Fast-Convergence Digital Signal Processing for Coherent PON Using Digital SCM

Abstract

Optical access networks have been evolving to meet the explosive growth of data traffic. It is foreseeable that the 100Gb/s/λ and beyond passive optical network (PON) will be required in future optical access networks. Coherent optical communication is a promising solution for the future beyond 100G PON. However, the traditional digital signal processing (DSP) for coherent optical communication is difficult to realize fast convergence due to blind and complex algorithms. In this paper, we design a specific preamble structure and propose a burst-mode DSP to achieve fast convergence for the coherent PON. For verifying the feasibility of the proposed scheme, pointto-multi-point (P2MP) coherent PON is experimentally built up based on digital subcarrier multiplexing (DSCM), which is a kind of frequency division multiple access. When the allocated frequency of the optical network unit is suddenly changed, the DSP should converge fast to ensure a low handoff latency. In P2MP coherent PON, the proposed specific preamble structure and burst-mode DSP jointly implement the fast convergence using a short preamble with only 416 symbols. The experimental results show that the 8-Gbaud/SC×8-SCs 400Gb/s-net-rate coherent PON in burst-mode detection achieves the receiver sensitivity of approximately −27dBm at the 20% soft-decision forward error correction limit and approximately 35.5dB optical power budget with an optical pre-amplifier.

Investigating CRYSTALS-Kyber Vulnerabilities: Attack Analysis and Mitigation

“…One noteworthy breakthrough is the creation of fast hardware designs for polynomial multiplication based on the Number Theoretic Transform (NTT) in CRYSTAL-Kyber and CRYSTAL-Dilithium, utilizing Digital Signal Processing (DSP) approaches [46]. With the dedicated DSP units for modular multiplication, butterfly operations, and Point-Wise Multiplication (PWM) found in these designs, critical route delays are significantly reduced, and area and performance are improved.…”

Untitled

“…The frame structure shown in Fig. 5 is designed for fast convergence to ensure a low handoff latency for real-time bandwidth allocation [57] . Different synchronization patterns (SPs) serve different functions, corresponding to the DSP processes in burst mode.…”

“…Recently, there have been studies proposing new specially designed SP structures and novel equalization methods to accelerate convergence rates and enhance the range of supported channel conditions in CPON systems [27,60,61] . By using an inserted pilot structure, it can realize fast SOP, carrier phase tracking, and channel estimation.…”

Key Technologies for a Beyond-100G Next-Generation Passive Optical Network

“…DSP technologies for coherent PON systems include simplified IQ imbalance compensation, adaptive equalization, clock recovery, polarization de-multiplexing, carrier frequency offset, and phase offset estimation schemes. In addition, in the upstream direction, the data flow of the coherent NG-PON system has a burst mode [45][46][47][48][49][50][51][52][53][54]. Particularly in the NG-PON with SOA transmission, the inherent large dynamic range (DR) of the burst-mode signaling is 19.5 dB [55].…”