Two-dimensional projection histogram assisted with low-overhead pilots for the common phase error compensation in CO-OFDM system

摘要

In this paper, we demonstrate a two-dimensional projection histogram assisted common phase error (CPE) compensation scheme in coherent optical orthogonal frequency division multiplexing (CO-OFDM) system. With the help of the low overhead pilots, the rough estimation can be obtained, and the pi/2 deviation problem of projection histogram (PH) assisted scheme can be efficiently solved, which can improve the estimation accuracy of CPE. And, with the processing of the two-dimensional projection histogram mapping, the fine estimation can be achieved. The numerical CO-OFDM system simulations over the single mode fiber (SMF) transmission are conducted. The corresponding results show that, compared to the pilot-aided (PA) estimation method, only lessoverhead pilots were employed for our scheme, but more accurate CPE estimation can be achieved, hence improving the system performance. Moreover, to achieve an optimal transmission performance, the overhead of pilots for the PA method should be set to 20%, while the proposed method can reduce to 1.25%.