在空時碼的系統中，除了么正空時調變(unitary space-time modulation, USTM) [12]與相差空時調變(differential space-time modulation, DSTM)[13]外，大部分的空時碼都要在通道狀態已知的情況下進行解碼。在[14]中提出了一種適用於無線衰退通道環境下，具有訓練符元(training symbols)之非同調空時區塊碼傳輸架構，此架構的解碼器藉由通道係數的估測值作同調解碼。在此篇論文中，我們針對使用超級正交空時籬柵碼(super-orthogonal space-time trellis codes, SOSTTCs)[10]及其他空時籬柵碼[7]的這種架構，提出一種基於決策回授方式的非同調重複解碼演算法，使能以低複雜度趨近最大可能性(maximum likelihood, ML)非同調解碼的錯誤效能。 Most of the space-time codes have to decode with channel state information except for Unitary Space-Time Modulation(USTM)[12] and Differential Space-Time Modulation(DSTM)[13] system. A noncoherent space-time block code transmission scheme with training symbols, which applies the estimated channel coefficients to perform coherent decoding, was proposed in [14] to work under wireless fading channels. In this thesis, we present a noncoherent iterative decoding algorithm in decision-feedback fashion under the framework of Super-Orthogonal Space-Time Trellis Codes(SOTTCs)[10] and some space-time trellis codes[7] to approach the error performance of a Maximum Likelihood(ML) noncoherent decoder with low complexity.
