Fast RFID tag identifying method

• US 10,055,622 B1
• Filed: 05/11/2017
• Issued: 08/21/2018
• Est. Priority Date: 03/28/2017
• Status: Active Grant

• Current Assignee: National Central University
• Original Assignee: National Central University
• Inventors: Jiang, Jehn-Ruey, Yeh, Ming-Kuei
• Primary Examiner(s): Vo, Tuyen K
• Application Number:
  US15/592,754
• Time in Patent Office: 467 Days
• Field of Search: 235383, 235385, 235451, 235492
• CPC Class Codes: G06K 7/10019 resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. collision between the communication channels used by wireless communication devices, where the solution is not particularly adapted for RFIDs or the like, H04W74/08

Abstract

A fast RFID tag identifying method includes an encoding step for encoding a pair of bits to be expressed by an RFID tag into a silence code to be used in a transmitting step for the RFID tag. The silence code is arranged such that the superposition of a plurality of silence codes from a plurality of RFID tags is decoded into a set of pairs of bits to be expressed by the RFID tags.

Claims

1. A fast RFID tag identifying method, comprising:

an encoding step for encoding a bit pair to be expressed by an RFID tag into a silent code to be used in a transmitting step for the RFID tag, wherein the silent code is arranged such that the superposition of a plurality of silent codes from a plurality of RFID tags is decoded into a set of bit pairs to be expressed by the RFID tags,

wherein the encoding step is performed by the RFID tag itself;

a signal form of the silent code is based on a Manchester code;

types of the silent code include Ø

, 0 and 1, in which Ø

is representative of no signal, 0 is representative of a low-to-high signal, and 1 is representative of a high-to-low signal; and

different bit pairs correspond to different silent codes, and each of the different silent codes has two symbols with one symbol being Ø

.

2. The fast RFID tag identifying method as claimed in claim 1, wherein bit pairs 00, 01, 10 and 11 correspond to silent codes Ø

0, 0Ø

, 1Ø and

Ø

1, respectively.

3. The fast RFID tag identifying method as claimed in claim 1, wherein types of the superposition of silent codes include Ø

, 0, 1 and X, in which Ø

is representative of no signal, 0 is representative of a low-to-high signal, 1 is representative of a high-to-low signal, and X is representative of a signal collision.

4. The fast RFID tag identifying method as claimed in claim 3, wherein the superposition of silent codes Ø

Ø

, Ø

0, 0Ø

, 1Ø

, Ø

1, 00, 10, Ø

X, XØ

, 01, 11, X0, 0X, 1X, X1 and XX correspond to sets of bit pairs { }, {00}, {01}, {10}, {11}, {00, 01}, {00, 10}, {00, 11}, {01, 10}, {01, 11}, {10, 11}, {00, 01, 10}, {00, 01, 11}, {00, 10, 11}, {01, 10, 11} and {00, 01, 10, 11}, respectively.

5. The fast RFID tag identifying method as claimed in claim 1, further comprising:

the transmitting step for transmitting the silent code by the RFID tag, wherein, during transmission, the silent code is superposed with another silent code transmitted from another RFID tag and turns into a superposed silent code;

a receiving step for receiving the superposed silent code by a reader; and

a decoding step for decoding the superposed silent code into a set of bit pairs.