Haiyun Xin

Low-latency dynamic wavelength and bandwidth allocation algorithm for NG-EPON

Recently, the IEEE 802.3ca Task Force has been working to standardize the next-generation Ethernet passive optical network (NG-EPON) to fulfill future bandwidth demands. NG-EPON allows an optical network unit (ONU) transmission to be scheduled on multiple wavelength channels simultaneously. This will increase network capacity up to 100 Gb/s, along with flexibility, as any of the channels can be allocated from the four wavelength channels, each having a capacity of 25 Gb/s. However, it also raises many technical aspects to be considered while deciding on an optimum scheduling strategy for NG-EPON (100G-EPON) architecture. This paper proposes a dynamic wavelength and bandwidth allocation (DWBA) algorithm for NG-EPON to schedule upstream wavelength channels while providing a low average packet delay and catering frame resequencing problem. An online scheduling framework with gated service grant sizing policy has been demonstrated in this work. The proposed DWBA algorithm’s performance is evaluated in comparison with legacy interleaved polling with an adaptive cycle time (modified- IPACT) and recently proposed water-filling algorithmbased DWBA (WF-DBA) algorithms. Simulation results confirmed the validity of the proposed DWBA algorithm.

High accuracy and non-pilot aided sampling frequency offset estimation algorithm in Multi-IFoF fronthaul

We propose a non-pilot aided sampling frequency offset (SFO) estimation algorithm in Multi-IFoF fronthaul with estimation error below 12ppb under SFO range from −100ppm to 100ppm and high robustness at received optical power as low as − 27dBm.

25Gbps two-dimensional trellis coded PAM4 TDM-PON transmission based on 10G optics

We demonstrate an alternative approach to 25Gbps 2D TCM PAM4 for TDM-PON with 10GHz optics, which employs M-algorithm at its decoder. Compared to PAM4, 2D TCM PAM4 brings the power budget up by ∼3dB with low complexity.

Intensity directed equalizer for the mitigation of DML chirp induced distortion in dispersion-unmanaged C-band PAM transmission

The directly modulated laser (DML) is one of the most cost-effective transmitter options in optical communication systems, but it introduces an additional impairment caused by the interaction between frequency chirp and chromatic dispersion for C-band transmission. In this paper, we propose a low-complexity intensity directed equalizer based on feedforward equalizer and decision feedback equalizer (FFE/DFE) to mitigate the chirp induced distortions, and remarkably improve the transmission performance of PAM signals generated by DML. The equalizer is based on the fact that the directly modulated PAM symbols with different intensity levels have different chirp frequencies, which will lead to different inter-symbol interference (ISI) contributions to their adjacent symbols due to the velocity difference caused by chromatic dispersion. To address this phenomenon, the proposed equalizer employs multiple sets of tap coefficients according to the intensity levels of PAM signals. With this equalizer and a commercial 16.8GHz DML, we demonstrate a 56Gb/s PAM4 transmission over a record 43km SSMF in the C-band without optical dispersion compensation under the 3.8 × 10−3 HD-FEC BER threshold.

Multi-FSR AWGR assisted uplink load aggregation in fronthaul with parallel signal detection

We proposed an uplink load aggregation scheme for fronthaul based on Multi-FSR AWGR and parallel uplink signal detection, in which receiver can serve one or multiple cell sites according to different traffic demands to save energy.