i am calculating bit error rate for bpsk modulation scheme. i get error that matrix size of transmitted and received data is not equal. how can i fix it? code is attached in body. Please anybody can help me out.

clc;clear all;close all;
mat=randint(1,1000);
sig1=(2*mat)-1;                     % mat converted to matrix of 1 and -1 form
len=length(sig1);                     % length of input data seq.
x=0:1/10:len*2*pi;
y=sin(x);                           % sinusoidal signal
len1=length(y);
len2=len1/len;                      % l2 is the length of one period of signal
j=1;

for i=1:len
   for k=1:len2
           z(j)=y(j)*sig1(i);       % multiply signal with corresponding bits
           sig(j)=sig1(i);          % stretch the data sequence
           k=k+1;
           j=j+1;
   end
  i=i+1;
end
ln=length(sig);
for i=1:ln
    if sig(i)<0
       sig(i)=0;
    end
end    
subplot(3,1,1);
stairs(sig,'linewidth',2); % display data sequence
axis([0 ln -2 3]);
title('Input data Sequence');
ylabel('Amplitude--->');
xlabel('Time--->');
subplot(3,1,2);
plot(y);axis([0 ln -1 1]);                            %plot sinusoidal signal
title('Sinusoidal Signal');
ylabel('Amplitude--->');
xlabel('Time--->');
subplot(3,1,3);
plot(z); axis([0 ln -1 1]);                           %plot the psk modulated signal
title('PSK Modulated Signal');
ylabel('Amplitude--->');
xlabel('Time--->');

   l0=length(y); 
   l1=length(z);
   for i=1:l1
       y1(i)=y(i);                   % Make both PSK signal matrix and carrier of same size
   end

   % Demodulation Of PSK signal
   for i=1:l1
        dsig(i)=y1(i)*z(i);          % Multiply with carrier
    end
  %   figure
  %   plot(dsig);

   % Process to make as 0 and 1 sequence
    for i=1:l1
       if dsig(i)>0
          dsig2(i)=1;
       else
          dsig2(i)=0;
       end    
   end
   figure
    stairs(dsig2,'linewidth',2); axis([0 ln -2 3]);
   title('Demodulated data Sequence');
   ylabel('Amplitude--->');
   xlabel('Time--->');
   [Num,rat] = biterr(mat,dsig2)