KR101349439B1 - Radio Frequency signal recognition system and method of radio frequency recognition - Google Patents

Abstract

RFID signal recognition system according to the present invention comprises a high frequency radiation unit for radiating a high frequency signal for energy supply to the tag; A power adjusting unit for adjusting the power of the high frequency signal; And a control unit for controlling the power adjusting unit and the high frequency radiating unit so as to radiate a high frequency signal differentiated in power, or to process a tag signal in data. RFID signal recognition method according to the present invention comprises the steps of radiating a high-frequency signal for energy supply to the tag; Receiving a tag signal and processing the signal into an I signal and a Q signal; Comparing the I signal and the Q signal; And as a result of the comparison, radiating high-frequency signals with different power when the I signal and the Q signal do not match, and processing the tag signal when the I signal and the Q signal match.

According to the present invention, since the tag signal not detected by the reader can be collected and provided to the reader, the recognition rate of the tag can be improved, the recovery rate of the tag signal is grasped, and the energy supply signal of various intensities is supplied, thereby providing the tag signal. There is an effect that can be processed stably.

Description

Radio frequency signal recognition system and method of radio frequency recognition

1 is a block diagram schematically showing the components of a typical RFID reader.

2 is a view schematically illustrating a mode in which a general RFID reader and an RFID tag transmit and receive radio waves.

Figure 3 is a block diagram schematically showing the components of the RFID signal recognition system according to an embodiment of the present invention.

Figure 4 is a block diagram schematically showing the components of the control unit of the RFID signal recognition system according to an embodiment of the present invention.

5 is a diagram schematically showing a standard of a transmission / reception signal used in an RFID signal recognition system according to an embodiment of the present invention.

6 is an enlarged view of an information request signal section of a signal standard used in an RFID signal recognition system according to an exemplary embodiment of the present invention.

7 is a flowchart illustrating a RFID signal recognition method according to an embodiment of the present invention.

Description of the Related Art

100: RFID signal recognition system 105: the first antenna

110: LNA 115: filter

120: mixer section 125: demodulation section

130: phase synchronization circuit 135: signal recovery unit

140: control unit 141: radiation signal control unit

142: power control unit 143: IQ comparison processing unit

144: CRC comparison processing unit 145: signal restoration control unit

146: interface unit 147: data processing unit

150: connection portion 155: high frequency radiation portion

160: power control unit 165: second antenna

The present invention relates to an RFID signal recognition system capable of improving the recognition rate of a tag.

Nowadays, ubiquitous network technology is attracting attention of many people. Ubiquitous network technology means a technology that makes it possible to connect to various networks smoothly regardless of time and place.

Examples of such ubiquitous network technology include RFID or USN technology, and among them, RFID technology introduced in commerce is representative.

Ubiquitous sensor network (USN) technology is a network configured to collect information collected from various sensors wirelessly, and by installing hundreds of sensor network nodes in vulnerable areas where human access is difficult to implement, human surveillance functions can be implemented. Can be.

In general, a commercial RFID system consists of an RFID tag attached to a product and embedded with details, an RFID reader that reads information of the RFID tag using RF communication, and the RFID tag attached to the product is located at which the RFID reader is located. Since information is transmitted through RF communication through the region, it provides a foundation for efficiently managing logistics / distribution such as distribution, assembly, price change, and sales of goods.

1 is a block diagram schematically showing the components of a general RFID reader 10.

Referring to FIG. 1, a general RFID reader 10 includes an antenna 11, a signal separator 12, an RF receiver 13, a baseband receiver 14, an Rx phase locked loop (PLL) 15, and an RF transmitter. (16), the baseband transmitter 17, the Tx PLL 18, and the controller 19.

The transmit / receive signal separator 12 separates the transmitted signal from the received signal and transmits the transmitted signal to the antenna 11 or transmits the received signal to the RF receiver 13, for example, a device such as a circulator. Can be implemented.

In addition, the baseband receiver 14 receives the reference frequency signal from the Rx PLL 15 and converts the RF received signal into a baseband signal, and the baseband transmitter 17 receives the reference frequency signal from the Tx PLL 18. Received to convert the baseband signal transmitted from the control unit 19 to an RF transmission signal.

