hi,

i m attaching my code kindly help me sample this modulated signal

consisting of four channels each at carriers 400,1000,1600 and

2600HZ respectively.

see also the time domain envelope of the composite signal being AM

modulated at these four carriers and the fourier spectrum...

how can i implement sample rate variation to extract these four

channels??? (impulse train sampling is prefferable)

kindly, ample me atleast the very first channel such that its

carrier reduces to zero(or low frequency) and i can simply extract

it using a LOW PASS FILTER...(Bandpass sampling theorem is helpful)

*****code attached*******

fm0; wm0*2*pi;

Fc100; wc100*2*pi;

Fs1@00; ws1@00*2*pi;

Fc200; wc200*2*pi;

Fs2d00; ws2d00*2*pi;

Fc3@0; wc3@0*2*pi;

Fs300; ws300*2*pi;

Fc4&00; wc4&00*2*pi;

Fs4400; ws4400*2*pi;

t=[1:200]/Fs2;

vc=1;

m=1;

Vam1=vc*(sin(wc1*t)+0.5*m*cos((wc1-wm)*t)-0.5*m*cos((wc1+wm)*t));

Vam2=vc*(sin(wc2*t)+0.5*m*cos((wc2-wm)*t)-0.5*m*cos((wc2+wm)*t));

Vam3=vc*(sin(wc3*t)+0.5*m*cos((wc3-wm)*t)-0.5*m*cos((wc3+wm)*t));

Vam4=vc*(sin(wc4*t)+0.5*m*cos((wc4-wm)*t)-0.5*m*cos((wc4+wm)*t));

Vam=Vam1+Vam2+Vam3+Vam4;

figure

plot(Vam)

zt(Vam);

zs(z(1:(length(z)/2)+1));

frq=[0:length(z)-1]*Fs2/length(z)/2;

figure

plot(frq,z)

grid

figure

t = 0:.00025:1; % Time vector

y = decimate(Vam,4);

%%View the original and decimated signals:

stem(Vam(1:200)), axis([0 200 -4 4]) % Original signal

title('Original Signal')

figure

stem(y(1:30)) % Decimated signal

title('Decimated Signal')

URGENT HELP IS REQUIRED PLZZZZZZZZZZZ

waiting 4 replies,thanx in advance

regardz

Nosheen