qpsk_demodulate.m

QPSK_Modulate,DS扩频仿真,QPSK_Demodulate,需要的下吧,大家换换资源.

%QPSK解调程序采用的是何种解调方式相干解调？
function bit=QPSK_Demodulate(Received_Data,d)

mapping=[d,j*d,-d,-j*d];

% numoferr=0;
for i=1:length(Received_Data),
    for k=1:4,
        metrics(k)=abs(Received_Data(i)-mapping(k));
    end;
    
    [min_metric decis]=min(metrics);
    
%     if (mapping(decis)~=Source_Data(i)),
%         numoferr=numoferr+1;
%     end;
    sym(i)=mapping(decis);
end;
for i=1:length(sym)
    if sym(i)==d
        bit(2*i-1)=1;bit(2*i)=1;
    else
        if sym(i)==j*d
            bit(2*i-1)=0;bit(2*i)=1;
        else
            if sym(i)==-d
                bit(2*i-1)=0;bit(2*i)=0;
            else
                if sym(i)==-j*d
                    bit(2*i-1)=1;bit(2*i)=0;
                end
            end
        end
    end
end
         
        
        

% Pe=numoferr;%Pe is error symbol numbers