Enhancing Orthogonal GPS L1C Signal Acquisition

The Global Positioning System (GPS) represents a significant leap in global navigation satellite systems. This is achieved through continuous localization, reliable navigation, and precise timing for various uses, such as civilian, commercial, and military. Among the multiple signals sent by GPS satellites, the L1C signal greatly enhances structure and performance, boosting user reliability (by employing binary offset carrier modulation to reduce multipath effects) and accuracy (by lengthening the ranging code). It features data and pilot components, enhancing resilience against multipath interference and strengthening the signal under challenging conditions. In this work, an orthogonal single-channel acquisition algorithm for the GPS L1C signal is proposed, and it is utilized to reduce the complexity of a conventional side-by-side/dual-channel configuration. The proposed scheme mathematically combines the data and pilot portions into one orthogonal channel, which approach has been shown to achieve a 3dB gain in signal-to-noise ratio (SNR) with 34% gain in computation complexity over the conventional implementation. The MATLAB-Simulink environment was used to simulate the GPS L1C parameters with a sampling frequency of 16.368 MHz and a dwell time of 10 ms. The simulations were carried out across various SNR levels to evaluate detection probability, and processing time. The results show that the proposed solution preserves detection probability and dramatically increases resource utilization. This work provides the first single-channel orthogonal design for GPS L1C acquisition and is an efficient step towards low-power, high-performance GNSS receivers.