Power control method for mobile RFID reader and RFID reader using the same

• US 20070126553A1
• Filed: 11/29/2006
• Published: 06/07/2007
• Est. Priority Date: 12/01/2005
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute, SK Telecom Co., Ltd.
• Original Assignee: Electronics and Telecommunications Research Institute, SK Telecom Co., Ltd.
• Inventors: Park, Chan-Won, Yoon, Gene-Hee, Lee, Joo-Moon, Yang, Hoe-Sung, Choi, Gil-Young, Chae, Jong-Suk, Lee, Dong-Han, Pyo, Cheol-Sig, Shin, Taejeen
• Granted Patent: US 7,893,834 B2
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: H04B 5/0056 for use in interrogation, identification or read/write systems record carriers G06K7/00, G06K19/00; for railways B61L3/12
• CPC Class Codes: H04B 5/02 using transceiver
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04W 52/04 TPC

Abstract

Provided is a power control method for a mobile Radio Frequency Identification (RFID) reader and an RFID reader using the same. The RFID reader includes: an RFID reader transmission/reception control unit for creating a message to be transmitted to an RFID tag and transmitting RFID tag information to a terminal control unit; a reader transmitting unit for encoding and modulating the created message; a power amplifier for amplifying an output signal; a reader receiving unit for demodulating and decoding the signal and transmitting the signal to the RFID reader transmission/reception control unit; and an RFID reader power control unit for controlling power, wherein when the RFID reader transmission/reception control unit receives a command for acquiring the RFID tag information, the RFID reader power control unit applies power to the power amplifier.

Claims

1. A Radio Frequency Identification (RFID) reader mountable to a wireless communication terminal, comprising:

an RFID reader transmission/reception control means for creating a message to be transmitted to an RFID tag and transmitting RFID tag information acquired from the RFID tag to a terminal control means of the wireless communication terminal;

a reader transmitting means for encoding and modulating the created message;

a power amplifier for amplifying an output signal of the RFID reader transmitting means;

a reader receiving means for demodulating and decoding the signal transmitted from the RFID tag; and

an RFID reader power control means for controlling power applied to the RFID reader transmission/reception control means, the RFID reader transmitting means, the power amplifier and the RFID reader receiving means,

wherein when the RFID reader transmission/reception control means receives a command for acquiring the RFID tag information from the terminal control means, the RFID reader power control means applies power to the power amplifier.

2. The RFID reader as recited in claim 1, wherein the RFID reader receiving means includes:

an RF receiver for performing frequency down-conversion on the signal transmitted from the RFID tag;

an analog-to-digital (AD) converter for converting the frequency downward converted-signal into a digital signal;

a demodulator for demodulating the converted digital signal; and

a decoder for decoding and transmitting the demodulated signal to the RFID reader transmission/reception control means.

3. The RFID reader as recited in claim 1, wherein when an RFID reader function is selected from the terminal control means, power is applied to the RFID transmission/reception control means.

4. The RFID reader as recited in claim 3, wherein when the RFID reader transmission/reception control means receives a command for acquiring the RFID tag information from the terminal control means, the RFID reader power control means additionally applies power to the RFID reader transmitting means, the power amplifier and the RFID reader receiving means.

5. The RFID reader as recited in claim 4, wherein when the RFID reader transmission/reception control means acquires the RFID tag information, the RFID reader power control means turns off power applied to the RFID reader transmitting means, the power amplifier and the RFID reader receiving means.

6. The RFID reader as recited in claim 3, wherein when the RFID reader control means receives a command to acquire the RFID tag information from the terminal control means according to a Listen Before Talk (LBT) method, the power control means additionally applies power to the RFID reader receiving means.

7. The RFID reader as recited in claim 6, wherein when the RFID reader transmission/reception control means ends channel detection for communication with the RFID tag, the RFID reader power control means additionally applies power to the RFID reader transmitting means and the power amplifier.

8. The RFID reader as recited in claim 7, wherein when the RFID reader transmission/reception control means acquires the RFID tag information, the RFID reader power control means turns off power applied to the RFID reader transmitting means, the power amplifier and the RFID reader receiving means.

9. The RFID reader as recited in claim 2, wherein the demodulator measures Received Signal Strength Indication (RSSI) of a channel signal transmitted through an RFID reader antenna and notifies the measured result to the RFID reader transmission/reception control means, and the RFID reader transmission/reception control means compares the RSSI with a threshold and detects a channel to be used for communication with the RFID tag.

10. The RFID reader as recited in claim 9, wherein the command for acquiring the RFID tag information is transmitted from the terminal control means, the RFID reader power control means applies power to the RFID reader transmission/reception control means, the RF receiver, the AD converter and the demodulator.

11. The RFID reader as recited in claim 10, wherein when the RFID reader transmission/reception control means detects a channel to communicate with the RFID tag, the RFID reader power control means additionally applies power to the decoder, the RFID reader transmitting means and the power amplifier.

12. The RFID reader as recited in claim 11, wherein when the RFID reader transmission/reception control means acquires the RFID tag information, the RFID reader power control means cuts off power to the RFID reader transmitting means, the power amplifier and the RFID reader receiving means.

13. A method for controlling power in an Radio Frequency Identification (RFID) reader, which includes an RFID reader transmission/reception control means creating a reader message to an RFID tag, a reader transmitting means for encoding and modulating the reader message, a power amplifier for amplifying an output signal of the RFID reader transmitting means, and a reader receiving means for demodulating and decoding the signal transmitted from the RFID tag, and receives an RFID reader operation command from a terminal control unit of a wireless communication terminal, comprising the steps of:

a) receiving a read command for acquiring RFID tag information from the terminal control means by communicating with the RFID tag; and

b) applying power to the power amplifier after receiving the read command.

14. The method as recited in claim 13, further comprising the step of:

f) when a power control signal for operating the RFID reader is initially inputted from the terminal control means, applying power to the RFID reader transmission/reception control means.

15. The method as recited in claim 14, further comprising the step of:

g) when the read command is transmitted from the terminal control means, applying power to the RFID reader transmitting means, the power amplifier and the RFID reader receiving means.

16. The method as recited in claim 15, further comprising the step of:

h) when the RFID tag information is acquired from the RFID tag, applying power to the RFID reader transmitting means, the power amplifier and the RFID reader receiving means.

17. The method as recited in claim 16, further comprising the step of:

i) when the read command is transmitted from the terminal control means, applying power to a Received Signal Strength Indication (RSSI) measuring means of a reception channel signal for performing a Listen Before Talk (LBT) method.

18. The method as recited in claim 17, further comprising the step of:

j) when a channel to be used for communication with the RFID tag is selected, applying power to the RFID reader transmitting means and the power amplifier.

19. The method as recited in claim 18, further comprising the step of:

k) when the RFID tag information is acquired from the RFID tag, power applied to the RFID reader transmitting means, the power amplifier and the RFID reader receiving means is turned off.