使用多根天線的無線通訊系統可以達到高頻寬效率，因此自二十世紀末以來，一直是熱門的研究主題，而其中，空間調變一次只使用一根天線傳送訊號，避免了傳送天線間的同步和干擾問題，而相差空間調變是一種不需要前導訊號和通道估測的空間調變技術。在剛被接受的論文裡，我們提出了低複雜度的相差空間調變，而在本兩年期研究計畫裡，我們將對相差空間調變進行更深入的研究。在本計畫的第一年，我們將研究各種增加多樣性的相差空間調變。藉由適當地設計複數天線索引矩陣和區塊碼，可以達到所需的多樣性數值。另一方面，在基地台裝設數百支以上天線之大規模多天線技術，已引起學術界和產業界很大的研究熱潮。目前的相差空間調變方法因為太過複雜，還無法用於大規模多天線。在本計畫的第二年，我們將研究極低複雜度的相差空間調變架構，使其能適用於大規模多天線系統。 ;Wireless communication systems equipped with multiple antennas can achieve high spectral efficiency, so it has been a hot research topic since the late 20th century. Among various multi-antenna techniques, spatial modulation (SM) uses a single antenna for transmission each time to avoid synchronization and interference among transmitter antennas. Differential SM (DSM) is a kind of SM technique which does not need pilot symbols and channel estimation. In our paper which was accepted recently, we propose low-complexity DSM. In this two-year project, we will do more advanced research on DSM. In the first year, we will research on increased-diversity DSM. By appropriately designing complex-valued antenna-index matrix and block codes, the desired diversity order can be achieved. On the other hand, massive multiple-input multiple-output (MIMO) systems where the base station is equipped with hundreds of antennas have attracted much attention in recent years. Existing DSM schemes are too complicated to be realized for massive MIMO systems. In the second year, we will research on extremely-low-complexity DSM which is suitable for massive MIMO systems.
