spreadunitray.m

这是一个TD-SCDMA系统的RAKE接收模型

clear all ;
close all

randn('state',sum(100*clock)); %reset the randn generator

minTestLength=100000; % test length should at least reach this number
maxTestLength=100000000; %test stops at this number 
% unitray matrix
matrix0=ones(6,1);
smatrix=diag(exp([i*2*pi/64 i*2*pi*18/64 i*2*pi*23/64 i*2*pi*39/64 i*2*pi*46/64 i*2*pi*57/64]));
Es=1;
Eb=Es;
index=1;

for EbN0=1:2;
N0=10^(-EbN0/10);
noiseRoot=sqrt(N0/2);
errorCount=0;
testCount=0;

while(1)
h0=(randn(1)+j*randn(1))*sqrt(0.5);


noise=(randn(16,44)+j*randn(16,44))*noiseRoot;

source=randn(1,42)>0; % source 
changesource=reshape(source,6,7);

dsource=zeros(6,7); % after decesion sign matrix

spreadcode1=zeros(1,44);% spread array 

unitraymatrix=zeros(6,7);  % unitray modulate matrix

rmatrix=zeros(1,42);   % receive matrix

rsource=zeros(1,42);  % after despread  sign

index1=1;
for ii=1:7  % construct unitrary matrix
number(index1)=[32 16 8 4 2 1]*changesource(:,ii);
index1=index1+1;
end

for iii=1:7 % construct matrix
smatrix1=smatrix^number(iii)*matrix0;
unitraymatrix(:,iii)=unitraymatrix(:,iii)+smatrix1;
end

spreadcode1=[reshape(unitraymatrix,1,42) zeros(1,2)];% symbols frame 

% t1=(randn(1,44))+j*(randn(1,44));
source1 =spreadcode1*WQ(1);
x1 = ovsf(1)' * source1;                 % spreading
s1 = x1.*(scramble'*ones(1,44));               

t2=(randn(1,44))+j*(randn(1,44));
source2 = t2*WQ(2);
x2 = ovsf(2)' * source2;                 % spreading
s2 = x2.*(scramble'*ones(1,44));               

 s = h0*(s1 + s2)+noise;
% s=s1+s2;

y1 = reshape(s,1,44*16) ;
%y = y + 1/sqrt(2)*( randn(size(y)) + j*randn(size(y)))*5;
r = reshape(y1,16,44);

% y2 = reshape(s,1,44*16) ;
% y = y + 1/sqrt(2)*( randn(size(y)) + j*randn(size(y)))*5;
% r2 = reshape(y2,16,44);

z1 = ones(44, 1)*scramble.*(ones(44, 1)*ovsf(1))*r;
rs1 = reshape(diag(z1)/16,1,44)./WQ(1);

%z11 = ones(44, 1)*scramble.*(ones(44, 1)*ovsf(1))*r2;
% rs11 = reshape(diag(z1)/16,1,44)./WQ(1);


 % z2 = ones(44, 1)*scramble.*(ones(44, 1)*ovsf(2))*r;
 % rs2 = reshape(diag(z2)/16,1,44)./WQ(2);
 for mmm=1:42
     rematrix(mmm)=rs1(mmm);
 end
 
dmatrix=reshape(rematrix,6,7);

for nn=1:7
    n=0;
    for nnn=0:63
     TR=trace( dmatrix(:,nn)'*(smatrix^nnn*matrix0)*(smatrix^nnn*matrix0)'*dmatrix(:,nn));
    % max angle
        if TR>n
         n=TR;
         length=nnn;
     end
 end
 dst=de2bi(length,6,'left-msb');
 dsource(:,nn)=dsource(:,nn)+dst';
end
rsource=reshape(dsource,1,42);
err=xor(rsource,source);
        errorCount=errorCount+sum(err);
        testCount=testCount+42;
        if(testCount<minTestLength)
            continue;
        end
        tempBER=errorCount/testCount;

         %test if the test length is large enough
        if(tempBER>0)
            thresholdTestLength=100/(tempBER);
        else
            thresholdTestLength=maxTestLength;
        end
        
        %Stop current EbN0 test when the test threshold is reached
        if(testCount>=thresholdTestLength)
            myTestLength(index)=testCount;
            Es=Eb/2;
            myEsN0(index)=10*log10(Es/N0)
            myEbN0(index)=EbN0
            myBER(index)=tempBER
            index=index+1;
            break;
        end
    end
end

%Draw curves for the results,Eb/N0
figure(1)
semilogy(myEbN0,myBER,'*-');
xlabel('Eb/N0 in dB');
ylabel('bit error rate');
grid

%Draw curves for the results, Es/N0
figure(2)
semilogy(myEsN0,myBER,'+-');
xlabel('Es/N0 in dB');
ylabel('bit error rate');
grid