16qam调制、接收、眼图、误码率曲线matlab仿真

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我是靠谱客的博主知性天空，这篇文章主要介绍16qam调制、接收、眼图、误码率曲线matlab仿真，现在分享给大家，希望可以做个参考。

MQAM (Multiple Quadrature Amplitude Modulation) 多进制正交幅度调制。4相相位键控信号其实也是一种二电平正交振幅键控。如果将二电平振幅键控进一步发展为多电平(例如4、8、16电平等)正交振幅键控，显然可以获得更高的频谱利用率。
效果展示：
（1）调制星座图

（2）信噪比13db接收星座图

（3）16qam信号眼图

（4）13db信噪比下16qam信号眼图

（5）误码率曲线（15db内）

代码说明
1、M可改，16qam，4qam等，snr信噪比可改。mqam_count信号数量可改。
2、代码在MATLAB2018上通过。

复制代码

clc
clear
M=16;%mqam的进制数
mqam_count =400;
snr=13;
%-------------------------------------&
bit_per_symbol=log2(M);
bit_length = mqam_count*bit_per_symbol;
bit_signal = round(rand(1,bit_length))';
bit_moded1 = qammod(bit_signal,M,'InputType','bit');
figure(1)
scatter(real(bit_moded1),imag(bit_moded1),'*y');
title('调制后的星座图');
%-------------------------------------%
signal_time_C_W_R=awgn(real(bit_moded1),snr);
signal_time_C_W_i=awgn(imag(bit_moded1),snr);
signal_time_C_W=complex(signal_time_C_W_R,signal_time_C_W_i);
figure(2)
scatter(1.5*real(signal_time_C_W),1.5*imag(signal_time_C_W),'.y');
title('接收的星座图');
%-------------------------------------%
eyediagram(bit_moded1,2)
eyediagram(signal_time_C_W,2)
%-------------------------------------%
snr_qq=0;
qq=zeros(150,1);
for i=0:149
bit_moded_qq = qammod(bit_signal,M,'InputType','bit');
snr_qq=snr_qq+0.1;
signal_time_C_W_R=awgn(real(bit_moded_qq),snr_qq);
signal_time_C_W_i=awgn(imag(bit_moded_qq),snr_qq);
signal_time_C_W=complex(signal_time_C_W_R,signal_time_C_W_i);
bit_demod_sig=qamdemod(signal_time_C_W,M,'OutputType','bit');
error_bit = sum(bit_demod_sig~=bit_signal);
error_rate = error_bit/length(bit_signal);
qq(i+1)=error_rate;
end
figure(5)
plot(0:0.1:14.9,qq)
title('误码率曲线16qam');
%-----------------------------------%
fs = 1000;
sps = 32;
txfilter = comm.RaisedCosineTransmitFilter('OutputSamplesPerSymbol',sps);
ed = comm.EyeDiagram('SampleRate',fs*sps,'SamplesPerSymbol',sps);
txSig = txfilter(signal_time_C_W);
ed(txSig)

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clc
clear
M=16;%mqam的进制数
mqam_count =400;
snr=13;
%-------------------------------------&
bit_per_symbol=log2(M);
bit_length = mqam_count*bit_per_symbol;
bit_signal = round(rand(1,bit_length))';
bit_moded1 = qammod(bit_signal,M,'InputType','bit');
figure(1)
scatter(real(bit_moded1),imag(bit_moded1),'*y');
title('调制后的星座图');
%-------------------------------------%
signal_time_C_W_R=awgn(real(bit_moded1),snr);
signal_time_C_W_i=awgn(imag(bit_moded1),snr);
signal_time_C_W=complex(signal_time_C_W_R,signal_time_C_W_i);
figure(2)
scatter(1.5*real(signal_time_C_W),1.5*imag(signal_time_C_W),'.y');
title('接收的星座图');
%-------------------------------------%
eyediagram(bit_moded1,2)
eyediagram(signal_time_C_W,2)
%-------------------------------------%
snr_qq=0;
qq=zeros(150,1);
for i=0:149
bit_moded_qq = qammod(bit_signal,M,'InputType','bit');
snr_qq=snr_qq+0.1;
signal_time_C_W_R=awgn(real(bit_moded_qq),snr_qq);
signal_time_C_W_i=awgn(imag(bit_moded_qq),snr_qq);
signal_time_C_W=complex(signal_time_C_W_R,signal_time_C_W_i);
bit_demod_sig=qamdemod(signal_time_C_W,M,'OutputType','bit');
error_bit = sum(bit_demod_sig~=bit_signal);
error_rate = error_bit/length(bit_signal);
qq(i+1)=error_rate;
end
figure(5)
plot(0:0.1:14.9,qq)
title('误码率曲线16qam');
%-----------------------------------%
fs = 1000;
sps = 32;
txfilter = comm.RaisedCosineTransmitFilter('OutputSamplesPerSymbol',sps);
ed = comm.EyeDiagram('SampleRate',fs*sps,'SamplesPerSymbol',sps);
txSig = txfilter(signal_time_C_W);
ed(txSig)