Pilot Distributions for Joint-Channel Carrier-Phase Estimation in Multichannel Optical Communications
Journal article, 2020

Joint-channel carrier-phase estimation can improve the performance of multichannel optical communication systems. In the case of pilot-aided estimation, the pilots are distributed over a two-dimensional channel-time symbol block that is transmitted through multiple channels. However, suboptimal pilot distributions reduce the effectiveness of the carrier-phase estimation and thus result in unnecessary pilot overhead, which reduces the overall information rate of the system. It is shown that placing pilots identically in all channels is suboptimal in general. By instead optimizing the pilot distribution, the mean squared error of the phase-noise estimates can be decreased by over 90% in some cases. Moreover, it is shown that the achievable information rate can be increased by up to 0.05, 0.16, and 0.41 bits per complex symbol for dual-polarization 20 GBd transmission of 64-ary, 256-ary, and 1024-ary quadrature amplitude modulation over 20 four-dimensional channels, respectively, assuming a total laser linewidth of 200 kHz.

phase noise

fiber-optic communications

multichannel transmission

Kalman filtering

Frequency combs

wavelength-division multiplexing

signal processing



space-division multiplexing


Arni Alfredsson

Chalmers, Electrical Engineering, Communication, Antennas and Optical Networks

Erik Agrell

Chalmers, Electrical Engineering, Communication, Antennas and Optical Networks

Magnus Karlsson

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Henk Wymeersch

Chalmers, Electrical Engineering, Communication, Antennas and Optical Networks

Journal of Lightwave Technology

0733-8724 (ISSN) 1558-2213 (eISSN)

Vol. 38 17 4656-4663 9095389

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Subject Categories


Communication Systems

Signal Processing



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