Quasi-Reference Phase Correction for Local Oscillator Drift
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Solution Overview
Problem
Existing distance measuring devices using a digital-controlled oscillator (DCO) direct modulation method for transmission and a super-heterodyne (SH) method for reception suffer from initial phase fluctuations in the local oscillator, leading to inaccurate distance measurements due to the dependence of phase information exchange between devices.
Innovation Solution
A phase correcting device with an all-digital phase-locked loop, a reference phase device, and a correction circuit is employed to detect and correct phase fluctuations, allowing for accurate distance measurement by generating a quasi-reference phase and calculating phase differences to stabilize the initial phase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a DCO direct modulation method is used for transmission and an SH method is used for reception to reduce power consumption, then power consumption is reduced, but initial phase fluctuates in the local oscillator leading to inaccurate distance measurement
Solution Approach 1:
The patent applies preliminary action by detecting the initial phase of the local oscillator before distance measurement and storing it as reference phase information. This pre-detection and storage of phase data allows the system to compensate for subsequent phase fluctuations without requiring continuous high-power operation of the local oscillator, thus maintaining measurement accuracy while enabling low-power modes.
Solution Approach 2:
The patent introduces reference phase information as an intermediary element that mediates between the fluctuating local oscillator phase and the distance measurement calculation. By comparing the current phase with the stored reference phase, the system can correct for oscillations and maintain accurate measurements even when the oscillator operates in low-power modes with inherent phase instability.
2Ease of operation
If reference signals between devices independently operate to enable communication, then communication is established, but initial phases differ leading to greatly deteriorated distance measurement accuracy
Solution Approach 1:
The patent applies feedback by having devices exchange reference phase information through communication channels. Each device detects its local oscillator's initial phase, transmits this information to the other device, and uses the received reference phase data to correct its own measurements. This feedback loop synchronizes the phase references between independently operating devices, maintaining measurement accuracy while preserving communication functionality.
3Measurement precision
If phase information is transmitted between devices to enable accurate distance measurement, then measurement accuracy is improved, but device complexity increases due to additional communication requirements
Solution Approach 1:
The patent applies universality by designing the communication system to serve multiple functions: it既能 transmit distance measurement data又能 exchange reference phase information. The same communication channels and protocols used for primary distance measurement purposes are also utilized for synchronizing phase references, eliminating the need for separate dedicated phase synchronization hardware or protocols and thus reducing overall system complexity.
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 solution enables accurate distance measurement by stabilizing the initial phase, thereby improving the accuracy of phase information exchange and reducing power consumption in distance measuring devices.
Implementation Method 1
a local oscillator that includes an all digital phase-locked loop configured to generate a local oscillation signal based on a reference clock
Implementation Method 2
a first phase detector included in the all digital phase-locked loop, and configured to detect a phase of the local oscillation signal to output the phase of the local oscillation signal
Implementation Method 3
a second phase detector configured to detect a fluctuation amount of a phase of the local oscillator, based on the phase detected by the first phase detector and the quasi-reference phase
Implementation Method 4
a correction circuit configured to correct the phase of the inputted signal by using a detection result of the second phase detector
Data Source
AI summary
A phase correcting device includes a local oscillator that includes an all digital phase-locked loop configured to output a local oscillation signal, a first phase detector configured to detect a phase of the local oscillation signal to output the phase of the local oscillation signal, a reference phase device configured to generate a quasi-reference phase corresponding to a reference phase of the local oscillation signal to output the quasi-reference phase, based on a reference clock, a second phase detector configured to detect a fluctuation amount of a phase of the local oscillator, based on the phase detected by the first phase detector and the quasi-reference phase, and a correction circuit configured to correct the phase of the inputted signal by using a detection result of the second phase detector.