generating unique random numbers with aes

I m studiying the possibility of generating unique random number with AES-128. When the input is unique, the output is also unique after executing the AES algorithm. The execution of the ares algorithm results a kind of vector let's note by Rand[].
Let's note the pseudo-random number pingOffset = (Rand[0] + Rand[1]x 256) modulo Period (the parameter "period indicates a periodicity fixed number for every pingOffset generation). Can I confirm so that the pingOffset is unique for every unique input. (The input is unique beacause it consist of a device address which is unique).