ask modulation and demodulation

ask modulation

Can anyone help me with modulation and demodulation of BASK with addition of noise and checking of error due to noise........

Please help me ASAP.... next 2 days......


Thanks Alot

modulation and demodulation

BASK??? or ASK???

you need a Math software specified?

Matlab, Octave, it++, or..?

ask demodulation

4 BASK and in matlab... its d modulation and demodulation


A binary signal m(t) should be transmitted over a channel and received in its
original form. For this to work the signal is mixed with a cosine function with specific carrier
frequency and then transmitted. The channel is noisy resulting in noise added to the modulated
signal. To recover the original signal back at the receiver, the combined signal is demodulated
by mixing it with the same cosine function and then filtering the sidebands.

If you need BPSK and its simulation. I may help.

ask modulation demodulation

Thx alot pal... but i need it on BASK... n dat in very next 2 dayz... can u help me...

as it is a finalz project 4 me... in signal n system....

modulation demodulation

see this general PSK type . you can modify it to ASK , it is very simple

clc;
clear all;
disp('M-Array PSK Modulation')
%create a random digital message
M=input ('M= '); %alphabet size
x=randint(input('Number of binary bit stream = '),1,M);
%%
nsample=40; %oversampling rate.
%%

%%
%use M-PSK modulation to produce y
y=modulate(modem.pskmod(M),x);
%%
%follow with rectangular pulse shaping.
ypulse=rectpulse(y,nsample);
stem(y(1:10),'filled'),grid;
%%
%%transmit signal through an AWGN Channel
ynoisy=awgn(ypulse,input('SNR in dB = '),'measured');
%%
%Create scattet plot from noisy data
scatterplot(ynoisy),grid;
%%
%Downsample at the reciever.
ydownsample=intdump(ynoisy,nsample);
%%
%Demodulate ynoisy to recover the message.
z=demodulate(modem.pskdemod(M),ydownsample);
figure;
subplot(2,1,1);
stem(x(1:10),'filled'),grid;
subplot(2,1,2);
stem(z(1:10),'filled'),grid;
%%
%Check symbole erroe rate.
[num ty]=symerr(x,z)
%%

enjoy
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Added after 2 minutes:

also see this file from matlab help "communication toolbox" it is very very very good and simple.

hallo..
i'm newbie..
i need help..
anyone can help me about ASK modulation?
anyone can give example bout it?
thx before

here the program os ASK modulation. It is very similar to the above program of the PSK modulation but just the psk replaced by ask.



clc;
clear all;
disp('M-Array ASK Modulation')
%create a random digital message
M=input ('M= '); %alphabet size
x=randint(input('Number of binary bit stream = '),1,M);
%%
nsample=40; %oversampling rate.
%%

%%
%use M-ASK modulation to produce y
y=modulate(modem.askmod(M),x);
%%
%follow with rectangular pulse shaping.
ypulse=rectpulse(y,nsample);
stem(y(1:10),'filled'),grid;
%%
%%transmit signal through an AWGN Channel
ynoisy=awgn(ypulse,input('SNR in dB = '),'measured');
%%
%Create scattet plot from noisy data
scatterplot(ynoisy),grid;
%%
%Downsample at the reciever.
ydownsample=intdump(ynoisy,nsample);
%%
%Demodulate ynoisy to recover the message.
z=demodulate(modem.askdemod(M),ydownsample);
figure;
subplot(2,1,1);
stem(x(1:10),'filled'),grid;
subplot(2,1,2);
stem(z(1:10),'filled'),grid;
%%
%Check symbole erroe rate.
[num ty]=symerr(x,z)
%%

enjoy

Re: modulation demodulation

Aya2002 said:

...
nsample=40; %oversampling rate....

Click to expand...

Is shaping is necessary after modulation, i.e.: does this affect the final result? What do you mean by oversampling, and how can we know the number that will be oversampling rate?

Regards

see any digital communications book. you will see more details.