In this thesis, we present Raptor-coded distributed unitary space-time modulation (USTM) schemes, in which neither the transmitter nor the receiver requires the knowledge of channel state information (CSI). Raptor code is a kind of rateless code with a variable code-rate since the transmitter progressively generates code bits until the receiver decodes the original information without error, regardless of channel conditions. We use the Raptor code to increase the maximum achievable rate of the system. A noncoherent maximum a posteriori (MAP) detector for the distributed USTM scheme is devised, and the related elaying strategies are also investigated. It is shown that the decode-and-forward (DF) protocols outperform the amplied-andforward (AF) protocol for the proposed distributed USTM scheme using Raptor codes, and is shown to be more robust to the variation of locations for the relay nodes.

在這個論文中，我們提出了使用速龍編碼 (Raptor-coded)的分散式么正空時調變(DUSTM) 架構。在這個分散式架構中，傳送端與接收端和中繼端 (relay)並不需要知道實際的通道狀況便可進行通訊。無碼率編碼包括了噴泉碼 (Fountain code)、盧比轉換碼 (Luby Transform Codes or LT Codes) 和速龍碼 (Raptor code)。這些通道編碼方式基於原始設計概念，使得其傳送端在任何通道狀況下皆會持續編碼並送出至接收端一直到接收端成功解碼，因此具有可變碼率的特性。我們使用無碼率編碼的目的是為了增加系統所的最大可達率 (achievable rate)並可避免通道偵測，以非同調的方法實現。而對於這個分散式的架構，我們研究並改變了原始么正空時調變結構和其非同調的最大事後機率 (maximum a posteriori, MAP) 檢測器並且安排了與之相關的中繼 (relaying protocol)傳送策略，包括解碼前送 (Decode-and-Forward, DF)和放大前送 (Amplify-and-Forward, AF)。在模擬結果中顯示，此分散式的架構系統內，中繼端的傳送策略若使用解碼前送協定 (DF)所造成的系統效能將會勝過使用放大前送協定 (AF)的系統效能，而且當中繼位置產生變化時，解碼前送協定 (DF)亦會具有較佳的結果相對於放大前送協定 (AF)的系統效能。

[1] S. M. Alamouti, "A simple transmitter diversity scheme for wireless communications," IEEE J. Select. Areas Commun., vol. 16, pp. 1451-1458, Oct. 1998.
[2] V. Tarokh, H. Jafarkhani, and A. R. Calderbank, "Space-time block codes for orthogonal designs," IEEE Trans. Inform. Theory, vol. 49,pp. 1456-1467, July 1999.
[3] A. Ashikhmin, G. Kramer, and S. ten Brink, "Design of low-density parity-check codes for modulation and detection," IEEE Trans. Commun., vol. 52, no. 4, pp. 670-678, Apr. 2004.
[4] Y. L. Ueng, C. J. Yeh, M. C. Lin, and C. L. Wang, "Turbo codedmultiple-antenna systems for near-capacity performance," IEEE J. Select. Areas Commun., vol. 27, no. 6, pp. 954-964, Aug. 2009.
[5] A. Stefanov and T. M. Duman, "Turbo-coded modulation for systems with transmit and receive antenna diversity over block fading channels:system model, decoding approaches, and practical considerations,"IEEE J. Select. Areas Commun., vol. 19, pp. 958-968, May 2001.
[6] Y. L. Ueng, Y. M. Chen, and J. Y. Lin, "A MIMO-BICM scheme using a convolutional interleaver for delay-sensitive applications," IEEE Trans.Vehicular Technology, vol. 59, no. 5, pp. 2380-2393, June 2010.
[7] B. M. Hochwald and T. L. Marzetta, "Unitary space-time modulation for multiple-antenna communications in Rayleigh
at fading," IEEE Trans.Inform. Theory, vol. 46, pp. 2041-2052, Mar. 2000.
[8] B. M. Hochwald, T. Marzetta, T. J. Richardson, W. Sweldens, and R.L. Urbanke, "Systematic design of unitary space-time constellations,"
IEEE Trans. Inform. Theory, vol. 46, no. 6, pp. 1962-1973, Sept. 2000.
