已知两个正弦信号x(t)=Asin(ωt+θ) y(t)=Aosin(ωt+θ-ψ)求其互相关函数
1个回答

这是一道关于t参数方程,消除参数t即可

x/a=sin(ωt+θ) (1)

y/a.=sin(ωt+θ-ψ)(2)

由三角函数和差化积可知:

(1)-(2)= x/a- y/a.=2cos(ωt+θ-ψ/2)sin(ψ/2) (3)

(1)+(2)= x/a+ y/a.=2sin(ωt+θ-ψ/2)cos(ψ/2) (4)

变换可知:

( x/a- y/a.)/2(sin(ψ/2))=cos(ωt+θ-ψ/2) (5)

( x/a-+y/a.)/2(cos(ψ/2))=sin(ωt+θ-ψ/2) (6)

(5)^2+(6)^2=

( x/a- y/a.)^2/(sin(ψ/2)^2+( x/a-+y/a.)^2/cos(ψ/2)^2 =4