SCMA中的消息传递算法MPA仿真程序.txt

1、function X,repeat_times=MPA(y,sigma2)%X=zeros(6,2);Lx=zeros(4,24);Ly=zeros(4,24);itera_max=10; %itera_count=0;L_getx=zeros(1,4);L_gety=zeros(3,4);rota_angle=1,exp(1i*2*pi/3),exp(1i*4*pi/3);F=1 1 1 0 0 0;1 0 0 1 1 0;0 1 0 1 0 1;0 0 1 0 1 1;for row_index=1:4 r=1; for column_index=1:6 if F(row_index,co

2、lumn_index)=1 F(row_index,column_index)=rota_angle(r); r=r+1; end endendglobal cdbook1 cdbook2cdbook1=0.4472+1.3416*1i,1.3416 - 0.4472*1i,-1.3416+0.4472*1i,-0.4472-1.3416*1i;cdbook2=1.3416+0.4472*1i,0.4472 - 1.3416*1i,-0.4472+1.3416*1i,-1.3416-0.4472*1i; %00 10 01 11% cdbook=-1-1i,1-1i,-1+1i,1+1i;c4

3、=de2bi(0:3);% 00 10 01 11% map=1 1 1 0 0 0;2 0 0 1 1 0;0 2 0 2 0 1;0 0 2 0 2 2;for k1=1:4 for k2=1:6 if F(k1,k2)=0 Ly(k1,(k2-1)*4+1)=0.25; Ly(k1,(k2-1)*4+2)=0.25; Ly(k1,(k2-1)*4+3)=0.25; Ly(k1,(k2-1)*4+4)=0.25; end endend% X_before2=zeros(1,12);X_before1=ones(1,12);X=X_before1-1;%for itera_count=1:i

4、tera_max %*Lx* for row_index=1:4 x_loca=find(F(row_index,:); %yx for t=1:3 column_index=x_loca(t); ent_k=1 2 3; ent_k(t)=; for k=1:3 % L_gety(k,1)=Ly(row_index,(x_loca(k)-1)*4+1); L_gety(k,2)=Ly(row_index,(x_loca(k)-1)*4+2); L_gety(k,3)=Ly(row_index,(x_loca(k)-1)*4+3); L_gety(k,4)=Ly(row_index,x_loc

5、a(k)*4); end %,3x64 x_map=zeros(1,3); for x_k=1:4 %xkt x_map(t)=const_map(x_k,row_index,x_loca(t);% for k2=1:4 x_map(ent_k(1)=const_map(k2,row_index,x_loca(ent_k(1);% for k3=1:4 x_map(ent_k(2)=const_map(k3,row_index,x_loca(ent_k(2);% x_map_rota=x_map.*rota_angle; y_map=sum(x_map_rota); temp=L_gety(e

6、nt_k(1),k2)*L_gety(ent_k(2),k3); dif_y(k2,k3)=y(row_index)-y_map; Lx_xk_temp(k2,k3)=temp*exp(-0.5/sigma2*(abs(dif_y(k2,k3)2); end end Lx(row_index,(column_index-1)*4+x_k)=sum(sum(Lx_xk_temp); end %normalization lamada=1/(Lx(row_index,(column_index-1)*4+1)+Lx(row_index,(column_index-1)*4+2)+Lx(row_in

7、dex,(column_index-1)*4+3)+Lx(row_index,(column_index-1)*4+4); Lx(row_index,(column_index-1)*4+1)=lamada*Lx(row_index,(column_index-1)*4+1); Lx(row_index,(column_index-1)*4+2)=lamada*Lx(row_index,(column_index-1)*4+2); Lx(row_index,(column_index-1)*4+3)=lamada*Lx(row_index,(column_index-1)*4+3); Lx(r

8、ow_index,(column_index-1)*4+4)=lamada*Lx(row_index,(column_index-1)*4+4); end end%*Ly*for column_index=1:6 y_loca=find(F(:,column_index); % xy for t=1:2 row_index=y_loca(t); % for k=1:2 if k=t L_getx(1)=Lx(y_loca(k),(column_index-1)*4+1); L_getx(2)=Lx(y_loca(k),(column_index-1)*4+2); L_getx(3)=Lx(y_

9、loca(k),(column_index-1)*4+3); L_getx(4)=Lx(y_loca(k),(column_index*4); end end for k1=1:4 Ly(row_index,(column_index-1)*4+k1)=L_getx(k1); end % lamada=1/(Ly(row_index,(column_index-1)*4+1)+Ly(row_index,(column_index-1)*4+2)+Ly(row_index,(column_index-1)*4+3)+Ly(row_index,(column_index-1)*4+4); Ly(r

10、ow_index,(column_index-1)*4+1)=lamada*Ly(row_index,(column_index-1)*4+1); Ly(row_index,(column_index-1)*4+2)=lamada*Ly(row_index,(column_index-1)*4+2); Ly(row_index,(column_index-1)*4+3)=lamada*Ly(row_index,(column_index-1)*4+3); Ly(row_index,(column_index-1)*4+4)=lamada*Ly(row_index,(column_index-1

11、)*4+4); endendend%*X*for t=1:6 y_loca=find(F(:,t); p00=Lx(y_loca(1),(t-1)*4+1)*Lx(y_loca(2),(t-1)*4+1); p10=Lx(y_loca(1),(t-1)*4+2)*Lx(y_loca(2),(t-1)*4+2); p01=Lx(y_loca(1),(t-1)*4+3)*Lx(y_loca(2),(t-1)*4+3); p11=Lx(y_loca(1),(t-1)*4+4)*Lx(y_loca(2),(t-1)*4+4); p=p00,p10,p01,p11;% ,K=max(p);% X_jud

12、ge(t,:)=c4(K,:); X_judge_out(t,:)=log(p10+p11)/(p01+p00),log(p01+p11)/(p10+p00);end% X=reshape(X_judge,1,12);% if itera_count1% if X_before1=X% repeat_times=itera_count;% itera_count=itera_max; % % end% else if itera_count=itera_max% repeat_times=itera_max;% end% end% end % endrepeat_times=10;X=reshape(X_judge_out,1,12);end