相差空間調變是一種不需要前導訊號和通道估計的空間調變，但是相差空間調變原始所用的非同調最大可能性檢測器非常複雜。在本論文中，我們提出了兩個低複雜度之相差空間調變架構，其一是針對傳送多樣性為2的區塊編碼之相差空間調變，來降低解碼複雜度的改良設計；另一個則是改良了相差空間調變的位元映射，成為具有多個位元映射組，且仍保持全速率的相差空間調變。與原方法相比，採用我們提出之複雜度的架構後，均將能應用於更多傳送天線的系統，並且同時還改善了錯誤性能。其中對於區塊編碼之相差空間調變的設計可分為，降低複雜度的檢測器，以及與檢測器匹配的複數值天線索引矩陣，雖此檢測器之錯誤性能略差於非同調最大可能性檢測器，但整體之錯誤性能仍優於原方法；而所設計的多個位元映射組，可應用於任一相差空間調變方案的位元映射步驟，來增加電腦模擬時映射之位元數的上限，同時些微地改善錯誤性能。;Differential Spatial modulation (DSM) is a kind of Spatial modulation technique that does not need pilot symbols and channel estimation. The original noncoherent detection for DSM is very complicated.In this thesis, we propose two low-complexity DSM schemes. One of them is an improved design to reduce the decoding complexity for block coded DSM (BC-DSM) with a transmission diversity of 2. The other is the bit-mapping of full-rate DSM with multiple mapping groups.Compared with the original method, our low-complexity schemes are suitable for systems with many transmission antennas, and have better error performance. The design of BC-DSM can be divided into a detector with reduced complexity, and complex-valued antenna-index matrices that matching with the detector. Although the error performance of this detector is slightly worse than the noncoherent maximum-likelihood detector, the overall error performance is still better than the original method.The designed multiple mapping groups can be applied to the bit-mapping step of any DSM to increase the upper limit of the number of mapped bits during the computer simulation, while slightly improving the error performance.
