Performance of momentum-based frequency-domain MIMO equalizer in the presence of feedback delay

Optics Express
Wenting YiRobert I Killey

Abstract

A frequency-domain multiple-input multiple-output (FD-MIMO) equalizer employing a momentum-based gradient descent update algorithm is proposed for polarization multiplexing coherent receivers. Its performance in operation with dynamically varying optical channels is investigated and the impact of filter update delays, arising from the latency of the fast Fourier transforms (FFTs) and other digital signal processing (DSP) operations in the feedback loop, is assessed. We show that the proposed momentum-based gradient descent algorithm used to control the equalizer response has significantly greater tolerance to feedback delay than the conventional gradient descent algorithm. We considered a 92 Gbaud dual-polarization 64 QAM receiver, with DSP operating at two samples per symbol, and with the equalizer operating on blocks of 512 and 1024 samples (i.e., 512/1024-point FFT). We found that at an optical signal-to-noise power ratio (OSNR) of 35 dB, the momentum-based gradient descent algorithm can successfully track state-of-polarization (SOP) rotation at frequencies of up to 50 kHz and with filter update delays of up to 14 blocks (39 ns). In comparison, using the conventional gradient descent algorithm in an otherwise identical recei...Continue Reading

References

Jun 11, 2008·Optics Express·Ezra IpJoseph M Kahn
Jun 11, 2008·Optics Express·Seb J Savory
Jul 1, 2011·Optics Express·Md Saifuddin Faruk, Kazuro Kikuchi

❮ Previous
Next ❯

Related Concepts

Related Feeds

Cell Imaging in CNS

Here is the latest research on cell imaging and imaging modalities, including light-sheet microscopy, in the central nervous system.

Related Papers

The New Physician
R Sorian
Journal of the National Medical Association
A C Gullattee
The American Journal of Nursing
F B Rosen
© 2021 Meta ULC. All rights reserved