Variance-Triggered Two-Step GPS Acquisition

Area of Science:

• Electrical Engineering
• Signal Processing
• Satellite Navigation

Background:

• Satellite signal acquisition is the most time-consuming and computationally complex step in Global Navigation Satellite System (GNSS) receivers.
• High Doppler shifts in signals increase acquisition complexity, impacting overall GNSS reception performance.
• Optimizing the acquisition process is crucial for enhancing GNSS receiver efficiency and cost-effectiveness.

Purpose of the Study:

• To develop and present a novel two-step GPS acquisition algorithm.
• To significantly reduce the computational complexity and execution time of the satellite signal acquisition process.
• To maintain or improve the accuracy and reliability of satellite signal detection.

Main Methods:

• A two-step acquisition strategy is proposed, building upon the conventional time-domain serial algorithm.
• The first step employs incremental correlation to determine a coarse estimate of signal phase and frequency.
• The second step refines the initial estimates, triggered by the variance of the highest correlation values.

Main Results:

• The proposed algorithm reduces the average execution time of GPS acquisition by approximately five times compared to conventional methods.
• The new method maintains modest logic hardware requirements and demonstrates slightly improved success and false-positive rates.
• Memory usage is reduced proportionally to the signal's sampling frequency.

Conclusions:

• The presented two-step GPS acquisition algorithm offers substantial improvements in speed and efficiency.
• This enhanced acquisition method leads to significant improvements in the overall performance and cost of GPS receivers.
• The algorithm provides a practical solution for optimizing GNSS receiver design and functionality.