FIG. 2 is a diagram schematically illustrating a general RFID reader 10 and RFID tags 20 and 21 transmitting and receiving radio waves. When the RFID reader 10 transmits an information request signal as shown in FIG. 20 and 21 thus have a communication form for transmitting tag information, where a signal from the tag 21 exceeding the reading distance does not reach the RFID reader 10 but leaks.

In addition, the tag 21 receives the energy supply signal from the RFID reader 10 and uses it as electric power for transmitting radio waves. As the tag 21 moves away from the RFID reader 10, the intensity of the energy supply signal increases. The tag 21 is unable to transmit tag information with sufficient power.

Therefore, even when the tag information is received from the tag 21, the RFID reader 10 may not be able to accurately interpret the signal.

When the signal of the tag is leaked or the energy supply signal becomes unstable, the RFID reader 10 cannot generate accurate logistic information, and in order to prevent such cases, a larger number of RFID readers 10 must be disposed. In this case, there is a problem in that radio interference between the readers 10 is severely generated, thereby lowering a tag recognition rate and a recognition distance and forming a complex network.

In other words, the reading distance and the transmission distance of the energy supply signal are limited so that the recognition rate of the tag does not reach 100%. Therefore, the hardware resource of the RFID reader for network connection configuration is compensated for by the more complicated system configuration. There is a problem that the increase in software resources and the installation cost increases.

The present invention provides an RFID signal recognition system that improves the recognition rate of a tag by collecting tag information and providing the tag to a reader.

In addition, the present invention is to process the tag information that is not detected through the minimized circuit configuration and network connection configuration, and improve the recognition rate of the tag by efficiently transmitting the signal for supplying energy to the tag and efficiently integrate the information of the tag. Provides an RFID signal recognition system that can be.

RFID signal recognition system according to the present invention comprises a high frequency radiation unit for radiating a high frequency signal for energy supply to the tag; A power adjusting unit for adjusting the power of the high frequency signal; And a control unit for controlling the power adjusting unit and the high frequency radiating unit so as to radiate a high frequency signal differentiated in power, or to process a tag signal in data.

RFID signal recognition method according to the present invention comprises the steps of radiating a high-frequency signal for energy supply to the tag; Receiving a tag signal and processing the signal into an I signal and a Q signal; Comparing the I signal and the Q signal; And as a result of the comparison, radiating high-frequency signals with different power when the I signal and the Q signal do not match, and processing the tag signal when the I signal and the Q signal match.

Hereinafter, an RFID signal recognition system and an RFID signal recognition method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The RFID signal recognition system includes a reader, a tag, and an RFID network. When the tag performs communication, it receives the leaked signal and complements it. Of course, the RFID signal recognition system according to the present invention can also be used in the USN system.

3 is a block diagram schematically showing the components of the RFID signal recognition system 100 according to an embodiment of the present invention.

Referring to FIG. 3, the RFID signal recognition system 100 according to an embodiment of the present invention includes a first antenna 105, a second antenna 165, a low noise amplifier (LNA) 110, a filter 115, and a mixer. The unit 120, the demodulator 125, the phase synchronization circuit 130, the controller 140, the signal restorer 135, the display unit 145, the connection unit 150, and a high frequency radiation unit (Power Carrier Shower) 155 ) And the power adjusting unit 160.

Although the signal transmitted from the reader, for example, the information request signal is not delivered to the tag and leaks, or a sufficient energy supply signal may not be transmitted from the reader, the RFID signal recognition system 100 according to the present invention may be a reader. Instead, the energy signal may be provided to the tag, and the leaked signal among the signals transmitted from the reader may be received and transmitted to the tag.

In addition, when tag information is received, the tag information may be processed in place of the reader and provided to the reader. According to the RFID signal recognition system 100 according to the present invention, the recognition rate and the recognition distance of the tag may be improved.

That is, since the reader and the RFID signal recognition system 100 according to the present invention can detect the signal transmitted from the tag at the same time, and the reader and the RFID signal recognition system 100 can transmit the energy signal at the same time, the surveillance area of the tag is This has the effect of extending the transmission distance.

