Indoor optical-wireless code-shift-keying with two-stages demodulation

In this paper, the code-shift-keying (CSK) system using the extended pseudo orthogonal M-sequence (EPOM) is considered in indoor optical-wireless channel. EPOM is one of optical pseudo-noise (PN) codes designed by the fusion of two PN codes. One is the modified pseudo orthogonal M-sequence sets (MPOMS), the other is the bi-orthogonal code. The CSK systems using the combined PN code demodulate with two stages. As the conventional optical PN code with two-stages demodulation, the pseudo-orthogonal extended prime code set (POEPC) has been proposed. This paper focuses on the comparison between the CSK system using EPOM and the CSK system using POEPC under the same information transmission efficiency. Consequently, the CSK system using EPOM is superior to the CSK system using POEPC.