Satellite-based localization using the global positioning systems (GPS) has attracted ever growing attention in the last few years. In this work, we present a signal processing technique for initial code acquisition and synchronization of a GPS signal, such as the one used by position location techniques in 3G wireless scenarios. Several computer simulations have been accomplished to validate the proposed PHD method for the acquisition and synchronization of a GPS signal, under a possible systematic frequency error or a nominal frequency offset. The numerical results obtained from our simulation trials confirm the validity of such approach which overcomes the conventional non-coherent techniques.