%DD解相關多用戶檢測器和CD傳統多用戶檢測器的誤碼率比較（八個用戶）
clear?all;
snr_indb=0:8;
for?k=1:length（snr_indb）
snr=10^（snr_indb（k）/10）;
sgma=1;
eb=2*（sgma^2）*snr;
LC=31;
echip=eb/LC;
N=10000;%number?of?bits??transmitted
%creat?PN?codes
fbconnection=[0?1?0?0?1];?
mseq=m_sequence（fbconnection）;?
fbconnection1=[0?0?1?0?1];
fbconnection2=[0?1?1?1?1];?
goldseq=gold_seq（fbconnection1fbconnection2）;?
%N=2^length（fbconnection）-1;?
ind1=find（mseq==0）;
mseq（ind1）=-1;
ind2=find（goldseq==0）;
goldseq（ind2）=-1????????????%creat?31*31?gold?sequence
temp=goldseq;
pn_seq1=temp（3:）;
pn_seq2=temp（4:）;
pn_seq3=temp（7:）;
pn_seq4=temp（10:）;
pn_seq5=temp（15:）;
pn_seq6=temp（20:）;
pn_seq7=temp（26:）;
pn_seq8=temp（31:）;

%?comput??matrix?R
pp=[pn_seq1;pn_seq2;pn_seq3;pn_seq4;pn_seq5;pn_seq6;pn_seq7;pn_seq8];
RR=（1/LC）*pp*pp‘;
R=inv（RR）;

%generate??codes

for??i=1:N
temp1=rand;
if（temp1<0.5）dsource1（i）=-1;
else???dsource1（i）=1;
end;
temp2=rand;
if（temp2<0.5）dsource2（i）=-1;
else???dsource2（i）=1;
end;
temp3=rand;
if（temp3<0.5）dsource3（i）=-1;
else???dsource3（i）=1;
end;
temp4=rand;
if（temp4<0.5）dsource4（i）=-1;
else???dsource4（i）=1;
end;
temp5=rand;
if（temp5<0.5）dsource5（i）=-1;
else???dsource5（i）=1;
end;
temp6=rand;
if（temp6<0.5）dsource6（i）=-1;
else???dsource6（i）=1;
end;
temp7=rand;
if（temp7<0.5）dsource7（i）=-1;
else???dsource7（i）=1;
end;
temp8=rand;
if（temp8<0.5）dsource8（i）=-1;
else???dsource8（i）=1;
end;
end;

number_of_err=0;
number_of_err1=0;

for??i=1:N
%將每個bit?repeat?LC=31?times
for??j=1:LC
????repeatdata1（j）=dsource1（i）;
????repeatdata2（j）=dsource2（i）;
????repeatdata3（j）=dsource3（i）;
????repeatdata4（j）=dsource4（i）;
????repeatdata5（j）=dsource5（i）;
????repeatdata6（j）=dsource6（i）;
????repeatdata7（j）=dsource7（i）;
????repeatdata8（j）=dsource8（i）;
end;
%tranmit?signal?is:

trans_sig1=sqrt（echip）*?repeatdata1.*pn_seq1;
trans_sig2=sqrt（echip）*?repeatdata2.*pn_seq2;
trans_sig3=sqrt（echip）*?repeatdata3.*pn_seq3;
trans_sig4=sqrt（echip）*?repeatdata4.*pn_seq4;
trans_sig5=sqrt（echip）*?repeatdata5.*pn_seq5;
trans_sig6=sqrt（echip）*?repeatdata6.*pn_seq6;
trans_sig7=sqrt（echip）*?repeatdata7.*pn_seq7;
trans_sig8=sqrt（echip）*?repeatdata8.*pn_seq8;

%add?AWGN??noise
noise=sgma*randn（1LC）;
?%?receive?signal
?for??j=1:LC
?????rtemp（j）=trans_sig1（j）+trans_sig2（j）+trans_sig3（j）+trans_sig4（j）+trans_sig5（j）+trans_sig6（j）+trans_sig7（j）+trans_sig8（j）;
?end;
?r=rtemp+noise;
r1=r;r2=r;r3=r;r4=r;r5=r;r6=r;r7=r;r8=r;

%CD?JUDGE
I1=sum（r1.*pn_seq1）;
I2=sum（r2.*pn_seq2）;
I3=sum（r3.*pn_seq3）;
I4=sum（r4.*pn_seq4）;
I5=sum（r5.*pn_seq5）;
I6=sum（r6.*pn_seq6）;
I7=sum（r7.*pn_seq7）;
I8=sum（r8.*pn_seq8）;

%?DD?JUDGE
I=R*[I1I2I3I4I5I6I7I8]‘;


%?DD?make?decision
if（I（1）<0）?desion1=-1;
else?desion1=1;
end;
if（I（2）<0）?desion2=-1;
else?desion2=1;
end;
if（I（3）<0）?desion3=-1;
else?desion3=1;
end;
if（I（4）<0）?desion4=-1;
else?desion4=1;
end;
if（I（5）<0）?desion5=-1;
else?desion5=1;
end;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件????????328??2007-06-03?19:08??MUD\goldseq.m

?????文件????????283??2007-06-03?19:08??MUD\m_sequence.m

?????文件???????5758??2007-06-04?10:43??MUD\mmse.m

?????文件???????3760??2007-06-03?19:08??MUD\sig.m

?????文件???????4790??2007-06-03?19:08??MUD\ddmulti_detect.m

?????文件????????315??2007-06-03?19:08??MUD\gold_seq.m

?????文件????????276??2007-06-03?19:08??MUD\goldcreat.m

?????目錄??????????0??2007-08-07?16:44??MUD

-----------?---------??----------?-----??----

????????????????15510????????????????????8