The first antenna 105 receives a tag signal or a reader signal, and the second antenna 165 transmits a high frequency signal for supplying energy (hereinafter, referred to as an "energy signal") to a tag, for example, a dipole. Antennas, monopole antennas, microstrip antennas, patch antennas and the like can be used.

The LNA 110 suppresses and amplifies a noise component of a received signal, and the filter 115 passes a frequency signal of a band allocated to an RFID communication channel and blocks a signal of an adjacent component or a signal of a noise component. Do this.

The mixer unit 120 mixes the oscillation frequency signal supplied from the phase synchronization circuit unit 130 with the reception signal and has a phase of 180 degrees and is an I-phase signal and a Q-quad-phase signal in a baseband signal state. To convert.

The demodulator 125 converts the baseband signal into a digital signal and transmits it to the control unit 140. The control unit 140 has a communication protocol to control wireless communication with a tag and a reader, and interprets the digital signal to tag information. And store and manage the reader information in memory.

The RFID signal recognition system 100 according to the present invention may provide an energy signal (which may include leader information) as a tag in place of a reader, and then process the received tag information and provide it to the reader (tag information). May be delivered to the reader through the connection 150).

The control unit 140 processes as follows according to the case where the signal to be processed is reader information or tag information.

First, the first processed signal is reader information, and the controller 140 interprets the digital signal as reader information and extracts an information request signal and synchronization information conforming to the RFID signal standard.

Accordingly, the high frequency radiation unit 155 may transmit the energy signal available in the tag to meet the RFID signal specification (with transmission timing) by using the synchronization information.

In this case, the high frequency radiation unit 155 may transmit not only an energy signal but also reader information on an RFID signal standard.

Second, when the first case is processed and the tag receives the energy signal and thus transmits the tag information, the control unit 140 interprets the digital signal as the tag information, stores it in the memory, and manages it or connects it to the connection unit 150. To pass.

The controller 140 includes a kernel to provide an interface with each component, to process an interrupt, and to assign a request processing time and an operation order so that each component is sequentially operated. The controller 140 manages the address of the storage means to control data input and output. The controller 140 will be described in detail with reference to FIG. 4.

4 is a block diagram schematically illustrating components of the control unit 140 of the RFID signal recognition system 100 according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the controller 140 may include a radiation signal controller 141, a power controller 142, an IQ comparison processor 143, a CRC comparison processor 144, a signal restoration controller 145, an interface unit 146, and the like. And a data processor 147.

The radiation signal control unit 141 transmits a control signal including synchronization information to the high frequency radiation unit 155 as described above, wherein the high frequency radiation unit 155 supplies an oscillation frequency signal from the phase synchronization circuit unit 130. And amplify it into an energy signal.

The IQ comparison processor 143 compares the I signal and the Q signal of the tag signal, and if the first criterion is not satisfied, the IQ comparison processor 143 operates the radiation signal controller 141 and the power controller 142 to generate an energy signal using a tag. Resupply

The power control unit 142 transmits an amplification / attenuation control signal to the power adjusting unit 160, and the power adjusting unit (which may be provided as an amplifying / attenuating unit) 160 controls the energy signal transmitted from the high frequency radiation unit 155. Adjust the power

Therefore, an energy signal with different power values may be repeatedly transmitted until a stable tag signal is received.

The first criterion is a primary criterion for determining whether the tag signal is stable. The first criterion is set to a value corresponding to a significant difference between the I signal and the Q signal.

For example, if there is a difference of 16 bits or more between the I signal and the Q signal, the two signals can be determined to be inconsistent signals, that is, signals containing different information.

On the other hand, if the IQ comparison processor 143 satisfies the first criterion as a result of comparing the I signal and the Q signal, the IQ comparison processor 143 operates the data processor 147 to process the tag information.

The CRC comparison processor 144 examines a tag signal that satisfies the first criterion by using a cyclic redundancy checking (CRC) method, and when the second criterion is satisfied, operates the data processor 147 to process the tag signal. Do it.

However, if the CRC check result does not satisfy the second criterion, the CRC comparison processor 144 operates the radiation signal controller 141 and the power controller 142, and the radiation signal controller 141 and the power controller 142 The power adjuster 160 and the high frequency radiator 155 are controlled to radiate the differentiated energy signal again.

