function softbit=QAM64Demod(symbol)
% 64QAM解調(diào)
% bin=sequence of 0/1bit
% 64QAM:    s5  s4  s3  s2  s1  s0      m1       mQ
%           0   0   0   0   0   0       3A       3A
%           0   0   0   0   0   1       3A       A
%           0   0   0   0   1   1        A       A 
%           0   0   0   0   1   0        A       3A
%           0   0   0   1   0   0       3A       5A   
%           0   0   0   1   0   1       3A       7A   
%           0   0   0   1   1   1        A       7A
%           0   0   0   1   1   0        A       5A
%           0   0   1   1   0   0       5A       5A
%           0   0   1   1   0   1       5A       7A
%           0   0   1   1   1   1       7A       7A
%           0   0   1   1   1   0       7A       5A
%           0   0   1   0   0   0       5A       3A
%           0   0   1   0   0   1       5A       A
%           0   0   1   0   1   1       7A       A
%           0   0   1   0   1   0       7A      3A

%           0   1   0   0   0   0       3A       -3A
%           0   1   0   0   0   1       3A       -A
%           0   1   0   0   1   1        A       -A 
%           0   1   0   0   1   0        A       -3A
%           0   1   0   1   0   0       3A      - 5A   
%           0   1   0   1   0   1       3A       -7A   
%           0   1   0   1   1   1        A       -7A
%           0   1   0   1   1   0        A       -5A
%           0   1   1   1   0   0       5A       -5A
%           0   1   1   1   0   1       5A      - 7A
%           0   1   1   1   1   1       7A      - 7A
%           0   1   1   1   1   0       7A      - 5A
%           0   1   1   0   0   0       5A      - 3A
%           0   1   1   0   0   1       5A      - A
%           0   1   1   0   1   1       7A      - A
%           0   1   1   0   1   0       7A      -3A

%           1   1   0   0   0   0       -3A       -3A
%           1   1   0   0   0   1       -3A       -A
%           1   1   0   0   1   1       -A        -A 
%           1   1   0   0   1   0       -A        -3A
%           1   1   0   1   0   0       -3A      - 5A   
%           1   1   0   1   0   1       -3A       -7A   
%           1   1   0   1   1   1       -A       -7A
%           1   1   0   1   1   0       -A       -5A
%           1   1   1   1   0   0       -5A       -5A
%           1   1   1   1   0   1       -5A      - 7A
%           1   1   1   1   1   1       -7A      - 7A
%           1   1   1   1   1   0       -7A      - 5A
%           1   1   1   0   0   0       -5A      - 3A
%           1   1   1   0   0   1       -5A      - A
%           1   1   1   0   1   1       -7A      - A
%           1   1   1   0   1   0       -7A      -3A

%           1   0   0   0   0   0       -3A       -3A
%           1   0   0   0   0   1       -3A       -A
%           1   0   0   0   1   1       -A        -A 
%           1   0   0   0   1   0       -A        -3A
%           1   0   0   1   0   0       -3A      - 5A   
%           1   0   0   1   0   1       -3A       -7A   
%           1   0   0   1   1   1       -A       -7A
%           1   0   0   1   1   0       -A       -5A
%           1   0   1   1   0   0       -5A       -5A
%           1   0   1   1   0   1       -5A      - 7A
%           1   0   1   1   1   1       -7A      - 7A
%           1   0   1   1   1   0       -7A      - 5A
%           1   0   1   0   0   0       -5A      - 3A
%           1   0   1   0   0   1       -5A      - A
%           1   0   1   0   1   1       -7A      - A
%           1   0   1   0   1   0       -7A      -3A
%  note:A=1/sqrt(42)
%
bitlength=length(bit);
A=1/sqrt(42);
% bit(ii*6)=s5,bit(ii*6-1)=s4,bit(ii*6-2)=s3,bit(ii*6-3)=s2,bit(ii*6-4)=s1,
% bit(ii*6-5)=s0
symlength=length(symbol);
A=1/sqrt(42);
for ii=1:symlength
    symangle=angle(symbol(ii));
    symabsreal=abs(real(symbol(ii)));
    symabsimag=abs(imag(symbol(ii)));
    if symangle>0&symangle<=pi/2
        softbit(ii*6-1:ii*6)=[00];
    elseif symangle>pi/2&symangle<=pi
        softbit(ii*6-1:ii*6)=[01];
    elseif symangle>-pi/2&symangle<=0
        softbit(ii*6-1:ii*6)=[10];
    else
        softbit(ii*6-1:ii*6)=[11];
    end
    if abs(symabsreal<4*A)
        softbit(ii*6-2)=0;
    if abs(symabsreal<2*A)
        softbit(ii*6-4)=1;
    else
        softbit(ii*6-4)=0;
    end
    else
        softbit(ii*6-2)=1;
        if abs(symabsreal<6*A)
            softbit(ii*6-4)=0;
        else
            softbit(ii*6-4)=1;
        end
    end
        if abs(symabimagingl<4*A)
            softbit(ii*6-3)=0;
            if abs(symabimagingl<2*A)
                softbit(ii*6-5)=1;
            else
                softbit(ii*6-5)=0;
            end
        else
            softbit(ii*6-3)=1;
            if abs(symabimagingl<6*A)
                softbit(ii*6-5)=0;
            else
                softbit(ii*6-5)=1;
            end
        end
end