Phase noise compensation method, module and system of CO-FBMC system

Abstract

The invention discloses a phase noise compensation method, module and system of a CO-FBMC system, and belongs to the field of optical communication. The compensation method comprises the following steps: performing first unscented transformation on posterior estimation of phase noise at a previous moment to obtain an initial Sigma point set, approximating a priori estimation value of the phase noise at the current moment according to the initial Sigma point set, performing second unscented transformation on the priori estimation value to obtain a multiplied Sigma point set, substituting the multiplied Sigma point set into a nonlinear equation for iteration, and obtaining a multiplied Sigma point set; and solving to obtain an estimated mean value and a covariance of the FBMC symbol at the current moment, calculating a Kalman gain matrix according to the estimated mean value and the covariance, and obtaining a posteriori estimated value of the phase noise at the current moment according to the Kalman gain matrix. The invention also provides an unscented Kalman filter compensation module and a CO-FBMC system. According to the method, a nonlinear equation does not need to be approximated to a linear equation, and the method has higher phase noise tolerance under the same precision. Meanwhile, a Jacobian matrix does not need to be solved, and the calculation amount is greatly reduced.

Description

technical field [0001] The invention belongs to the field of optical communication, and more particularly, relates to a phase noise compensation method, module and system of a CO-FBMC system. Background technique [0002] Coherent Optical-offset Quadrature Amplitude Modulation-based filterbank multicarrier (CO-FBMC / OQAM: Coherent Optical-offset Quadrature Amplitude Modulation-based filterbank multicarrier) in traditional optical communication Compared with CO-OFDM system, CO-FBMC / OQAM system has long symbol length and high peak-to-average power ratio, and the phase noise mainly comes from laser linewidth and link nonlinearity, so CO-FBMC / OQAM system The transmission performance of the system is easily affected by phase noise, resulting in the rotation and divergence of the QAM modulation constellation at the receiving end, resulting in an increase in the bit error rate. Therefore, how to efficiently monitor and compensate for phase noise is a key issue for CO-FBMC / OQAM syst...

AI Technical Summary

Problems solved by technology

[0003] The traditional solution to system phase noise estimation and compensation is based on the extended Kalman filter algorithm compensation scheme. This compensation scheme not only needs to calculate the Jacobian matrix of the nonlinear model, but it also requires a large amount of calculation.

More importantly, when solving the nonlinear equation, it is necessary to approximate the nonlinear equation to a linear equation and ignore the second-order and higher-order terms in the Taylor expansion of the nonlinear equation, which affects the estimation accuracy. prone to misjudgment

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