False Synchronization Detection in Satellite Receivers
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Solution Overview
Problem
Existing methods for detecting false synchronization in satellite receivers are either time-consuming or dependent on the specific spreading codes used, which can lead to inefficiencies and discontinuity in satellite positioning services.
Innovation Solution
A method for detecting false synchronization that involves analyzing correlation values derived from pilot and data channels, as well as shifted correlations, to determine if the receiver has synchronized with the intended satellite, independent of the spreading codes used.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the conventional method of checking consistency between ephemeris and almanac is used to detect false synchronization, then false synchronization can be detected, but the detection process is time-consuming and can take up to two minutes
Solution Approach 1:
The patent applies preliminary action by performing false synchronization detection during the signal acquisition phase, before the receiver commits to the tracking phase. The method calculates a detection metric using correlation values between the received signal and local replica codes, and compares this metric against a threshold to determine if false synchronization exists. This allows early detection and avoidance of false synchronization without requiring the time-consuming ephemeris collection process, thus reducing detection time while maintaining reliability
Solution Approach 2:
The patent extracts the essential detection function from the conventional ephemeris-based method by using only the correlation values between received signals and local replica codes. This extracted metric is sufficient to detect false synchronization without needing to collect and process full ephemeris data from multiple satellites, thereby significantly reducing the time required for detection while maintaining the core functionality of false synchronization detection
2Reliability
If the receiver collects all ephemeris data to detect false synchronization, then detection accuracy is improved, but the operation of the receiver is penalized and continuity of service is not ensured
Solution Approach 1:
The patent applies partial action by using only the necessary correlation values from the acquisition phase to perform false synchronization detection, rather than collecting all ephemeris data from multiple satellites. This partial use of available data is sufficient to detect false synchronization while avoiding the excessive time and computational resources required by conventional methods, thus maintaining detection accuracy without penalizing receiver operation efficiency
Solution Approach 2:
The patent performs false synchronization detection during the acquisition phase before the receiver commits to tracking a satellite. By using the correlation values already calculated during acquisition to compute a detection metric and compare it against a threshold, the system can identify false synchronization early and avoid entering the tracking phase with incorrect synchronization, thereby maintaining continuous service without requiring additional ephemeris collection
3Reliability
If existing false synchronization detection methods are used, then detection capability is provided, but the methods are dependent on specific spreading codes and lead to inefficiencies
Solution Approach 1:
The patent applies universality by creating a false synchronization detection method that works with any spreading code used in GNSS systems. The detection metric is calculated using correlation values between the received signal and local replica codes without requiring knowledge of the specific spreading code structure. This universal approach allows the same detection algorithm to be applied across different GNSS constellations and spreading code types, providing both detection capability and spreading code independence
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 method allows for rapid and efficient detection of false synchronization, ensuring continuous and accurate satellite positioning without reliance on specific spreading codes, thereby improving the overall performance and reliability of satellite receivers.
Implementation Method 1
analyzing correlation values derived from pilot and data channels, as well as shifted correlations
Data Source
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AI summary
A method for detecting false acquisition of a navigation signal comprising the steps (110) of determining a plurality of pilot channel point correlations and a plurality of data channel point correlations, and determining a first value based on these point correlations; determining (120) a plurality of pilot channel partial correlations, and determining a second value based on these partial correlations; determining (130) a plurality of pilot channel staggered correlations, and determining a third value based on these pilot channel staggered correlations. The convergence phase further comprises the step (140) of determining false synchronization when at least one of said correlations exceeds a predetermined threshold.