Theoretical analysis of parallel combinatory spread-spectrum communication system for optical wireless communications

In this paper, an N-CSK (N parallel Codes Shift Keying) using modified pseudo orthogonal M-sequence sets (MPOMS) for applying the parallel combinatory spread-spectrum (PC/SS) communication system to the optical communication is presented. Moreover, the bit error rate (BER) performance and the data transmission rate of the proposed system are evaluated through theoretical analysis by taking into account the scintillation, background-noise, avalanche photodiode (APD) noise, thermal noise, and signal dependence noise. Also, the performance comparison between the proposed system and the conventional systems (OOK/CDM, SIK/CDM, and N-CSK/CDM) are presented. Consequently, the proposed system can realize high data rate optical wireless communication because the data transmission rate of the proposed system is better than those of the conventional systems, and can achieve more than 1.0 [bit/chip].