我們在非同調GLRT檢測器上,研究使用多層次編碼的區塊編碼正交振幅調變(NBC-QAM),在衰退通道下,我們提出兩個方法對傳送QAM時通道係數的振幅大小做估測,在AWGN通道下,我們提出一個適用於已知通道振幅大小的GLRT檢測器及其相關的非同調距離。我們分別推導由多層次編碼得到的區塊編碼QAM之最小非同調距離,並根據此最小非同調距離的分析,提出NBC-8QAM新的建構方式,在NBC-QAM的系統中,借由改變星座圖內外圈比使其錯誤效能最佳化。模擬結果亦顯示,NBC-QAM新的建構方式有較好的錯誤效能。 We investigate block-coded QAM constructed by multilevel coding for the noncoherent generalized likelihood ratio test (GLRT) detector. For the fading channel, we proposed two method to estimate the fading amplitude. For the AWGN channel, we derive a new GLRT detector and the corresponding distance. The minimum noncoherent distance of block-coded QAM is derived and new construction of noncoherent block-coded QAM (NBC-QAM) are proposed accordingly. In the NBC-QAM scheme, the error performance can be optimized by adjusting the constellation. The superior error performances of NBC-QAM are verified by simulation results.