Chromatic Dispersion Estimation Based on CAZAC Sequence for Optical Fiber Communication Systems

Feilong Wu,Yaojun Qiao,Peng Guo,Aiying Yang

doi:10.1109/access.2019.2944026

Abstract

We propose a chromatic dispersion (CD) estimation method based on constant amplitude zero-autocorrelation (CAZAC) sequence and fractional Fourier transform (FrFT) algorithm for optical fiber communication systems, which extends the application of CAZAC sequence. By applying FrFT on the CAZAC sequence signal, the optimal order is searched and employed to estimate the accumulated CD because that the CAZAC sequence shares similar properties with chirp signal. We demonstrate the feasibility of the proposed method by the simulation of a 28 GBaud polarization-division-multiplexed (PDM) quadrature phase-shift keying (QPSK) optical fiber communication system. The error of CD estimation is less than 70 ps/nm for the standard single mode fiber (SSMF) link of 2000 km with OSNR in the range of 10–20 dB and the launch power in the range of 0–4 dBm per channel in a five channel system. It shows that the method is robust to ASE noise and optical fiber nonlinearity. Furthermore, the proposed method has been experimentally verified with the error of CD estimation less than 50 ps/nm after 100–900 km fiber link transmission.

Highlights

Chromatic dispersion (CD) is one of the important factors affecting the performance of optical fiber communication systems [1], and the CD compensation is necessary before clock recovery, carrier synchronization and channel estimation [2], [3]
Wu et al.: CD Estimation Based on constant amplitude zero-autocorrelation (CAZAC) Sequence for Optical Fiber Communication Systems which extends the application of CAZAC sequence
We organize the rest of the paper as follows: In Section II, we introduce the principle of CD estimation based on CAZAC sequence and fractional Fourier transform (FrFT)

Summary

Introduction

Chromatic dispersion (CD) is one of the important factors affecting the performance of optical fiber communication systems [1], and the CD compensation is necessary before clock recovery, carrier synchronization and channel estimation [2], [3]. Different from the method of estimating CD using the QPSK signal proposed in [9], [10], [13], the CAZAC

Results

Conclusion