MATLAB Implementation of GPS Signal Tracking Using Phase-Locked Loop

In this documentation, we present a MATLAB-based approach for GPS signal tracking utilizing phase-locked loop (PLL) technology. Phase-locked loops represent a widely adopted technique in communication and control systems that regulates output signal frequency and phase based on input signal phase differences, thereby enabling precise signal tracking and synchronization. For GPS signal tracking applications, the PLL framework is implemented through two primary components: the code tracking loop and carrier tracking loop. The code tracker employs correlation techniques to synchronize with the GPS spreading code, facilitating navigation data extraction through pseudorange measurements. The carrier tracking loop maintains phase coherence with the GPS signal's carrier wave, enabling Doppler shift estimation and carrier-phase-based positioning. This implementation typically utilizes MATLAB's communication system toolbox functions such as comm.PhaseLockedLoop for carrier recovery and custom correlation algorithms for code tracking. The architecture significantly enhances GPS signal tracking accuracy and robustness, reliably supporting various applications including navigation systems, precision measurements, and location-based services through proper loop filter design and adaptive threshold mechanisms.