TMBOC Signal Correlation Using Partial Functions to Remove Side Peaks
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Solution Overview
Problem
The ambiguity problem in tracking binary offset carrier (BOC) signals, specifically the TMBOC(6,1,4/33) signal, arises due to multiple side peaks in the auto-correlation function, leading to synchronization issues and reduced positioning accuracy.
Innovation Solution
A method is developed to generate an unambiguous correlation function for the TMBOC(6,1,4/33) signal using partial correlation functions, involving a delay lock loop (DLL) with early and late delayed signal pairs, partial correlation units, and sub-correlation units to eliminate side peaks and enhance main peak sharpness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If BOC modulation scheme is used to improve signal tracking performance and spectral separation, then signal tracking performance is improved and spectral efficiency is enhanced, but side peaks appear in the auto-correlation function causing ambiguity problems
Solution Approach 1:
The patent segments the correlation function generation process into multiple partial correlation functions, each corresponding to different BOC signal components. By processing and combining these segmented correlation functions, the system eliminates side peaks while preserving the main peak, thus resolving the ambiguity problem caused by BOC modulation's inherent side lobes.
Solution Approach 2:
The patent introduces an intermediary processing step involving the generation and combination of partial correlation functions. This intermediary process acts as a mediator between the BOC signal input and the final correlation output, filtering out harmful side peaks while maintaining the desired main peak characteristics for accurate synchronization.
2Adaptability or versatility
If MBOC(6,1,111) modulation method is adopted to ensure backward compatibility and performance improvement, then compatibility is maintained and performance is enhanced, but ambiguity problem persists due to side peaks
Solution Approach 1:
The patent segments the MBOC signal into its constituent BOC components and generates separate partial correlation functions for each. This segmentation allows the system to maintain compatibility with MBOC modulation while selectively processing correlation functions to eliminate side peaks that cause ambiguity, thus preserving synchronization accuracy.
Solution Approach 2:
The patent develops a universal correlation function generation method that works with both conventional BOC signals and MBOC signals. The method of combining partial correlation functions serves multiple purposes: maintaining backward compatibility with existing BOC signals while also resolving the ambiguity problem in MBOC signals, making it applicable across different signal types.
3Reliability
If TMBOC(6,1,4/33) signal structure is used with time-multiplexed BOC components, then spectral separation is achieved and tracking performance is improved, but side peaks cause synchronization ambiguity
Solution Approach 1:
The patent segments the TMBOC signal processing into distinct partial correlation functions corresponding to different time-multiplexed BOC components. By generating and combining these segmented correlation functions, the system maintains the tracking performance benefits of TMBOC while eliminating the side peaks that complicate synchronization establishment.
Solution Approach 2:
The patent converts the harmful side peaks into a beneficial process by using the structure of partial correlation functions. The method transforms the ambiguity-causing side peaks into identifiable components that can be systematically processed and eliminated through the combination of partial correlation functions, turning the ambiguity problem into a structured solution opportunity.
Data Source
AI summary
A method of generating an unambiguous correlation function for a TMBOC(6,1,4/33) signal, an apparatus for tracking a TMBOC signal, and a satellite navigation signal receiver system using the same are disclosed herein. The method of generating a correlation function for a TMBOC(6,1,4/33) signal includes generating a delayed signal delayed based on a phase delay with respect to the signal pulse train of a TMBOC(6,1,4/33)-modulated received signal; generating BOC(1,1) partial correlation functions and BOC(6,1) partial correlation functions by performing an auto-correlation operation on the received signal and the delayed signal with respect to the total time; generating a BOC(1,1) sub-correlation function; obtaining a first intermediate correlation function, obtaining second to eleventh intermediate correlation functions, and generating the BOC(6,1) sub-correlation function by summing all the first to eleventh intermediate correlation functions; and generating a main correlation function by combining the BOC(1,1) and BOC(6,1) sub-correlation functions.