窗函数带宽计算器 — 公式

How to Determine Sampling Rate

The Nyquist theorem states the minimum sampling rate is twice the highest signal frequency.

Formulas

f_sample_min = 2 x f_max

f_sample_practical = Oversampling Ratio x f_max

In practice, engineers oversample (4x to 8x or more) because:

  • Perfect brick-wall anti-aliasing filters do not exist
  • Oversampling reduces quantization noise
  • It allows simpler, cheaper analog filters

    • 计算示例

    Capture audio up to 20 kHz with 2x oversampling.

    1. Minimum (Nyquist): 2 x 20,000 = 40,000 Hz
    2. Practical rate: 2 x 20,000 = 40,000 Hz
    3. Data rate (16-bit): 40,000 x 16 = 640,000 bits/s = 640 kbps