GNSS Antenna Array Phase Correction After Spatial Interference Filtering
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Solution Overview
Problem
Existing methods for interference suppression in satellite navigation signals distort the carrier phase, making accurate position determination challenging, especially in high-precision applications like RTK and PPP, and require costly antenna array measurements or restrict antenna arrangements.
Innovation Solution
A method using a multi-antenna system with intrinsic beamformers to correct distorted carrier phases by calculating parameters from current and previous eigenbeamformers, compensating for phase changes due to interference suppression without requiring antenna array measurements or knowledge of signal directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spatial filtering is applied to suppress interference signals, then interference suppression capability is improved, but carrier phase accuracy deteriorates
Solution Approach 1:
The patent applies preliminary action by measuring and storing the spatial phase signature of the antenna array before interference suppression is applied. This pre-measured signature is then used to correct the carrier phase after interference suppression, thereby recovering the phase accuracy that would otherwise be lost. The correction is calculated based on the pre-stored spatial characteristics and the actual signal directions.
Solution Approach 2:
The patent implements feedback by using the measured spatial phase signature to calculate and apply a correction to the distorted carrier phase. The system continuously monitors the phase distortion caused by spatial filtering and applies real-time corrections based on the pre-measured antenna characteristics and current signal conditions, creating a closed-loop correction mechanism.
2Measurement precision
If spatial phase signature is measured in test chamber to correct carrier phase, then carrier phase correction accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent performs the complex measurement of spatial phase signature in advance during a one-time calibration process in a test chamber. This pre-measured data is stored and reused for carrier phase correction in actual operation, eliminating the need for repeated complex measurements while maintaining high correction accuracy.
Solution Approach 2:
The patent creates a digital copy of the antenna array's spatial phase characteristics during calibration and stores this information for reuse. This digital replica allows the system to apply accurate corrections without needing to physically remeasure or recalibrate the antenna array under different operating conditions.
3Productivity
If conventional beamforming is applied to all satellite navigation signals, then signal processing efficiency is improved, but direction-dependent phase errors increase
Solution Approach 1:
The patent applies local quality by customizing the beamforming process for each individual satellite navigation signal based on its specific direction of arrival. Instead of using a uniform beamforming approach for all signals, the system adapts the spatial phase correction to the local characteristics of each signal, thereby maintaining processing efficiency while eliminating direction-dependent phase errors.
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
The method effectively stabilizes carrier phases post-interference suppression, allowing accurate position determination in dynamic environments with arbitrary antenna arrangements and strong interference, enhancing precision in GNSS receivers.
Implementation Method 1
the signals are multiplied by a complex factor (beamforming weight) and then summed
Implementation Method 2
spatial filtering, in conjunction with noise suppression, modifies the carrier phases of the satellite navigation signals
Implementation Method 3
the signal processing unit modifies the carrier phase of at least one or each of the satellite navigation signals by calculating parameters from the current and previous eigenbeamformers associated with the respective satellite navigation signal
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
The invention relates to a method for reducing the effects of noise suppression on the measurement of the phases of satellite navigation signals at the point of their reception, wherein, in the method, a one-dimensional or multi-dimensional antenna array is provided with multiple reception antennas, satellite navigation signals received by the reception antennas are processed in a signal processing unit, the received satellite navigation signals undergo noise suppression in the signal processing unit by means of a spatial filter, i.e., by means of spatial filtering, for example by a power inversion (PI) filter or a projection filter, and after the noise suppression by means of the signal processing unit, the carrier phase of at least one or each satellite navigation signal is determined and is corrected by calculating parameters of one or more eigen-beam formers.