最近有一種新的相差編碼器被提出，它是藉由查表法所得到。本篇論文以此一主題，建立各種星座圖的多重符號相差編碼，並使最小非同調距離最大化。除此之外，查表法的相差編碼可以被描述成籬柵式的相差編碼，因此，我們在相差檢測器可以使用維特比(Viterbi)演算法以改善錯誤效能。並且也利用一定理來降低籬柵解碼時的狀態數量。此外，也使用決策回授與集合分割降低在多重符號相差解碼的籬柵複雜度。Recently, a new differential encoder by a look-up table was proposed. In this thesis, we construct tables of multiple-symbol differential encoding for various constellations that maximize the minimum noncoherent distance. Because differential encoding by a table can be described as differential encoding by a trellis, we use the Viterbi algorithm at the differential detector to improve the error performance. We use a theorem to reduce the number of states of the decoding trellis. Besides, we use decision feedback and set partition to decrease the trellis complexity of multiple-symbol differential decoding.
