Patent attributes
A system for accessing or providing operational control of a vehicle includes a network device and a control module. The network device includes: an antenna module including antennas with different polarized axes; a transmitter transmitting a series of tones via the antenna module from the vehicle to a second network device and change the frequencies of the tones during the transmission of the series of tones, where, at any moment in time, at least one of the antennas is not cross-polarized with an antenna of the second network device; and a receiver receiving the series of tones from the second network device. The control module: determines differences in phases of the series of tones versus differences in frequencies of the series of tones; and based on the differences in the phases and the differences in the frequencies, determines a distance between the first network device and the second network device.
