L5 GNSS Direct Acquisition Engine for Interference Resilience

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Solution Overview

Problem

Conventional hybrid L1/L5 GNSS receivers face performance limitations due to the difficulty in directly acquiring L5 signals without the aid of L1 signals, especially when L1 signals are interfered with, leading to impaired positioning capabilities.

Innovation Solution

Incorporating an L5 GNSS direct acquisition engine that can operate independently through an API interface, using frequency domain correlation with discrete Fourier transforms to acquire L5 signals without relying on L1 signal acquisition, and switching between time and frequency domain correlators based on assistance data availability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hybrid L1/L5 GNSS receivers use sequential acquisition (L1 first, then L5), then L5 signal acquisition becomes feasible, but positioning performance deteriorates when L1 signals are unavailable due to interference

Engineering Contradiction:

Improvepositioning capabilityVSAvoidsignal acquisition flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent divides the acquisition engine into separate L1 and L5 acquisition components. The L5 acquisition engine operates independently without requiring L1 signal assistance, enabling the receiver to acquire L5 signals directly even when L1 signals are unavailable due to interference or jamming.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic selection between different acquisition modes (L1-aided L5 acquisition vs. direct L5 acquisition) based on signal availability and interference conditions. The system adapts its acquisition strategy in real-time to maintain positioning capability under varying environmental conditions.

Inventive Principle:

Principle #15Dynamics

2Reliability

If GNSS receivers implement direct L5 signal acquisition without L1 assistance, then resilience against L1 interference improves, but acquisition complexity increases

Engineering Contradiction:

Improveinterference resistanceVSAvoidacquisition engine complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses copied and adapted signal processing algorithms from L1 acquisition (such as frequency domain correlation and code phase search methods) to implement L5 acquisition. This allows direct L5 acquisition to be achieved by reusing proven acquisition techniques rather than developing entirely new methods, thereby managing complexity.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent designs a unified acquisition framework that can handle both L1 and L5 signals using similar processing pipelines. The same correlation engine, frequency search algorithms, and code phase detection mechanisms are applied to both frequency bands, reducing overall system complexity despite the added capability for direct L5 acquisition.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If hybrid receivers depend on L1 signal acquisition before L5 acquisition, then acquisition process becomes simpler, but positioning performance is impaired when L1 signals are blocked

Engineering Contradiction:

Improveacquisition process simplicityVSAvoidpositioning availability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent performs preliminary frequency domain correlation and code phase search for L5 signals independently of L1 acquisition status. By preparing L5 signal parameters and correlation results in advance without waiting for L1 acquisition, the system ensures L5 positioning capability is available whenever needed, regardless of L1 signal availability.

Inventive Principle:

Principle #10Preliminary action

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

Enhances the ability of GNSS receivers to determine positions by enabling direct acquisition of L5 signals even when L1 signals are unavailable, improving performance and resilience against interference.

Implementation Method 1

using frequency domain correlation with discrete Fourier transforms to acquire L5 signals without relying on L1 signal acquisition

Methodology Applied

Scientific EffectFrequency domain correlation:

Data Source

PatentUS20250093524A1GNSS receivers and methods for operating GNSS receivers

Publication Date: 2025.03.20 ONENAV INC

AI summary

Systems and methods for GNSS receivers are described. A system for processing GNSS signals includes one or more GNSS antennas, one or more GNSS measurement engines, and one or more processing systems. The one or more GNSS measurement engines are coupled to the one or more GNSS antennas. The one or more GNSS measurement engines correlate and process received GNSS signals in an L5 radio frequency band. The one or more processing systems are coupled to a first memory which stores an application programming interface (API) which includes one or more of parameters or instructions for processing GNSS signals. The one or more processing systems use the API to control operation of the one or more GNSS measurement engines.