GNSS Snapshot Delay Estimation Using Correlator Co-Phasing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Accurate estimation of GNSS signal delays is challenging in multipath scenarios, especially when power saving requires non-continuous snapshots, as conventional tracking loops are ineffective.
Innovation Solution
A method that processes individual GNSS signal snapshots using correlators to compute complex and real values, selecting a reference complex value to suppress non-line-of-sight components and estimate delays accurately, even in multipath conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional closed tracking loops are used to estimate delays, then continuous signal processing is required, but power consumption increases and non-continuous snapshots cannot be processed
Solution Approach 1:
The patent replaces continuous tracking loops with periodic snapshot processing. Instead of continuously processing signals through closed loops, the system takes discrete snapshots at specific intervals, processes them independently using the proposed complex value computation and co-phasing methods, and updates delay estimates periodically. This periodic approach maintains measurement precision while dramatically reducing power consumption by allowing the receiver to enter low-power states between snapshots.
2Use of energy by moving object
If individual non-continuous snapshots are processed for power saving, then power consumption decreases, but delay estimation accuracy deteriorates without closed tracking loops
Solution Approach 1:
The patent transforms the processing approach by changing from real-valued correlation outputs to complex value representations. Each snapshot is processed to generate complex values, which are then co-phased using reference complex values derived from multiple correlators. This parameter transformation enables accurate delay estimation from single snapshots by exploiting the phase information in the complex domain, achieving precision comparable to continuous tracking while consuming less power.
Solution Approach 2:
The patent introduces reference complex values as intermediaries between the raw correlator outputs and the final delay estimation. These reference values, computed from multiple correlators observing the same snapshot, serve as mediators that enable the co-phasing operation. By using these intermediary reference values, the system can accurately estimate delays from individual snapshots without requiring continuous tracking loops.
3Measurement precision
If multiple correlators with different delays are used, then delay estimation accuracy in multipath scenarios improves, but computational complexity increases
Solution Approach 1:
The patent merges the outputs from multiple correlators by computing reference complex values that combine information from all correlators. Instead of processing each correlator output independently, the method combines them through the co-phasing operation using the reference complex values as a unified reference. This merging approach reduces computational complexity while maintaining the ability to resolve multipath components, as the combined reference contains information from all delay taps.
Data Source
AI summary
A method for processing GNSS signals comprises obtaining respective output sequences from N correlators for a snapshot of a received GNSS signal, wherein each sequence has K values, and the N correlators correspond to N different delays of a PRN code sequence; computing one or more complex values using the output sequence; computing a reference complex value using the one or more complex values; for each output sequence, computing respective one or more real values using the reference complex value and the respective one or more complex values of the output sequence; and estimating a delay of the received GNSS signal using the one or more real values of the output sequences.