6.2.1二进制数字振幅键控(2ASK) P=P(O)P(/0)+P(DP(0/1) =P(O)P(x>b)+P(1)P(x<b) =P(0)()dx +P(1(d Q 判决门限b=a/2,r为信噪比：三 262 n         = 2 2 1 r erfc p P(0)P(1/ 0) P(1)P(0/1) e = + x d x b P b f x d x P f P P x b P P x b ( ) 1 ( ) (1) 0 (0) (0) ( ) (1) ( )  +  −  = =  +  判决门限b=a/2，r为信噪比： 2 2 2 n a r  = 6.2.1 二进制数字振幅键控（2ASK）