Performance evaluation of single carrier 40-Gbit/s downstream for long-reach passive optical networks

This paper presents a new long reach PON (LR-PON) scenario operating at a single carrier of 40-Gbit/s for downstream, as an upgrade option of the LR-PON evolutionary strategy. An electrical 3-level duobinary modulation format was proposed for the 40-Gbit/s downstream transmission. In this paper the required optical signal to noise ratio (OSNR) and optical power budget were investigated based on analytic calculation of OSNR requirements and cascaded analysis with an optical link model. Numerical simulation results show that the 40-Gbit/s downstream operating at the wavelength of 1.5 μm can support a long reach up to 100 km and a high split ratio up to 256.