Burst-mode timing recovery based on fourth-power phase detector for passive optical networks

2026-09-13

AI Summary

本文提出基于四次幂相位检测器的突发模式时序恢复方法，解决50G-PON中1-SPS信号的时序恢复问题，无需训练序列即可快速收敛。

Abstract

Driven by the ever-increasing capacity demands, 50G passive optical network (50G-PON) is ready for practical application. It is highly challenging to realize 50GHz burst-mode analog components; therefore, based on 25GHz burst-mode analog devices, burst-mode digital signal processing (DSP) is introduced to achieve the reception and processing of 50Gb/s on-off keying burst signals. To optimize the power consumption and area of the DSP chip, a one-sample-per-symbol (1-SPS) analog-to-digital converter has been applied in 50G-PON. One of the main challenges is implementing burst-mode timing recovery (BM-TR) for the 1-SPS burst signal in 50G-PON. In this paper, we first propose a BM-TR based on the fourth-power phase detector (4PPD) for 50G-PON. We mathematically verify that 4PPD can directly compute the timing phase offset (TPO) from the 1-SPS signal without using training sequences, allowing for immediate BM-TR initialization within 20 cycles to prevent long convergence times. After the initialization, the feedback loop structure tracks the TPO changes based on the sign of 4PPD, the loop filter, and the numerically controlled oscillator. In conclusion, training-sequence-free 4PPD-based BM-TR achieves low burst overhead via fast convergence and is particularly effective for handling burst signals in 50G-PON.

Problem

• burst-mode timing recovery
• 50G-PON
• one-sample-per-symbol
• digital signal processing
• power consumption

Innovation

• fourth-power phase detector
• burst-mode timing recovery
• training-sequence-free
• 50G-PON