orthogonal code & interleaving

When I consider orthogonal code (e.g., 01 and 10 for two sequences), I got the same as the interleaving mechanism, really funnly. If I use 11 and 1-1 like what has been done in CDMA, I will come up with values beyond 1 and 0 so that the length of the signal is actually spreaded almost four times the original signal, which is frustrating in my approach, in other words, the interleaving mechanism is a better choice.