Sum capacity of the OCDMA/OCDMA signature sequence set

The sum capacity of the OCDMA/OCDMA (O/O) signature sequence set is investigated under the assumption of equal average-input-energy constraints and perfect synchronization of the users. It is shown that the spectral efficiency of the O/O signature sequence set is only dependent on the SNR and load, but independent of the choice of the orthogonal bases. Moreover, this sequence set is found to be only slightly less efficient in terms of sum capacity than the Welch-bound equality sequences.