Joint polarization tracking and channel equalization based on radius-directed linear Kalman filter

Zhang, Qun; Zhong, Kangping; Liu, Jie; Wu, Xiong; Yao, Yong

doi:10.1016/j.optcom.2017.08.036

Cited by 17 publications

(6 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…14 Especially, there are a number of significant publications which Kalman filter was used in polarization impairments equalization such as RSOP, PMD and polarization dependent loss (PDL). [15][16][17][18][19][20] However, Kalman filter has not shown as good a performance as expected. For example, although Kalman filter based RSOP equalization schemes reported can achieve a response tracking speed as high as several mega-radian per second but there is a consistent one-to-one match between equalization model and channel RSOP model.…”

Section: Introductionmentioning

confidence: 75%

“…In recently years, Kalman filter has been found to be used in the equalization in optical fiber communication system and showed good impairment equalization abilities, such as carrier frequency offset estimation, 10 linear or non‐linear phase noise tracking, 11–13 nonlinear channel impairments mitigation 14 . Especially, there are a number of significant publications which Kalman filter was used in polarization impairments equalization such as RSOP, PMD and polarization dependent loss (PDL) 15–20 …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fast tracking of polarization impairments using DSP algorithms in fiber for a coherent optical communication system

Cui

Zhang

2021

Micro & Optical Tech Letters

View full text Add to dashboard Cite

In a 100G coherent optical fiber communication system, the equalization algorithm of polarization effects in fibers is generally integrated in digital signal processing (DSP) using a multiple input/multiple output (MIMO) equalizer to overcome the impairment due to the polarization effects in fiber. However, it was found in some extreme scenarios, such as the lightning strikes near the fiber cables, the Kerr effect and Faraday effect would induce very fast time‐varying state‐of‐polarization (SOP) and transient variation of principal‐state‐of‐polarization (PSP) of polarization mode dispersion (PMD) which would result in the coherent receivers unlocking. Faced with the difficulty, we propose a 3‐parameter RSOP model and design a window‐split structured Kalman filter equalization scheme instead of conventional MIMO equalizer to cope with this extreme scenario of large PMD combined with ultra‐fast rotation of SOP in presence of residual chromatic dispersion (RCD). The proposed equalization method has an excellent performance and can cope with RCD in the range of ±820 ps/nm under RSOP from 100 krad/s to 3 Mrad/s and DGD = 200 ps.

show abstract

Section: Introductionmentioning

confidence: 75%

Section: Introductionmentioning

confidence: 99%

Fast tracking of polarization impairments using DSP algorithms in fiber for a coherent optical communication system

Cui

Zhang

2021

Micro & Optical Tech Letters

View full text Add to dashboard Cite

show abstract

“…As a promising method, many methods based on Kalman filter have been proposed to cope the polarization impairments 5 – 11 In 2016, a joint multi-polarization-effect tracking and equalization method based on two extended Kalman filters (EKF) was proposed. This method can cope with state of polarization (SOP) tracing, polarization demultiplexing, equalization for polarization dependent loss, and PMD in PDM-M-QAM coherent optical communication system 5 .…”

Section: Introductionmentioning

confidence: 99%

“…In article, 10 , 11 radius-directed (RD) idea was introduced into linear Kalman filter (LKF) to compensate for polarization impairments. Despite the similarity in nomenclature, it is imperative to highlight that the LKF and EKF represent distinct compensation routes.…”

Section: Introductionmentioning

confidence: 99%

Joint equalization of fast RSOP and large PMD based on RD-EKF for PDM-MQAM system

Liu,

Ji,

Wang

et al. 2024

Opt. Eng.

