Development and Implementation of GPS Correlator Structures in MATLAB and Simulink with Focus on SDR Applications: Implementation of a Standard GPS Correlator Architecture (Baseline) Implementation of the MIT Quicksynch Sparse Algorithm Development and Implementation of Parallel Circular Correlator Constructs.

摘要

We developed a basic correlator design (baseline) using MATLAB code and a Simulink model. This standard method is used to validate the results and performance yielded by new techniques when actual GPS satellite signal records. We also developed our own MATLAB code for the MIT Quicksync algorithm [2] and implemented this algorithm in a Simulink model that, at the moment, works only with simulated data. The MATLAB implementation of the Quicksync algorithm [2] takes into consideration the Doppler Effect in order to be able to validate our implementation with real GPS signal records. Another development is the formulation and implementation of alternative parallel architectures to perform a circular correlation by decomposing the initial circular correlation into several smaller circular correlations. Such subcorrelations are independent of each other and can be processed in parallel [3]. Even though these results may be applied to any system that performs circular convolution or circular correlation, we will apply it to the acquisition of Global Navigation Satellite System (GNSS) signals using a, FFT-based, Parallel Code-phase Search (PCS) on the GPS L1 C/A signal. The parallel approach may have advantages for hardware-based implementations using Field Programmable Gate Array.