摘要: | 最近有一種新的非同調籬柵碼,稱為差分籬柵編碼調變,在不同的狀態上使用不同的相差編碼,並藉由集合分割來設計籬柵圖,以達到較好的錯誤效能。本篇論文將這個非同調籬柵碼延伸到多根天線的系統上,稱為差分空時籬柵碼,首先我們以空時區塊碼為例子,將8PSK,32組可能的訊號做集合分割,接著在4、8、16的狀態下做籬柵相差編碼, 並對幾種不同狀態數的籬柵碼做距離分析,與原本的未編碼差分空時調變相比,有較大的最小非同調距離,而電腦程式所獲得模擬結果也顯示其錯誤效能較好。除此之外,我們還運用在超級正交空時籬柵碼上,並做集合分割及在不同的狀態下做相差編碼,根據距離分析,發現在4、8狀態下的超級正交差分空時籬柵碼與8、16狀態下的差分空時籬 柵碼有相同的最小非同調距離,而模擬結果顯示有非常接近的錯誤效能。 ;Recently there is a new noncoherent trellis codes, called differential trellis coded modulation used in the different states differ in different coding and split by collection designed trellis codes, in order to achieve better error performance. In this thesis, this incoherent trellis extends to multiple antennas system called differential space-time trellis code, first we STBC as an example, the 8PSK, 32 group may make a collection of signal segmentation, then do the fence in the state 4,8,16 difference coding, and several different states from the trellis code to do the analysis, compared with the original uncoded modulation differential space-time, a larger minimum noncoherent distance, and obtained a computer program simulation results also show a better performance of its errors. In addition, we also use the super-orthogonal space-time trellis codes, and make the collection division and in different states do differ coding, depending on the distance analysis, we found differential quadrature empty super state in 4,8 differential space-time fence gate code and 8,16 state trellis codes when the same minimum noncoherent distance, and simulation results show that there is very close to the error performance. |