US-12625242-B2 - Positioning based on inter-packet arrival time

US12625242B2US 12625242 B2US12625242 B2US 12625242B2US-12625242-B2

Abstract

Disclosed are techniques for wireless communication. In an aspect, a radio frequency identification (RFID) station may receive a first packet from an RFID tag at a first arrival time. The RFID station may receive a second packet from the RFID tag at a second arrival time after the first arrival time. The RFID station may estimate a distance between the RFID station and the RFID tag based on an inter-packet arrival time between the first packet and the second packet, the inter-packet arrival time being based on a time difference between the first arrival time and the second arrival time.

Inventors

Xiaojie Wang
Mohammad Tarek FAHIM
Jing Sun
Xiaoxia Zhang

Assignees

QUALCOMM INCORPORATED

Dates

Publication Date: 20260512
Application Date: 20230524

Claims (13)

1 . A method of operating a radio frequency identification (RFID) station, the method comprising: receiving a first packet from an RFID tag at a first arrival time; receiving a second packet from the RFID tag at a second arrival time after the first arrival time; determining a mapping relationship based on capability information of the RFID tag that includes: an energy harvesting efficiency characteristic of the RFID tag; a power consumption level for sending the first packet or the second packet by the RFID tag; an accuracy of monitoring an energy level of an energy storage device of the RFID tag by the RFID tag; an accuracy of monitoring a signal strength of radio frequency waves from the RFID station by the RFID tag; or a combination thereof; and estimating a distance between the RFID station and the RFID tag based on an inter-packet arrival time between the first packet and the second packet and the mapping relationship, the inter-packet arrival time being based on a time difference between the first arrival time and the second arrival time.
2 . The method of claim 1 , further comprising transmitting radio frequency waves to energize the RFID tag.
3 . The method of claim 2 , wherein the radio frequency waves are transmitted continuously at least from the first arrival time to the second arrival time.
4 . The method of claim 1 , wherein the receiving the first packet and the receiving the second packet are performed based on active transmission from the RFID tag.
5 . The method of claim 1 , further comprising updating or calibrating the mapping relationship based on one or more training packets from one or more training devices at one or more known locations.
6 . The method of claim 1 , further comprising sending, to the RFID tag, configuration information regarding at least transmission of the second packet.
7 . The method of claim 6 , wherein the configuration information indicates: a configured level of an energy level of an energy storage device of the RFID tag corresponding to the energy storage device having stored a configured amount of energy to power the RFID tag to transmit the second packet after the first packet being transmitted; a start time, an end time, or a duration of a time period during which radio frequency waves from the RFID station for energy harvesting are continuously transmitted; or a combination thereof.
8 . The method of claim 7 , further comprising: receiving capability information of the RFID tag; and determining the configured level, determining the start time, the end time, or the duration of the time period, or both, based on the capability information of the RFID tag.
9 . The method of claim 8 , wherein the capability information of the RFID tag indicates: an energy harvesting efficiency characteristic of the RFID tag; a power consumption level for sending the first packet or the second packet by the RFID tag; an accuracy of monitoring the energy level of the energy storage device by the RFID tag; an accuracy of monitoring a signal strength of the radio frequency waves from the RFID station by the RFID tag; or a combination thereof.
10 . The method of claim 8 , further comprising transmitting a capability inquiry to the RFID tag, wherein the capability information is reported by the RFID tag based on the capability inquiry.
11 . A radio frequency identification (RFID) station, comprising: at least one memory; at least one transceiver; and at least one processor communicatively coupled to the at least one memory and the at least one transceiver, the at least one processor configured to: receive, via the at least one transceiver, a first packet from an RFID tag at a first arrival time; receive, via the at least one transceiver, a second packet from the RFID tag at a second arrival time after the first arrival time; determine a mapping relationship based on capability information of the RFID tag that includes: an energy harvesting efficiency characteristic of the RFID tag; a power consumption level for sending the first packet or the second packet by the RFID tag; an accuracy of monitoring an energy level of an energy storage device of the RFID tag by the RFID tag; an accuracy of monitoring a signal strength of radio frequency waves from the RFID station by the RFID tag; or a combination thereof; and estimate a distance between the RFID station and the RFID tag based on an inter-packet arrival time between the first packet and the second packet and the mapping relationship, the inter-packet arrival time being based on a time difference between the first arrival time and the second arrival time.
12 . The RFID station of claim 11 , wherein the at least one processor is further configured to transmit, via the at least one transceiver, radio frequency waves to energize the RFID tag.
13 . The RFID station of claim 11 , wherein the at least one processor is further configured to send, via the at least one transceiver to the RFID tag, configuration information regarding at least transmission of the second packet.

