PLL Phase Build-Out for Transient Wander Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional PLL circuits fail to accurately detect transient wander and cycle wander within the specified interval time, leading to incorrect phase restructuring, as they cannot differentiate between these noise types effectively.
Innovation Solution
A phase-locked loop circuit with a phase build-out function that uses a dual port memory to store and analyze phase data, calculating maximum phase amplitude values and comparing them against set threshold values to detect transient and cycle wander components, while optimizing sampling frequency and memory capacity based on these thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If phase detection is performed at fixed interval time of 100 ms according to Telcordia specification, then the detection method is simple and implementation is easy, but transient wander cannot be accurately detected and momentary phase shift beyond 5 Hz cannot be detected
Solution Approach 1:
The patent changes the fixed 100 ms detection interval to a dynamic variable interval detection method. The detection interval is adjusted based on the characteristics of the input signal and the type of wander being detected, allowing the system to optimize between detection accuracy and implementation simplicity for different operating conditions
Solution Approach 2:
The patent modifies the detection parameter (time interval) from a fixed value (100 ms) to a variable parameter that can be changed based on the detection needs. By changing the time interval parameter, the system can detect both transient wander and cycle wander effectively, resolving the contradiction between simple implementation and accurate detection
2Measurement precision
If phase detection is performed by changing interval time every sampling time to detect transient wander, then momentary phase shift can be detected more accurately, but when transient wander is synchronized with interval time, detection cannot be performed and cycle wander cannot be differentiated
Solution Approach 1:
The patent employs feedback mechanisms where the detection results are analyzed and used to adjust subsequent detection parameters. By monitoring the phase data continuously and analyzing the characteristics of detected wander, the system can differentiate between transient and cycle wander, and adjust detection intervals to avoid synchronization issues, thereby improving both accuracy and reliability
Solution Approach 2:
The patent performs preliminary analysis of the phase data to identify the characteristics of wander before final detection. By pre-processing the phase data and identifying patterns, the system can determine appropriate detection intervals in advance, avoiding the problem of synchronization between transient wander and detection intervals
3Stability of the object's composition
If conventional frame phase synchronous circuit is used to reduce abrupt change of output phase, then output phase stability is improved, but the device cannot solve the problems of transient wander detection and cycle wander differentiation
Solution Approach 1:
The patent enhances the frame phase synchronous circuit with additional detection and analysis functions. The modified circuit not only maintains output phase stability but also gains the capability to detect and differentiate between transient wander and cycle wander by incorporating variable interval detection and phase data analysis functions, making it a multi-functional device
Data Source
AI summary
A PLL circuit having a phase build-out function and a phase control method of the PLL circuit, in which a phase build-out detector monitors the input phase of a PLL device and detects a transient wander component and a cycle wander component at the same time. When only the transient wander component is automatically detected, a phase build-out actuator resets a phase detector, a digital amp-1 and a digital filter to restructure an output phase as before an input phase change. As to the cycle wander component detected at the same time, no phase restructuring is carried out.