Power of faded signal after selection combiner

Hello,

I have written a MATLAB code which plots the power of faded signal after passing through selection combiner. For this, I have created two independent Rayleigh faded signals and then used the concept of selection combiner. However, I am getting an error "Subscript indices must be real positive integers or logicals". I would deeply appreciate any help in this matter. Is there any syntax error or am I completely off the topic and my logic is flawed? Following is my code:

N=2000;
Ts = 1e-4; % Sample period (s)
fd = 100; % Maximum Doppler shift

%various channels 
c1 = rayleighchan(Ts,fd); % Generate the channel fade
c2 = rayleighchan(Ts,fd);

sig = ones(2000,1); % Generate signal

y1 = filter(c1,sig);
y2 = filter(c2,sig);

%following code gives the dB values of faded signal
dbval1 = mag2db(abs(y1));
dbval2 = mag2db(abs(y2));

t = (0:N-1)'*Ts

plot(t,dbval1,'b');
ylabel('dB');
xlabel('Time');

hold on

plot(t,dbval2,'r');

for i = 0:N-1
   if dbval1>dbval2
       dbval3(i,:)= dbval1(i,:);
   else
       dbval3(i,:) = dbval2(i,:);
   end

end

plot(t,dbval3, 'g');

Answer 1

[Tasos]

The problem is exactly what the error message says. The indices to your vectors/matrices must start from 1 in Matlab not 0, e.g. i=1:N.