8qam调制比较

给出了两种8qam调制方法和2种解调方法，通过比较得出误比特率情况

function  sout = demodu_8qam_cir（ sinabtype ）

%%%%%%%%%%%%%%%%%%%%%%%% baisc parameters %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
N = length（sin）;
sout = zeros（1N）;
Psum = （2*b*b+a*a）/2;
Prms = sqrt（Psum）;
%%%%%%%%%%%%%%%%%%%%%%%%%% demodilate 1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 if type==1;
am = zeros（1N）;
thita = zeros（1N）;
c =0.5*（a + b*sqrt（2））/Prms;
lable = b*sqrt（2）>a;
for i=1:N;
am（i） = abs（sin（i））;
thita（i） = angle（sin（i））;
flag = am（i） > c;
if （~xor（flaglable））
    if（thita（i）>0 && thita（i）        sout（i） = 1;
    elseif（thita（i）>pi/2 && thita（i）        sout（i） = 2;
    elseif（thita（i）>-pi && thita（i）<-pi/2）
        sout（i） = 7; 
      else
        sout（i） = 4;
     end;            
else
   if（thita（i）>-pi/4 && thita（i）           sout（i） = 0;
     elseif（thita（i）>pi/4 && thita（i）<3*pi/4）
           sout（i） = 3;
      elseif（thita（i）>-3*pi/4 && thita（i）<-pi/4）
           sout（i） = 5;
     else
           sout（i） = 6;
    end;   
end;

%%%%%%%%%%%%%%%%%%%%%%%%%% 格雷解码 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 if sout（i）==2;sout（i）=3;
    elseif sout（i）==3;sout（i）=2;
    elseif sout（i）==4;sout（i）=7;
    elseif sout（i）==5;sout（i）=6;
    elseif sout（i）==6;sout（i）=4;
    elseif sout（i）==7;sout（i）=5;
  else
     sout（i）=sout（i）;
  end;
end;

%%%%%%%%%%%%%%%%%%%%%%%%%% demodilate 2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
elseif type == 2;
    xp = [ab-b0b0-a-b]/Prms;
    yp = [0bba-b-a0-b]/Prms; 
    dis =zeros（18）;
    for i=1:N;
        for j=1:8
        dis（j） = sqrt（（real（sin（i））-xp（j））.^2 + （imag（sin（i））-yp（j））.^2）;
        end;
        [xxnum] = min（dis）;
        sout（i） = num-1;
%%%%%%%%%%%%%%%%%%%%%%%%%% 格雷解码 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 if sout（i）==2;sout（i）=3;
    elseif sout（i）==3;sout（i）=2;
    elseif sout（i）==4;sout（i）=7;
    elseif sout（i）==5;sout（i）=6;
    elseif sout（i）==6;sout（i）=4;
    elseif sout（i）==7;sout（i）=5;
 else
     sout（i）=sout（i）;
 end;
    end;
    
%%%%%%%%%%%%%%%%%%%%%%%%%% demodilate 3 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%    
elseif type == 3;        
end;

%%%%%%%%%%%%%%%%%%% change the octal sequnece into binary sequnece %%%%%%%%%%%%%%%%%%% 
sout = de2bi（sout3‘left-msb‘）;
sout = reshape（sout‘13*N）;       %change the octal sequnece into binary sequnece
sout = sout‘;   
%%%%%%%%%%%%%%%%%%%%%%   End    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     文件        2421  2013-05-05 21:25  demodu_8qam_cir.m
     文件        3207  2013-05-05 21:25  demodu_8qam_mat.m
     文件         993  2013-05-05 21:25  mapping_cir.m
     文件         974  2013-05-05 21:25  mapping_mat.m
     文件        1265  2013-05-05 21:25  modu_8qam_cir.m
     文件        1250  2013-05-05 21:25  modu_8qam_mat.m
     文件        3560  2013-05-05 21:25  work1.m
     文件        1651  2013-05-05 21:25  work2.m
     文件        1553  2013-05-05 21:25  work3.m
     文件        1851  2013-05-05 21:25  work4.m