Example 4.1 Consider the example where so =-b,s=b occurring with a priori probabilitieso=0.8 and元，=0.2.We will assume that b is larger than zero.If the noise pdf is a zero-mean Gaussian random variable with variance 902 (4.13) UESTC 99 UESTC Example 4.1 Consider the example where occurring with a priori probabilities and . We will assume that b is larger than zero. If the noise pdf is a zero-mean Gaussian random variable with variance , 0 1 s b s b = − = , 0  = 0.8 1  = 0.2 2  2 2 1 ( ) exp( ) (4.13) 2 2 n n p n    = −