Other Important Random Variables - Random Signals and Processes Primer with MATLAB - page 353

a

n1: σ 1=0.6325,ME=1 n2: σ =0.4472,ME=1

30 15

20 10

10 5

0 0 0

200 400 600 0 200 400 600

n n

SUM: n=n1+n2

30

20

10

0

0 50 100 150 200 250 300 350 400 450 500

n

b n1: σ =0.6325,ME=1 n2: σ =0.4472,ME=1

0.4 0.4

0.3 0.3

0.2 0.2

0.1 0.1

0 0

0 5 10 15 20 0 5 10 15

Range Range

SUM: n=n1+n2

0.2

0.15

0.1

0.05

0

0 5 10 15 20 25

Range

Fig. 5.26 Sum of lognormal variables. ( a ) Lognormal random variables. ( b ) Densities