Diversity type global positioning system for motor vehicles

摘要

This diversity type GPS system for a vehicle has first and second antennas mounted at first and second locations, respectively, inside a vehicle. First and second high frequency amplifiers and an antenna changer apply the signals received by the first and second antennas to first and second SS demodulators. The first and second SS demodulators simultaneously perform search operations for satellites, and demodulate rf signals (demodulated data) from the searched out satellites. An arithmetic and control unit computes a position of the vehicle from the demodulated data once three or more sets of demodulated data are available. The arithmetic and control unit also controls the antenna changer to switch the antenna from which a demodulator receives signals so as to improve the searching operations of the demodulators.