Remote PHY Device CPD Detection via Synchronous Signal Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In modern hybrid-fiber coax (HFC) networks with Converged Cable Access Platform (CCAP) architecture and remote PHY devices, detecting common path distortion (CPD) is challenging due to increased bandwidth and the transition from analog to digital signals, making it difficult to identify and locate sources of CPD, especially with existing methods requiring large data capture and power consumption.
Innovation Solution
A method and apparatus for synchronous capture of forward and return signals at a remote PHY device using a coupling element, CPD simulator circuit, and filter to generate a reference CPD signal, allowing for detection and location of CPD sources without modifying the remote PHY device, reducing power consumption, and minimizing data capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If synchronous capture of forward and return signals is implemented at remote PHY device, then detection precision and location accuracy of CPD sources are improved, but device complexity increases
Solution Approach 1:
The system divides the CPD detection function into two parts: the remote PHY device performs synchronous signal capture and generates a reference CPD signal, while the headend performs the actual CPD detection and source location using cross-correlation. This segmentation allows precise measurement without overcomplicating the remote device.
Solution Approach 2:
A reference CPD signal is generated as an intermediary at the remote PHY device and transmitted to the headend. This reference signal acts as a mediator that enables precise CPD detection and source location without requiring complex processing at the remote device, resolving the contradiction between measurement precision and device complexity.
2Measurement precision
If large amounts of data are captured for CPD detection, then detection sensitivity is improved, but data processing requirements and power consumption increase
Solution Approach 1:
The invention extracts only the essential synchronous signal capture function at the remote PHY device, generating a compact reference CPD signal. The bulk of data processing is extracted and moved to the headend, reducing power consumption at the remote device while maintaining detection sensitivity through the reference signal.
Solution Approach 2:
The remote PHY device performs preliminary action by capturing synchronous signals and generating the reference CPD signal before transmission to the headend. This preliminary processing reduces the data volume and complexity for subsequent detection, lowering power consumption while preserving detection sensitivity.
3Adaptability or versatility
If synchronous capture method is implemented, then ability to identify and locate multiple CPD sources is improved, but implementation complexity and compatibility requirements increase
Solution Approach 1:
The system creates a copy of the forward signal characteristics in the form of a reference CPD signal at the remote PHY device. This copy enables the headend to identify and locate multiple CPD sources through cross-correlation without requiring complex processing at the remote device, resolving the contradiction between adaptability and implementation complexity.
4Measurement precision
If remote PHY device is modified to enable synchronous capture, then detection capability is improved, but ease of operation and deployment are worsened
Solution Approach 1:
The synchronous capture and reference CPD signal generation functions are designed to be universal and compatible with most existing remote PHY devices. The headend performs the specialized detection processing, allowing the system to achieve improved detection capability without requiring modifications to deployed remote devices, thus maintaining ease of operation and deployment.
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
Enables efficient detection and location of CPD sources within the coaxial cable plant, reducing data processing requirements and power consumption, while being compatible with most remote PHY devices, thus improving proactive network maintenance.
Implementation Method 1
a coupling element (202) coupleable to the remote PHY device for capturing the forward signal
Implementation Method 2
The IM of the forward signals is the result of a so-called 'diode effect' caused by, e.g., corrosion of the above-mentioned components and elements in the network
Implementation Method 3
A component or element (or an affected part thereof) exhibiting nonlinear behavior (or a nonlinear response) is sometimes referred to herein as a 'CPD source'
Implementation Method 4
a bandpass filter (410) substantially selects from the multiplicity of frequency components the frequency components within the return channel
Data Source
Figure 1
Figure 2~3
Figure 4~5D
AI summary
This application concerns detection of common path distortion (CPD) by synchronous capture of a forward signal and a related actual CPD signal at a remote physical layer (PHY) device (1908). The steps are: (a) operating a receiver (l922b) in the remote PHY device to capture the actual CPD signal and a leaked portion of the forward signal (2000); (b) transmitting to a headend (102) of an HFC network (100) the actual CPD signal and the leaked forward signal (2000); (c) at the headend (102) or other device (118), generating from the leaked forward signal a reference CPD signal substantially simulating the actual CPD signal (2108); (d) performing a cross-correlation of the reference and actual CPD signals to produce a correlation peak (2110); and (e) detecting the actual CPD signal from the correlation peak (2112).