GNSS Correlation Aiding for DCXO Temperature Drift Compensation
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Solution Overview
Problem
Existing methods for temperature compensation in digital controlled crystal oscillators (DCXO) in GNSS receivers apply corrections at infrequent intervals, such as every 20 milliseconds, which is inadequate for frequent temperature variations, affecting the accuracy of GNSS signal processing.
Innovation Solution
Implementing correlation aiding in the GNSS receiver system to apply DCXO temperature corrections at a higher frequency, such as every 1 millisecond, by using a correlation module to monitor temperature and adjust NCO state data before correlation processing, allowing more frequent compensation for frequency variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If corrections are applied after correlation processing using large blocks of PDI data, then the data block size is large, but the update rate of corrections is low (20 milliseconds interval)
Solution Approach 1:
The patent segments the correction application process by introducing an intermediate buffer that stores correction values separately from the main signal processing flow. This allows corrections to be applied in smaller, more frequent intervals (1 millisecond or less) rather than waiting for large PDI data blocks to accumulate, thus increasing the update rate while maintaining data integrity
Solution Approach 2:
The patent applies corrections upstream in the signal processing chain, before correlation processing occurs. By calculating and applying DCXO temperature corrections to the NCO state data prior to correlation, the system can use much smaller data blocks (or continuous streams) rather than waiting for large post-detection integration blocks, thereby significantly increasing the correction update rate
2Productivity
If corrections are applied upstream before correlation, then the update rate of corrections increases (1 millisecond or less), but the complexity of the correction system increases
Solution Approach 1:
The patent introduces an intermediate correction buffer as a mediator between the temperature monitoring system and the signal processing chain. This buffer stores pre-calculated correction values that can be applied upstream without requiring complex real-time calculations during the high-speed signal processing, thus increasing update rate while managing system complexity through buffer-mediated decoupling
3Measurement precision
If corrections are applied frequently to compensate for temperature variations, then the accuracy of GNSS signal processing improves, but the computational load increases
Solution Approach 1:
The patent performs correction calculations in advance and stores them in an intermediate buffer before they are needed in the main signal processing flow. By pre-calculating DCXO temperature corrections based on temperature sensor readings and storing them for later application, the system achieves frequent updates (improving accuracy) without requiring intensive real-time computational resources during the critical signal processing phases
Data Source
AI summary
A system and a method are disclosed for compensating a global navigation satellite system (GNSS) signal, including obtaining, by a correlation module, sample data which corresponds to a GNSS signal obtained based on an oscillator frequency of a crystal oscillator; obtaining, by the correlation module, aiding information which is determined based on information about the crystal oscillator; performing, by the correlation module, compensation processing on numerically-controlled oscillator (NCO) state data based on the aiding information, to obtain compensated NCO state data; performing, by the correlation module, correlation processing on the sample data based on the compensated NCO data; storing the compensated NCO state data in an NCO memory; and determining location information about a location of an electronic device corresponding to the correlation module based on the compensated sample data.