Sensitivity Improvement of A Low Cost Commercial GPS Receiver Through Software Approach (Preprint)

摘要

This paper reports sensitivity improvement of a stationary GPS receiver using software GPS approach. The experiments were conducted using both simulated and real GPS signals. The sensitivity improvement can be as much as 10 dB. This paper discusses the software algorithms developed to perform the code acquisition and tracking that enabled the sensitivity improvement. The commercial GPS receiver has an unusual sampling frequency of 5.455657x106 Hz. The paper will discuss techniques used to handle such odd sampling rate in the software algorithms, also, the determination of the time skew (fine time) between clock phase and initial phase of C/A code when working with this odd sampling rate. The techniques discussed in this paper is not only limited to work with the specific commercial receiver. They can be applied to software receiver with any sampling frequency. Experimental set up and procedures used to evaluate the sensitivity improvements are also discussed.