QPSK :: Homework solution, help required

qpsk

hello,
i really want a matlab code that make quadrature phase shift keying, in this code i want each two bits represent a symbol and each code line explained in details because this my last communication project...i hope that any one can help me

qpsk

samoofcuk do your own homework!

Ask for help not solution

PLZ I REALLY DONT KNOW HOW TO MAKE IT????

Added after 2 hours 11 minutes:

really this is not home work i m in my bachelor year this is a presentation to how can u present code in matlab help is open ..open book all things is available but u have to explain each line in matlab so i told u i want the code with explain of each line so plz if u have this code can u send for me

use

qpskmod and qpskdemod functions from matlab communication toolbox.

Regards

mankeer said:

use

qpskmod and qpskdemod functions from matlab communication toolbox.

Regards

Click to expand...

yes i agree with you, for example see this code copied from the matlab help:

This code briefly illustrates the steps in modulation and demodulation.

x = randint(10,1,8); % Create a signal source.
h = modem.qammod(8) % Create a modulator object
% and display its properties.
y = modulate(h,x); % Modulate the signal x.
g = modem.qamdemod(h) % Create a demodulator object
% from a modem.qammod object
% and display its properties.
z = demodulate(g,y); % Demodulate the signal y.

and this another code from matlab help:
nSamp = 8; numSymb = 100;
M = 4; SNR = 14;
hStr = RandStream('mt19937ar', 'Seed', 12345);
numPlot = 10;
msg_orig = randi(hStr, [0 M-1], numSymb, 1);
stem(0:numPlot-1, msg_orig(1:numPlot), 'bx');
xlabel('Time'); ylabel('Amplitude');
hMod = modem.pskmod('M', M, 'PhaseOffset', pi/4, 'SymbolOrder', 'Gray');
msg_tx = modulate(hMod, msg_orig);
msg_tx = rectpulse(msg_tx,nSamp);
h1 = scatterplot(msg_tx);
msg_rx = awgn(msg_tx, SNR, 'measured', hStr, 'dB');
h2 = scatterplot(msg_rx);
hDemod = modem.pskdemod('M', M, 'PhaseOffset', pi/4, 'SymbolOrder', 'Gray');
close(h1(ishghandle(h1)), h2(ishghandle(h2)));
msg_rx_down = intdump(msg_rx,nSamp);
msg_demod = demodulate(hDemod, msg_rx_down);
stem(0:numPlot-1, msg_orig(1:numPlot), 'bx'); hold on;
stem(0:numPlot-1, msg_demod(1:numPlot), 'ro'); hold off;
axis([ 0 numPlot -0.2 3.2]); xlabel('Time'); ylabel('Amplitude');
[errorBit ratioBit] = biterr(msg_orig, msg_demod, log2(M));
[errorSym ratioSym] = symerr(msg_orig, msg_demod);



it is very simple, just use the matlab help and you will find every thing ready to use.

regards