Performance of High Order Modulation Formats in Coexistence of Gigabit (GPON) and Next-Generation Passive Optical Network (XG-PON)

The continually increasing of transmission capacity demands are not only matter of a core and metropolitan optical networks but nowadays also local access networks too. Although the transmission rates of first passive optical networks were 622 Mbit/s the current technologies support more than 10 Gbit/s. The rapid development in the last decade opens problem with utilizing of already installed infrastructure and coexistence older standards with new one. The modulation formats like differential phase shift keying and differential quadrature phase shift keying appear to be potential for increasing performance of nowadays used gigabit passive optical networks and next-generation passive optical networks. The simulations show improvement of bit error rate estimation approximately 2 dB.