JP2013004054A - Active rfid communication control method and rfid wireless device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system of which the miniaturization is achieved and the power consumption is lowered for mounting a passive RFID reader/writer function and a short-range wireless communication function on a portable terminal such as a cellular phone.SOLUTION: Based on ISO/IEC 18000-6 Type C which is a communication standard of the internationally standardized UHF band passive RFID reader/writer, a communication mode and a communication procedure are made which are obtained by expanding the communication standard to a short-range wireless communication, so that a passive RFID reader/writer function and an active RFID function which is the short-range wireless communication are made common, and a one-chip LSI having two functions of the passive RFID reader/writer and the active RFID and a compact wireless module are constructed.

Description

  The present invention relates to an antenna built-in radio module and a terminal on which the module is mounted. In particular, it relates to so-called active RFID.

  As shown in FIG. 1, an RFID system that reads and writes data stored in RFID (Radio Frequency Identification) by wireless communication generally includes a terminal 100 called a reader / writer, and an RFID 120 that does not require a battery ( Hereinafter, it is referred to as passive RFID). The passive RFID 120 includes an IC chip 121 and an antenna 122. The reader / writer 100 generally includes a main body 101 and an antenna 102, and the main body 101 includes an RF (Radio Frequency) and Logic circuit 103, a CPU (Central Processing Unit) 104, and a memory 105.

  The communication method in the passive RFID system transmits an unmodulated wave or modulated wave 110 to the passive RFID 120, and the passive RFID 120 is operated by itself from the unmodulated wave or modulated wave 110 emitted from the reader / writer 100. In addition to taking out the operating power, the data is demodulated from the modulated wave 110, and the IC chip 121 is relaunched according to the demodulated data, and the reader / writer 100 receives and demodulates it.

  In the passive RFID system, since the passive RFID 120 uses the unmodulated wave or modulated wave 110 emitted from the reader / writer 100 as the operating power, even when the transmission output of the reader / writer 100 is 1 W at the antenna end, it is about several meters. It is a communication distance.

  Passive RFID systems are often used in logistics / distribution applications. For example, as shown in FIG. 2, when the forklift 200 passes through the gate 220, it is attached to an article 210 loaded on the forklift 200. The read / write RFID is read / written through the plurality of reader / writer antennas 230, or the RFID attached to the article 310 flowing on the belt conveyor 300 as shown in FIG. Through this, applications that read and write are being considered. In addition, passive RFID tags are attached to books and used to manage book lending in libraries and books using a small handy reader / writer.

  On the other hand, short-range wireless communication includes wireless LAN, and the communication distance is from several tens of meters to several hundreds of meters, which is 10 to 100 times different from the communication distance of the passive RFID system. However, these short-range wireless communication terminals require batteries.

  As the usage scenes of short-range wireless communication, home security, safety and security for children and the elderly, health management, home / building facility control, factory control, monitoring, hospital management, automatic meter reading, etc. are assumed. Yes.

  In recent years, a system combining a passive RFID system and short-range wireless communication has been considered. For example, as shown in FIG. 4, a module 410 having both a reader / writer function for communicating with passive RFID and a short-range wireless function is installed in a personal mobile phone 400 so that the individual can receive various services. It is.

  An example of the service is an information distribution service for customers in the distribution / retail field. In this service, a customer (pedestrian) who becomes a service user first moves around the city with a mobile phone. When moving to a storefront such as a supermarket where a short-range wireless communication terminal is installed, special sales information and store information (such as a map) are distributed to the mobile phone through short-range wireless communication. Visitors who are attracted to special sales information enter the store and travel around the store while referring to the received store map.

  When the mobile phone is brought close to the passive RFID attached to the front of the shelf when it is in front of the shelf of the recommended product during excursion, the product stored in the passive RFID is produced through the passive RFID reader / writer function. Read basic information about the land and information such as discount coupons, and finally move on to purchasing behavior. Such a thing is considered.

JP 2002-183183 A

  In order to implement a passive RFID reader / writer function and a short-range wireless communication function in a portable terminal such as a cellular phone, downsizing and low power consumption are essential.

