## 2008/08/24

### 香农极限 带宽计算公式

• If S/N >> 1, then
$C \approx 0.332 \cdot B \cdot \mathrm{SNR (in \ dB)}$
where
$\mathrm{SNR (in \ dB)} = 10\log_{10}{S \over N}$
• Similarly, if S/N <<>
$C \approx 1.44 \cdot B \cdot {S \over N}$
In this low-SNR approximation, capacity is independent of bandwidth if the noise is white, of spectral density N0 watts per hertz, in which case the total noise power is $B \cdot N_0$.
$C \approx 1.44 \cdot {S \over N_0}$