How does matlab change the constellation mapping mode of 8QAM

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