Frequency-Sweep Propagation Timing for NLOS Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional localization and ranging technologies face challenges in accurately determining device location due to Non-Line of Sight (NLOS) conditions caused by obstacles, leading to inaccurate distance and orientation estimates, particularly in environments with furniture, walls, or people, which degrade the performance of localization algorithms and are critical in safety applications.
Innovation Solution
The method involves transmitting and measuring propagation times using different carrier frequencies to detect NLOS conditions by comparing propagation times at varying frequencies, leveraging the frequency-dependent radio wave velocity variation through obstacles to distinguish between NLOS and Line of Sight (LOS) conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional localization algorithms are used, then the system is simple and easy to operate, but the measurement precision degrades under NLOS conditions
Solution Approach 1:
The patent changes the parameter of carrier frequency by transmitting signals at multiple different frequencies (e.g., 6 GHz and 8 GHz) and comparing the propagation time differences. This frequency-based parameter change enables the system to detect NLOS conditions by observing how different frequencies experience different propagation characteristics when passing through obstacles, thereby improving measurement precision without requiring complex additional hardware.
Solution Approach 2:
The system implements feedback by comparing the propagation time measurements from different carrier frequencies and using this comparison information to detect NLOS conditions. The processor uses the difference in propagation times between frequencies as feedback to determine whether NLOS conditions exist, allowing the system to adapt its localization calculations based on this feedback information.
2Reliability
If single-frequency signals are used, then the device complexity is low, but the reliability of localization degrades in NLOS environments
Solution Approach 1:
The patent applies multi-functionality by using a single processing system to perform multiple functions: transmitting signals at different frequencies, measuring propagation times for each frequency, comparing the propagation time differences, and detecting NLOS conditions. This universal approach allows one system to achieve both reliable NLOS detection and maintain localization functionality without requiring separate dedicated systems for each function.
3Measurement precision
If multiple carrier frequencies are used to detect NLOS, then the measurement precision improves, but the use of energy increases
Solution Approach 1:
The patent applies partial action by using multiple carrier frequencies (e.g., just 6 GHz and 8 GHz) rather than transmitting at all possible frequencies. This selective approach provides sufficient measurement precision to reliably detect NLOS conditions while minimizing the additional energy consumption that would result from using a full frequency spectrum. The system uses only the necessary minimum number of frequencies to achieve reliable detection.
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 allows for reliable detection and mitigation of NLOS conditions, enabling precise and accurate localization and ranging by differentiating between LOS and NLOS scenarios, thereby improving the reliability of localization systems.
Implementation Method 1
estimating a first propagation time between a first device and a second device using a first signal communicated at a first carrier frequency. The method may further include estimating a second propagation time between the first device and the second device using a second signal communicated at a second carrier frequency
Implementation Method 2
leveraging the frequency-dependent radio wave velocity variation through obstacles to distinguish between NLOS and Line of Sight (LOS) conditions
Data Source
AI summary
Systems, devices, and methods for detecting Non-Line of Sight conditions using frequency-sweep techniques are disclosed. In an exemplary aspect, a method is disclosed. In some embodiments, the method includes estimating a first propagation time between a first device and a second device using a first signal communicated at a first carrier frequency. The method may further include estimating a second propagation time between the first device and the second device using a second signal communicated at a second carrier frequency, wherein the second carrier frequency is different than the first carrier frequency. The method may further include determining whether a Non-Line of Sight (NLOS) condition exists between the first device and the second device based on the first propagation time and the second propagation time.