A method of communicating with a portable access device includes iteratively performing an algorithm via an access module of a vehicle. The algorithm includes a series of operations including: selecting a frequency from multiple frequencies; selecting an antenna pair from multiple possible antenna pairs, where antennas of the possible antenna pairs include antennas with different polarized axes; transmitting a packet to the portable access device via the selected antenna pair; receiving a first RSSI and a response signal from the portable access device, the first RSSI corresponds to the transmission of the packet; and measuring a second RSSI of the response signal; based on the first RSSIs and the second RSSIs. A best one of the frequencies and a best antenna pair of the possible antenna pairs are selected. One or more additional packets are transmitted using the selected best frequency and the selected best antenna pair.

A system for detecting a range extension type relay attack includes a transmitter, a receiver and a module. The transmitter transmits a RF signal from one of a vehicle and a portable access device to the other one of the vehicle and the portable access device. The receiver receives a response signal in response to the RF signal. The module: generates a parameter associated with the transmission of the RF signal and the reception of the response signal; based on the parameter, detects the range extension type relay attack performed by an attacking device, where at least one of (i) the RF signal is relayed via the attacking device from the vehicle to the portable access device, or (ii) the response signal is relayed via the attacking device from the portable access device to the vehicle; and perform a countermeasure in response to detecting the range extension type relay attack.

A system for providing operational control of a vehicle includes a first network device and control module. The first network device includes: polarized antennas; a transmitter transmitting an initiator packet via the polarized antennas from the vehicle to a second network device including a synchronization access word and a CW tone, one of the first and second network devices is implemented within the vehicle, the other one of the first and second network devices is a portable access device, and at any moment in time, at least one of the polarized antennas is not cross-polarized with an antenna of the second network device; and a receiver receiving a response packet from the second network device including the synchronization access word and the first CW tone. A control module determines a difference in RTT between the initiator and response packets and detects a range extension type relay attack.

A multi-axis polarized RF antenna assembly includes a circular polarized antenna, a circular isolator, and a linear polarized antenna. The circular polarized antenna includes a conductive ring-shaped body having an inner hole. The circular isolator is connected to the conductive ring-shaped body. The linear polarized antenna is connected to the circular polarized antenna and the circular isolator and extending outward from the circular isolator. The linear polarized antenna includes a sleeve and a conductive element extending through the sleeve. The linear polarize antenna extends orthogonal to a radius of the circular polarized antenna.

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.

A system for accessing or providing operational control of a vehicle includes initiator and sniffer devices. The initiator device includes: polarized antennas; a transmitter transmitting a first tone signal via the polarized antennas from the vehicle to a responder/portable access device; and receiver receiving a second tone signal from the responder device in response to the first tone signal. The sniffer device includes: second polarized antennas; and a second receiver receiving, via the second polarized antennas, the first tone signal from the transmitter and the second tone signal from the responder device. The sniffer device determines states of the first and second tone signals including respective phase delays. The initiator or sniffer device estimates a first distance from the vehicle to the responder device or a second distance from the responder device to the sniffer device based on the states including respective phase delays.

A system includes a transmitter, a receiver and a control module. The transmitter transmits a RF signal from one of a vehicle and a portable access device to the other one of the vehicle and the portable access device. The receiver receives a response signal from one of the vehicle and the portable access device in response to the RF signal. The control module: converts the response signal to in-phase and quadrature-phase signals; based on the RF, in-phase signal and quadrature-phase signals; detects a range extension type relay attack performed by an attacking device to obtain at least one of access to or operational control of the vehicle; where the RF signal is relayed via the attacking device from the vehicle to the portable access device or the response signal is relayed via the attacking device from the portable access device to the vehicle; and performs a countermeasure.

A control system includes: a transmission device that transmits a plurality of signals having different frequencies from one of a first communication unit mounted in a vehicle and a second communication unit mounted in a mobile device carried by a user in such a manner that the plurality of signals are combined to generate a predetermined composite signal in an area located at a distance from the first communication unit, the distance being not more than a predetermined distance; and a permission device that permits a predetermined action of the vehicle when the predetermined composite signal generated in the area from the plurality of signals transmitted by the transmission device is detected and an authentication signal transmitted by the second communication unit is authenticated as an authorized authentication signal for the vehicle.

Systems, apparatuses, and methods for implementing efficient power optimization in a computing system are disclosed. A system management unit configured to track computing activity of a computing device while processing each frame of a plurality of frames. The computing activity is tracked at least for a given period of time comprising a plurality of time slices. The system management unit further correlates a time slice associated with a given frame with a time slice associated with at least one previously processed frame from the plurality of frames, based at least in part on the tracked computing activity. The system management unit predicts a clock frequency to render the given frame, based at least in part on the correlation and renders the given frame using the predicted clock frequency.

A system for includes master and sniffer devices. The master device includes: first antennas with different polarized axes; a transmitter transmitting a challenge signal via the first antennas from the vehicle to a slave device, where the slave device is a portable access device; and a receiver receiving a response signal in response to the challenge signal from the slave device. The sniffer device includes: second antennas with different polarized axes; and a receiver receiving, via the second antennas, the challenge signal from the transmitter and the response signal from the slave device. The sniffer device measures when the challenge signal and the response signal arrive at the sniffer device to provide arrival times. The master or sniffer device estimates at least one of a distance from the vehicle to the slave device or a location of the slave device relative to the vehicle based on the arrival times.