Design Of A GPS Software Receiver And Weak-Singal Processing

GPS technology has been deveploping rapidly during the past 10 years. In addition to an equipment of navigation and positioning, GPS has also embodied its distinguished magnificence in scientific researches, such as 'GNSS-R Oceanographic Remote Sensing'. The development of GPS application places an increasingly high demand on the capacity of GPS receiver. Compared with the traditional GPS hardware receiver, GPS software receiver is featured by its expansiveness,convenience and flexibility etc., suitable for research and development of various sophisticated algorithm, and thus attract enthusiasm of numerous research institutions in recent years. In the oceanographic remote sensing where GPS reflection signals are used, the features of GPS reflection signals have to be comprehensively considered. The peculiarity of the GPS software receiver makes it more suitable for the research and development of sophisticated algorithm such as weak-signal processing. The research of GPS software receiver for weak-signal processing lays solid foundation for the research of oceanographic remote sensing.The basic principle and architecture of a GPS software receiver and the principle of weak-signal processing were introduced in this paper. The requirements of the acquisition process were analyzed. The parallel code phase search algorithm was chosen as the signal acquisition algorithm. The principle and implementation of code tracking and carrier tracking were proposed. The GPS signal simulator was developed to test the receiver. This present research compared the various methods of weak-signal acquisition and realized one of the algorithm through revising the original GPS software, and it can be used for the succeeding research of GNSS-R oceanographic remote sensing.