设发送端符号为X:x1=0,x2=1;接收端符号为Y:y1=0,y2=1;已知P(x1)=0.55, P(x2)=0.45; P(y1|x1)=P(y2|x2)=0.9, P(y2|x1)=P(y1|x2)=0.1;则下列计算与判断正确的是( )。
A.
P(y1)=P(x1)P(y1|x1)+P(x2)P(y1|x2)=0.55*0.9+0.45*0.1=0.54
B.
P(y2)=P(x1)P(y2|x1)+P(x2)P(y2|x2)=0.55*0.1+0.45*0.9=0.46
C.
P(x1,y1)=P(x1)P(y1|x1)=0.55*0.9=0.495; P(x1|y1)=P(x1,y1)/P(y1)=0.495/0.54=0.917
D.
P(x1,y2)=P(x1)P(y2|x1)=0.55*0.1=0.055; P(x1|y2)=P(x1,y2)/P(y2)=0.055/0.46=0.12
E.
P(x2,y1)=P(x2)P(y1|x2)=0.45*0.1=0.045; P(x2|y1)=P(x2,y1)/P(y1)=0.045/0.54=0.083
F.
P(x2,y2)=P(x2)P(y2|x2)=0.45*0.9=0.405; P(x2|y2)=P(x2,y2)/P(y2)=0.405/0.46=0.88
G.
P(x2|y1)≠P(x1|y2),P(x1|y1)≠P(x2|y2),所以该信道不是对称信道。