Asymmetric Time of Flight Estimation via Correction Metrics
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Solution Overview
Problem
Conventional methods for time of flight estimation in wireless communication environments are prone to errors due to multipath fading, especially in asymmetric systems where one device has superior capabilities, leading to inaccurate separation distance calculations.
Innovation Solution
The first device generates a wireless channel estimation and a correction metric to compensate for errors in the second device's timing calculations, allowing for accurate time of flight estimation by leveraging its superior capabilities and sharing this information to correct multipath fading effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional two-way transmitting scheme is used for time of flight estimation, then both devices can perform timing calculations, but measurement precision deteriorates due to multipath fading errors in both devices' line of sight estimations
Solution Approach 1:
The patent applies asymmetry by having only the first device (with superior capabilities) perform line of sight estimation and generate correction metrics, while the second device simply uses these corrections. This asymmetric division of computational tasks exploits the capability difference between devices to achieve higher measurement precision without requiring both devices to have equal processing power.
Solution Approach 2:
The patent introduces correction metrics as an intermediary element that mediates between the first device's superior measurement capabilities and the second device's timing calculations. The correction metrics act as a bridge, allowing the second device to benefit from the first device's accurate line of sight estimation without needing to perform complex estimations itself.
2Measurement precision
If both devices perform line of sight estimations to determine accurate time of arrival, then timing accuracy improves, but device complexity increases due to requiring superior capabilities in both devices
Solution Approach 1:
The patent resolves this contradiction by creating an asymmetric system where only the first device needs superior processing capabilities for line of sight estimation. The second device can be simpler since it only needs to receive and apply correction metrics, not perform complex estimations itself. This asymmetric capability requirement reduces overall system complexity while maintaining accuracy.
Solution Approach 2:
The first device performs self-service by generating correction metrics based on its own superior line of sight estimation capabilities and sharing them with the second device. This allows the system to achieve accurate timing without requiring the second device to independently perform complex estimations, thereby reducing the complexity burden on the less capable device.
3Adaptability or versatility
If conventional methods are used in asymmetric systems, then simpler devices can participate, but measurement precision deteriorates due to errors from the less capable device's timing calculations
Solution Approach 1:
The correction metrics serve as an intermediary that enables devices with different capabilities to work together accurately. The first device generates these metrics using its superior capabilities, and the second device applies them to correct its timing calculations. This intermediary mechanism allows asymmetric device participation while maintaining high measurement precision.
Solution Approach 2:
The system implements feedback by having the first device provide correction metrics back to the second device based on its line of sight estimation. This feedback loop allows the less capable device to compensate for its limitations by incorporating corrections from the more capable device, thereby maintaining accuracy while preserving device versatility.
Data Source
AI summary
Embodiments for accurately performing time of flight estimations are provided. These embodiments include using a first wireless device to monitor a wireless link and subsequently generate a wireless link estimation based on the monitoring. The embodiments also include deriving a correction metric based on the generated wireless link estimation and transmitting the correction metric from the first wireless device to a second wireless device. The second wireless device may then calculate a time of arrival of a first signal received from the first wireless communication device and correct any errors associated with the time of arrival calculation using the received correction metric. Further, the second wireless device may transmit the corrected time of arrival back to the first wireless device, such that the first wireless device can use the corrected time of arrival to estimate the time of flight of the first signal.