A method and a system for ultra high frequency communication with and location of a portable device for “hands-free” access to a motor vehicle, the motor vehicle having an on-board communication device comprising an ultra high frequency transceiver, an electrical power supply source and at least one antenna, the motor vehicle including a first arrangement, in which the transceiver is connected to the antenna, and a second arrangement, in which the transceiver is disconnected from the antenna. The transceiver is connected to an attenuation module located at a predetermined distance from the transceiver. The attenuation module includes an impedance of predetermined value connected to ground. The predetermined distance between the transceiver and the attenuation module, as well as the predetermined value of the impedance, defining a locating area of the portable device in and around the motor vehicle.

A method and an electronic device for ranging are provided. An ultra-wideband (UWB) signal is received from an external device through a first antenna. A communication state between the external device and the electronic device is identified using information about communication quality included in the UWB signal. A signal received through a second antenna is identified by decoding the received signal based on the identified communication state. A distance between the electronic device and the external device is determined based on whether the received signal is a low frequency (LF) signal.

A method and an electronic device for ranging are provided. An ultra-wideband (UWB) signal is received from an external device through a first antenna. A communication state between the external device and the electronic device is identified using information about communication quality included in the UWB signal. A signal received through a second antenna is identified by decoding the received signal based on the identified communication state. A distance between the electronic device and the external device is determined based on whether the received signal is a low frequency (LF) signal.

In a general aspect, a method for determining a location of motion detected by wireless communication devices in a wireless communication network includes obtaining a set of motion indicator values associated with a time frame. The set of motion indicator values indicates motion detected from wireless links during the time frame, each motion indicator value associated with a respective wireless link. The method also includes identifying a subset of the wireless links based on a magnitude of their respective motion indicator values relative to other motion indicator values in the set of motion indicator values. The method additionally includes generating count values for the wireless communication devices connected to the wireless communication network during the time frame. The method further includes generating a probability vector based on the count values and comprising values for the connected wireless communication devices.

A method for determining the distance to source of a passive intermodulation (PIM) product for a distributed base station is provided. The method includes generating a test signal; transmitting the test signal on a front haul communication link between a baseband unit and a remote radio head of the distributed base station; receiving the PIM product as a reflected signal at the remote radio head; multiplying the reflected signal by a conjugate of the test signal to create a sinewave; determining a frequency of the sinewave; and determining the distance to the source of the PIM based on the determined frequency of the sinewave.

A method for determining the distance to source of a passive intermodulation (PIM) product for a distributed base station is provided. The method includes generating a test signal; transmitting the test signal on a front haul communication link between a baseband unit and a remote radio head of the distributed base station; receiving the PIM product as a reflected signal at the remote radio head; multiplying the reflected signal by a conjugate of the test signal to create a sinewave; determining a frequency of the sinewave; and determining the distance to the source of the PIM based on the determined frequency of the sinewave.

A method for locating, via ultra high frequency, a mobile device (T) for hands-free access to a vehicle (V), via a locating device (D) on board the vehicle (V), the locating device (D) including an ultra high frequency transceiver (10), an electrical power supply source (Vcc) and an antenna (A), the locating method being noteworthy in that the transceiver (10) is disconnected from the antenna (A), and that the transceiver (10) is connected to an attenuation module (M1, M2, M3) located at a predetermined distance (L1, L2, L3) from the transceiver (10) and including an impedance (Z1, Z2, Z3) of predetermined value connected to ground, the predetermined distance (L1, L2, L3) between the transceiver (10) and the attenuation module (M1, M2, M3) and the predetermined value of the impedance (Z1, Z2, Z3) defining an area (A1, A2, A3) for locating the mobile device (T) around the vehicle (V).

A method for determining the distance to source of a passive intermodulation (PIM) product for a distributed base station is provided. The method includes generating a test signal; transmitting the test signal on a front haul communication link between a baseband unit and a remote radio head of the distributed base station; receiving the PIM product as a reflected signal at the remote radio head; multiplying the reflected signal by a conjugate of the test signal to create a sinewave; determining a frequency of the sinewave; and determining the distance to the source of the PIM based on the determined frequency of the sinewave.

Certain aspects of the present disclosure provide techniques and apparatus for improved machine learning. Impedance information for a wireless transmitter of a device is determined, and impedance change information is generated based on a difference between the impedance information and prior impedance information for the wireless transmitter. An off-body characteristic is generated based on processing the impedance change information using a trained machine learning model, where the off-body characteristic indicates a probability that the device was off-body when the impedance information was determined.

A method for locating, via ultra high frequency, a mobile device (T) for hands-free access to a vehicle (V), via a locating device (D) on board the vehicle (V), the locating device (D) including an ultra high frequency transceiver (10), an electrical power supply source (Vcc) and an antenna (A), the locating method being noteworthy in that the transceiver (10) is disconnected from the antenna (A), and that the transceiver (10) is connected to an attenuation module (M1, M2, M3) located at a predetermined distance (L1, L2, L3) from the transceiver (10) and including an impedance (Z1, Z2, Z3) of predetermined value connected to ground, the predetermined distance (L1, L2, L3) between the transceiver (10) and the attenuation module (M1, M2, M3) and the predetermined value of the impedance (Z1, Z2, Z3) defining an area (A1, A2, A3) for locating the mobile device (T) around the vehicle (V).