Error in demodulation QAM-16 signal

% This code, after demodulation, produces a sequence of 4 values, although the number of values should be equal to the modulation factor M. What could be the problem?

clc
close all
clear all
M = 16;
L=10000;
T=10;
W=43; %SNR

bits1 = randi([0 M-1], 1, L);
bits2 = randi([0 3], 1, L/T);
mod1 = qammod(bits1, M,’UnitAveragePower’, true);
% scatterplot(mod1)
mod2 = qammod(bits2, 4, ‘UnitAveragePower’,true);
% scatterplot(mod2)
for i = 1:length(bits2)
sym(i,:)=[mod1((i-1)*T+1:i*T) mod2(i)];
end
f=0;
for k=1:L/T
for j=1:T+1
f=f+1;
symbols(f)=sym(k,j);
end
end
% scatterplot(symbols)

% symbols = awgn(symbols,W,"measured");
pnoise = comm.PhaseNoise(‘Level’,[-70 -104 -110],’FrequencyOffset’,[1e4 1e5 2e5], ‘SampleRate’, 28e6);
symbols2 = pnoise([zeros(1e5,1);symbols’]);
% symbols2 = pnoise(symbols);
fc = 1e6; % Carrier frequency in Hz
fs = 28e6; % Sample rate in Hz.
phNzLevel = [-70 -104 -110]; % in dBc/Hz
phNzFreqOff = [1e4 1e5 2e5]; % in Hz
Nspf = 6e6; % Number of Samples per frame
freqSpan = 400e3; % in Hz, for spectrum computation
sinewave = dsp.SineWave( …
Amplitude=1, …
Frequency=fc, …
SampleRate=fs, …
SamplesPerFrame=Nspf, …
ComplexOutput=true);
pnoise = comm.PhaseNoise( …
Level=phNzLevel, …
FrequencyOffset=phNzFreqOff, …
SampleRate=fs);
sascopeRBW100 = spectrumAnalyzer( …
SampleRate=fs, …
Method="welch", …
FrequencySpan="Span and center frequency", …
CenterFrequency=fc, …
Span=freqSpan, …
RBWSource="Property", …
RBW=100, …
SpectrumType="Power density", …
SpectralAverages=10, …
SpectrumUnits="dBW", …
YLimits=[-150 10], …
Title="Resolution Bandwidth 100 Hz", …
ChannelNames={‘signal’,’signal with phase noise’}, …
Position=[79 147 605 374]);
x = sinewave();
y = pnoise(x);
sascopeRBW100(x,y)
symbols2 = symbols2(1e5+1:end);

prim(1,:)=symbols2(1:T);
for i = 1:length(bits2)-1
prim(i+1,:)=symbols2(i*T+i+1:i*T+i+T);
end
for b = 1:length(mod2)
qam4(b)=symbols2((T+1)*b);
end
h=0;
for u=1:L/T
for l=1:T
h=h+1;
priem(h)=prim(u,l);
end
end
for g = 1:L/T
phase_error(g) = angle(qam4(g) / mod2(g));
compensated4(g) = qam4(g) .* exp(-1i * phase_error(g));
end
for v = 1:L/T
phase_errorM((v-1)*T+1:v*T)=phase_error(v);
end
for f = 1:L
compensatedM(f) = priem(f) .* exp(-1i*phase_errorM(f));
end
demod=qamdemod(compensatedM, M, ‘bin’,’OutputType’,’bit’);
% scatterplot(qam4)
% scatterplot(symbols2)
% scatterplot(compensatedM)
[number,ratio]=biterr(bits1,demod);
evm = lteEVM(demod,bits1);
figure(‘Position’,[200 200 1080 540])
subplot(1,2,1)
scatter(real(symbols2),imag(symbols2),300,".")
subplot(1,2,2)
scatter(real(compensatedM),imag(compensatedM),300,".")% This code, after demodulation, produces a sequence of 4 values, although the number of values should be equal to the modulation factor M. What could be the problem?

clc
close all
clear all
M = 16;
L=10000;
T=10;
W=43; %SNR

prim(1,:)=symbols2(1:T);
for i = 1:length(bits2)-1
prim(i+1,:)=symbols2(i*T+i+1:i*T+i+T);
end
for b = 1:length(mod2)
qam4(b)=symbols2((T+1)*b);
end
h=0;
for u=1:L/T
for l=1:T
h=h+1;
priem(h)=prim(u,l);
end
end
for g = 1:L/T
phase_error(g) = angle(qam4(g) / mod2(g));
compensated4(g) = qam4(g) .* exp(-1i * phase_error(g));
end
for v = 1:L/T
phase_errorM((v-1)*T+1:v*T)=phase_error(v);
end
for f = 1:L
compensatedM(f) = priem(f) .* exp(-1i*phase_errorM(f));
end
demod=qamdemod(compensatedM, M, ‘bin’,’OutputType’,’bit’);
% scatterplot(qam4)
% scatterplot(symbols2)
% scatterplot(compensatedM)
[number,ratio]=biterr(bits1,demod);
evm = lteEVM(demod,bits1);
figure(‘Position’,[200 200 1080 540])
subplot(1,2,1)
scatter(real(symbols2),imag(symbols2),300,".")
subplot(1,2,2)
scatter(real(compensatedM),imag(compensatedM),300,".") % This code, after demodulation, produces a sequence of 4 values, although the number of values should be equal to the modulation factor M. What could be the problem?

clc
close all
clear all
M = 16;
L=10000;
T=10;
W=43; %SNR

prim(1,:)=symbols2(1:T);
for i = 1:length(bits2)-1
prim(i+1,:)=symbols2(i*T+i+1:i*T+i+T);
end
for b = 1:length(mod2)
qam4(b)=symbols2((T+1)*b);
end
h=0;
for u=1:L/T
for l=1:T
h=h+1;
priem(h)=prim(u,l);
end
end
for g = 1:L/T
phase_error(g) = angle(qam4(g) / mod2(g));
compensated4(g) = qam4(g) .* exp(-1i * phase_error(g));
end
for v = 1:L/T
phase_errorM((v-1)*T+1:v*T)=phase_error(v);
end
for f = 1:L
compensatedM(f) = priem(f) .* exp(-1i*phase_errorM(f));
end
demod=qamdemod(compensatedM, M, ‘bin’,’OutputType’,’bit’);
% scatterplot(qam4)
% scatterplot(symbols2)
% scatterplot(compensatedM)
[number,ratio]=biterr(bits1,demod);
evm = lteEVM(demod,bits1);
figure(‘Position’,[200 200 1080 540])
subplot(1,2,1)
scatter(real(symbols2),imag(symbols2),300,".")
subplot(1,2,2)
scatter(real(compensatedM),imag(compensatedM),300,".") qam16, demodulation, ber MATLAB Answers — New Questions

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