Patent ID: 7812762

Claim:
A relative inter-vehicle position calculation apparatus for use in a first vehicle, the apparatus comprising: a control unit having a phase determination unit, a phase information reception unit, and a calculation unit; an inter-vehicle communication unit for performing an inter-vehicle communication with a second vehicle; and a receiver for receiving from a plurality of navigation satellites a radio wave, wherein the phase determination unit determines a carrier wave phase of the radio wave through reception of the radio wave from the plurality of navigation satellites, the carrier wave phase being determined as a first carrier wave phase, the phase information reception unit receives, by the inter-vehicle communication unit, information on the carrier wave phase from the second vehicle that (a) receives the radio wave from the plurality of navigation satellites and (b) transmits the information on the carrier wave phase together with navigation data included in the radio wave, the received information on the carrier wave phase being determined as a second carrier wave phase, the calculation unit calculates a detailed relative position of the first vehicle relative to the second vehicle based on a difference between (a) the second carrier wave phase being received by the phase information reception unit and (b) the first carrier wave phase being determined by the phase determination unit based on the navigation data transmitted from the second vehicle, and reception of the radio wave in the first vehicle is performed by using the navigation data when the navigation data is transmitted from the second vehicle to the first vehicle subsequent to the reception in the second vehicle.