Evaluation of the pseudorange performance by using software GPS receiver

An algorithm is developed to process IF signal data from a GPS RF front-end module, which consists of a down converter and an ADC. The down converter converts the signal from RF to IF, the ADC samples the IF signal. All the other processing including signal acquisition, tracking, data decoding and solving position are implemented in software using base-band signal processing techniques. The local C/A codes and carrier replica signal are pre-generated, stored in memory, and used respectively during signal acquisition and tracking. In order to evaluate the algorithm, this paper demonstrates standalone positioning using the measured pseudoranges of which accuracy depends on DLL parameter of the correlator of early/late spacing. This paper presents the explanation and evaluation of the algorithm.