A new family of wavelength-time codes for optical CDMA

In this paper, a new family of wavelength-time codes, which is based on (n, w, 1, 2) time-spreading optical orthogonal codes (OOCs), is proposed. By having cross-correlation values of at most two, the new two-dimensional (2D) codes provide larger code cardinality to accommodate more subscribers and support heavier code weight to result in better code performance. Under certain conditions, our results show that the new codes outperform other 2D codes that have the cross-correlation values of at most one, such as our previously studied multiple-wavelength OOCs and 2D codes based on (n, w, 2, 1) OOCs.