close?all;
clear;clc;
users=2;????????????%?Number?of?Users
%------------------Generation?of?Walsh?code--------------------------------

n?=4;???????????????????????????????%Number?of??Data?Sub-Carriers
walsh=hadamard（n）;??????????????
code1=walsh（2:）;???????????????????%Taking?2nd?row?of?walsh?code?for?User1
code2=walsh（4:）;???????????????????%Taking?3rd?row?of?walsh?code?for?User2

%------------------Generating?data?for?User1-------------------------------

N=10^4;?????????????????????????????%?Number?of?Bits?for??data_user1
data_user1=?rand（1N）>0.5;??????????%?Generation?of?data?for?user1
data_user1bpsk?=?2*data_user1-1;????%?BPSK?modulation?0?->?-1;?1?->?0?

%------------------Spreading?&?IFFT?for?User1------------------------------

data_user11=data_user1bpsk‘;
spdata1_user1=data_user11*code1;????%?Spreading?
spdata12=（spdata1_user1）‘;
ifftdata_user1=ifft（spdata12）;??????%?Taking?the?IFFT
ifftdata12=ifftdata_user1‘;

%------------------Append?Cyclic?Prefix1?for?User1-------------------------

y1=[ifftdata12（:[（n-2）:n]）?ifftdata12];
transdata1=y1‘;
tx_user1=transdata1;????????????????%?Transmitting?data?for?user1

%------------------Generating?data?for?User2-------------------------------

M=10^4;?????????????????????????????%?Number?of?Bits?for??data_user2
data_user2=?rand（1M）>0.5;??????????%?Generation?of?data?for?user2
data_user2bpsk?=?2*data_user2-1;????%?BPSK?modulation?0?->?-1;?1?->?0?

%-----------------Spreading?&?IFFT?for?User2-------------------------------

data_user21=data_user2bpsk‘;
spdata2=data_user21*code2;??????????%?Spreading?
spdata22=（spdata2）‘;
ifftdata_user2=ifft（spdata22）;??????%?Taking?the?IFFT
ifftdata22=ifftdata_user2‘;

%-----------------Append?Cyclic?Prefix1?for?User2--------------------------

y2=[ifftdata22（:[（n-2）:n]）?ifftdata22];
transdata2=y2‘;
tx_user2=transdata2;????????????????%?Transmitting?data?for?user2



%----------------------Adding?data?for?Transmission?of?All?User------------
x=tx_user1+tx_user2;
%----------------------Creating?Rayleigh?Channel---------------------------

Taps=4;????????????????????????????????????????%?Number?of?Taps
p1=0.5/2.3;???????????????????????????????????????%?Power?of?Tap1
p2=0.9/2.3;?????????????????????????????????????%?Power?of?Tap2
p3=0.7/2.3;?????????????????????????????????????%?Power?of?Tap3
p4=0.2/2.3;
gain1=sqrt（p1/2）*[randn（1N）?+?j*randn（1N）];???%?Gain?for?Tap1
gain2=sqrt（p2/2）*[randn（1N）?+?j*randn（1N）];???%?Gain?for?Tap2
gain3=sqrt（p3/2）*[randn（1N）?+?j*randn（1N）];???%?Gain?for?Tap3
gain4=sqrt（p4/2）*[randn（1N）?+?j*randn（1N）];???%?Gain?for?Tap4
x11=x（:）;
x12=reshape（x111length（x11））;
i=1:length（x12）;????????
delay1=1;?
for?i=delay1+1:length（x12）?%?Producing?one?sample?delay?in?Tap2?w.r.t.?Tap1
???x13（i）=x（i-delay1）;
end
delay2=2;
for?i=delay2+1:length（x12）?%?Producing?two?sample?delay?in?Tap2?w.r.t.?Tap1
???x14（i）=x（