Carrier Phase Ambiguity Search Using Terrestrial Spatial Constraints
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently resolving satellite positioning system carrier phase integer ambiguity, particularly in non-open-sky environments, which hinders high-precision positioning and satellite signal acquisition.
Innovation Solution
Constraining the satellite positioning system carrier phase integer ambiguity search space using spatial information derived from terrestrial-based signals, such as range, angle, and position estimates, to bound the search space and reduce uncertainty.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the satellite positioning system carrier phase integer ambiguity search space is not constrained, then the system can maintain simplicity in processing, but the positioning precision and signal acquisition speed deteriorate due to large search space and high uncertainty
Solution Approach 1:
The patent applies preliminary action by obtaining spatial information from terrestrial signals (such as range, angle, and position estimates) before conducting satellite carrier phase ambiguity resolution. This pre-acquired spatial information is used to constrain the search space boundaries, thereby reducing the complexity of the ambiguity resolution process while improving positioning precision. The terrestrial signal processing is performed in advance to prepare constraints that will guide the subsequent satellite signal analysis.
2Speed
If the integer ambiguity search space is large, then the system can maintain ease of operation, but the signal acquisition speed and sensitivity worsen
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the search space parameters (boundaries and constraints) based on spatial information derived from terrestrial signals. By changing the search space parameters from a fixed large range to a dynamically constrained range, the system achieves faster signal acquisition speed while maintaining operational simplicity. The spatial parameters (range, angle, position) are used to modify the search space boundaries, making the ambiguity resolution process more efficient.
3Reliability
If terrestrial-based spatial information is used to constrain the search space, then the positioning accuracy improves, but the system complexity increases due to additional signal processing
Solution Approach 1:
The patent applies merging by combining terrestrial signal processing with satellite signal processing into a unified positioning system. The spatial information from terrestrial signals is merged with the carrier phase measurements from satellite signals to jointly resolve integer ambiguities. This integration improves positioning reliability by using multiple signal sources while managing complexity through a coordinated processing approach that leverages the complementary strengths of both terrestrial and satellite systems.
Data Source
AI summary
A method of determining an integer ambiguity search space includes: obtaining, at an apparatus, a code phase measurement of a satellite vehicle signal comprising a pseudorandom noise code and a carrier signal; obtaining, at the apparatus, spatial information corresponding to a wireless terrestrial signal transferred between the apparatus and a terrestrial base station; determining, at the apparatus, a satellite positioning system carrier phase integer ambiguity search space based on the code phase measurement; and constraining a size of the satellite positioning system carrier phase integer ambiguity search space based on the spatial information.