Title :
Low Complexity FFT-Based Frequency Offset Estimation for M-QAM Coherent Optical Systems
Author :
Junxiong Xiao ; Jie Feng ; Jilong Han ; Wei Li ; Rong Hu ; Qi Yang ; Shaohua Yu
Author_Institution :
Wuhan Nat. Lab. for Optoelectron., Huazhong Univ. of Sci. & Technol., Wuhan, China
Abstract :
Frequency offset estimation algorithms for M-ary quadrature amplitude modulation based on the maximization of the periodogram of fourth-power samples have been investigated. In this letter, a low complexity estimation algorithm using interpolated discrete Fourier transform approach is introduced to replace the gradient descent (GD) or the chirp z transform (CZT) methods. The numerical simulations and complexity analysis demonstrate that the proposed estimator has much lower computational complexity than that of GD and CZT without performance degradation.
Keywords :
Fourier transform optics; computational complexity; discrete Fourier transforms; interpolation; optical communication; optimisation; quadrature amplitude modulation; M-QAM coherent optical systems; M-ary quadrature amplitude modulation; chirp z transform; complexity analysis; fast Fourier transform; fourth-power samples; frequency offset estimation; gradient descent method; interpolated discrete Fourier transform approach; low complexity FFT; low complexity estimation algorithm; periodogram maximization; Accuracy; Complexity theory; Discrete Fourier transforms; Frequency estimation; Frequency modulation; Optical polarization; Optical receivers; Coherent optical communication; Discrete Fourier transform (DFT); M-ary quadrature amplitude modulation (M-QAM); discrete Fourier transform (DFT); frequency offset estimation; interpolation;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2015.2421507
