QPSK和16QAM信号通过AWGN信道的误比特率

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% 本程序用于仿真QPSK，16QAM，通过AWGN信道的BER随SNR的变化规律。

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clear all;

clc

M_4psk = 4; % 4psk的进制数

k_4psk = log2(M_4psk); % 4psk的一个符号包含的比特数

M_16qam = 16; % 16qam的进制数

k_16qam = log2(M_16qam); % 16qam一个符号包含的比特数

NumSymbols = 10^6; % 定义要发送的比特数

rng default % 使用默认的随机数生成器

dataIn = randi([0 1],NumSymbols,1); % 生成二进制发送数据

dataInMatrix_4psk = reshape(dataIn,length(dataIn)/2,2); % 将发送二进制数据整理成两个一行，准备进行进制转换

dataSymbolsIn_4psk = bi2de(dataInMatrix_4psk); % 转换成十进制

dataInMatrix_16qam = reshape(dataIn,length(dataIn)/4,4); % 将发送二进制数据整理成四个一行，准备进行进制转换

dataSymbolsIn_16qam = bi2de(dataInMatrix_16qam); % 转换成十进制

dataModG_4psk = pskmod(dataSymbolsIn_4psk,M_4psk,0,'gray'); % 4psk调制以及格雷码编码

dataModG_16qam = qammod(dataSymbolsIn_16qam,M_16qam,0,'gray'); % 16qam调制以及格雷码编码

EbNo = [-2:2:15]; % 设置SNR范围

berG_4psk = zeros(1,length(EbNo)); % 定义4psk误码率数组

berG_16qam = zeros(1,length(EbNo)); % 定义16qam误码率数组

for index = 1:length(EbNo)

% 计算以db表示的SNR

snr_4psk = EbNo(index) + 10*log10(k_4psk);

snr_16qam = EbNo(index) + 10*log10(k_16qam);

%信号通过AWGN信道

receivedSignalG_4psk = awgn(dataModG_4psk,snr_4psk,'measured');

receivedSignalG_16qam = awgn(dataModG_16qam,snr_16qam,'measured');

%解调以及格雷码解码

dataSymbolsOutG_4psk = pskdemod(receivedSignalG_4psk,M_4psk,0,'gray');

dataSymbolsOutG_16qam =

qamdemod(receivedSignalG_16qam,M_16qam,0,'gray');

dataOutMatrixG_4psk = de2bi(dataSymbolsOutG_4psk,k_4psk); % 十进制转二进制，准备计算BER

dataOutG_4psk = dataOutMatrixG_4psk(:); % 将数据转化成一维向量

dataOutMatrixG_16qam = de2bi(dataSymbolsOutG_16qam,k_16qam); % 十进制转二进制，准备计算BER

dataOutG_16qam = dataOutMatrixG_16qam(:); % 将数据转化成一维向量

[numErrorsG_4psk,berG_4psk(index)] =

biterr(dataIn,dataOutG_4psk); % 计算4psk误码率

[numErrorsG_16qam,berG_16qam(index)] =

biterr(dataIn,dataOutG_16qam); % 计算16qam误码率

end

%计算信号通过AWGN信道的理论误比特率

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TheoryBER_4psk = berawgn(EbNo,'psk',4,'nondiff'); % 计算4psk通过AWGN

理论误比特率

TheoryBER_16qam = berawgn(EbNo,'qam',16); % 计算16qam通过AWGN理论误比特率

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%画图

semilogy(EbNo,TheoryBER_4psk,'b-',EbNo,TheoryBER_16qam,'r-'); % 画出理论BER曲线

hold on;

semilogy(EbNo,berG_4psk,'b*',EbNo,berG_16qam,'r*'); % 画出仿真BER曲线

grid on;

xlabel('Eb/N0 (dB)'); ylabel('BER'); % 横纵坐标

legend('QPSK理论BER','16QAM理论BER','QPSK仿真BER','16QAM仿真BER'); % 图例

title('QPSK/16QAM 通过AWGN信道'); % 题目