用香农公式计算一下，假定信道带宽为3100Hz

C=B*log(1+S/N)

即

35Kbps = 3100 * log[2](1 + x);

35Kbps * 1.6 = 3100 * log[2](1 + y);

x = 2503.4880

y = 274128.8678

y/x = 109.50倍

3100 * log[2](1 + 274128.8678 * 11) = 66728.4952

66728.4952 / (35000 * 1.6) = 1.1917

不足20%