Performance Comparison of OIDMA and Optical LDS-CDMA

Non-orthogonal multiple-access (NOMA) schemes are viable solutions to enhance the spectral efficiency of wire-less networks. In this paper, we modify the interleave-division multiple-access (IDMA) and low-density spreading code-division multiple-access (LDS-CDMA) techniques for use in non-coherent optical communications, such as visible light communications (VLC) systems, and compare their performance. Simulation results show that optical IDMA outperforms optical LDS-CDMA in terms of bit-error rate (BER).