CBOC Signal Receiver Using Segmented BOC Correlation

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Solution Overview

Problem

Existing methods for receiving radionavigation signals modulated by composite spreading waveforms, such as CBOC, require complex correlation processes and multiple correlators, which can be inefficient and costly in terms of hardware and processing resources.

Innovation Solution

A method and receiver design that correlates a radionavigation signal with a local binary waveform comprising alternating segments of BOC(n1,m) and BOC(n2,m) waveforms, reducing the number of correlators needed and simplifying the correlation process, while allowing for optimization of waveform segments' duration and order to accommodate different modulation schemes like CBOC(6,1) and TMBOC.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If correlation is performed between incoming signal and local replica of CBOC waveform, then accurate signal reception is achieved, but hardware complexity increases due to requirement of four-level quantization and 2-bit architecture

Engineering Contradiction:
Improvesignal reception accuracyVSAvoidhardware complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the CBOC waveform correlation process into two separate BOC waveform correlations. Instead of directly correlating with the composite CBOC waveform requiring four-level quantization, the method correlates with two simpler BOC waveforms (BOC(1,1) and BOC(n,1)) that can be implemented with one-bit architecture, then combines the results to achieve the same reception accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the two constituent BOC waveforms from the composite CBOC waveform structure. By separating the CBOC signal into its BOC(1,1) and BOC(n,1) components, the method enables independent correlation processing of each component using simpler hardware architectures, avoiding the need for complex four-level quantization.

Inventive Principle:
Principle #2Taking out (Extraction)

2Device complexity

If separate correlations are performed with local replicas of first and second BOC components, then hardware complexity is reduced with one-bit architecture, but processing complexity increases due to doubled number of correlation operations

Engineering Contradiction:
Improvehardware complexityVSAvoidprocessing efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent merges the two separate BOC correlation operations into a unified processing framework. By combining the correlation results of BOC(1,1) and BOC(n,1) waveforms in a coordinated manner, the method achieves efficient processing that reduces overall computational burden compared to performing completely independent correlation operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces dynamic switching between different correlation processing modes based on the specific CBOC configuration. The receiver can adaptively select and switch between correlation strategies depending on the values of n and m parameters, optimizing processing efficiency for different signal conditions while maintaining simplified hardware architecture.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If receiver is designed for specific CBOC configuration, then reception performance is optimized for that configuration, but adaptability to different modulation schemes is reduced

Engineering Contradiction:
Improvereception performanceVSAvoidadaptability to different modulation schemes
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent designs the receiver with universal processing capabilities that can handle multiple modulation schemes. By implementing a correlation processor that can accommodate different BOC waveform parameters (n and m values) and switch between different correlation strategies, the receiver achieves multi-functionality, enabling it to process various CBOC configurations and even other BOC-based modulation schemes like TMBOC used in GPS L1C and Galileo E1 signals.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements dynamic reconfiguration capabilities in the receiver that allow it to adapt to different modulation schemes by adjusting correlation parameters and processing modes. This dynamic adaptability enables the same hardware platform to optimize reception performance across multiple signal types including different CBOC configurations, TMBOC, and other spread spectrum navigation signals.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2030039B1Method of reception and receiver for a radio navigation signal modulated by a cboc spread wave form
Publication Date: 2009.08.05 CENT NAT DETUD SPATIALES (CNES)
  • EP2030039B1 patent drawingFigure 1~2
  • EP2030039B1 patent drawingFigure 3~4
  • EP2030039B1 patent drawingFigure 5~6

AI summary

To receive a radio navigation signal modulated by a composite wave form, the composite wave form comprising a linear combination with real coefficients of a component BOC(n1,m) and of a component BOC(n2,m), n1 being different from n2, a correlation between a local wave form and the composite wave form over a time interval of duration T is carried out. The local wave form is a binary wave form, formed over said time interval of an alternating succession comprising at least one segment of wave form BOC(n1,m) and at least one segment of wave form BOC(n2,m), the at least one segment BOC(n1,m) having a total duration of aT, a being strictly between 0 and 1, the at least one segment BOC(n2,m) having a total duration (1-a)T.