GPS Software Receiver Plotting Functions

This article presents a set of plotting functions specifically designed for GPS software receivers. These functions cover various signal processing techniques including CA code analysis, BOC signal characterization, S-curve generation, signal acquisition, and tracking operations. The implementation includes functions to visualize CA (Coarse/Acquisition) codes, which serve as fundamental modulation signals for GPS positioning and measurement applications. For BOC (Binary Offset Carrier) signals, the plotting functions demonstrate their advanced modulation characteristics and advantages in mitigating multipath interference. The S-curve plotting functionality illustrates phase and frequency estimation techniques commonly used in demodulation and tracking processes. The acquisition plotting functions display correlation results and detection metrics to identify satellite signals, while tracking plots show carrier and code loop performance metrics including phase error discriminators and lock indicators. These MATLAB-based functions typically involve algorithms for signal correlation, frequency domain analysis using FFT operations, and real-time data visualization. Key implementation aspects include generating PRN sequences, computing correlation matrices, plotting constellation diagrams, and displaying time-frequency analysis results. The code structure often separates data processing layers from visualization components, allowing for modular testing and performance optimization. Overall, these GPS software receiver plotting functions integrate knowledge from multiple technical domains and require comprehensive understanding of digital signal processing, satellite navigation principles, and software-defined radio implementation techniques.