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題 名 | The Two-Dimensional Abstracting Theorem and Its Properties |
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作 者 | 趙晉棠; | 書刊名 | 中原學報 |
卷 期 | 14 1985.12[民74.12] |
頁 次 | 頁95-105 |
分類號 | 448.533 |
關鍵詞 | |
語 文 | 英文(English) |
中文摘要 | 本文主要是為了介紹『非傳統的抽象理論及凸緣濾波音量』之概念。許多種性狀及其應用均將于以簡明地研討。文中最重要的突破是將謝能抽樣理論中之限制加以擴展。此一理論的骨幹是以每週期一元素之理論代替謝能所主張的每赫芝兩樣本。此處所談的新方法對於高品質信號之傳送頗具功用。例如高傳真放大系統需要1.5兆的每秒位元率。如採用新法,則傳送速率將可大為減低,而在反抽象的過程中是既簡單又不需濾波器。通常在理論上搏碼調變需要一個理想濾波器。事實上理想濾波器是無法實現的。因此有一些近似的方法必需使用,以便設計搏碼調變系統的低通濾波器。所以搏碼調變制含有三種失真,即量化誤差,傳送誤差,及濾波器的近似值與理想值之誤差。然而對波形抽象制而言,其量化誤差部份之影響不如搏碼調變制那樣厲害。又因為不須使用濾波器,因此由不良濾波器所造成之失真將可完全免除,而此一不用濾波器之顯著好處,在此一新方法中將顯而易見。 |
英文摘要 | The unconventional abstracting theorem and the concept of a convex filter are introduced in this paper. Various properties and their applications are briefiy studied. The important breakthrough of the paper is to expand the limit given by the Shannon's theorem. The basis of the new theorem is one element per period instead of two samples per Hz as Shannon asserted. The new method stated here is more useful for quality signal transmission. For example, the Hi-Fi system needs 1.5M bits/sec [2]. If the the new method is used, the transmission rate can be reduced drastically and there is no filter needed for inverse abstracting. Usually the decoding of a PCM system needs an ideal filter theoretically, wbich is unrealizable in the physical world. So some approximations must be made for tbe design of the lowpass filter of a PCM system. So the distortion of a PCM system has three parts. They are quantization error, transmission error, and filter approximation. Yet for a system of waveform abstracting the quantization error of a waveform element is not as serious as that of samples for PCM systems. Since no filter is needed,therefore the distortion caused by filters is thus eliminated. The prominent advantage of not using an ideal filter is obvious in the new method. |
本系統中英文摘要資訊取自各篇刊載內容。