performance_ctr_snr_15_coba2.m

ini merupakan STC code dimana dia mengkodekan melalui STC

clear all
clc
jmluser=2;
coba=2;
for ulang=1:coba;
%state=1;
snr_SR_db=15;
snr_SD_db=snr_SR_db;
snr_RD_db=25;

for z=0:snr_RD_db
    
snr_RD=10^((z)/10);
snr_SR=10^((snr_SR_db)/10);
snr_SD=10^((snr_SD_db)/10);

varians_SR = 1/(sqrt(2*snr_SR));
varians_RD = 1/(sqrt(2*snr_RD));
varians_SD = 1/(sqrt(2*snr_SD));

jdata=10000;

datauser1=randint(1,jdata,[0 1]);
datauser2=randint(1,jdata,[0 1]);
datauser=[datauser1 datauser2];
b=[datauser1;datauser2];
b=2*b-1;
for k=1:jmluser
    s(k,1)=1;
    for n=2:length(b(1,:));
        s(k,n)=b(k,n)*s(k,n-1);
    end
end
s1=s(1,:);
s2=s(2,:);

%Pembangkitan Kanal

randn('seed',11);
hR0=(randn(1,length(s1)));
randn('seed',21);
hI0=(randn(1,length(s1)));
hs1=abs((0.707).*(hR0+i*hI0));

randn('seed',31);
hR1=sqrt(1/16).*(randn(1,length(s1)));
randn('seed',41);
hI1=sqrt(1/16).*(randn(1,length(s1)));
hs2=abs((0.707).*(hR1+i*hI1));

randn('seed',51);
hR2=sqrt(1/16).*(randn(1,length(s1)));
randn('seed',61);
hI2=sqrt(1/16).*(randn(1,length(s1)));
h21=abs((0.707).*(hR2+i*hI2));
% hs1=1;
% hs2=1;
% h21=1;

% %Pembangkitan Noise AWGN
% %Noise BS_U1
% randn('seed',71);
% noise1_real= randn(1,length(s1));
% es1_real= noise1_real.*varians_SR;
% 
% randn('seed',81);
% noise1_imag= randn(1,length(s1));
% es1_imag= noise1_imag.*varians_SR;
% 
% es1=es1_real+i*es1_imag;
% 
% %Noise BS_U2
% randn('seed',91);
% noise2_real= randn(1,length(s2));
% es2_real= noise2_real.*varians_SD;
% 
% randn('seed',101);
% noise2_imag= randn(1,length(s2));
% es2_imag= noise2_imag.*varians_SD;
% 
% es2=es2_real+i*es2_imag;
% 
% %Noise U1_U2
% randn('seed',111);
% noise21_real= randn(1,length(s1));
% es21_real= noise21_real.*varians_RD;
% 
% randn('seed',121);
% noise21_imag= randn(1,length(s1));
% es21_imag= noise21_imag.*varians_RD;
% 
% es21=es21_real+i*es21_imag;

%%
%Data yang dikirim BS ke user1 dan BS ke user2 timeslot 1
BS_U1=s1+i*s2;
BS_U2=s1+i*s2;

BS_U11=awgn(BS_U1,snr_SR,'measured',ulang)
BS_U22=awgn(BS_U2,snr_SD,'measured',ulang)

%Data yang diterima user1 dan user2 dari BS pada timeslot 1
Rs1=hs1.*BS_U11;
Rs2=hs2.*BS_U22;

%Hasil deteksi user1
SE11=real(Rs1);             %Hasil deteksi s1 oleh user1
SE21=imag(Rs1);             %Hasil deteksi s2 oleh user1
r1=[SE11;SE21];             %Real baris 1 dan imajiner baris 2
for k=1:jmluser
    be(k,1)=1;
    for n=2:length(b(1,:));
        be(k,n)=r1(k,n)*conj(r1(k,n-1));       %Proses decode oleh user 1 dari data Rs1
    end
end
dc_11=(be(1,:));        %sinyal s1 
be_11=sign(be(2,:));    %sinyal s2 -->b estimasi data user 2 oleh user 1 timeslot 1

%Sinyal yang dikirim user1 ke user2 timeslot 3
s12=1;
for n=2:length(b(1,:));  
    s12(n)=be_11(n)*s12(n-1);
end
s12=-i*conj(s12);  % di jurnal -js2*
s12_noise=awgn(s12,snr_RD,'measured',ulang);
%%
%Hasil deteksi user2
r2=[real(Rs2);imag(Rs2)];
for k=1:jmluser
    be_2(k,1)=1;
    for n=2:length(b(1,:));
        be_2(k,n)=r2(k,n)*conj(r2(k,n-1));
    end
end

dc_21=(be_2(2,:));         %sinyal s2 
be_21=sign(be_2(1,:));     %sinyal s1

%Sinyal yang dikirim user2 ke user 1 timeslot 2
s21=1;
for n=2:length(b(1,:));
    s21(n)=be_21(n)*s21(n-1);
end
s21=-i*conj(s21);    %di jurnal -js1*
s21_noise=awgn(s21,snr_RD,'measured',ulang);
%Sinyal yang dikirim BS ke user 1 pada timeslot 2
BS_U1_2=real(BS_U11);

%Sinyal yang dikirim BS ke user 2 pada timeslot 3
BS_U2_3=imag(BS_U22);

%Sinyal yang diterima user 1 timeslot 2
Rs21=real(hs1.*BS_U1_2+i*h21.*s21_noise);
Rs21=sign(Rs21);
be_12(1)=1;
for n=2:length(b(1,:));
    be_12(n)=Rs21(n)*conj(Rs21(n-1));
end
dc_12=be_12;

%Sinyal yang diterima user 2 timeslot 3
Rs12=real(hs2.*BS_U2_3+i*h21.*s12_noise);
Rs12=sign(Rs12);
be_23(1)=1;
for n=2:length(b(1,:));
    be_23(n)=Rs12(n)*conj(Rs12(n-1));
end
dc_23=be_23;

decision_1=dc_11+dc_12
decision_1=sign(decision_1);
decision_2=dc_21+dc_23
decision_2=sign(decision_2);

Terima_1=(decision_1+1)/2
Terima_2=(decision_2+1)/2
Terima_total=[Terima_1 Terima_2];

[N(ulang,z+1),BER(ulang,z+1)]=biterr(datauser,Terima_total);
end
end

BER_tot = sum(BER)/coba;

%Teori Validasi
SNR=0:25;
SNRrat=10.^((SNR)./10);
BER2=0.5*erfc(sqrt(0.5*SNRrat));
hold on
semilogy(SNR,BER_tot,'k-^');
%semilogy(SNR,BER2,'o-');

grid on
title('Performance of CTR')   
%title('CTR dengan noise dan kanal absolute')