[9] I. Bahceci and T. M. Duman, "Combined turbo coding and unitary space-time modulation," IEEE Trans. Commun., vol. 50, no. 8,
pp. 1244-1249, Aug. 2002.
[10] N. H. Tran, H. H. Nguyen, and T. Le-Ngoc, "Coded unitary space-time modulation with iterative decoding: Error performance and mapping design," IEEE Trans. Commun., vol. 55, no. 4, pp. 703-716, Apr. 2007.
[11] Y. M. Chen and Y. L. Ueng, "Turbo coded noncoherent space-time modulation using information-bearing pilots and spatial multiplexing," to appear in IEEE Trans. Commun., vol. 61, no. 6, June 2011.
[12] A. Sendonaris, E. Erkip, and B. Aazhang, "User cooperation diversity -part I & II," IEEE Trans. Commun., vol. 51, pp. 1927-1948 Nov. 2003.
[13] J. N. Laneman, D. N. C. Tse, and G. W.Wornell, "Cooperative diversity in wireless networks: Ecient protocols and outage behavior," IEEE Trans. Inf. Theory, vol. 50, no. 12, pp. 3062-3080, Dec. 2004.
[14] J. N. Laneman and G. W.Wornell, "Distributed space-time-coded protocols for exploiting cooperative diversity in wireless networks," IEEE Trans. Inform. Theory, vol. 49, no. 10, pp. 2415-2425, Oct. 2003.
[15] S. Yiu, R. Schober, and L. Lampe, "Distributed space-time block coding," IEEE Trans. Commun., vol. 54, no. 7 pp. 1195-1206, July 2006.
[16] T. Wang, Y. Yao, and G. B. Giannakis, "Non-coherent distributed space-time processing for multiuser cooperative transmissions," IEEE Trans. Wireless Commun., vol. 5, no. 12, pp. 3339-3343, Dec. 2006.
[17] D. H. N. Nguyen, H. H. Nguyen, and H. D. Tuan, "Power allocation and error performance of distributed unitary space-time modulation in wireless relay networks," IEEE Trans. Vehicular Technology, vol. 58, no. 7, pp. 3333-3346, Sept 2009.
[18] M. Janai, A. Hedayat, T. E. Hunter, and A. Nosratinia, "Coded cooperation in wireless communications: Space-time transmission and iterative decoding," IEEE Trans. Signal Processing, vol. 52, no. 2, pp. 362-371, Feb. 2004.
[19] Z. Zhang and T. M. Duman, "Capacity approaching turbo coding and iterative decoding for relay channels," IEEE Trans. Commun., vol. 53, pp. 1895-1905, Nov. 2005.
[20] M. Luby, "LT codes," in Proc. 43rd Annual IEEE Symposium Foundations Computer Science (FOCS), 2002, pp. 271-280.
[21] A. Shokrollahi, "Raptor codes," IEEE Trans. Inform. Theory, vol. 52, no. 6, pp. 2551-2567, June 2006.
[22] J. Castura and Y. Mao, "Rateless coding for wireless relay channels," IEEE Trans. Wireless Commun., vol. 6, no. 5, pp. 1638-1642, May 2007.
[23] G. Yu, C. Wang, Y. Zhang, and B. Li, "Performance of rateless codes in half-duplex collaborative relay networks" inProc. 12th IEEE Int. Conf. on Communication Technology (ICCT), Nanjing, China, pp. 971-974, Nov. 2010.
[24] O. Etesami and A. Shokrollahi, "Raptor codes on binary memoryless symmetric channels," IEEE Trans. Inform. Theory, vol. 52, no. 5,
pp. 2033-2051, May 2006.
[25] M. Uppal, G. Yue, X. Wang, and Z. Xiong, "A rateless coded protocol for half-duplex wireless relay channels," IEEE Trans. Signal Processing, vol. 59, no. 1, pp. 209-222, Jan. 2011.