Expanding search code acquisition receiver structure, simulation and analysis

In the area of direct sequence spread spectrum (DSSS) communications, a code phase search is required for coarse code acquisition. In the case of a typical Global Positioning System (GPS) receiver, the receiver acquisition of the C/A code narrows the uncertainty for Precise (P) code acquisition. Depending upon the pdf of the code phase uncertainty, various search algorithms may be employed for P code acquisition. This paper discusses an expanding search code acquisition algorithm which is commonly used for P code acquisition in Global Positioning System (GPS) receivers. A detailed baseband receiver simulation of the expanding search receiver structure is presented. The model was developed using the Alta Group's (formerly Comdisco) Signal Processing Workstation (SPW) and is suitable for hardware implementation. Monte Carlo simulation results using the model are presented and discussed. Analytic results and a PC simulation are used to validate the model.