In this case, since there is a need to increase or decrease the power of the energy signal according to the receiving environment of the tag, the power adjusting unit 160 cyclically adjusts the power of the energy signal in such a manner that the power of the energy signal is increased from the initial transmission and then lowered again.

The second criterion is a secondary criterion for determining whether or not the tag signal is stable. For example, the second criterion may be applied when a CRC error occurs more than 4 bits.

CRC is a method of performing a redundancy check based on a binary division operation on bits in order to solve a group error. That is, the sender applies a 16 / 32-bit polynomial (the ITU-T establishes a standard for polynomials used to obtain the code to be added to the block) to the data block, and adds the resulting code to the block. The receiver then applies the same polynomial to the data and compares the result with that sent by the sender.

Subsequently, the CRC comparison processing unit 144 reapplies the tag signal by applying a third criterion. If the third criterion is not satisfied, the CRC comparison processing unit 144 operates the signal restoration control unit 145.

That is, as a result of the CRC comparison, if the data bit having a difference is greater than or equal to the third criterion and less than the second criterion, the tag signal is considered to be capable of restoring the signal, and the signal restoration controller 145 transmits a control signal to restore the signal. The unit 135 is operated.

The third criterion is a third criterion for determining whether or not the tag signal is stable. For example, the third criterion may be applied when a CRC error is generated by 2 bits (third reference) or more and 4 bits (second reference) or less.

The signal restorer 135 synchronizes the tag signal Rx command data and the reader signal Tx command data according to the synchronization information, and compares the two signals to restore the tag signal. This is a signal recovery operation performed by considering that a transmission signal of a feedback component acts as an interference signal to a tag signal.

The signal reconstructed tag signal is transferred to the data processor 147 and processed as tag information.

On the other hand, when the CRC check result is satisfied (when the CRC error is less than 2 bits), the CRC comparison processor 144 operates the data processor 147 to process the tag signal.

As such, the IQ comparison processor 143 and the CRC comparison processor 144 determine the stability of the tag signal over three orders. If the criteria are not met, the IQ comparison processor 143 and the CRC comparison processor 144 operate the radiation signal controller 141 and the power controller 142. Resupply the energy signal or operate the signal recovery controller 145 to command signal recovery.

In addition, if it is determined whether the stability is satisfied and the criteria are met, the IQ comparison processor 143 and the CRC comparison processor 144 operate the data processor 147 to process the signal normally.

The interface unit 146 processes the tag information generated by the data processor 147 into graphical user interface (GUI) data, and the GUI data is transmitted to the display unit 145.

The display unit 145 includes a driving circuit, a display device, and the like, and provides the processed tag information on a user graphic screen.

The connection unit 150 receives tag information from the data processing unit 147 and transmits the tag information to the reader through a wired / wireless network.

For reference, when the reader requests the RFID signal recognition system 100 according to the present invention to process the tag information, the information request signal may be transmitted through the connection unit 150 as well as the information request signal as described above. It may be.

The connection unit 150 may be a wireless device such as Wi-Fi (Wireless LAN), UWB (Ultra Wide Band), Bluetooth, Bluetooth, World Interoperability for Microwave Access (Zigbee), Zigbee, Dedicated Short Range Communication (DSRC). It can be connected to the reader via a network or a wired network such as a universal asynchronous receiver / transmitter (UART), the Internet (TCP / IP), a switch hub, or a serial / parallel cable.

The signal transmitted from the tag corresponds to the information request signal originally requested from the reader, and must comply with the RFID signal standard. Accordingly, the data processor 147 interprets the signal specification of the reader information to generate tag information.

5 is a diagram schematically showing the specifications of the transmission and reception signals used in the RFID signal recognition system 100 according to an embodiment of the present invention, Figure 6 is a RFID signal recognition system 100 according to an embodiment of the present invention An enlarged view of the information request signal section among the signal standards used.

In Fig. 5, the section "A" is a section for monitoring whether the tag has entered the communication area, and the section "B" is a section during which the reader transmits an information request signal.

