GPS Signal Structure and Use
The purpose of this chapter is to explain the elements of the GPS radio signal that will allow the receiver to solve for user position and receiver clock error. The GPS radio signal has a complex signal structure. Fortunately we do not need to address all of it, only the parts we need. By investigating a simplified model of the SV transmitter, we can focus on the essential elements of the GPS signal that address the specific information we will need to solve for user position and receiver clock error. Also in this chapter, a method is presented that allows the receiver to properly “set” the replica clock Dials above the 1 ms Dial using the GPS data stream. Finally, the effects of Doppler on the GPS signal and its repercussions at the receiver are discussed at the end of this chapter.