UWB Spectrum Sharing for 1 cm Vehicle Positioning
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Solution Overview
Problem
In urban areas, GPS signals are often weak or unavailable, leading to poor accuracy in vehicle position determination, which is inadequate for safety applications like accident prediction and lane identification, necessitating alternative methods for accurate position data.
Innovation Solution
A novel ultra-wide band (UWB) spectrum sharing scheme that allocates a regular time slot for UWB position determination signals, allowing for synchronization of UWB transceivers using a master site with GPS or SDARS signals, enabling vehicles to calculate their position to within 1 cm accuracy by measuring the time of flight of synchronized pulses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS signals are used for vehicle position determination, then position data can be obtained, but in urban canyon areas with tall buildings, GPS signals become weak or unavailable, leading to poor position accuracy
Solution Approach 1:
The patent introduces UWB transceivers as intermediary devices installed in urban areas to provide position determination signals when GPS is blocked. These transceivers act as mediators between the vehicle and the positioning system, enabling accurate position calculation through local signal transmission and time-of-flight measurement without relying on satellite signals that are blocked by tall buildings.
Solution Approach 2:
The patent replaces the satellite-based GPS electromagnetic signal system with a local UWB radio signal system for position determination in urban canyons. This substitution allows vehicles to obtain accurate position data through local UWB transceiver signals instead of relying on blocked GPS satellite signals.
2Object-affected harmful factors
If a 2.4 GHz solution with 10 MHz bandwidth is used for position determination, then position data can be obtained in urban areas, but the accuracy is poor (6-10 meters), which is inadequate for safety applications
Solution Approach 1:
The patent changes the frequency parameter from 2.4 GHz to UWB frequencies (3.1-5.3 GHz), and more importantly, changes the bandwidth parameter from narrowband (10 MHz) to ultra-wideband (multiple GHz). This parameter change enables significantly higher position accuracy (within 1 meter or less) through precise time-of-flight measurement of the wideband signals.
3Productivity
If UWB spectrum is shared among multiple services, then spectrum utilization is improved, but interference between services may occur, affecting signal quality
Solution Approach 1:
The patent implements periodic time-sliced operation where UWB position determination signals are transmitted in designated time slots (e.g., 20 msec intervals during every half second). This periodic transmission pattern allows other services to operate during non-UWB time slots while ensuring dedicated, interference-free intervals for high-accuracy position determination signals.
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 provides accurate vehicle positioning in areas with weak or no GPS, reducing interference and enabling precise location determination, even in dense urban environments, supporting safety applications with high accuracy.
Implementation Method 1
vehicles receiving these pulses can calculate their respective positions to within 1 cm accuracy, by calculating the time of flight from each received site's pulse train
Data Source
AI summary
Systems and methods are presented for sharing the ultra-wide band (“UWB”) spectrum. The systems and methods can include allocating a designated time slice for UWB position determination signals on a primary basis to ensure that the UWB transmissions would be free of interference. The systems and methods can also include synchronizing a plurality of UWB transceivers and emitting synchronized pulses, during the designated time slice.