  To have both a passive RFID reader / writer function and a short-range wireless communication function, use two types: a chip and wireless module with a passive RFID reader / writer function and a chip and wireless module with a short-range wireless communication function. For example, it can operate as a function, but it is difficult to mount these two types of modules in a mobile phone because there is no space for mounting, and power consumption also increases from the viewpoint of power consumption. However, there is a problem that battery consumption of mobile phones becomes intense.

  As a problem that hinders downsizing and low power consumption, the passive RFID reader / writer function and the short-range wireless communication function operate with different communication methods and communication procedures. It is necessary or a modulation / demodulation circuit is necessary.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a technique for a communication method and a communication procedure that are common to a passive RFID reader / writer and short-range wireless communication.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  Based on ISO / IEC 18000-6 Type C, which is a communication standard for internationally standardized UHF band passive RFID reader / writers, this communication standard is extended to short-range wireless communication and communication procedures and procedures are created. .

  As a result, the passive RFID reader / writer function and the active RFID function, which is short-range wireless communication, can be shared, and a one-chip LSI and a small wireless module with two types of functions, passive RFID reader / writer and active RFID, can be realized. Thus, it is possible to reduce the size and power consumption for mounting on mobile terminals such as mobile phones.

  Of the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  One-chip LSI with two types of functions, passive RFID reader / writer function and active RFID function, will be possible, miniaturization and low power consumption as a wireless module, and mounting on mobile terminals such as mobile phones Become.

It is a general RFID system configuration diagram. It is a RFID system diagram when RFID is read and written by a reader / writer when RFID attached to an article is carried by a forklift. FIG. 3 is an RFID system diagram when RFID is read and written by a reader / writer when RFID attached to an article is moving on a belt conveyor. It is a figure which shows the radio | wireless module provided with the mobile phone, the passive RFID reader-writer function, and the short-distance wireless function. It is a figure which shows the outline | summary of ISO / IEC 18000-6 Type C which is a communication standard of a UHF band passive RFID system. It is a figure which shows the communication frame in ISO / IEC 18000-6 Type C. It is a figure which shows the communication frame of active RFID which is this invention. It is a figure which shows the command and response format of active RFID which are this invention. It is a figure which shows the command and response format of active RFID which are this invention. It is a figure which shows the communication flow of the active RFID master and active RFID slave which are this invention. It is a figure which shows the communication flow between the active RFID master which is this invention, and several active RFID slaves. It is a figure which shows a part of RF and Logic circuit of a general passive RFID reader / writer. It is a figure which shows the received data detection part of the logic circuit of a general passive RFID reader / writer. It is a figure which shows the transmission data generation part of the logic circuit of a general passive RFID reader / writer. It is a figure which shows the memory access flow which is this invention. It is a figure which shows the structure which made the active RFID and the passive RFID reader-writer into one chip and one module.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in all the drawings for explaining the embodiments, the same members are denoted by the same reference numerals, and the repeated explanation thereof is omitted.

(Embodiment 1)
FIG. 5 shows an outline of the standard of ISO / IEC 18000-6 Type C, which is a communication standard for UHF band passive RFID systems that are internationally standardized.

  From the reader / writer, an unmodulated wave or an ASK (Amplitude shift keying) modulated wave is transmitted to the passive RFID. The data code of the ASK modulated wave is a PIE (Pulse-interval encoding) code. The passive RFID decodes the ASK modulated wave transmitted from the reader / writer, and returns data in the built-in memory according to the decoding result. The reply uses load modulation ASK or PSK (Phase shift keying), and the data code uses FM0 code or Miller Subcarrier code. As shown in FIG. 6, the frame format when the FM0 code is used transmits an FM0 preamble prior to FM0 data transmission. Therefore, the reader / writer receives the load-modulated ASK FM0 preamble returned from the passive RFID, and then decodes the FM0 data.

  FIG. 7 shows an active RFID communication system invented this time. The communication frequency band is 860 to 960 MHz, which is the same as that of a passive RFID reader / writer. First, as in the reader / writer, the active RFID that starts communication is set as the master 700, and the other is set as the slave 710. Master 700 and slave 710 transmit and receive using ASK modulation / demodulation waves. The data code is FM0 similar to passive RFID, and the communication frame format is similar to passive RFID, and FM0 preamble is transmitted before FM0 data. The FM0 data immediately after the FM0 preamble has a new meaning, the first bit immediately after the FM0 preamble is the bit indicating the active master or slave, and if it is “1”, it indicates that the active master is transmitting, “0” indicates that the active slave is transmitting. The following 16 bits indicate the number of bytes of data. The end of the data is CRC (Cyclic redundancy check).

