GNSS Timing Extraction Using Time-Delay Compensation for Reflected Signals
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Solution Overview
Problem
In environments with multi-path propagation, such as indoor or challenging outdoor settings, extracting reliable timing information from satellite radio signals is hindered by the attenuation of directly propagated components and the dominance of reflected components, which traditional circular polarized antennas fail to address effectively.
Innovation Solution
A device and method that extract preliminary timing information from both directly propagated and reflected circular polarized components of satellite radio signals, with a processing system that measures and compensates for time-delays using stored correction data to produce accurate timing information, even when reflected components are stronger.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reflected components are used for timing extraction, then signal availability is improved in indoor environments, but time-delay errors are introduced due to the longer propagation path
Solution Approach 1:
The system implements feedback mechanisms to measure and compensate for time-delay errors. By analyzing the characteristics of reflected components and comparing them with expected direct path delays, the processing system can identify and correct time-delay errors. This feedback loop allows the system to use reflected components for timing extraction while maintaining accuracy by compensating for the additional propagation time.
Solution Approach 2:
The patent replaces traditional hardware-based signal filtering mechanisms with software-based processing methods. Instead of using physical filters or antenna configurations to eliminate reflected components, the system uses digital signal processing techniques to identify, separate, and correct reflected signal components, thereby maintaining timing accuracy while utilizing previously unusable signal paths.
2Measurement precision
If traditional circular polarized antennas attenuate reflected components, then signal quality is improved in open sky environments, but signal strength is reduced in environments where direct components are already weak
Solution Approach 1:
The antenna system is divided into multiple elements with different polarization characteristics or reception patterns. One element receives and processes directly propagated components while another element receives reflected components. This segmentation allows the system to maintain high signal quality for direct components while separately capturing reflected components that would otherwise be attenuated, thereby increasing total received signal power without sacrificing quality.
Solution Approach 2:
The system changes the reception parameters dynamically based on the propagation environment. Instead of using a fixed circular polarization that attenuates reflected components, the system can adjust polarization parameters, gain settings, and processing characteristics to optimize both signal quality and power reception. This includes adjusting the degree of circular polarization or switching between different reception modes based on environmental conditions.
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 ensures reliable extraction of timing information by compensating for time-delays, thereby enhancing the accuracy and availability of timing data in environments where direct signals are weak and reflected signals are dominant.
Implementation Method 1
a processing system for producing the timing information based on at least one of the following: the first preliminary timing information and the second preliminary timing information
Implementation Method 2
A radio signal transmitted by a satellite of a GNSS has typically a circular polarization in which the electric field of a passing electromagnetic wave changes direction in a rotary manner
Implementation Method 3
using stored correction data for reducing the effect of the time-delay on the timing information when producing the timing information based on at least the second preliminary timing information
Data Source
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Figure 2a
AI summary
A device for producing timing information comprises equipment (101) that extracts first preliminary timing information from a first circular polarized component of a radio signal and second preliminary timing information from a second circular polarized component of the radio signal. The second circular polarized component has an opposite handedness and a time-delay with respect to the first circular polarized component. The device comprises a processing system (102) that produces the timing information based on the first preliminary timing information and/or the second preliminary timing information, and uses stored correction data for reducing the effect of the time-delay on the timing information when using the second preliminary timing information for producing the timing information. Thus, the timing information corresponds to the first preliminary timing information also when the timing information is produced based on the second preliminary timing information.