Communications_Engineer
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Hi,
I have created a QPSK modulator for passband in matlab; created baseband BPSK and then upconverted.
So, how to demodulate it?
Use a bandpass filter centered at 1KHz (wouldn't have much affect would it?) and then start to sample it (bandpass sampling)
This is the first time I'm doing this and even though I can think of many things, I would like if someone can share their views on how to demodulate it.
PS. Its nice to see that our experts have started to participate in discussions
I have created a QPSK modulator for passband in matlab; created baseband BPSK and then upconverted.
Code:
Fs = 10000;
fc = 1000;
n = 0:1/Fs:1;
M = 4;
datlen = 100;
I = cos(2*pi*fc*n);
Q = sine(2*pi*fc*n);
Dat = randint(1,datlen);
Sym = pskmod(Dat,M); % I know simply writing pskmod won't be the correct QPSK (incorrect constellation)
% but lets ignore it for a while
Sig = real(Sym) * I + j*imag(Sym) * Q;
So, how to demodulate it?
Use a bandpass filter centered at 1KHz (wouldn't have much affect would it?) and then start to sample it (bandpass sampling)
This is the first time I'm doing this and even though I can think of many things, I would like if someone can share their views on how to demodulate it.
PS. Its nice to see that our experts have started to participate in discussions