How to generate AWGN using randn

[nigosawa]

hey guys
i saw a similar post few days back in this forum. i m facing the same prob
i m told to generate AWGN and then plot its pdf
when i generate it by randn(setting mean=0 variance=1) i get normally distributed sequence of numbers. then i sort them using sort function. but when i plot them i dont get a bell shaped curve.
if instead of randn i use rand function(which produces numbers uniformly distributed) and then plots it pdf, then i get a bell shaped curve.

i asked teacher if i could use rand instead of randn, he said no kuz then purpose of gaussian noise fails.

so help me out how to do it
below is the code i use


x1=randn(1,10000);
m=mean(x1)
s_d=std(x1)
x=sort(x1);
%px=(exp(-((x-m).^2)/(2*s_d*s_d)))/(sqrt(2*pi)*s_d); %pdf formula
px=normpdf(x,0,1); %pdf formula

plot(px);

here i the second last line and line before second last one, i have used two ways of calculating pdf. anyone can be used and the other can be left commented

 

[mahdithdn]

AWGN

Hi,

just replace "plot(x,px);" instead of "plot(px)".

regards

 

[nigosawa]

Re: AWGN

thnx alot mahdithdn
u know i have been trying this for days and couldnt see this small mistake in my code

thnx once again man
u have helped me several times
god bless ya
cheers