m = 16； % letter size
x = randi([0 M- 1]，5000， 1)； % random symbol
% uses 16-QAM modulation.
hMod = modem . QAM mod(M)；
HD emod = modem . QAM demod(hMod)；
% Create scatter plot and display constellation.
Scatter chart = CommScope. Scatter chart ('SamplesPerSymbol', 1, ...
Constellation, hMod. Constellation);
Scatter chart plot settings . Constellation = ' on '；
% modulation
y = modulate(hMod，x)；
% transmit signals through AWGN channel.
Ynoisy = awgn(y, 15,' actually measured');
% Create a scatter plot from noise data.
Update (scatter plot, y noisy);
% demodulate ynoisy to recover the message.
Z = demodulation (hDemod, ynoisy);
% Check the symbol error rate.
[num，rt] = symerr(x，z)
The output and scatter plot are as follows. Your numerical results and
The diagram may be different because this example uses random numbers.
Quantity =
83
rt =
0.0 166