Description

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure Aspects of the disclosure relate generally to wireless communications. 2. Description of the Related Art Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G), a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks), a third-generation (3G) high speed data, Internet-capable wireless service and a fourth-generation (4G) service (e.g., Long Term Evolution (LTE) or WiMax). There are presently many different types of wireless communication systems in use, including cellular and personal communications service (PCS) systems. Examples of known cellular systems include the cellular analog advanced mobile phone system (AMPS), and digital cellular systems based on code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), the Global System for Mobile communications (GSM), etc. A fifth generation (5G) wireless standard, referred to as New Radio (NR), enables higher data transfer speeds, greater numbers of connections, and better coverage, among other improvements. The 5G standard, according to the Next Generation Mobile Networks Alliance, is designed to provide higher data rates as compared to previous standards, more accurate positioning (e.g., based on reference signals for positioning (RS-P), such as downlink, uplink, or sidelink positioning reference signals (PRS)), and other technical enhancements. These enhancements, as well as the use of higher frequency bands, advances in PRS processes and technology, and high-density deployments for 5G, enable highly accurate 5G-based positioning. SUMMARY The following presents a simplified summary relating to one or more aspects disclosed herein. Thus, the following summary should not be considered an extensive overview relating to all contemplated aspects, nor should the following summary be considered to identify key or critical elements relating to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects relating to the mechanisms disclosed herein in a simplified form to precede the detailed description presented below. In an aspect, a method of operating a radio frequency identification (RFID) station includes receiving a first packet from an RFID tag at a first arrival time; receiving a second packet from the RFID tag at a second arrival time after the first arrival time; and estimating a distance between the RFID station and the RFID tag based on an inter-packet arrival time between the first packet and the second packet, the inter-packet arrival time being based on a time difference between the first arrival time and the second arrival time. In an aspect, a method of operating a radio frequency identification (RFID) tag includes transmitting a first packet to an RFID station at a first transmission time, an energy level of an energy storage device of the RFID tag being reset as a result of the first packet being transmitted; harvesting energy at least based on radio frequency waves from the RFID station after the first packet being transmitted, and storing the harvested energy in the energy storage device; and transmitting, based on the energy level of the energy storage device reaching a configured level, a second packet to the RFID station at a second transmission time after the first transmission time to enable the RFID station to determine an inter-packet arrival time between the first packet and the second packet. In an aspect, a radio frequency identification (RFID) station includes at least one memory; at least one transceiver; and at least one processor communicatively coupled to the at least one memory and the at least one transceiver, the at least one processor configured to: receive, via the at least one transceiver, a first packet from an RFID tag at a first arrival time; receive, via the at least one transceiver, a second packet from the RFID tag at a second arrival time after the first arrival time; and estimate a distance between the RFID station and the RFID tag based on an inter-packet arrival time between the first packet and the second packet, the inter-packet arrival time being based on a time difference between the first arrival time and the second arrival time. In an aspect, a radio frequency identification (RFID) tag includes at least one memory; at least one transceiver; and at least one processor communicatively coupled to the at least one memory and the at least one transceiver, the at least one processor configured to: transmit, via the at least one transceiver, a first packet to an RFID station at a first transmission time, an energy level of an energy storage device of the RFID tag being reset as a result of the first packet being transmitted; harvest