% 
%	function y = sqr_rc(L,eta,betta)
%
%
%	L = pulse length (length times the symbol time)
%	eta = oversampling (# points per T)
%	betta = roll off factor 0 < betta < 1
%
%
%	Written by P. Orten, july 1996

function y = sqr_rc(L,eta,betta)

if (rem(L*eta,2) == 1) 
   i=(L*eta+1)/2;                      % odd number of taps
   for k = 1/eta:1/eta:L/2
       i= i+1;	
       if ( k == 1/(4*betta) )
	      k = k +0.000000001
       end
       h1(i)= sin( pi*(1-betta)*(k)) ...
				    /( pi*(1-(4*betta*(k)) ^2)*(k));
       h2(i) =  4*betta*(k)*cos(pi*(1+betta)*(k)) ...
			/( pi*(1-(4*betta*(k)) ^2)*(k));
       h1(L*eta-i+1) = h1(i);
       h2(L*eta-i+1) = h2(i);	
   end
   h= h1+h2;
   h((L*eta+1)/2) = (4*betta+pi*(1-betta)) / pi;
else
   i=(L*eta)/2;                     % even number of coefficients
   for k = 1/eta/2:1/eta:L/2
       i= i+1;	
       if ( k == 1/(4*betta) )
	      k = k +0.000000001
       end
       h1(i)= sin( pi*(1-betta)*(k)) ...
				    /( pi*(1-(4*betta*(k)) ^2)*(k));
       h2(i) =  4*betta*(k)*cos(pi*(1+betta)*(k)) ...
			/( pi*(1-(4*betta*(k)) ^2)*(k));
       h1(L*eta-i+1) = h1(i);
       h2(L*eta-i+1) = h2(i);	
   end
   h = h1+h2;
end %if rem

y= h;

return;