Geometric Clustering for Hardware-Efficient Implementation of Chromatic Dispersion Compensation

TL;DR

This paper introduces a hardware-efficient clustering method for chromatic dispersion compensation in optical communications, demonstrating significant energy and resource savings through FPGA implementation and parallelization techniques.

Contribution

It presents a novel Time-Domain Clustered Equalizer (TDCE) technique, theoretical analysis of tap overlapping, and FPGA-based hardware implementation for improved efficiency.

Findings

Achieves up to 70.7% energy savings over FDE

Reduces multiplier usage by 71.4% compared to FDE

Validates hardware efficiency through FPGA implementation for 640 km fiber links

Abstract

Power efficiency remains a significant challenge in modern optical fiber communication systems, driving efforts to reduce the computational complexity of digital signal processing, particularly in chromatic dispersion compensation (CDC) algorithms. While various strategies for complexity reduction have been proposed, many lack the necessary hardware implementation to validate their benefits. This paper provides a theoretical analysis of the tap overlapping effect in CDC filters for coherent receivers, introduces a novel Time-Domain Clustered Equalizer (TDCE) technique based on this concept, and presents a Field-Programmable Gate Array (FPGA) implementation for validation. We developed an innovative parallelization method for TDCE, implementing it in hardware for fiber lengths up to 640 km. A fair comparison with the state-of-the-art frequency domain equalizer (FDE) under identical conditions is also conducted. Our findings highlight that implementation strategies, including parallelization and memory management, are as crucial as computational complexity in determining hardware complexity and energy efficiency. The proposed TDCE hardware implementation achieves up to 70.7\% energy savings and 71.4\% multiplier usage savings compared to FDE, despite its higher computational complexity.