JP-2026514547-A - Distancing system and method using channel sounding

Abstract

A system and method for determining the distance between a first device (e.g., an object device) and a second device (e.g., a remote device) based on phase characteristics determined with respect to transmission from a first device to a second device, and optionally, return transmission from the second device to the first device.

Inventors

• ジョンソン ミチェル
• クーパー カイル
• スミス エリーク ジェイ

Assignees

• 株式会社デンソー

Dates

Publication Date

20260511

Application Date

20240409

Priority Date

20231130

Claims (20)

1. A system for determining the distance between a remote device and an object, A first device including a first antenna system positioned in a fixed location relative to an object and configured to receive a first tone signal from a remote device and/or transmit a first tone signal to a remote device, A control system configured to determine the first and second phase characteristics of a first tone signal at a first frequency and a second frequency. The first and second phase characteristics indicate the first phase rotation of the first tone signal between the first device and the remote device. The control system is operable to determine a first distance between a first device and a remote device based on a first phase rotation of a first tone signal. A second device includes a second antenna system positioned at a fixed location relative to an object and configured to monitor a first tone signal between the first device and a remote device, and a control system configured to determine a second phase rotation of the first tone signal monitored by the second device. The control system is configured to determine the second device clock offset between the second device and the remote device based on a first phase rotation and a second phase rotation.
2. The system according to claim 1, wherein the control system is configured to determine the relative clock offset between the first device and the second device based on the second device clock offset.
3. The control system is configured to determine a third phase rotation between a first device and a second device without using clock ambiguity based on relative clock offsets and ambiguous phase rotation between a first device and a second device determined based on a monitored first tone signal, according to claim 2.
4. The second device is configured to receive a second tone signal from the remote device and/or to transmit a second tone signal to the remote device. The first device is configured to monitor the second tone signal between the second device and the remote device. The control system is configured to determine the third phase rotation of the second tone signal between the second device and the remote device. The system according to claim 2, wherein the control system is configured to determine a fourth phase rotation between the remote device and the first device based on (1) a second tone signal monitored by the first device and (2) a second device clock offset between the second device and the remote device.
5. The system according to any one of claims 1 to 4, wherein the first frequency and the second frequency are different.
6. The system according to any one of claims 1 to 5, wherein the control system is provided in the first device, and the first device is capable of operating as an initiator.
7. The system according to claim 6, wherein the remote device can operate as a reflector.
8. The control system is provided as a first control system and a second control system, respectively, which are separately arranged within the first device and the second device, according to claim 6.
9. The system according to any one of claims 1 to 8, wherein the remote device can operate as an initiator and the first device can operate as a reflector.
10. The control system is operable to determine the third phase characteristic of the first tone signal at the third frequency. The system according to claim 9, wherein the third phase characteristic indicates a first phase rotation of the first tone signal between the first device and the remote device.
11. The system according to claim 10, wherein the first frequency, the second frequency, and the third frequency are different from each other.
12. The first tone signal is the initiator tone signal. The system according to any one of claims 1 to 11, wherein the first phase characteristic and the second phase characteristic are determined by the remote device with respect to the reception of an initiator tone signal from the first device.
13. The first tone signal is a reflector tone signal. The system according to any one of claims 1 to 12, wherein the first phase measurement and the second phase characteristic are determined by the first device with respect to the reception of a reflector tone signal from a remote device.
14. The first phase characteristic of the reflector tone signal shows the bidirectional phase rotation of the initiator tone signal and the reflector tone signal at the first frequency. The system according to claim 13, wherein the second phase characteristic of the reflector tone signal indicates a bidirectional phase rotation between the initiator tone signal and the reflector tone signal at a second frequency.
15. The system according to claim 14, wherein the control system is operable to determine a first distance based on (1) the difference between a first phase characteristic and a second phase characteristic, and (2) the difference between a first frequency and a second frequency.
16. The control system is configured to compensate for the movement of the remote device relative to the first device, according to any one of claims 1 to 15.
17. The control system is configured to reduce the influence of the estimated velocity vector from at least one of the first phase rotation and the second phase rotation, as described in claim 16.
18. The control system is configured to compensate for multi-phase effects in the environment, according to any one of claims 1 to 17.
19. The control system is configured to generate a K-space mapping of phase rotations and to identify multipath artifacts based on the K-space mapping, according to any one of claims 1 to 18.
20. The system according to any one of claims 1 to 19, wherein the remote device can operate as a reflector and the first device can operate as an initiator.

Description

This disclosure relates to a system and method for determining the distance between a remote device and an object such as a vehicle. The real-time location and positioning of objects is becoming increasingly prevalent across a wide range of applications. Real-time location systems (RTLS) are trusted and used to track objects such as portable and remote devices in many fields, including automotive, storage, retail, security access for authentication, and security access for authorization. A conventional RTLS in the automotive sector includes a transmitter located within the vehicle that can communicate with a remote device via radio frequency (RF). Often, the signal strength of the communication between the transmitter and the remote device is used as a basis for determining the location of the remote device relative to the transmitter or vehicle. For example, a low signal strength may indicate that the remote device is farther away from the vehicle than a high signal strength indicates. Generally, the signal strength decreases as the distance between the remote device and the vehicle increases. Communication between the transmitter and the remote device can be intercepted (sniffed) by sensors placed on the object. The signal strength of such intercepted communication can be used as a basis for determining the distance between the remote device and each sensor. The distance to each of these sensors allows for the determination of the remote device's location relative to the object. Environmental and external interference can significantly impact the accuracy of determining position and distance based on communication. For example, the environment can produce reflections that negatively affect sensor measurements. RF interference can similarly negatively impact the ability to accurately determine the position of a remote device relative to an object, based on communication characteristics such as signal strength. In general, one innovative aspect of the subject matter described herein can be embodied in a system for determining the distance between a remote device and an object. The system may include a first device, which includes a first antenna system positioned at a fixed location relative to the object and configured to receive and/or transmit a first tone signal from the remote device. A control system may be configured to determine first and second phase characteristics of the first tone signal at first and second frequencies. These first and second phase characteristics may indicate a first phase rotation of the first tone signal between the first device and the remote device. The first control system may be operable to determine a first distance between the first device and the remote based on the first phase rotation of the first tone signal. The system may include a second device positioned at a fixed location relative to the object. The second device may include a second antenna system configured to monitor a first tone signal between the first device and a remote device. The control system may be configured to determine a second phase rotation of the first tone signal monitored by the second device. Based on the first and second phase rotations, the control system may be configured to determine a second device clock offset between the second device and the remote device. The embodiments described above and other embodiments may each optionally include one or more of the following features, either individually or in combination. In particular, one embodiment includes all combinations of the following features. In some embodiments, the control system may be configured to determine the relative clock offset between the first and second devices based on the second device clock offset. In some embodiments, the control system may be configured to determine a third phase rotation between the first and second devices without using clock ambiguity based on relative clock offsets and ambiguous phase rotation between the first and second devices determined based on a monitored first tone signal. In some embodiments, the second device may be configured to receive a second tone signal from a remote device and/or transmit a second tone signal to the remote device. The first device may be configured to monitor the second tone signal between the second device and the remote device, and the control system may be configured to determine a third phase rotation of the second tone signal between the second device and the remote device. The control system may be configured to determine a fourth phase rotation between the remote device and the first device based on (1) the second tone signal monitored by the first device and (2) the second device clock offset between the second device and the remote device. In some embodiments, the first frequency and the second frequency are different. In some embodiments, the control system is provided in the first device, in which case the first device can operate as an initiator. I