Phase-Based Ranging with Doppler Compensation for Pseudo-Random Hopping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing phase-based ranging methods are biased by Doppler shift, particularly in environments with pseudo-random channel hopping, such as mandated by US FCC regulation 47 CFR § 15.247, and do not provide accurate distance measurements.
Innovation Solution
A Doppler-compensated phase-based ranging method using neural networks to process doppler-compensated two-way phase measurements, even in the absence of a linear frequency sweep, allowing for accurate ranging in pseudo-random channel hopping scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a linear frequency sweep is used for phase-based ranging, then Doppler compensation can be achieved, but the method cannot be used with pseudo-random channel hopping required by FCC regulations
Solution Approach 1:
The patent changes the fundamental parameter of frequency sweeping from linear to pseudo-random hopping, while introducing new parameters (phase difference measurements at same frequency, time difference calculations) to maintain Doppler compensation capability without requiring linear frequency progression
Solution Approach 2:
The patent introduces an intermediary calculation step that uses phase measurements at the same frequency taken at different times to estimate Doppler shift, which then serves as a mediator to correct the range estimates obtained from pseudo-random frequency hopping measurements
2Productivity
If FFT-based or super-resolution algorithms are used for range estimation, then the method works with linear frequency sweep, but it produces biased results in the presence of Doppler shift
Solution Approach 1:
The patent performs preliminary Doppler estimation and compensation calculations before final range estimation, using phase measurements at the same frequency to pre-correct for Doppler effects, thereby eliminating the bias that would otherwise affect the range estimation algorithms
Solution Approach 2:
The patent implements a feedback mechanism where phase measurements at the same frequency are used to estimate Doppler shift, which then feeds back to correct the range estimates from pseudo-random frequency hopping, creating a closed-loop system that compensates for motion effects
3Measurement precision
If Doppler compensation is applied to pseudo-random frequency hopping measurements, then accurate ranging is achieved, but the complexity of processing increases
Solution Approach 1:
The patent segments the frequency hopping measurements into groups, identifying specific pairs of measurements at the same frequency to use for Doppler estimation, thereby reducing the complexity of processing all frequency measurements while maintaining accuracy
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
The method achieves precise and robust distance determination by synergistically combining Doppler compensation with neural networks, efficiently utilizing hardware resources and adhering to regulatory compliance.
Implementation Method 1
In the presence of Doppler shift, e.g., during movement of one or both of the devices, the range estimate will be biased. calculating a relative speed between said first device and said second device based at least on said first measurement and said second measurement; doppler-compensating a plurality of measurements
Data Source
AI summary
A method of phase-based ranging between a first device and a second device, comprises receiving a plurality two-way phase-measurements between the first device and the second device performed at a plurality of frequencies; identifying a first measurement and a second measurement of said plurality of two-way phase measurements, said first measurement and said second measurement having been performed at a same frequency; calculating a relative speed between said first device and said second device based at least on said first measurement and said second measurement; doppler compensating a plurality of measurements of said plurality of two-way phase measurements based on the calculated relative speed; and calculating a distance between said first device and said second device based on the doppler compensated measurements, wherein said calculating comprises inputting the doppler compensated measurements to a neural network.