A position determination device determines the position of a terminal. A signal of a sensor attached to one or both of a beacon and a terminal is sampled, so that a signal of the beacon may be transmitted and received only when the beacon or the terminal has moved. A plurality of beacons sequentially transmit beacon signals to determine the terminal position by determining a distance between the respective beacons and the terminal based on a time to receive the beacons. The device includes a beacon for transmitting a beacon signal; a terminal for receiving the beacon signal; and a first sensor attached to the terminal to sense movement of the terminal and to output a first sensing signal indicative of the sensed movement. The terminal has a reception mode for receiving the beacon signal and turns on/off the reception mode based on the first sensing signal.

A signal evaluation system is provided for evaluating a first EM signal and a second EM signal for use in a passive coherent location system. The signal evaluation system includes: a spectrum detecting component that detects the first EM signal and the second EM signal; a signal characterization component that generates a first characterization of the first EM signal and to generate a second characterization of the second EM signal; and a ranking component that ranks the EM signals for use in the passive coherent location system. The first characterization is based on an amplitude associated with the first EM signal and one of range resolution, Doppler resolution, and combinations thereof associated with the first EM signal. The second characterization is based on an amplitude associated with the second EM signal and one of range resolution, Doppler resolution, and combinations thereof associated with the second EM signal.

A signal evaluation system is provided for evaluating a first EM signal and a second EM signal for use in a passive coherent location system. The signal evaluation system includes: a spectrum detecting component that detects the first EM signal and the second EM signal; a signal characterization component that generates a first characterization of the first EM signal and to generate a second characterization of the second EM signal; and a ranking component that ranks the EM signals for use in the passive coherent location system. The first characterization is based on an amplitude associated with the first EM signal and one of range resolution, Doppler resolution, and combinations thereof associated with the first EM signal. The second characterization is based on an amplitude associated with the second EM signal and one of range resolution, Doppler resolution, and combinations thereof associated with the second EM signal.

A communication device includes an antenna, a driving unit, a first acquisition unit, an input unit, and a second acquisition unit. The driving unit moves a position of the antenna. The first acquisition unit acquires tag data of each radio tag based on a radio wave of each radio tag received by the antenna at a plurality of positions of the antenna. The input unit inputs the tag data of each radio tag at the plurality of positions of the antenna into a learned model. The second acquisition unit acquires, from the learned model, data indicating whether each radio tag is included in a first range or a second range based on the input of the tag data of each radio tag into the learned model by the input unit.

A communication device includes an antenna, a driving unit, a first acquisition unit, an input unit, and a second acquisition unit. The driving unit moves a position of the antenna. The first acquisition unit acquires tag data of each radio tag based on a radio wave of each radio tag received by the antenna at a plurality of positions of the antenna. The input unit inputs the tag data of each radio tag at the plurality of positions of the antenna into a learned model. The second acquisition unit acquires, from the learned model, data indicating whether each radio tag is included in a first range or a second range based on the input of the tag data of each radio tag into the learned model by the input unit.

Aspects presented herein may improve the performance and accuracy of RF-based positioning. Aspects presented herein may enable a device to use RF Doppler measurements to detect and mitigate multipath effects in RF-based positioning. The RF-based positioning may include satellite navigation, terrestrial positioning system, and/or indoor positioning. In one aspect, a UE receives, via a receiver, signals from one or more entities. The UE determines whether each received signal is a multipath signal based on a Doppler shift measurement. The UE de-weights or excludes one or more signals of the received signals in estimating a position of the UE based on whether the respective received signal is determined to be a multipath signal.

Aspects presented herein may improve the performance and accuracy of RF-based positioning. Aspects presented herein may enable a device to use RF Doppler measurements to detect and mitigate multipath effects in RF-based positioning. The RF-based positioning may include satellite navigation, terrestrial positioning system, and/or indoor positioning. In one aspect, a UE receives, via a receiver, signals from one or more entities. The UE determines whether each received signal is a multipath signal based on a Doppler shift measurement. The UE de-weights or excludes one or more signals of the received signals in estimating a position of the UE based on whether the respective received signal is determined to be a multipath signal.