clear?all;
Nt=2;
Nr=1;
M=4;
Sdata=256;?????????%?256?data?symbol?per?frame?to?ifft
Slen=256;????
Nsym=200;%?幀數(shù)
GI=Sdata/4;%?guard?interval?length
GIlen=GI+Slen;%?symbol?with?GI?insertion
Ndata=Sdata*Nsym;????%?all?transmitted?data?symbol?
%A=[1?1/exp（0.5）?];%功率時延譜
%?h1=[10.5];
h1=[1?0.5?0.25];
H1=diag（fft（h1Sdata+GI））;
%?h2=[10.6];
h2=[1?0.5?0.25];
H2=diag（fft（h2Sdata+GI））;
SNR=0:2:20;
constellation=qammod（（0:M-1）M）;

tx_bit?=?randint（Ndata1?M）;

S1=[];
S2=[];
for?ii=1:length（SNR）
????error=0;
????
???for?jj=1:Nsym
???????G1=[];
???????G2=[];
???????x=zeros（Sdata1）;
???????for?i=1:Sdata
????????y（i）=tx_bit（i+（jj-1）*Sdata）;
??????y=y.‘;
???????end
?????y_sym=qammod（yM）;
%?????for?k=1:Sdata/2
%?????????S1（2*k-1）=y_sym（2*k-1）;
%?????????S1（2*k）=-conj（y_sym（2*k））;
%?????????S2（2*k-1）=（y_sym（2*k））;
%?????????S2（2*k）=conj（y_sym（2*k-1））;
%?????????
%?????end
%?????S1_ofdm=ifft（S1）;
%?????S2_ofdm=ifft（S2）;
%?????for?i=1:Sdata
%?????????G1（i+GI）=S1_ofdm（i）;
%?????????G2（i+GI）=S2_ofdm（i）;
%?????end
%?????for?i=1:GI
%?????????G1（i）=S1_ofdm（i+Sdata-GI）;
%?????????G2（i）=S2_ofdm（i+Sdata-GI）;
%?????end
%?????G1=G1.‘;
%?????G2=G2.‘;
%?????[H?h_f]=creat_channel（NtNrASdata+GI）;
%????for??i=1:（Sdata+GI）
%?????????G（2*i-1）=G1（i）;
%?????????G（2*i）=G2（i）;
%????end
%?????G=G.‘;
%?????x=H*G;
???%?x=x+sqrt（0.5/（10^（SNR（ii）/10）））*（randn（size（x））+j*randn（size（x）））;
%?????x=H1*G1+H2*G2;
%?????rec_time_symbol=x（GI+1:end）;
%??????rec_symbol=fft（rec_