PLL Clock Synchronization for Accurate Channel Sounding Ranging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current network protocols face challenges in accurately determining distance between network devices using Channel Sounding due to phase ambiguity between transmit and receive circuits, which can vary and make it difficult to predictably measure distance, especially in two-way ranging applications.
Innovation Solution
Incorporating a divider within the phase locked loop with a reset mechanism to ensure a constant phase relationship between transmit and receive clocks, using a clock generation circuit that includes a signal source, phase locked loop, detector, loop filter, oscillator, and multi-modulus divider, and a quadrature signal generator to output clocks with a predetermined phase difference, thereby maintaining a consistent phase relationship for accurate distance measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate transmit and receive circuits are used for distance measurement, then functional versatility is improved, but phase relationship stability deteriorates
Solution Approach 1:
The patent merges the transmit and receive clock generation functions into a single phase-locked loop circuit. The PLL generates a master clock signal that is distributed to both transmit and receive circuits, ensuring they share a common time reference. This consolidation maintains functional versatility while guaranteeing stable phase relationships between transmit and receive operations.
Solution Approach 2:
The patent introduces a phase-locked loop as an intermediary mechanism that mediates between the master clock source and the transmit/receive circuits. The PLL acts as a buffer that synchronizes both circuits to the same clock phase, eliminating direct phase relationship issues between separate circuits while maintaining their operational independence.
2Device complexity
If independent clock generation is used for transmit and receive circuits, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent combines the clock generation functionality into a single shared phase-locked loop that serves both transmit and receive circuits. This merging approach maintains relatively low device complexity while dramatically improving measurement precision by eliminating phase ambiguity between independent clock sources.
Solution Approach 2:
The patent implements feedback control through the phase-locked loop mechanism. The PLL continuously monitors and adjusts the clock phases to maintain synchronization between transmit and receive operations. This feedback mechanism ensures high measurement precision without requiring overly complex independent clock generation systems.
3Ease of operation
If phase relationship varies between transmit and receive circuits, then ease of operation is improved, but reliability of distance measurement deteriorates
Solution Approach 1:
The phase-locked loop serves as an intermediary that automatically manages the phase relationship between transmit and receive circuits. This mediator handles the complexity of phase synchronization internally, maintaining ease of operation for users while ensuring reliable distance measurements through consistent phase relationships.
Solution Approach 2:
The feedback mechanism in the PLL automatically corrects any phase drift or variations between transmit and receive circuits. This continuous adjustment maintains measurement reliability without requiring manual intervention, preserving ease of operation while ensuring consistent phase relationships for accurate ranging.
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 ensures a constant phase difference between transmit and receive clocks, allowing for reliable and accurate distance calculations between network devices, enhancing the predictability of Channel Sounding measurements.
Implementation Method 1
a detector to determine a difference between the REFCLK signal and a feedback signal
Implementation Method 2
a loop filter to filter the output to create a filtered output
Implementation Method 3
an oscillator to generate a clock signal with a frequency related to the filtered output
Implementation Method 4
a divider to divide the clock signal by a quantity
Implementation Method 5
a multi-modulus divider in communication with an output of the divider, to further divide the output of the divider and supply the feedback signal to the detector
Implementation Method 6
a quadrature signal generator comprises a shift register and combinational logic, wherein the shift register and the combinational logic are used to generate the receive clock and the transmit clock
Data Source
AI summary
A system and method for accurately determining a distance between two network devices using a Channel Sounding application is disclosed. The network devices each guarantee a fixed phase relationship between the transmit circuit and the receive circuit. In one embodiment, this is achieved by incorporating the divider within the phase locked loop. The divider may have a reset, such that it can be initialized to a predetermined state. Further, by utilizing a divider disposed within the phase locked loop with a reset, the quadrature signal generator is guaranteed to output clocks for the transmit circuit and the receive circuit that have a constant phase relationship.