In addition, the section "C" is a section in which the tag transmits a response signal, and the section "D" is a section in which tag information is transmitted after the response signal is transmitted (which may be shared with the transmission section of the energy signal).

In FIG. 6, the section "B1" is a section in which the preamble signal is transmitted, the section "B2" is a section in which the information data signal is transmitted, and the section "B3" is a section in which the transmission end signal is transmitted. In addition, the section "B4" means a section of the energy supply signal.

The controller 140 interprets the reader signal and synchronizes data timing according to the signal standard. For example, the tag information may be synchronized with the signal standard of the “D” section.

The high frequency radiation unit 155 receives the synchronization information and transmits an energy signal. For example, the energy signal may be transmitted in synchronization with the “B4” section.

Hereinafter, an RFID signal recognition method according to an embodiment of the present invention will be described with reference to the accompanying drawings.

7 is a flowchart illustrating a RFID signal recognition method according to an embodiment of the present invention.

First, the high frequency radiation unit 155 radiates an energy signal having an average power value as a tag (S100), and then the tag signal received through the first antenna 105 is the LNA 110 and the filter 115. In operation S105, the mixer 120 and the demodulator 125 process the I and Q signals in the baseband signal state.

The IQ comparison processing unit 143 compares the I signal and the Q signal (S110), and if the comparison result does not satisfy the first criterion (NO in S115), the high frequency radiation unit 155 and the power adjusting unit 160 By operating the power to emit a differentiated energy signal (S120).

Thereafter, steps S100 to S120 are repeatedly performed until the received tag signal satisfies the first criterion.

On the other hand, if the first criterion is satisfied as a result of the comparison (YES in S115), the CRC comparison processing unit 144 is operated to check the CRC of the tag signal as the second criterion (S125).

If the check result does not satisfy the second criterion (No in S130), the CRC comparison processor 144 operates the high frequency radiator 155 and the power adjuster 160 to radiate the differentiated energy signal. (S120).

Thereafter, steps S100 to S130 are repeatedly performed until the received tag signal satisfies the second criterion.

On the other hand, if the check result satisfies the second criterion (YES in S130), the CRC comparison processing unit 144 checks the CRC of the tag signal as the third criterion, and the check result does not satisfy the third criterion ( "No" in S135), the deception restoration control unit 145 operates the signal restoration unit 135 to restore the tag signal (S140).

If the check result satisfies the third criterion (YES in S 135), the CRC comparison processing unit 144 operates the data processing unit 147.

Finally, the data processor 147 processes the tag signal whose stability has been verified or the restored tag signal through tag information as tag information and stores it in memory (S145).

Thereafter, the display unit 145 provides a GUI screen for tag information to be monitored by an administrator, and the connection unit 150 transmits tag information to a reader.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications not illustrated in the drawings are possible. For example, each component specifically shown in the embodiments of the present invention can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

According to the RFID signal recognition system according to the present invention, since the tag signal not detected by the reader can be collected and provided to the reader, the recognition rate of the tag can be improved.

In addition, according to the present invention, it is possible to stably process the tag signal by grasping the recovery rate of the tag signal and supplying an energy supply signal of various intensities.

In addition, according to the present invention, it is possible to extend the recognition distance of the tag and to extend the application area of the RFID network through a simple system configuration.

In addition, according to the present invention, the RFID signal recognition system can be manufactured in a small size and at a low cost by minimizing the circuit components, and there is no need to provide a separate network management system.

Claims (19)