View full text Add to dashboard Cite

Extended Kalman filter (EKF) is a popular method to address the fast rotation of the state of polarization and large polarization mode dispersion in coherent optical communication. But it is usually underperforming in high-order modulation. Radiusdirected idea is introduced to enhance the performance of EKF-based method. We call the proposed scheme radius-directed extended Kalman filter (RD-EKF). The performance of the proposed Kalman scheme is verified both in the polarizationdivision multiplexed 16QAM and 64QAM system. By the results, the RD-EKF scheme has better performance and less complexity than conventional EKF method in the high modulation format system.

show abstract

“…The algorithms that were mentioned above such as CMA+BPS can be used for polarization tracking and carrier phase recovery. While we also have another choice, the extended Kalman filter (EKF) has been demonstrated in coherent optical transmission systems [15][16][17][18][19]. This is a joint scheme and can be used for polarization tracking and carrier phase recovery simultaneously, the overall computational complexity is lower than CMA+BPS.…”

mentioning

confidence: 99%

A Pilot Symbols Aided Adaptive Kalman Filter for Joint Carrier Phase and Polarization Tracking in Coherent Optical System

et al. 2018

Self Cite

View full text Add to dashboard Cite

Featured Application: This work can good candidate for parameter estimation and channel equalization in elastic optical networks (EON).Abstract: A joint compensation scheme based on pilot symbols aiding adaptive Kalman filter (AKF) for phase noise and polarization cross-talk is proposed and investigated via numerical simulation and experimental demonstration. In the proposed scheme, the optimizing parameter Q is adaptively adjusted according to signal parameters or channel conditions. This improvement avoids the drawback of conventional extended Kalman filter (EKF), and its performance is strongly dependent on Q. Another improvement is that the convergence speed of AKF is improved. Pilot quadrature phase shift keyin (QPSK) symbols are inserted into 16 quadrature amplitude modulation (QAM) signals periodically. Besides accelerating convergence speed, the employment of pilot symbols also improves the tracking capability of AKF. The format ratio between pilot symbols and payload symbols is suggested under different system environments, for instance, optical signal-to-noise rate, polarization rotation frequency drift rate, and laser linewidth. With the proposed scheme, it has excellent tolerance to initial parameter Q and dramatically improves the performances in convergence speed, polarization rotation frequency drift rate tracking, and carrier phase recovery. Both the numerical simulation and experimental demonstration achieve convergence improvement for around 40 times than the original AKF. Additionally, the improvements in tracking ability are also demonstrated.Regarding polarization tracking, the traditional algorithms are the constant modulus algorithm (CMA) and its variants [11][12][13]. The CMA algorithm is capable of tracking polarization rotation of up to 1 Mrad/s [14], which is not enough for meeting the requirements imposed by dynamic or burst optical detection scenarios.For coherent optical communication system, both polarization tracking and carrier phase recovery are essential. The algorithms that were mentioned above such as CMA+BPS can be used for polarization tracking and carrier phase recovery. While we also have another choice, the extended Kalman filter (EKF) has been demonstrated in coherent optical transmission systems [15][16][17][18][19]. This is a joint scheme and can be used for polarization tracking and carrier phase recovery simultaneously, the overall computational complexity is lower than CMA+BPS. However, it is commonly known that the tuning parameters' Q value is significant for determining EKF performance. The higher laser linewidth, the larger Q value should be configured theoretically. The same rule exists in the case of tracking polarization rotation. Therefore, an adaptive Kalman filter (AKF) scheme is expected, in which Q value can change along with the conditions in an intelligent manner [20]. The convergence speed should be improved further in the case of high-order modulation format to meet the requirement of the next-generation dynamic optical transmission.Based on our prev...

show abstract

Joint polarization tracking and channel equalization based on radius-directed linear Kalman filter

Cited by 17 publications

References 20 publications

Fast tracking of polarization impairments using DSP algorithms in fiber for a coherent optical communication system

Fast tracking of polarization impairments using DSP algorithms in fiber for a coherent optical communication system

Joint equalization of fast RSOP and large PMD based on RD-EKF for PDM-MQAM system

A Pilot Symbols Aided Adaptive Kalman Filter for Joint Carrier Phase and Polarization Tracking in Coherent Optical System

Contact Info

Product

Resources

About