Zero-Power Gaps for Multipath Interference Detection in Optical Links
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Solution Overview
Problem
Current methods are ineffective in accurately measuring and detecting multipath interference (MPI) in optical fiber links, which degrades signal quality and performance, and there is a lack of a cost-effective solution for identifying and quantifying MPI in optical communication systems.
Innovation Solution
The method involves inserting zero-power gaps into the transmission signal, allowing for the determination of MPI by measuring power outside and inside these gaps, both in the main signal and its reflection, using digital signal processors to calculate the strength of MPI without additional hardware costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional testing methods are used to detect MPI, then measurement capability is partially achieved, but measurement precision is insufficient and additional hardware costs are incurred
Solution Approach 1:
The existing digital signal processor in the optical communication system performs MPI measurement functions using its own computational resources. The system utilizes the DSP's existing capabilities to analyze signal power during zero-power gaps, eliminating the need for separate measurement hardware while achieving accurate MPI detection
Solution Approach 2:
The digital signal processor is made multi-functional by enabling it to perform both standard signal processing tasks and MPI measurement functions. The same DSP hardware that processes communication signals is also used to detect and quantify multipath interference, reducing overall system hardware complexity
2Measurement precision
If zero-power gaps are inserted into the transmission signal, then MPI detection capability is improved, but signal transmission efficiency is reduced
Solution Approach 1:
Zero-power gaps are inserted periodically into the transmission signal at specific intervals rather than continuously. This periodic insertion provides sufficient opportunities for MPI measurement while minimizing the impact on overall signal transmission efficiency, as the gaps occur only during designated measurement periods
Solution Approach 2:
The zero-power gaps are inserted only partially into the transmission signal structure, occupying a small portion of the total signal time. This partial insertion provides adequate measurement capability without excessively reducing transmission efficiency, striking a balance between measurement needs and data transmission requirements
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables efficient detection and measurement of MPI, improving signal quality and system performance by using existing digital signal processors, thus providing a cost-effective solution for identifying and quantifying multipath interference in optical communication systems.
Implementation Method 1
MPI can occur when an optical signal can be transmitted to the destination via more than one path. This can be caused by double Rayleigh backscattering (DRBS) in the fiber
Implementation Method 2
MPI can occur when an optical signal can be transmitted to the destination via more than one path. This can be caused by double Rayleigh backscattering (DRBS) in the fiber, as well as multi-reflections.
Data Source
AI summary
There is provided a method, apparatus and system for determining multipath interference (MPI) in optical communications. It is object of embodiments of the present disclosure to provide an effective, low-cost way of detecting or measuring MPI. To effectively detect and measure the MPI, multiple zero-power gaps are inserted into the transmission signal (optical signal) in time domain. In some embodiments, at least some of the zero-power gaps inserted in the main signal do not overlap the zero-power gaps of the reflection of the main signal. Using the zero-power gaps contained the main signal and the reflection (where applicable), power inside and outside the zero-power gaps are determined. Then, the strength of the MPI is determined based on the determined power inside and outside the zero-power gaps.