Automatic Parameter Determination for Real-Time Acquisition using Frequency Domain Methods in a High Sensitivity Software Receiver

This paper presents a systematic approach to design and configure frequency-domain acquisition architectures for the high-sensitivity Global Navigation Satellite Systems (GNSS) software receiver developed by the Position, Location and Navigation (PLAN) Group at the University of Calgary, GSNRx (TM) (O'Driscoll et al 2009). An automatic tuning mechanism based on processing power, timing benchmarks, and sensitivity models is developed to optimise the acquisition architecture with constraints on acquisition sensitivities. The four main contributions of this work are as follows: i) the introduction of a systematic method for deploying software receivers on personal computers with different configurations, ii) the development of a versatile acquisition architecture for timing-sensitivity analysis and improvement, iii) a detailed analysis of processing loss involved in parallel frequency-domain acquisition using FFT, and iv) the establishment of a baseline model for benchmarking acquisition with software receivers. The optimisation process and the FFT architecture were implemented and tested on a personal computer with an Intel (R) Core 2 Duo 2.4 GHz dual-core processor running the Microsoft (R) Windows (TM) XP operating system. The typical configuration resulted from the configuration process supports four more simultaneous satellite channels and provides a 34% time-to-first-fix (TTFF) improvement over the baseline serial-search method.