qam16mod.m

来自「《OFDM关键技术与应用》中16QAM的调制与解调源程序。」· M 代码 · 共 88 行

function Symbol=QAM16Mod(bit)
% 16QAM modulation
% s3 s2 s1 s0    ml   mQ
%  0  0  0  0    3A   3A
%  0  0  0  1     A   3A
%  0  0  1  1    -A   3A
%  0  0  1  0    -3A  3A
%  0  1  0  0    3A    A
%  0  1  0  1     A    A
%  0  1  1  1    -A    A
%  0  1  1  0    -3A   A
%  1  1  0  0     3A  -A
%  1  1  0  1     A   -A
%  1  1  1  1    -A   -A
%  1  1  1  0    -3A  -A
%  1  0  0  0    3A   -3A
%  1  0  0  1    A    -3A
%  1  0  1  1    -A   -3A
%  1  0  1  0    -3A  -3A
% note:A=1/sqrt(10)
%
bitlength=length(bit);
A=1/sqrt(10);

%bit(ii*4)=s3,bit(ii*4-1)=s2,bit(ii*4-2)=s1,bit(ii*4-3)=s0
for ii=1:bitlength/4
    if bit(ii*4)==0
        if bit(ii*4-1)==0  %00**
            if bit(ii*4-2)==0
                if bit(ii*4-3)==0
                    QAM16(ii)=3*A+3*A*j;
                else
                    QAM16(ii)=A+3*A*j;
                end
            else
                if bit(ii*4-3)==0
                    QAM16(ii)=-3*A+3*A*j;
                else
                    QAM16(ii)=-A+3*A*j;
                end
            end
        else   %01**
            if bit(ii*4-2)==0
                if bit(ii*4-3)==0
                    QAM16(ii)=3*A+A*j;
                else
                    QAM16(ii)=-A+A*j;
                end
            else
                if bit(ii*4-3)==0
                    QAM16(ii)=-3*A+A*j;
                else
                    QAM16(ii)=-A+A*j;
                end
            end
        end
    else 
        if bit(ii*4-1)==0  %10**
            if bit(ii*4-2)==0
                if bit(ii*4-3)==0
                    QAM16(ii)=-3*A-3*A*j;
                else
                    QAM16(ii)=-A-3*A*j;
                end
            else
                if bit(ii*4-3)==0
                    QAM16(ii)=-3*A-3*A*j;
                else
                    QAM16(ii)=-A-3*A*j;
                end
            end
        else       %11**
            if bit(ii*4-2)==0
                if bit(ii*4-3)==0
                    QAM16(ii)=-3*A-A*j;
                else
                    QAM16(ii)=-A-A*j;
                end
            else
                if bit(ii*4-3)==0
                    QAM16(ii)=-3*A-A*j;
                else
                    QAM16(ii)=-A-A*j;
                end
            end
        end
    end
end