Three Code-Mapping Methods for Optical CDMA

Abstract

In this paper, we propose three code-mapping methods, which make use of existing optical codes of one dimension to construct optical codes of a different dimension. A reverse code-mapping method is first introduced, which allows the generation of 1-D prime codes from their 2-D counterparts. Afterwards, the one-to-one correspondence between 1-D and 2-D optical codes is established with the use of the Chinese remainder theorem. This theorem is then used for the first time to generate rare, difficult-to-construct 1-D optical codes of cross-correlation values of at most two. Finally, an improved zero-padding folding method for mapping 1-D to 2-D optical codes with more flexible selection of code parameters than previous methods is detailed.