Adaptive Frequency-Domain Power Optimization for NOMA-SCM Passive Optical Networks

In this paper, we experimentally demonstrate a non-orthogonal multiple access (NOMA) based subcarrier multiplexing (SCM) with an adaptive frequency-domain power optimization for 50Gb/s passive optical network (PON). In the NOMA-based SCM PON, the signals for different optical network units (ONUs) can be multiplexed in both frequency-domain and power domain to increase the number of access subscribers. Due to the limited bandwidth and chromatic dispersion, the high-frequency subcarriers suffer from severe power fading. The maximum number of access subscribers is limited by the performance of high-frequency subcarriers. We propose the adaptive frequency-domain power optimization to improve the performance of high-frequency subcarriers for maximizing the number of access subscribers. The experimental results show that number of access subscribers in the 50Gb/s NOMA-based SCM PON is twice that in the SCM PON when the adaptive frequency-domain power optimization is employed.