Subcarrier Digital Modulation Based Passive Optical Network

This paper proposes a Subcarrier Digital Modulation based Passive Optical Network (SDM-PON) architecture to economically provide higher bit rate services to users. As a first step, we assume that 16-QAM is used as a digital modulation, and service bit rate of 1 Gbps is constantly provided to each user. To examine its feasibility, we first discuss an electrical SDM-PON that yields comprehensive studies by simplified simulations. We next investigate an optical SDM-PON that is our objective. For an electrical SDM-PON, we show the feasibility of the system that supports up to 32 ONUs. For an optical SDM-PON, we show that the system can support up to 16 ONUs; we clarify each ONU needs to send signals using different wavelength to avoid the beating noise. We also propose a new assignment of subcarriers to the wavelengths to increase the interval of the subcarrier frequency in the optical domain. We also specify the subcarrier frequencies for an optical SDM-PON.