Summary
International Symposium on Extremely Advanced Transmission Technologies
2019
Session Number:P
Session:
Number:P-25
Equalization Enhanced Phase Noise Penalty for M-Quadrature Amplitude Modulation Formats in Short-Haul Few-Mode Fiber Transmission Systems with Time-Domain MIMO Equalization
Jos? Manuel Delgado Mendinueta, Werner Klaus, Jun Sakaguchi, Satoshi Shinada, Hideaki Furukawa, Yoshinari Awaji, Naoya Wada,
pp.-
Publication Date:2019/5/29
Online ISSN:2188-5079
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Summary:
"Few-mode fiber (FMF) transmission systems have recently gained a lot of research attention due to the ability to multiplex several data streams on different orthogonal modes, extending the capacity limits of single mode fibers (SMF) [1]. At the receiver, a multiple-input multiple-output (MIMO) equalizer is used to demultiplex the modes that may get coupled though propagation and/or at the edge mode-coupling devices (MCDs), and to compensate for the differential mode delay (DMD), caused by the difference in propagation speed of the individual modes. However, the interaction of the transmitter and receiver phase noise produces equalization enhanced phase noise (EEPN) which may significantly degrade the system performance and hence the maximum reach of FMF systems [2]. In this work, we conduct a numerical investigation to quantify the impact of the EEPN penalty in terms of the optical signal to noise ratio (OSNR) in a 3-mode FMF transmission system, shown in Fig. 1(a), at 25 GBd, for QPSK, 16QAM, 32QAM and 64QAM modulation formats [3]. In short-reach FMF transmission systems, the FMF can be modeled in the weakly-coupled regime [4], and either mode-selective MCDs, analyzed in our model A, or non-model-selective MCDs, analyzed in our model B, can be employed. The receiver digital signal processing (DSP) is based on a time-domain MIMO equalizer and the blind phase search (BPS) carrier-phase recovery (CPR) algorithm with optimized parameters of B = 32 and N = 10. The results demonstrate that the EEPN in FMF systems causes no degradation for model A, i.e., mode-selective MCDs. However, for model B, i.e., non-mode-selective MCDs, the OSNR penalty quickly grows as the DMD of the system increases which limits the maximum transmission reach. "