Apparatus and method for locating RFID tag

• US 8,633,803 B2
• Filed: 12/23/2009
• Issued: 01/21/2014
• Est. Priority Date: 02/25/2009
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Mo, Sang-Hyun, Lee, Jae-Heum, Myong, Seung-Il, Yang, Hoe-Sung, Lee, Heyung-Sub, Chae, Jong-Suk, Cha, Jongsub, Lee, Kang-Bok, Shin, Dong-Beom
• Primary Examiner(s): BROWN, VERNAL U
• Application Number:
  US12/646,784
• Publication Number:
  US 20100214067A1
• Time in Patent Office: 1,490 Days
• Field of Search: 340/10.1, 340/505, 340/12.5, 705/28, 455/41.2
• US Class Current: 340/10.1
• CPC Class Codes: H04B 5/0062 in RFID [Radio Frequency Identification] Systems
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04Q 2213/13095 PIN / Access code, authentication
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Provided are a Radio Frequency Identification (RFID) tag and apparatus and method for locating a RFID tag without comparing arrival times of blink signals transmitted from the RFID tag in order to quickly trace a location of the RFID tag. The RFID tag includes a tag ID generator configured to generate a tag ID of the RFID tag, a blink generator configured to generate a plurality of sub-blink signals that form the blink signal, a sub-blink ID generator configured to generate sub-blink IDs for the generated sub-blink signals, a sub-blink ID inserter configured to insert the generated sub-blink IDs into the sub-blink signals, and a transmitter configured to transmit the blink signal having the tag ID and the sub-blink IDs.

Claims

1. A radio frequency identification (RFID) tag for transmitting a blink signal to locate a position of a target object, comprising:

a tag ID generator configured to generate a tag ID of the RFID tag;

a blink generator configured to generate a plurality of sub-blink signals that form the blink signal;

a sub-blink ID generator configured to generate sub-blink IDs for the sub-blink signals;

a sub-blink ID inserter configured to insert the sub-blink IDs into the sub-blink signals; and

a transmitter configured to transmit the blink signal having the tag ID and the sub-blink IDs,

wherein the sub-blink IDs are generated according to a generation time order for each of the sub-blink signals.

3. The RFID tag of claim 1, wherein the sub-blink ID is included in a payload of the sub-blink signal.

2. The RFID tag of claim I , wherein the transmitter modulates the blink signal having the tag ID and the sub-blink IDs using a direct sequence spread spectrum scheme.

4. A method for controlling a radio frequency identification (RFID) tag, comprising:

generating a tag ID of the RFID tag;

generating a plurality of sub-blink signals that form the blink signal;

generating sub-blink identifications (ID) for the sub-blink signals, and inserting the sub-blink IDs to the sub-blink signals; and

transmitting the blink signals having the tag ID and the sub-blink IDs,

wherein the sub-blink IDs are generated according to a generation time order for each of the sub-blink signals.

5. The method of claim 4, further comprising modulating the blink signal having the tag ID and the sub-blink IDs using a direct sequence spread spectrum (DSSS) signal.

6. The method of claim 4, wherein the sub-blink ID is included in a payload of the sub-blink signal.

7. An apparatus for locating a radio frequency identification (RFID) tag that transmits a blink signal, comprising:

a blink signal receiver configured to receive a plurality of sub-blink signals having a tag ID and sub-blink IDs of each RFID tag from a plurality of radio RFID tags;

a memory configured to store information including tag IDs and sub-blink IDs of each one of the plurality of sub-blink signals, and arrival time information of each one of the plurality of sub-blink signals;

a first grouping unit configured to group the stored information by a same tag ID among the stored tag IDs;

a second grouping unit configured to group the tag-ID grouped information by a same sub-blink ID among the stored sub-blink IDs; and

a tag location calculator configured to calculates a coordinate of the RFID tag when the number of the grouped sub-blink IDS is more than three.

8. The apparatus of claim 7, further comprising a tag coordinate transmitter configured to transmit the calculated coordinate to a server for managing a history of locations of the RFID tag.

9. The apparatus of claim 7, wherein the tag coordinate calculator does not calculate a coordinate of the RFID tag when the number of the grouped sub-blink IDs is less than three.

10. The apparatus of claim 7, wherein the tag location calculator uses a time difference of arrival of the sub-blinks.

11. A method for tracking a location of a radio frequency identification (RFID) tag that transmits a blink signal, comprising:

receiving a plurality of sub-blink signals including a tag ID and sub-blink IDs of each RFID tag from the plurality of RFID tags;

storing information including the tag IDs, the sub-blink IDs, and arrival time information of the plurality of sub-blink signals;

grouping the stored information by a same tag ID among the stored tag IDs;

grouping the tag-ID grouped information by a same sub-blink ID among the stored sub-blink IDs; and

calculating a coordinate of the RFID tag when the number of the grouped sub-blink IDS is more than three.

12. The method of claim 11, further comprising:

transmitting the calculated coordinate to a server that manages a history of locations of a tag.

13. The method of claim 11, wherein in said calculating a coordinate of the RFID tag, a location coordinate of the RFID tag is not calculated when the number of the grouped sub-blink IDs is less than three.

14. The method of claim 11, wherein in said calculating a coordinate of the RFID tag, a time difference of arrival (TDOA) algorithm is used to arrival time information of the sub-blinks.