Implementation of Carrier Phase Recovery Circuits for Optical Communication
Licentiate thesis, 2020

Fiber-optic links form a vital part of our increasingly connected world, and as the number of Internet users and the network traffic increases, reducing the power dissipation of these links becomes more important. A considerable part of the total link power is dissipated in the digital signal processing (DSP) subsystems, which show a growing complexity as more advanced modulation formats are introduced. Since DSP designers can no longer take reduced power dissipation with each new CMOS process node for granted, the design of more efficient DSPalgorithms in conjunction with circuit implementation strategies focused on power efficiency is required.

One part of the DSP for a coherent fiber-optic link is the carrier phase recovery (CPR) unit, which can account for a significant portion of the DSP power dissipation, especially for shorter links. A wide range of CPR algorithms is available, but reliable estimates of their power efficiency is missing, making accurate comparisons impossible. Furthermore, much of the current literature does not account for the limited precision arithmetic of the DSP.

In this thesis, we develop circuit implementations based on a range of suggested CPR algorithms, focusing on power efficiency. These circuits allow us to contrast different CPR solutions based not only on power dissipation, but also on the quality of the phase estimation, including fixed-point arithmetic aspects. We also show how different parameter settings affect the power efficiency and the implementation penalty. Additionally, the thesis includes a description of our field-programmable gate-array fiber-emulation environment, which can be used to study rare phenomena in DSP implementations, or to reach very low bit-error rates. We use this environment to evaluate the cycle-slip probability of a CPR implementation.

Communication Systems

Digital Signal Processing

Energy efficiency

fiber-optic communications

Application-Specific Integrated Circuits

Carrier Phase Recovery

Online
Opponent: Prof. Gabriella Bosco, Department of Electronics and Telecommunications, Polytechnic University of Turin, Italy

Author

Erik Börjeson

Chalmers, Computer Science and Engineering (Chalmers), Computer Engineering (Chalmers)

VLSI Implementations of Carrier Phase Recovery Algorithms for M-QAM Fiber-Optic Systems

Journal of Lightwave Technology,; Vol. 38(2020)p. 3616-3623

Journal article

Towards FPGA Emulation of Fiber-Optic Channels for Deep-BER Evaluation of DSP Implementations

Optics InfoBase Conference Papers,; Vol. Part F137-SPPCom 2019(2019)

Paper in proceeding

Cycle-Slip Rate Analysis of Blind Phase Search DSP Circuit Implementations

2020 Optical Fiber Communications Conference and Exhibition, OFC 2020 - Proceedings,; (2020)

Paper in proceeding

E. Börjeson, and P. Larsson-Edefors, "Energy-efficient implementation of carrier phase recovery for higher-order modulation formats"

Subject Categories

Telecommunications

Communication Systems

Other Electrical Engineering, Electronic Engineering, Information Engineering

Publisher

Chalmers

Online

Online

Opponent: Prof. Gabriella Bosco, Department of Electronics and Telecommunications, Polytechnic University of Turin, Italy

More information

Latest update

8/27/2020