數(shù)字濾波器簡介外文翻譯-文庫吧資料
2025-05-22 01:46本頁面
【正文】 noisereduction, video signal enhancement, graphic equalisers in hifi systems, and many other areas. There are wellestablished standard techniques for designing an analog filter circuit for a given requirement. At all stages, the signal being filtered is an electrical voltage or current which is the direct analogue of the physical quantity (. a sound or video signal or transducer output) involved. A digital filter uses a digital processor to perform numerical calculations on sampled values of the signal. The processor may be a generalpurpose puter such as a PC, or a specialised DSP (Digital Signal Processor) chip. The analog input signal must first be sampled and digitised using an ADC (analog to digital converter). The resulting binary numbers, representing successive sampled values of the input signal, are transferred to the processor, which carries out numerical calculations on them. These calculations typically involve multiplying the input values by constants and adding the products together. If necessary, the results of these calculations,which now represent sampled values of the filtered signal, are output through a DAC (digital to analog converter) to convert the signal back to analog form. Note that in a digital filter, the signal is represented by a sequence of numbers, rather than a voltage or current. The following diagram shows the basic setup of such a system. Advantages of using digital filters The following list gives some of the main advantages of digital over analog filters. 1. A digital filter is programmable, . its operation is determined by a program stored in the processor39。 類似于之前 ， x1和 x2取 0。（之后，我們將著眼于更有效的低通濾波器。 5. 均值濾波器 ： 該 輸出值是當前輸入值和前一個輸入值的平均值（算術(shù)平均）。 4. 差分濾波器： y n = x n x n1 在 t = nh時的輸出值等于當前輸入值 xn與前一個輸入值 xn1的差值： 即輸出值是最近一次采樣值間隔 h輸入的變化 。 3. 純延遲濾波器： y n = x n1 在 t = nh 時的輸出值只是簡單的等于 t = (n1)h 時的輸入值，即信號延遲時間 h： y0 = x1 y1 = x0 y2 = x1 y3 = x2 ... etc 注意，由于抽樣是在 t = 0 開始，輸入值 x 1 在 t = h 是不確定的。 當 K 1
畢業(yè)設(shè)計相關(guān)推薦
鄂ICP備17016276號-1