Common phase error estimation in coherent optical OFDM systems using best-fit bounding box.

Area of Science:

• Optical Communications
• Signal Processing
• Image Processing Applications

Background:

• Coherent optical Orthogonal Frequency Division Multiplexing (OFDM) systems are susceptible to phase errors.
• Accurate phase error estimation is crucial for maintaining system performance and spectral efficiency.
• Existing methods like pilot-aided and blind phase searching have limitations in accuracy or complexity.

Purpose of the Study:

• To investigate and characterize a new best-fit bounding box method for phase error estimation.
• To adapt techniques from image processing (2-D convex hull) for optical communication signal processing.
• To evaluate the proposed method's performance against established techniques.

Main Methods:

• Calculating the 2-D convex hull of the received signal constellation.
• Performing root mean square error analysis.
• Analyzing laser linewidth tolerance, noise tolerance, and computation complexity through simulations and experiments.

Main Results:

• The best-fit bounding box method achieves significantly improved spectral efficiency.
• System performance is comparable to the pilot-aided method.
• The proposed method demonstrates good estimation accuracy and reduced computational complexity compared to blind phase searching.

Conclusions:

• The best-fit bounding box method offers a promising alternative for phase error estimation in coherent optical OFDM systems.
• It balances spectral efficiency, accuracy, and computational load effectively.
• The adaptation of image processing techniques shows potential for optical communication advancements.