Data-Aided Versus Blind Single-Carrier Coherent Receivers

TLDR

Fiber‑optic signal processing for first‑generation coherent systems relied on blind receivers, but next‑generation high‑order modulation systems demand scalable, modular designs, prompting a reassessment of data‑aided versus blind algorithms for coherent optical receivers. In this paper, blind and data‑aided receivers are compared for coherent single‑carrier optical systems in terms of complexity, tracking ability, and convergence speed. The study compares blind and data‑aided receivers for coherent single‑carrier optical systems, evaluating complexity, tracking ability, and convergence speed, and discusses time‑domain and frequency‑domain equalization methods covering the most important algorithms. The general superiority of data‑aided frequency‑domain equalization is demonstrated.

Abstract

Fiber-optic research in signal processing for the first generation of coherent communication systems was dominated by receivers with blind adaptation. Next-generation systems will require a scalable and modular design for higher order modulation formats. Due to the nature of the fiber channel and the required parallelization in high-speed receivers, data-aided and blind algorithms call for a general reassessment when used in coherent optic receivers employing higher order modulation formats. In this paper, blind and data-aided receivers are compared for coherent single-carrier optical systems in terms of complexity, tracking ability, and convergence speed. Methods for equalization are discussed for time-domain- and frequency-domain-based receivers covering the most important algorithms. The general superiority of data-aided frequency-domain equalization is demonstrated.