文頁數:59
中文關鍵詞:球體解碼
外文關鍵詞:K-Best Decoding
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The channel variation due to vehicle mobility produces time
selective fading among OFDM symbols. An OFDM symbol suffers from inter-carrier interference that severely degrades the performance in high vehicle mobility environment.
Traditional sphere decoding and K-Best decoding are suboptimal MIMO detections but still could not suit the high mobility environment well. To solve the problem, an
ICI cancellation method combing the ICI aware K-Best
decoding is proposed. Under the architecture of ICI cancellation, The proposed method considering both residual ICI and noise power gets better performance than that of the original adaptive K-Best decoding and do not need much complexity. As the analysis showed in the following, the proposed method has a trade off property easily finding how many subcarriers should be taken for ICI cancellation
most efficiently.
正交分頻多工(Orthogonal Frequency Division Multiplexing,OFDM)的技術已被廣泛應用在許多通訊系統上。然而在高速移動的環境下,無線傳輸的通道會符合時間選擇通道模型(Time-selective Channel Model),造成載波間的互相干擾(Inter-carrier Interference,ICI),使得載波之間失去正交性,若不補償此效應則會明顯的降低系統的良率。在系統架構很大的情況下,載波干擾消除(ICI Cancellation)是個不可避免的補償措施,然而載波干擾絕大部分都分佈在鄰近的載波上,因此對所有的載波干擾都消除並不是個明智的選擇。

K-Best球體解碼(K-Best Decoding)是一種近乎最佳解的解碼方法。適應性K-Best球體解碼(Adaptive K-Best Decoding)將環境中的雜訊考慮在演算法當中,但在高速移動的環境下良率還是不高。本篇論文中,我們提出和載波干擾相關的K-Best球體解碼(ICI Aware K-Best Decoding),結合載波干擾消除的架構,並將剩餘的載波干擾考慮進演算法中。利用此方法,可以有效的在高速移動環境下提升系統的良率。

在所提出的系統架構下,良率的表現會跟載波干擾消除的量的取捨有絕對性的關係,因為剩餘的載波干擾會被用來控制K的大小,影響解碼的準確性。最後我們利用此特性可以輕易的決定出使用硬體最有效率的載波干擾消除的量。
1 Introduction............................................1
2 ICI of OFDM System in Fast Fading Channel...............3
2.1 OFDM System Model...................................4
2.1.1 OFDM Basics.....................................4
2.1.2 OFDM Transmitter................................4
2.1.3 OFDM Receiver...................................5
2.2 Digital Implementation of OFDM System...............6
2.2.1 Cyclic Prefix...................................7
2.2.2 Digital Implementation with Cyclic Extension....9
2.3 Channel Model......................................10
2.3.1 Jake's Model...................................10
2.3.2 Modified Jake's Model..........................11
2.4 System Model.......................................12
2.4.1 ICI in OFDM System.............................13
3 Sphere Decoding and K-Best Decoding for MIMO Detection.15
3.1 Concept of Sphere Decoding.........................16
3.2 Algorithm of Sphere Decoding.......................17
3.3 Complex Sphere Decoding............................21
3.4 Concept of K-Best Decoding.........................24
3.5 Algorithm of K-Best Decoding.......................25
3.6 Sorted QR Decomposition............................26
4 Proposed ICI Aware K-Best MIMO Detection for Fast Fading
Channel................................................29
4.1 Adaptive K-Best Decoding with SNR estimation.......30
4.2 Adaptive K-Best Decoding without SNR estimation....30
4.3 Proposed ICI Aware K-Best Decoding.................32
5 Simulation Results.....................................35
5.1 The Simulation of Channel in Frequency Domain......36
5.2 K-Best Decoding with and without ICI Cancellation..37
5.3 Adaptive K-Best Decoding with SNR estimation.......40
5.4 Adaptive K-Best Decoding without SNR estimation....44
5.5 Proposed ICI Aware K-Best Decoding.................47
6 Conclusion.............................................55
[1] Weinstein, S., and Ebert, P., "Data Transmission by
Frequency-Division Multiplexing Using the Discrete
Fourier Transform," IEEE Transactions on
Communications, vol.19, pp.628-634, Oct.1971.
