On the Multidimensional Signal Constellation Design for Few-Mode-Fiber-Based High-Speed Optical Transmission

• Main Authors: Ivan B. Djordjevic, Tao Liu, Lei Xu, Ting Wang
• Format: Article
• Language: English
• Published: IEEE 2012-01-01
• Series: IEEE Photonics Journal
• Subjects: Microwave photonics signal processing; few-mode/few-core fiber optics communications; orbital angular momentum (OAM) modulation; low-density parity-check (LDPC) codes; multidimensional coded modulation
• Online Access: https://ieeexplore.ieee.org/document/6243161/
• ISSN: 1943-0655

In this paper, we propose an algorithm to determine the -dimensional optimum signal constellation design (DD-OSCD), in minimum mean-square error sense, for channel capacity achieving source distribution. We then describe a -dimensional coded modulation scheme, employing orbital angular momentum modes, two polarization states, and two in-phase/quadrature coordinates, suitable for use in future few-mode fiber (FMF) applications. Monte Carlo simulations indicate that the proposed low-density parity-check (LDPC)-coded polarization-division-multiplexed (PDM) quadrature-multiplexed (QM) DD-OSCD significantly outperforms conventional PDM-QAM (by 4.32 dB for 64-ary 3-D constellation at a BER of ). In addition, the DD-OSCD outperforms sphere packing constellations (by 0.33 dB for 8-ary 3-D constellation at a BER of ).