%>>>>>>>>>>>>>>>>>> Matlab code for M ary-QAM modulation >>>>>>>>>>>>>>>>>%
clc;
clear all;
close all;
M=4;
%M=input(' enter the value of M array for QAM modulation : ');
fprintf('\n\n\n');
%XXXXXXXXXXXXXXXXXXXXXXXXXXX input chaking loop XXXXXXXXXXXXXXXXXXXXXXXXXX
Ld=log2(M);
ds=ceil(Ld);
dif=ds-Ld;
if(dif~=0)
error('the value of M is only acceptable if log2(M)is an integer');
end
%XXXXXXXXXXXXXXXXXXX binary Information Generation XXXXXXXXXXXXXXXXXXXXXXXX
nbit=16; %number of information bits
msg=round(rand(nbit,1)); % information generation as binary form
disp(' binary information at transmitter ');
disp(msg);
fprintf('\n\n');
%XX representation of transmitting binary information as digital signal XXX
x=msg;
bp=.000001; % bit period
bit=[];
for n=1:1:length(x)
if x(n)==1;
se=ones(1,100);
else x(n)==0;
se=zeros(1,100);
end
bit=[bit se];
end
t1=bp/100:bp/100:100*length(x)*(bp/100);
figure(1)
subplot(3,1,1);
plot(t1,bit,'lineWidth',2.5);grid on;
axis([ 0 bp*length(x) -.5 1.5]);
ylabel('amplitude(volt)');
xlabel(' time(sec)');
title('transmitting information as digital signal');
% binary information convert into symbolic form for M-array QAM modulation
M=M; % order of QAM modulation
msg_reshape=reshape(msg,log2(M),nbit/log2(M))';
disp(' information are reshaped for convert symbolic form');
disp(msg_reshape);
fprintf('\n\n');
size(msg_reshape);
for(j=1:1:nbit/log2(M))
for(i=1:1:log2(M))
a(j,i)=num2str(msg_reshape(j,i));
end
end
as=bin2dec(a);
ass=as';
figure(1)
subplot(3,1,2);
stem(ass,'Linewidth',2.0);
title('serial symbol for M-array QAM modulation at transmitter');
xlabel('n(discrete time)');
ylabel(' magnitude');
disp('symbolic form information for M-array QAM ');
disp(ass);
fprintf('\n\n');
%XXXXXXXXXXXXXX Mapping for M-array QAM modulation XXXXXXXXXXXXXXXXXXXXXXXX
M=M; %order of QAM modulation
x1=[0:M-1];
p=qammod(ass,M) %constalation design for M-array QAM acording to symbol
sym=0:1:M-1; % considerable symbol of M-array QAM, just for scatterplot
pp=qammod(sym,M); %constalation diagram for M-array QAM
scatterplot(pp),grid on;
title('consttelation diagram for M-array QAM');
%XXXXXXXXXXXXXXXXXXXXXX M-array QAM modulation XXXXXXXXXXXXXXXXXXXXXXXXXXX
RR=real(p)
II=imag(p)
sp=bp*2; %symbol period for M-array QAM
sr=1/sp; % symbol rate
f=sr*2;
t=sp/100:sp/100:sp;
ss=length(t);
m=[];
for(k=1:1:length(RR))
yr=RR(k)*cos(2*pi*f*t); % inphase or real component
yim=II(k)*sin(2*pi*f*t); % Quadrature or imagenary component
y=yr+yim;
m=[m y];
end
tt=sp/100:sp/100:sp*length(RR);
figure(1);
subplot(3,1,3);
plot(tt,m);
title('waveform for M-array QAM modulation acording to symbolic information');
xlabel('time(sec)');
ylabel('amplitude(volt)');
%XXXXXXXXXXXXXXXXXXXX M-array QAM demodulation XXXXXXXXXXXXXXXXXXXXXXXXXXXX
m1=[];
m2=[];
for n=ss:ss:length(m)
t=sp/100:sp/100:sp;
y1=cos(2*pi*f*t); % inphase component
y2=sin(2*pi*f*t); % quadrature component
mm1=y1.*m((n-(ss-1)):n);
mm2=y2.*m((n-(ss-1)):n);
z1=trapz(t,mm1) % integration
z2=trapz(t,mm2) % integration
zz1=round(2*z1/sp)
zz2=round(2*z2/sp)
m1=[m1 zz1]
m2=[m2 zz2]
end
%XXXXXXXXXXXXXXXXXXX de-mapping for M-array QAM modulation XXXXXXXXXXXXXXXX
clear i;
clear j;
for (k=1:1:length(m1))
gt(k)=m1(k)+j*m2(k);
end
gt
ax=qamdemod(gt,M);
figure(3);
subplot(2,1,1);
stem(ax,'linewidth',2);
title(' re-obtain symbol after M-array QAM demodulation ');
xlabel('n(discrete time)');
ylabel(' magnitude');
disp('re-obtain symbol after M-array QAM demodulation ');
disp(ax);
fprintf('\n\n');
bi_in=dec2bin(ax);
[row col]=size(bi_in);
p=1;
for(i=1:1:row)
for(j=1:1:col)
re_bi_in(p)=str2num(bi_in(i,j));
p=p+1;
end
end
disp('re-obtain binary information after M-array QAM demodulation');
disp(re_bi_in')
fprintf('\n\n');
%XX representation of receiving binary information as digital signal XXXXXX
x=re_bi_in;
bp=.000001; % bit period
bit=[];
for n=1:1:length(x)
if x(n)==1;
se=ones(1,100);
else x(n)==0;
se=zeros(1,100);
end
bit=[bit se];
end
t1=bp/100:bp/100:100*length(x)*(bp/100);
figure(3)
subplot(2,1,2);
plot(t1,bit,'lineWidth',2.5);grid on;
axis([ 0 bp*length(x) -.5 1.5]);
ylabel('amplitude(volt)');
xlabel(' time(sec)');
title('receiving information as digital signal after M-array QAM demoduation');
%>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> end of program <<<<<<<<<<<<<<<<<<<<<
QAM.rar_MOD_demod_qam
版权申诉
171 浏览量
2022-09-14
22:17:02
上传
评论
收藏 2KB RAR 举报
局外狗
- 粉丝: 66
- 资源: 1万+
最新资源
- 以简单、易用、高性能为目标、开源的时序数据库,支持Linux及Windows, Time Series Database.zip
- python-leetcode面试题解之第198题打家劫舍-题解.zip
- python-leetcode面试题解之第191题位1的个数-题解.zip
- python-leetcode面试题解之第186题反转字符串中的单词II-题解.zip
- 一个基于python的web后端高性能开发框架,下载可用
- python-leetcode面试题解之第179题最大数-题解.zip
- python-leetcode面试题解之第170题两数之和III数据结构设计-题解.zip
- python-leetcode面试题解之第168题Excel表列名称-题解.zip
- python-leetcode面试题解之第167题两数之和II输入有序数组-题解.zip
- python-leetcode面试题解之第166题分数到小数-题解.zip
资源上传下载、课程学习等过程中有任何疑问或建议,欢迎提出宝贵意见哦~我们会及时处理!
点击此处反馈