问答题 采用相干接收法解调下面已调信号,信道噪声为高斯白噪声,完成题下表。
【正确答案】
AM
DSB
SSB
VSB
FM
输入信号功率
frac{A_{0}^{2}}{2}+frac{overline{m^{2}(t)}}{2}
frac{overline{m^{2}(t)}}{2}
frac{overline{m^{2}(t)}}{4}
frac{overline{m^{2}(t)}}{4}
frac{A_{0}^{2}}{2}
输入噪声功率
n0BAM
n0BDSB
n0BSSB
n0BVSB
n0BFM
输入信噪比
frac{A_{0}^{2}+overline{m^{2}(t)}}{4n_{0}f_{m}}
frac{overline{m^{2}(t)}}{4n_{0}f_{m}}
frac{overline{m^{2}(t)}}{4n_{0}f_{m}}
frac{overline{m^{2}(t)}}{4n_{0}B_{VSB}}
frac{A_{0}^{2}}{4n_{0}(bigtriangleup f+f_{m})}
输出信号功率
frac{overline{m^{2}(t)}}{4}
frac{overline{m^{2}(t)}}{4}
frac{overline{m^{2}(t)}}{16}
frac{overline{m^{2}(t)}}{16}
(k_{d}k_{f})^{2}overline{m^{2}(t)}
输出噪声功率
frac{1}{2}n_{0}f_{m}
frac{1}{2}n_{0}f_{m}
frac{1}{4}n_{0}f_{m}
frac{1}{4}n_{0}B_{VSB}
frac{8pi ^{2}k_{d}^{2}n_{0}f_{m}^{3}}{3A_{0}^{2}}
输出信噪比
frac{overline{m^{2}(t)}}{2n_{0}f_{m}}
frac{overline{m^{2}(t)}}{2n_{0}f_{m}}
frac{overline{m^{2}(t)}}{4n_{0}f_{m}}
frac{overline{m^{2}(t)}}{4n_{0}B_{VSB}}
frac{3A_{0}^{2}k_{f}^{2}overline{m^{2}(t)}}{8pi ^{2}n_{0}f_{m}^{3}}
信噪比增益
frac{2overline{m^{2}(t)}}{A_{0}^{2}+overline{m^{2}(t)}}
2
1
1
3m2f(mf+1)
【答案解析】