本論文擬對一新型調變家族—正交多工正交振幅調變訊號[10]在數位傳輸實現上做一探究。此一調變家族既使在不同時限(time-limited)基底建構下，仍可將正交多工正交振幅調變訊號表示為一系列相同頻率間隔、相互正交之子載波，經由對應資料振幅調變的形式。這樣的結果便可類比於正交分頻多工(Orthogonal Frequency-Division Multiplexing)的調變方式，因而藉此引進離散反傅力葉轉換(Inverse Discrete Fourier Transform)來完成基頻數位調變，並訴諸快速傅力葉轉換演算法來降低運算複雜度。使用上述方法實現的正交多工正交振幅調變，送入快速傅力葉轉換的輸入資料在某些基底不全選擇的情況中有許多數值為零的資料。因此可在基數-2之快速傅力葉演算法中加入檢查機制，進一步節省運算量。論文並探討在不同基底、不同參數選擇的調變下所能減少的運算複雜度，且推論各參數調整與所能節省複雜度之間的趨勢關係。 A digital realization of a novel modulation family called orthogonally multiplexed orthogonally amplitude-modulated (OMOAM) signals [10] is investigated in this thesis. Even if can be constructed by different time-limited basis sets, OMOAM signals can be represented by data-amplitude-modulated subcarriers which have equal frequency spacing and are orthogonal to each other. This result is analogous with the modulation scheme of the orthogonal frequency-division multiplexing. Therefore, the inverse discrete Fourier transform is applied to process digital baseband modulation and can be implemented by the IFFT algorithm to reduce computational complexity. Realized as mention above, OMOAM feeds many zero-valued data into IFFT in some cases when not all of the bases are chosen. Consequently, a checking mechanism can be involved in the radix-2 FFT algorithm to reduce computational complexity more. The amount of reduced complexity is discussed when OMOAM signals are constructed in different basis sets with different parameters. And the performance trend related to each parameter is inferred.
