放大轉送中繼站網路正交分頻多工通道估測技術

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研究生：	莊文雄 Wen-hsiung Chuang
論文名稱：	放大轉送中繼站網路正交分頻多工通道估測技術 OFDM Channel Estimation Techniques for Amplify-and-Forward Relay Networks
指導教授：	林嘉慶 Jia-Chin Lin
口試委員:
學位類別：	碩士 Master
系所名稱：	資訊電機學院 - 通訊工程學系 Department of Communication Engineering
畢業學年度：	99
語文別：	英文
論文頁數：	49
中文關鍵詞：	放大轉送中繼站網路、通道估測
外文關鍵詞：	channel estimation, AF relay networks
相關次數：	點閱：8 下載：0
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近年來，由於合作式通訊技術可以提供空間分集，並且在無線通訊上能夠有效降低通道衰減的影響而不增加行動裝置的複雜度，因此受到許多重視。合作式通訊的概念主要是多用戶將他們的資源做整合，透過閒置的行動裝置作為中繼站，幫助傳送端傳送資料，這種中繼站網路形成一個分散式的虛擬天線陣列。然而，高資料傳輸率的正交分頻多工技術需要通道狀態資訊。因此，在合作式通訊藉由正交分頻多工的通道估測將會是一項挑戰。在假設所有節點之間的通道都為暫態穩態並為平坦衰減的前提之下，我們的估測方式是在放大前傳的中繼站網路中，將原本串接的傳送端到中繼站再到接收端連線的通道狀態資訊拆解成從傳送端到中繼站以及中繼站到接收端。並介紹通道估測的方法，如：最小平方以及最小均方誤差的演算法，做出一些比較以及討論

Cooperative communications have been interesting popularity recently since spatial diversity can be provided so as to mitigate fading over wireless transmission without hardware complexity of mobile devices. Multiple users pool their resources form a virtual antenna array that realizes spatial diversity gain in distributed fashion. However, high data rate transmission with orthogonal frequency division multiplexing (OFDM) requires the channel state information (CSI), and therefore OFDM channel estimation for cooperative communication can be a challenging problem. Consider that all channels between each node are assumed to be quasi-stationary frequency-flat fading. We use a channel estimation scheme for destination to disintegrate the CSIs of source to relay (S-R) link and relay to destination (R-D) link from the cascaded S-R-D link in amplify-and-forward (AF) relay networks. The channel estimation error of the proposed scheme is also analyzed. Especially, least square (LS) algorithm and minimum mean square error (MMSE) algorithm for the CSI estimation of source to destination and relay to destination link are compared.

Contents
Abstract  i
List of Figures  vi
List of Tables  vii
Chapter 1 Introduction 1
1 Background 1
2 Motivation 2
3 Organization 3
Chapter 2 Channel Characteristics 4
1 Introduction 4
2 AWGN channel model 4
3 Large scale fading 5
3.1 Path loss 5
3.2 Shadowing 6
4 Small scale fading 7
4.1 Multipath channel model 9
4.2 Channel autocorrelation function 9
4.3 Coherence bandwidth of the channel 11
4.4 Coherence time of the channel 11
4.5 Categories of small-scale fading 12
5 Rayleigh fading channel model 14
5.1 Channel mathematical models 15
Chapter 3 Relay-based Cooperative Communication Systems  17
1 Cooperative communication 17
2 System model 17
2.1 Signal models in AF relay networks  19
2.2 Discussion for AF signal models 23
3 Overview of OFDM systems 24
3.1 The concept of OFDM 24
3.2 Generation of subcarriers using the IFFT 25
3.3 Guard time and cyclic prefix 27
Chapter 4 Channel estimation and simulation results 29
1 Pilot signal arrangement 29
1.1 Common pilot arrangement 29
1.2 Two major pilot arrangements 30
2 Pilot estimation techniques 32
2.1 Frequency domain least-squares (LS) pilot channel estimation 33
2.2 Frequency domain linear minimum mean square error (MMSE) pilot channel estimation 34
2.3 Time-domain least-squares channel estimation 35
2.4 Linear interpolation channel estimation 36
3 Relay network channel estimation 37
3.1 Relay network diversity combining 38
4 Simulation results 40
Chapter 5 Conclusions 46
Bibliography 47

                                

