“…Proof: For any two distinct matrices , , , , and , , , , , if cross-correlation is greater than 1, we have at least two coincidence of pulses of the same spatial channel and wavelength in any cyclic shift of the matrices in time, which means following equations are simultaneously satisfied for , (12) (13) (14) Subtracting (14) from (13), we obtain (15) Since , (15) is valid only when for . As a result, the assumption , , , , , , , , is violated.…”