Study on the Characteristics of Matched Filtering for Coherent Optical Fiber Transmission System

Abstract

Aiming at the influence of matched filter (e.g.root raised cosine filter) on the coherent optical fiber communication system, the effect of roll-off factor (Rf) are studied under different value of optical bandwidth, residual dispersion and nonlinearity. Simulations are carried out for 256 Gbit/s Polarization Division Multiplexing-16 Quadrature Amplitude Modulation (PDM-16QAM) signals when the optical bandwidth are 33, 50 and 100 GHz, the residual dispersion ranging from-300 to 300 ps/nm and launched power ranging from-3 to 4 dBm in a 1 200 km optical fiber link. The simulations show that a good transmission performance can be achieved for limited optical bandwidth system when Rfis set to the value of (1+Rf) B (Bis the Baud rate of the signal) that similar to the system optical bandwidth. When optical bandwidth near or exceed 2 times Baud rate of signals, Rfshould be set between 0.2 and 0.5 to achieve a better transmission performance.

Keywords

• coherent optical communications
• matched filter
• root raised cosine
• single mode fiber