Bibliography
[1] J. Laneman, D. Tse, and G. Womell, "Cooperative diversity in wireless networks: Efficient protocols and outage behavior~" IEEE Trans. Inform. Theory, vol. 50, no. 12, pp. 3062-3080, December 2004.
[2] A. Sendonaris, E. Erkip, and B. Aazhang, "User Cooperation Diversity. Part I and II,," IEEE Trans. Commun, vol. 51, no. 11, pp. 1927-1948, November 2003.
[3] A. K. Sadek, W. Su and K. J. Ray Liu, "Multinode cooperative communications in wireless networks ," IEEE Trans. on Signal Processing. vol. 55, nl, pp. 341-355, Jan. 2007.
[4] Nosratinia and A. Hedayat, “Cooperative communication in wireless networks,” IEEE Commun. Mag., vol. 42, no. 10, pp. 74–80, Oct. 2004.
[5] D. Tse and P. Viswanath, Fundamentals of Wireless Communication. Cambridge University Press, 2005.
[6] T. S. Rappaport, Wireless Communications: Principles and Practice, 2nd ed. Englewood Cliffs, NJ: Prentice-Hall, 1996.
[7] C. Y. Lee, Mobile Communications Design Fundamental, 2nd ed. New York: John Wiley & Sons, 1993.
[8] X. Liu, S. S. Mahal, A. Goldsmith, and J. K. Hedrick, “Effects of communication delay on string stability in vehicle platoons,’’ in Proc. IEEE Internet. Conf. Intell. Transp. Syst., pp. 625-30, August 2001.
[9] Nosratinia and A. Hedayat, “Cooperative communication in wireless networks,” IEEE Commun. Mag., vol. 42, no. 10, pp. 74–80, Oct. 2004.
[10] R. U. Nabar, H.Bolcskei, and F. Kneubuhler, “Fading relay channels: Performance limits and space-time signal designs,” IEEE J. Select. Areas Commun., vol. 22, no. 6, pp. 1099-1109, Aug. 2004.
[11] J. N. Laneman and G. W.Wornell, “Distributed space-time-coded protocols for exploiting cooperative diversity in wireless networks,” IEEE Trans. Inf. Theory, vol. 49, no. 10, pp. 2415–2425, Oct. 2003.
[12] C. S. Patel, G. L. Stüber, and T. G. Pratt, “Statistical properties of amplify and forward relay channels,” IEEE Trans. Veh. Technol., vol. 55,no. 1, pp. 1-9, Jan. 2006.
[13] Chirag S. Patel and Gordon L. Stuber, "Channel Estimation for Amplify and Forward Relay Based Cooperation Diversity Systems, " IEEE Trans. Wireless Commun. , vol. 6, pp. 2348-2356, Jun. 2007.
[14] S. Yang and J.-C. Belfiore, “Optimal space–time codes for the MIMO amplify-and-forward cooperative channel,” IEEE Trans. Inf. Theory, vol. 53, pp. 647–663, Feb. 2007.
[15] C. T. K. Ng, J. N. Laneman, and A. J. Goldsmith, “The role of SNR in achieving MIMO rates in cooperative systems,” in Proc. IEEE Information Theory Workshop, 2006.
[16] M. Yuksel and E. Erkip, “Multiple-antenna cooperative wireless systems: A diversity multiplexing tradeoff perspective,” IEEE Trans. Inf. Theory, vol. 53, no. 10, pp. 3371–3393, Oct. 2007.
[17] S. K. Jayaweera, “A virtual MIMO-based cooperative communications architecture for energy-constrained wireless sensor networks,” IEEE Trans. Wireless Commun., 2004, submitted.
[18] R. V. Nee, R. Prasad. OFDM for Wireless Multimedia Communications. Boston: Artech House, 2000.
[19] J.-C. Lin, “Least-squares channel estimation assisted by self-interference cancellation for mobile PRP-OFDM applications,” IET Commun., vol. 3, iss. 12, pp.1907-1918, Dec. 2009.
[20] J.-C. Lin, “Channel estimation assisted by postfixed pseudo-noise sequences padded with zero samples for mobile orthogonal-frequency-division- multiplexing communications,” IET Commun., vol. 3, iss. 4, pp. 561-570, Apr. 2009.
[21] B. Karakaya and H. Arslan. “Channel estimation for LTE uplink in high Doppler spread,” in Proc. WCNC, pp. 1126-1130, Mar. 2008.
[22] Y. Zhao and A. Huang, “A novel channel estimation method for OFDM mobile communication systems based on pilot signals and transfer-domain processing, ” in Proc. VTC, May 1997, pp. 2089-2093.
[23] J.-C. Lin, “Least-squares channel estimation for mobile OFDM communication on time-varying frequency-selective fading channels,” IEEE Trans. Vehic. Technol., vol. 57, no. 6, pp. 3538-3550, Nov. 2008.
[24] J.-J. van de Beek, O. Edfors, M. Sandell, S. K. Wilson, and P. O. Borjesson, “On channel estimation in OFDM systems,” in Proc. VETEC, Jul. 1995, vol. 2, pp.815-819.
[25] M. K. mehmet and H. Arslan, “Channel estimation for wireless OFDM systems,” Commun. Surveys Tuts., vol. 9, no. 2, pp. 18-48, 2nd quarter 2007.
[26] S. Coleri, M. Ergen, A. Puri, and A. Bahai, “Channel estimation techniques based on pilot arrangement in OFDM systems, ” IEEE Trans. Broacast., vol 48, no. 3, pp. 223-229, Sep. 2002.
[27] H. Shin and J. B. Song, “MRC analysis of cooperative diversitywith fixed-gain relays in Nakagami-m fading channels," IEEE Trans. Wireless Commun., vol. 7, no. 6, pp. 2069-2074, June 2008.
[28] Y. Zhao, R. Adve, and T. J. Lim, “Symbol error rate of selection amplify and-
forward relay systems," IEEE Commun. Lett., vol. 10, pp. 757-759, Nov. 2006.

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