GNSS Receiver Multi-Antenna Detection of NLOS Signals
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Solution Overview
Problem
Conventional GNSS receivers struggle to differentiate between direct GNSS signals from satellites and non-line-of-sight (NLOS) signals, such as multipath and spoofing signals, which affect positioning accuracy.
Innovation Solution
A GNSS receiver equipped with at least two antennas, a satellite direction acquisition module, an estimation module, and a determination module, which uses timing differences and angular spectra to distinguish between direct and NLOS signals by comparing the viewed satellite direction with estimated arrival directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional antenna designs are used to suppress multipath signals, then some multipath suppression is achieved, but complete elimination of multipath and inability to determine signal origin remain
Solution Approach 1:
The patent divides the signal reception function across multiple antennas (at least two) positioned at different locations. Each antenna captures signals with different characteristics, allowing the system to segment the analysis of signal origins and distinguish between direct and reflected waves through comparative processing.
Solution Approach 2:
The patent introduces an intermediary processing system that analyzes timing differences and signal characteristics between multiple antennas. This intermediary processing enables indirect determination of signal origin by comparing relative arrival times and signal properties rather than directly filtering at the antenna level.
2Measurement precision
If signal filtering methods are used to eliminate NLOS signals, then positioning accuracy improves, but the ability to identify and filter spoofing signals remains insufficient
Solution Approach 1:
The patent employs dynamic signal processing that adapts to different signal types (direct waves, reflected waves, spoofing signals). The system dynamically adjusts its analysis based on timing differences and signal characteristics, enabling versatile discrimination among various signal types rather than using a static filtering approach.
Solution Approach 2:
The patent changes multiple parameters including timing differences, signal strength ratios, and arrival direction information to distinguish between different signal types. By analyzing multiple parameters simultaneously, the system can identify and filter various NLOS signals including spoofing attempts while maintaining high positioning accuracy.
3Measurement precision
If multiple antennas are used to determine signal arrival direction, then direct wave identification improves, but device complexity increases
Solution Approach 1:
The patent assigns specific functional roles to different antennas based on their local positions and signal reception characteristics. Each antenna contributes specific local information about signal arrival, and the system processes these local qualities differently to achieve accurate arrival direction estimation without requiring complex symmetric configurations.
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
Enables accurate identification of direct GNSS signals, effectively filtering out NLOS signals like multipath and spoofing, thereby improving positioning accuracy and stability.
Implementation Method 1
estimates the arrival direction of the GNSS signal on the basis of the difference in timing when the GNSS signal is received by the plurality of antennas
Data Source
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AI summary
Problem(s) To provide a GNSS receiver capable of easily determining whether a GNSS signal received by an antenna is based on a direct wave from a satellite or not. Solution(s) A GNSS receiver includes at least two antennas, a satellite direction acquisition module, an estimation module, and a determination module. A satellite direction acquisition module acquires the direction when viewing the satellite corresponding to the GNSS signal received by the antenna based on the satellite orbit information. The estimation module estimates the arrival direction of the GNSS signal on the basis of the difference in timing when the GNSS signal is received by the plurality of antennas. The determination module compares the direction in which the satellite is viewed from the antenna with the arrival direction estimated by the estimation module to determine whether the GNSS signal received by the antenna is a direct GNSS signal based on a direct wave from the satellite or an NLOS GNSS signal.