Analysis and brief review on noise processing for phase-extracted signals in coherent Φ-OTDR

This review begins by elucidating the rationale for selecting phase optical time domain reflectometry (-OTDR) based on coherent detection as the subject of study, underscoring the necessity and significance of analyzing noise suppression methodologies.With the aid of in-phase/quadrature (I/Q) demodulation process for phase extraction, the review analyzes the impact of noise on phase-extracted results in coherent -OTDR.Subsequently, nine specific implementable pathways to mitigate noise effects are explored within three categories: amplitude signal, phase signal, and the data itself.For each pathway, the review summarizes the advancements in noise suppression research, providing a typical implementation case to deepen the reader's understanding of noise processing principles and techniques.Finally, the review not only identifies the shortcomings but also provides insights into noise processing in coherent -OTDR, underlining the current limitations and suggesting potential avenues for future investigation.