The Study on GPS Signal Acquisition Algorithm in Time Domain

There are three signal acquisition approaches mainly: the serial search algorithm, circular correlation and the delay-and-multiply approach. The serial search algorithm searches for a satellite sequentially at each possible code delay and Doppler shift in time domain. Because only addition and multiplication operations are needed, it is easy to implement in time domain. This approach has been extensive applications. Because the serial search algorithm has to do much glide correlation in a real GPS receiver, this exhausting correlation also tends to be the main weakness of the serial search acquisition. To overcome the shortage of the serial search algorithm, the objective of the study is to shorten the amount of correlation, and a new method is given. It can decrease the amount acquisition time efficient. If this method is implemented in civil GPS receivers, the serial search algorithm will become more feasible and popular. The method aim at not only the GPS coarse code, but also the method of research is suitable for other CDMA systems.