相差空間調變是一種一次只使用一根天線傳送訊號的多天線技術，藉由選擇傳送天線可以多傳額外的資料位元，並避免前導(pilot)訊號的浪費。而當相差空間調變延伸為廣義相差空間調變時，每次傳輸則會使用多於一根的傳送天線。
在本篇論文，我們提出兩種方法來增加廣義相差空間調變的多樣性。第一種方式是一次使用四根天線，有別於以往一次使用兩根天線，可再增加傳送多樣性。第二種方法是通過適當地設計區塊碼和複數天線索引矩陣，實現所期望的傳送多樣性。對於這兩種方法，我們也在相差空時調變上使用了符元交錯，可以擁有更高的資料傳輸速率。

Differential spatial modulation (DSM) is a multi-antenna technique that uses only one antenna to transmit signals at a time and avoids pilot overhead. By selecting the transmitting antenna, additional data bits can be transmitted. DSM is extended to generalized DSM (GDSM) where more than one transmit antennas are activated each time.
In this paper, we propose two schemes to increase the transmit diversity of generalized differential spatial modulation. The first scheme is to use four antennas at a time, which is different from using two antennas at a time in the past, which can increase the transmit diversity. The second scheme is to appropriately design the block code and complex antenna index matrix to achieve the transmit diversity we except. For these two schemes, we also use symbol interleaving in differential space-time modulation, which can have a higher data transmission rate.

[1] R. Mesleh, H. Haas, S. Sinanovic, C. Ahn, and S. Yun, “Spatial modulation,” IEEE Trans. Veh. Technol., vol. 57, no. 4, pp. 2228–2242, Jul. 2008.
[2] J. Jeganathan, A. Ghrayeb, and L. Szczecinski, “Spatial modulation: Optimal detection and performance analysis,” IEEE Commun. Lett., vol. 12,no. 8, pp. 545–547, Aug. 2008.
[3] J. Jeganathan, A. Ghrayeb, L. Szczecinski, and A. Ceron, “Space shift keying modulation for MIMO channels,” IEEE Trans. Wireless Commun.,vol. 8, no. 7, pp. 3692–3703, Jul. 2009.
[4] M. Renzo, H. Haas, and P. Grant, “Spatial modulation for multiple-antenna wireless systems: A survey,” IEEE Commun. Mag., vol. 49,no. 12, pp. 182–191, Dec. 2011.
[5] S. Sugiura, S. Chen, and L. Hanzo, “A universal space-time architecture for multiple-antenna aided systems,” IEEE Commun. Surveys & Tutorials,vol. 14, no. 2, pp. 401–420, May 2012.
[6] P. Yang, M. D. Renzo, Y. Xiao, S. Li and L. Hanzo, “Design guidelines for spatial modulation,” IEEE Commun. Surveys & Tutorials, vol. 17, no. 1, pp. 6-26, First Quarter 2015.
[7] Y. Bian, X. Cheng, M. Wen, L. Yang, H. V. Poor, and B. Jiao,“Differential spatial modulation,” IEEE Trans. Veh. Technol., vol. 64,no. 7, pp. 3262-3268, Jul. 2015.
[8] N. Ishikawa and S. Sugiura, “Unified differential spatial modulation,”IEEE Wireless Commun. Lett., vol. 3, no. 4, pp. 337-340, Aug. 2014.
[9] A. G. Helmy, M. D. Renzo, and N. Al-Dhahir, “Differential spatially modulated space-time block codes with temporal permutations,” IEEE Trans. Veh. Technol., vol. 66, no. 8, pp. 7548-7552, Aug. 2017.
[10] L. Xiao, Y. Xiao, P. Yang, J. Jiu, S. Li, and W. Xiang, “Space-time block coded differential spatial modulation,” IEEE Trans. Veh. Technol., vol. 66, no. 10,pp. 8821-8834, Oct. 2017.
[11] S. M. Alamouti, “A simple transmitter diversity scheme for wireless communications,” IEEE J. Select. Areas Commun., vol. 16, pp. 1451-1458, Oct. 1998.
[12] B. L. Hughes, “Differential space-time modulation,” IEEE Trans. Inform.Theory, vol. 46, pp. 2567-2578, no. 7, Nov. 2000.
[13] B. M. Hochwald and W. Swelden, “Differential unitary space-time modulation,” IEEE Trans. Commun., vol. 48, pp. 2041-2052, Dec. 2000.
[14] R. Y. Wei and T. Y. Lin, “Low-complexity differential spatial modulation,”IEEE Wireless Commun. Lett., vol. 8, no. 2, pp. 356-359, Apr.2019.
[15] S. Sayegh, “A class of optimum block codes in signal space,” IEEE Trans. Commun., vol. 30, pp. 1043-1045, Oct. 1986.
[16] T. Kasami, T. Takata, T. Fujiwara and S. Lin, “On multilevel block modulation codes,” IEEE Trans. Inform. Theory, vol. 37, pp. 965-975, July 1991.
[17] 蔡譯偉, “相差空間調變的進階結果” 國立中央大學通訊工程研究所,碩士論文, 六月. 2019.
[18] 林育宏, “使用符元交錯DSTM的廣義相差空間調變” 國立中央大學通訊工程研究所,碩士論文, 六月. 2020.
[19] 陳式倫, “各種相差空間調變的進階結果” 國立中央大學通訊工程研究所,碩士論文, 六月. 2021.
[20] H.Jafarkhani“Space-Time Coding,”CAMBRIDGE UNIVERSITY PRESS.