A high frequency radiation unit for radiating an energy supply high frequency signal with a tag; A power adjusting unit for adjusting the power of the high frequency signal; When the I signal and the Q signal of the tag signal are compared, and if the I signal and the Q signal do not match, the radio frequency radiator and the power adjusting unit are controlled to radiate high frequency signals with different powers. RFID recognition system including a control unit for processing the tag signal data. delete The method of claim 1, wherein the control unit Inspects the tag signal determined to match the I signal and the Q signal by using a cyclic redundancy checking (CRC) method, and if an error exists over a predetermined bit, controls the power adjusting unit and the high frequency radiator to radiate a high frequency signal differentiated in power. RFID data recognition system for processing the tag signal if an error less than a predetermined bit. The method of claim 3, wherein the predetermined bit for determining the error is RFID signal recognition system of 4 bits to 16 bits. The method of claim 1, And a signal restoring unit for restoring a tag signal by comparing and calculating a tag signal and a reader signal. The controller checks the tag signal determined to be the same as the I signal and the Q signal by using a CRC method, and if an error exists over a predetermined bit, operates the signal restorer to process the restored tag signal or to perform an error. RFID signal recognition system for processing the tag signal data if present. The method of claim 5, wherein the predetermined bit for determining the error is RFID signal recognition system of 2 to 4 bits. The method according to any one of claims 1, 3, and 5, RFID signal recognition system comprising a display unit for providing the data processing tag information to the user graphic screen. The method according to any one of claims 1, 3, and 5, RFID signal recognition system including a connection for transmitting the data processing tag information to the reader through a wired / wireless network. The method of claim 1, A first antenna for receiving a tag signal or a reader signal; A second antenna for transmitting the high frequency signal to a tag; A mixer unit for processing a tag signal or a reader signal as a baseband signal; A demodulator for demodulating the baseband signal into a digital signal; And RFID signal recognition system including a phase synchronization circuit for supplying an oscillation frequency signal to the mixer or the high frequency radiation unit. The method of claim 1, wherein the control unit RFID signal recognition system for generating a synchronization information by interpreting the reader signal, and processing the received tag signal as a digital signal by the synchronization information. The method of claim 1, The controller generates the synchronization information by interpreting the reader signal, The radio frequency radiator using the synchronization information, RFID signal recognition system for emitting the high frequency signal for energy supply to meet the standard of the RFID transmission and reception signal. The method of claim 1, wherein the control unit A radiation signal control unit for operating the high frequency radiation unit; A power controller for transmitting an amplification / attenuation control signal to the power regulator; A data processor which processes a tag signal or a reader signal; And An IQ comparison processing unit for comparing the I signal and the Q signal of the tag signal, and operating the radiation signal controller and the power controller if the I signal and the Q signal do not match, and operating the data processor if the I signal and the Q signal match. RFID signal recognition system comprising. 13. The apparatus of claim 12, wherein the control unit Checks the tag signal determined to match the I signal and the Q signal by using a cyclic redundancy checking (CRC) method, and if the error exists over a predetermined bit, operates the radiation signal controller and the power controller, and an error exists below a predetermined bit. And a CRC comparison processing unit for operating the data processing unit. The method of claim 12, And a signal restoring unit for restoring a tag signal by comparing and calculating a tag signal and a reader signal. Wherein, If the I / Q signal is judged to be matched using the CRC method, and the error is detected by a predetermined bit or more, the signal recovery unit is operated to perform data processing on the restored tag signal or when the error is less than the predetermined bit. A CRC comparison processor for operating the data processor; And RFID signal recognition system including a signal recovery control unit for operating the signal recovery unit in accordance with the inspection result. Radiating a high frequency signal for energy supply to a tag; Receiving a tag signal and processing the signal into an I signal and a Q signal; Comparing the I signal and the Q signal; And When the comparison result, if the I signal and the Q signal does not match, the power is differentiated high frequency signal, and if the I signal and Q signal match, RFID signal recognition method comprising the step of data processing. 16. The method of claim 15, wherein the step of data processing the tag signal Examining a tag signal determined to be matched with an I signal and a Q signal by using a cyclic redundancy checking (CRC) method; Radiating a high frequency signal differentiated in power when a preset first bit error exists and processing a tag signal when the error exists below the first bit. 17. The method of claim 16, wherein processing the tag signal when the error is less than the first bit comprises: Checking a tag signal in which the first sub-bit error exists using a CRC scheme; As a result of the inspection, if there is an error greater than or equal to the second bit lower than the first bit, the tag signal may be compared with the reader signal, and the tag signal may be restored. RFID signal recognition method comprising. 16. The method of claim 15, wherein the step of data processing the tag signal RFID signal recognition method comprising the step of providing the data processing tag information to the user graphic screen. 16. The method of claim 15, wherein the step of data processing the tag signal RFID signal recognition method comprising the step of transmitting the data processing tag information to the reader via a wired / wireless network.

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