Open AccessAdaptive threshold adjustment for signaldistortion- free digital-coherent optical demodulation system
Author(s) -
Akira Chibá,
Takahide Sakamoto,
Tetsuya Kawanishi
Publication year - 2008
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.021647
Subject(s) - demodulation , quadrature amplitude modulation , computer science , qam , distortion (music) , electronic engineering , modulation (music) , optics , digital signal processing , signal (programming language) , bit error rate , pulse amplitude modulation , optical modulation amplitude , optical communication , telecommunications , physics , bandwidth (computing) , optical amplifier , computer hardware , engineering , laser , acoustics , detector , decoding methods , amplifier , channel (broadcasting) , pulse (music) , programming language
Optical quadrature amplitude modulation (QAM) attracts considerable attention in the enhancement of communications capacity, due to its high spectral efficiency. However, this modulation format is more sensitive to signal distortion than conventional formats, making it more difficult to create, transmit, and detect signals. In this paper, we propose an adaptive scheme for demodulation of the distorted optical signals with paying attention to use of DSP-technology. The scheme is based on the adjustment of the thresholds against the signal distortion. Successful demodulation of optical QAM signals is demonstrated with a sufficiently low bit-error rate.