Thread Subject: Trapezoid Plot (X-Y) for AM on Matlab

Hi,

I would like to perform an X-Y plot of an AM signal
X -> message signal
Y -> carrier signal
I think people whos studied communication would know what I exactly want. (i.e triangle when its 100% modulated, trapezoid when its under modulated, double triangle when its over modulated)

I've done the following code, but its not working...

clear all;
close all;
fs = 5000e3;
Ts = 1/fs;
N = 10000;
T0 = N*Ts;
t = 0:Ts:T0-Ts;

A = 1;
B = 1;
m = 1.5;
u = 1000*2*pi;
w = 100000*2*pi;

AM1 = A*(1+m*cos(u*t));
AM2 = B*cos(w*t);

AM = AM1.*AM2;

plot(AM1,AM2);
title('Amplitude Modulation X-Y');



Thanks in advance,
Regards,
Simon

Anyone can help?

On Apr 19, 4:50=A0pm, "Simon Luk"
<simon....@student.uts.edu.au.REMOVETHIS> wrote:
> Anyone can help?

I'm afraid my crystal ball is a bit cloudy today.
You will have to tell us in what way it is "not working".

Does the code run correctly?
If not, what is the error message.
If it runs correctly, describe what's wrong with the result.

Hi Tideman,

thanks for replying,

your question triggered me to think and i have found what was wrong with my code.

the plot function should be

plot(AM1,AM);
where x = message signal
          y = AM signal




Thanks again Tideman :)