Gps Signal Capture To Track The Design And Implementation Of Multi-mode Satellite Navigation Chipset

With the widely use of GNSS(Global navigation satellite systems), its meaning to economics and military affairs becomes more important. Among these systems, the GPS system of the United States has the most mature technology and is most widely used in the world.The conception of how a GPS receiver determines its position with GPS and some issues about the structure of GPS signal is discussed. Two GPS simulators which are used to afford basic data for the receiver's development are discussed base on the throes. Means while something about the GPS signals adaptor and a software simulator are introduced. Finally the algorithm to catch and track the GPS signal is focused on.GPS signal is a CDMA spread-spectrum signal, and useful signal is drowned in the noise, making GPS signal reception level more difficult. Firstly, we do a useful analysis to the characteristics of the GPS Coarse/acquisition (C/A) code, and response to this attribute, found a way to catch the GPS signals in the noise. But for the movement between the satellite and receiver, Doppler frequency shift is induced, which leads to the lost of signal. So PLL and DLL are needed to keep tracking the signals. Then the GPS signal acquisition and tracking methods in timing and frequency domain are studied first and realized with Matlab. At last we get the navigation and receiver's position based the tracking results. The software receiver provides theoretical support and verification platform for the hardware receiver design. A detailed discussion about the hardware design including PLL, DLL of the GPS signal acquisition and tracking is focused on.