[2] Kwanghoon Kim, and Hyuncheol Park, "A Low Complexity
ICI Cancellation Method for High Mobility OFDM
Systems," IEEE Vehicular Technology Conference,
vol.5, pp.2528-2532, 2006.
[3] Xiaodong Cai, and G.B. Giannakis, "Bounding
performance and suppressing intercarrier interference
in wireless mobile OFDM," IEEE Transaction on
Communications, vol.51, pp.2047-2056, Dec.2003.
[4] Viterbo, E.; Boutros, J., "A universal lattice code
decoder for fading channels," IEEE Transactions on
Information Theory, vol.45, pp.1639-1642, July 1999.
[5] Damen, O.; Chkeif, A.; Belfiore, J.-C., "Lattice code
decoder for space-time codes," IEEE Communications
Letters, vol.4, pp.161-163, May 2000.
[6] K. W. Wong, "Reduced-complexity architectures of
symbol detection algorithms in MIMO channel," Thesis,
the Hong Kong University of Science and Technology,
August, 2001.
[7] K. W. Wong, C. Y. Tsui, R. S. K. Cheng, and W. H. Mow,
"A VLSI archetecture of a K-best lattice decoding
algorithm for MIMO channnels," in symposiac IEEE
Personal and Indoor Mobile Radio Communication
(PIMRC), 2002.
[8] Matsuda, H.; Honjo, K.; Ohtsuki, T., "Signal detection
scheme combining MMSE V-BLAST and variable K-best
algorithms based on minimum branch metric, IEEE
Vehicular Technology Conference,
vol.1, pp.19-23, Sept 2005.
[9] Kawai, H.; Higuchi, K.; Maeda, N.; Sawahashi, M.,
"Adaptive control of surviving symbol replica
candidates in QRM-MLD for OFDM MIMO multiplexing,"
IEEE Journal on Selected Areas in Communications,
vol.24, pp.1130-1140, June 2006.
[10] William. C. Jakes, "Microwave Mobile Communications,"
New York: Wiley, 1974.
[11] Dent, P.; Bottomley, G.E.; Croft, T., "Jakes fading
model revisited," IEEE Electronics Letters,
vol.29, pp.1162-1163, June 1993.
[12] Harmuth, H. F.; Lee, Joseph D., "Transmission of
Information by Orthogonal Functions," IEEE
Transactions on Systems, Man and Cybernetics,
vol.1, pp.188-188, April 1971.
[13] Kou, Y.J.; Lu, W.-S.; Antoniou, A., "Application of
sphere decoding in intercarrier-interference reduction
for OFDM systems," IEEE Pacific Rim Conference on
Communications, Computers and signal Processing,
pp.360-363, Aug 2005.
[14] Hassibi, B.; Vikalo, H., "On the expected complexity
of sphere decoding," IEEE the Thirty-Fifth Asilomar
Conference on Signals, Systems and Computers,
vol.2, pp.1051-1055, Nov 2001.
[15] Xinming Huang; Cao Liang; Jing Ma, "System
Architecture and Implementation of MIMO Sphere
Decoders on FPGA," IEEE Transactions on Very Large
Scale Integration (VLSI) Systems,
vol.16, pp.188-197, Feb 2008.
[16] Hochwald, B.M.; ten Brink, S., "Achieving near-
capacity on a multiple-antenna channel," IEEE
Transactions on Communications,
vol.51, pp.389-399, March 2003.
[17] Wubben, D.; Bohnke, R.; Rinas, J.; Kuhn, V.; Kammeyer,
K.D., "Efficient algorithm for decoding layered space-
time codes," IEEE Electronics Letters,
vol.37, pp.1348-1350, Oct 2001.
[18] Qingwei Li; Zhongfeng Wang, "Improved k-best sphere
decoding algorithms for MIMO systems," IEEE
International Symposium on Circuits and Systems,
pp.1159-1162, 2006.
[19] Bong-seok Kim; Kim, H.; Kwonhue Choi, "An Adaptive K-
best Algorithm without SNR Estimation for MIMO
Systems," IEEE Vehicular Technology Conference,
pp.817-821, May 2008.
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