psk8_t1_r1.m

8PSK误码率分析 误码率（BER：biterror）是衡量数据在规定时间内数据传输精确性的指标。误码率=传输中的误码/所传输的总码数*100 。如果有误码就有误码率。

close all;
clear all;
rand('state',sum(100*clock));%Initialize RAND
randn('state',sum(100*clock));%Initialize RANDN
pi=3.1415926;
PSK8_C=[sqrt(2),1+j,j*sqrt(2),-1+j,-sqrt(2),-1-j,-j*sqrt(2),1-j]; %Signal set
PSK8_B=[0 0 0; 0 0 1;0 1 1;0 1 0;1 1 0;1 1 1;1 0 1;1 0 0]; %Binary mapping

SizeOfSignalSet=size(PSK8_B,1);%The size of the signal set
BitsPerSymbol=size(PSK8_B,2); %number of bits carried by one symbol
Es=sum(PSK8_C.*conj(PSK8_C))/length(PSK8_C); %Average symbol energy
Eb=Es/BitsPerSymbol; %bit energy

recIndex=1;
for EbN0=0:2:30
    N0=Eb*10^(-EbN0/10); %get the noise power,larger equal to 1,lower equal to 10^-3
    testCount=0;
    errCount=0;
    while(1)
        h=(randn(1)+j*randn(1))/sqrt(2);%Generate the channel (Complex gaussian, Rayleigh apmlitude),complex conjugate divide 2

        %Randomly generate a source symbol
        SrcIndex=floor(rand(1)*SizeOfSignalSet)+1;
        x=PSK8_C(SrcIndex); %get the signal symbol

        %Generate the noise
        n=(randn(1)+j*randn(1))/sqrt(2);
        n=n*sqrt(N0); %control the noise power, N0,complex conjugate multiply

        %The channel with noise
        r=h*x+n;

        %Detect the signal
        y=r/h;

        %Decision
        Error=(y-PSK8_C);
        Dist=Error.*conj(Error);%calculate distance of every set
        [minVlaue DecIndex]=min(Dist);%find minimum distance and set
        if(DecIndex ~= SrcIndex)
           errBinary=mod(PSK8_B(SrcIndex,:)+PSK8_B(DecIndex,:),3);%calculate difference of set point
            errCount=errCount+sum(errBinary);%numbers of real error bit 
        end
        testCount=testCount+1;
        testLength=testCount*BitsPerSymbol;%Get the binary length

        %stop control
        if(testLength<100000) %test length lower bound less than 100/10^-3
            continue;
        end
        BER=errCount/testLength;
        if(BER<1e-10)%errCount not equal to naught/zero
            continue;
        end

        testLevel=500.0/BER; %confidence level,errCount >= 10^3 / BitsPerSymbol
        if(testLength>testLevel)
            break;
        end
    end
    BER_rec(recIndex)=BER;%record the test result
    EbN0_rec(recIndex)=EbN0;
    recIndex=recIndex+1;
    
    %Display the results
    BER_rec
    EbN0_rec
end

semilogy(EbN0_rec,BER_rec,'-');
xlabel('Eb/N0 in dB');
ylabel('Bit error ratio');
title('PSK8 relation of Tx1 Rx1 BER');
grid