GPS OTA Testing Using Rotating Table and Signal Map
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Solution Overview
Problem
Current GPS OTA testing methods are inefficient, taking excessively long times and being costly due to the need for extensive measurements of radiated sensitivity at multiple points, which is time-consuming and expensive.
Innovation Solution
A GPS OTA testing method and system that utilizes a rotating table and a GPS satellite signal generator to quickly acquire satellite signal strength at various angles and polarization directions, forming a signal strength direction map to find optimal angles and polarization directions, allowing for the calculation of sensitivity using a reference terminal's sensitivity and signal-to-noise ratio, thereby reducing the need for individual point measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the traditional AGPS method is used to measure EIS values at multiple points individually, then measurement precision is improved, but testing time increases significantly
Solution Approach 1:
The patent applies partial action by measuring EIS at only one point (the point with highest C/N0 in the upper hemisphere) rather than all required points, and uses calculation to obtain the complete EIS pattern. This reduces the 120 individual measurements to just 1 measurement plus calculations, achieving the same result with partial direct measurement.
Solution Approach 2:
The patent performs preliminary measurement of the antenna pattern and C/N0 values at all 60 discrete positions before the actual EIS measurement. This preliminary data collection enables the calculation of EIS at all points from a single measured EIS value, rather than measuring each point individually during the EIS test phase.
2Reliability
If extensive measurements at multiple angles and polarizations are performed, then reliability of GPS OTA testing is improved, but device complexity increases
Solution Approach 1:
The patent extracts the essential information needed for reliable GPS OTA testing by identifying that only one EIS measurement point is necessary when combined with preliminary antenna pattern data. This extraction approach maintains reliability by preserving the calculation methodology while removing the complexity of measuring all points directly.
Solution Approach 2:
The patent uses the antenna pattern data (which is already measured) as a template to calculate and derive EIS values at all positions. Instead of physically measuring at each position, the system copies the spatial distribution characteristics from the antenna pattern to generate the complete EIS pattern through mathematical calculation.
3Measurement precision
If individual EIS measurement at one point is performed for each DUT, then measurement accuracy is maintained, but productivity decreases
Solution Approach 1:
The patent measures only one EIS value per DUT (at the point with highest C/N0) rather than multiple values, achieving the same measurement accuracy through calculation while dramatically improving productivity. The single measurement combined with antenna pattern data produces the complete EIS pattern for each device.
Solution Approach 2:
The patent changes the measurement approach from direct EIS measurement at multiple points to calculation-based EIS derivation using antenna pattern parameters (C/N0 values) already obtained during spherical coverage measurement. This parameter transformation maintains accuracy while enabling batch processing of multiple DUTs.
Data Source
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AI summary
A GPS OTA testing method and system is provided. The GPS OTA testing method comprises: placing a terminal under test on a rotating table in a darkroom, and generating a GPS signal by a GPS satellite signal generator in the darkroom; acquiring the satellite signal strength at each of the angles and in each of the polarization directions, and forming a signal strength direction map; searching for an optimal angle and an optimal polarization direction and acquiring a sensitivity corresponding to the optimal angle and the optimal polarization direction; and acquiring a sensitivity at each of the angles and in each of the polarization directions according to the sensitivity corresponding to the optimal angle and the optimal polarization direction and according to the signal strength direction map and integrating the sensitivities to acquire an antenna signal strength. Thereby, the present disclosure can reduce the testing time, improve the testing efficiency, simplify the testing system and reduce the cost.