Help me make a graph of ASK PSK FSK in Matlab

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Hello guys

I have been reading on FSK , PSK and ASK and have been asked to produce a graph ( attached ) by writing few lines of Matlab code.. :|

Could any one possibly tell me how to get started on this please?

Thanks guys
 

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  • 1.bmp
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Re: Ask psk fsk - matlab

ASK shown in the diagram is actually OOK(on-off keying). Generate input sq.wave. Then Generate a carrier(cosine wave) with a higher frequency as compared to sq.wave.. just multiply both u will get ASK..
 
Re: Ask psk fsk - matlab

Many thanks , I will try this for ASK , but do u have any other idea for the PSK and FSK?

Thank you
 

Re: Ask psk fsk - matlab

For ASK input square wave should have levels 0 and 1.. Change the levels to -1 and +1.. follow the similar procedure to obtain PSK.. For FSK u have to generate two carriers(sinusoidal and triangular as in the diagram).. Using an if loop switch the output depending on whether the input is 1 or 0..
 
Re: Ask psk fsk - matlab

Hello again
For ASK do i need to use a Cosine or a sine waveform? as some txt books say cosine and others say sine..
which one do i use?

---------- Post added at 22:19 ---------- Previous post was at 21:05 ----------

Guys why does it keep giving thsi error when i try to multiply the two waves together?
??? Error using ==> mtimes
Inner matrix dimensions must agree.

BUt i made sure they are the same dimensions! I dono what the problem is!

ur help would be appriciated
 

Re: Ask psk fsk - matlab

U can use either since it is merely concerned with the generation of a waveform..

---------- Post added at 12:05 ---------- Previous post was at 12:04 ----------

TRy .* operator instead of *
 
Re: Ask psk fsk - matlab

Hello Ill post my code here, would u mind having a look at it please
thanks

This is for ASK


% Generating a input square wave
x1 = 0pi/100)10*pi);
y1 = square(x1);
A = plot(x1,y1);
figure(1),A,title( 'Square wave');xlabel('x'); ylabel('y');ylim([0,1]);grid;

% Generating a carrier(cosine wave) with a higher frequency as compared to sq.wave
f=0.8
t = 0pi/100)10*pi);
y2 = cos(2*pi*f*t);
figure(2),B = plot(t,y2),title( 'Sine wave');xlabel('x'); ylabel('y');ylim([-2,2]); xlim([0,35]);grid;

ASK = A.*B;
figure(3),plot(t,ASK),title('ASK');xlabel('x'); ylabel('y');ylim([-2,2]); xlim([0,35]);grid;
 

Re: Ask psk fsk - matlab

ANY ONE? help?
 

Re: Ask psk fsk - matlab

A and B are jus plots.. you have to multiply y1 and y2.. Also for the referred diagram square wave should have levels 1 and 0 instead of 1 and -1.
 
can anyone tell me abt the comparison of ASk,FSK and PSK in terms of their performance with mathematical equations
 
i think your problem is in coding. there are lot of blogs giving sugetions and direct programs or codes i think this will help u
kemppro.blogspot.com
 

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