function qtbl(N)

j = sqrt(-1);
signI = [+1 -1 -1 +1]
signQ = [+1 +1 -1 -1]
rot = pi/4;
Ns = sqrt(N)
Nq = N/4
Nsq = sqrt(Nq)
stepIQ = sqrt(2)/(Ns-1)


qq = 1/sqrt(2);
ii = 1/sqrt(2);

even = 1;
c = 1;
close all;
figure(1);
axis ([-1 1 -1 1]);
grid;
hold;
for m=1:Nsq
	for n=1:Nsq
		I = ii;
		Q = qq;
		for q = 0:3,
			IQ(Nq*q+c) = I*signI(q+1) + j*Q*signQ(q+1);
			T = I;
			I = Q;
			Q = T;
		end;
		ii = ii - even*stepIQ;
		c = c + 1;
	end;	
	qq = qq - stepIQ;
	ii = ii + even*stepIQ;
	even = -even;
end;

for c=1:N,
sym =  c - 1
    plot(IQ(c), '+');
    pause;
end;
IQ