T. Janz, S. Obermüller, A. Zunker, and S. ten Brink, “Soft-Output from Covered Space Decoding of Product Codes,” in 2025 13th International Symposium on Topics in Coding (ISTC), 2025, pp. 1–5.
Abstract
In this work, we propose a new soft-input soft-output decoder called soft-output from covered space (SOCS) decoder. It estimates the a posteriori reliability based on the space explored by a list decoder, i.e., the set of vectors for which the list decoder knows whether they are codewords. This approach enables a more accurate calculation of the a posteriori reliability and results in gains of up to 0.25dB for turbo product decoding with SOCS compared to Chase-Pyndiah decoding.BibTeX
Abstract
An optimized version of Mueller-Muller (MM) timing recovery algorithm for equalization-enhanced phase noise mitigation is introduced and compared to standard MM showing gains of 0.15dB. Addtionally, a comparable adaptive post-equalizer is adjusted outperforming both MM designs by up to 0.4dB.BibTeX
S. Jung, T. Janz, V. Aref, and S. ten Brink, “Equalization-Enhanced Phase Noise: Modeling and DSP-Aware Analysis,” Journal of Lightwave Technology, pp. 1–10, 2025.
Abstract
In coherent optical communication systems the laser phase noise is commonly modeled as a Wiener process. We propose a sliding-window based linearization of the phase noise, enabling a novel description. We show that, by stochastically modeling the residual error introduced by this approximation, equalization-enhanced phase noise (EEPN) can be described and decomposed into four different components. Furthermore, we analyze the four components separately and provide a stochastical model for each of them. This novel model allows to predict the impact of well-known algorithms in coherent sigital signal processing (DSP) pipelines such as timing recovery (TR) and carrier phase recovery (CPR) on each of the terms. Thus, it enables to approximate the resulting signal affected by EEPN after each of these DSP steps and helps to derive appropriate ways of mitigating such effects.BibTeX
S. Jung, T. Janz, and S. ten Brink, “Mitigating Equalization-Enhanced Phase Noise Using Adaptive Post Equalization,” in ECOC 2024; 50th European Conference on Optical Communication, 2024, pp. 942–945.
Abstract
A simple but efficient post-equalization is presented which mitigates undesired equalization-enhanced phase noise (EEPN). The proposed feed-forward architecture is able to achieve a gain of up to 1 dB in simulation of 100GBd 16-QAM coherent transmission over a link of 5000km of fiber.BibTeX
T. Janz, H. Liu, R. Bitar, and F. R. Kschischang, “Secure Storage Using Maximally Recoverable Locally Repairable Codes,” in
2024 IEEE International Symposium on Information Theory (ISIT), 2024, pp. 1450–1455 [Online]. Available:
https://ieeexplore.ieee.org/document/10619149Abstract
This paper considers data secrecy in distributed storage systems (DSSs) using maximally recoverable locally repairable codes (MR-LRCs). Conventional MR-LRCs are in general not secure against eavesdroppers who can observe the transmitted data during a global repair operation. This work enables nonzero secrecy dimension of DSSs encoded by MR-LRCs through a new repair framework. The key idea is to associate each local group with a central processing unit (CPU), which aggregates and transmits the contribution from the intact nodes of their group to the CPU of a group needing a global repair. The aggregation is enabled by so-called local polynomials that can be generated independently in each group. Two different schemes - direct repair and forwarded repair - are considered, and their secrecy dimension using MR-LRCs is derived. Positive secrecy dimension is enabled for several parameter regimes.BibTeX
