An Optimized Vector Tracking Architecture for Pseudo-Random Pulsing CDMA Signals.

Area of Science:

• Satellite Navigation Systems
• Signal Processing
• Geomatics Engineering

Background:

• Traditional vector tracking loops (VTL) excel in Global Navigation Satellite Systems (GNSS) but are incompatible with pseudolite positioning systems (PLPS).
• PLPS utilize pseudo-random pulsing CDMA signals to mitigate the near-far effect, posing challenges for conventional VTLs.
• Existing VTL architectures struggle with the discontinuous and non-overlapping signal structures inherent in PLPS.

Purpose of the Study:

• To propose an optimized VTL architecture specifically designed for pseudo-random pulsing CDMA signals used in PLPS.
• To address the limitations of traditional VTLs in handling the unique signal characteristics of PLPS.
• To improve tracking accuracy and mitigate estimation biases in PLPS environments.

Main Methods:

• Development of an optimized VTL architecture incorporating irregular update periods (IUP) pre-filters.
• Implementation of a measurement prediction mechanism to synchronize sampling times from inconsistent pseudolite signals.
• Adjustment of update cycles based on active timeslot intervals to minimize estimation biases.

Main Results:

• The proposed VTL architecture demonstrates superior performance compared to traditional pre-filter-based VTLs.
• The optimized VTL significantly outperforms existing IUP pre-filter-based VTLs in PLPS simulations.
• Enhanced tracking accuracy and reduced jitter degradation were observed with the proposed VTL.

Conclusions:

• The novel VTL architecture is highly effective for pseudo-random pulsing CDMA signals in PLPS.
• The proposed method offers a robust solution for improving positioning accuracy in systems relying on pseudolites.
• This advancement addresses critical compatibility issues between VTL technology and PLPS signal structures.