  In this way, in active RFID communication, the communication frequency band is the same as the communication frequency of the passive RFID system, and the communication format is the FM0 format of ASK modulation / demodulation, so that the passive RFID reader / writer receiving circuit can be used as it is. . For this reason, it is possible to share the circuits of the active RFID communication and the passive RFID reader / writer, and the active RFID and the passive RFID reader / writer can be made into one chip and one module. FIG. 16 shows a configuration in which an active RFID and a passive RFID reader / writer are made into one chip and one module.

  Further, by defining the definition of the active RFID master or slave and the number of data bytes in the FM0 data portion immediately after the FM0 preamble, it becomes possible to improve master / slave communication and data reliability.

  Furthermore, active RFID master / slave communication is possible by matching the FM0 data part to the command / response system of ISO / IEC 18000-6 Type C, which is a communication standard for passive RFID reader / writers. FIG. 8 and FIG. 9 show a list of commands and response data in a communication procedure in which a command transmitted by the active RFID master and an active RFID slave that has received the command respond to the command.

  In this way, in the active RFID communication system, by extending the communication system of ISO / IEC 18000-6 Type C, which is a communication standard for passive RFID, the RF and Logic circuit of a general passive RFID reader / writer shown in FIG. 1 can be used as it is, and the RF and Logic circuit can be made into a one-chip LSI and a small wireless module using this one-chip LSI can be manufactured.

  The operation of FIG. 12 will be described as follows. The modulated RF signal received by the antenna (102 in FIG. 1) is amplified as RF IN by an LNA (Low Noise Amplifier) 1201 and input to the mixer 1202. The mixer 1202 multiplies the amplified modulated RF signal and the unmodulated RF signal output from the VCO (Voltage-Controlled Oscillator) 1210 to extract the modulated signal and outputs it to the filter 1203. The filter 1203 removes an unnecessary noise signal other than the modulation signal and outputs it to an ADC (Analog-to-Digital Converter) 1204. The ADC 1204 converts the modulation signal, which is an analog signal, into a digital signal and outputs it to the logic circuit 1205.

  As for the output of the modulated RF signal, digital transmission data is generated by the logic circuit 1205 and output to a DAC (Digital-to-Analog Converter) 1206. The DAC 1206 converts the digital transmission data into an analog signal and outputs it to the filter 1207. Filter 1207 removes unnecessary noise signals other than analog transmission data (modulated signal) and outputs the result to mixer 1208. The mixer 1208 generates a modulated RF signal by multiplying the modulated signal and the unmodulated RF signal output from the VCO 1210 and outputs the modulated RF signal to the transmission amplifier 1209. The transmission amplifier 1209 amplifies the modulated RF signal.

  FIG. 13 shows a configuration diagram of the received data detection 1211 in the logic circuit 1205 of FIG. The received modulation signal converted into a digital signal by the ADC 1204 in FIG. 12 is searched by the preamble detection 1301 for a preamble pattern in the input signal, and when the preamble is detected, the data excluding the preamble pattern is detected. Is output to FM0 data decoding 1302. The FM0 data decoding unit 1302 converts the input FM0 encoded data into an NRZ (Non Return to Zero) code and outputs it to the data length / CRC check 1303 and the response recognition 1304 at the same time. The data length / CRC check 1303 recognizes the data length from the transmitted data string and simultaneously performs the CRC check, and outputs the CRC check result to the response recognition 1304. The response recognition 1304 recognizes the response from the data string sent from the FM0 data decryption 1302 and at the same time recognizes whether the received data is normal or not based on the CRC check result sent from the data length / CRC check 1303. .

  FIG. 14 shows a configuration diagram of transmission data generation 1212 in the logic circuit 1205 of FIG. When transmitting a command to the passive tag or the active tag, the command generation 1401 generates an NRZ code data string excluding the preamble and CRC, and outputs it to the CRC generation and addition 1402. In CRC generation / addition 1402, CRC calculation is performed on the data sent from the command generation 1401 to generate CRC data, CRC data is added to the sent data, and output to the FM0 data encoding 1403 . The FMO data encoding 1403 converts the NRZ data sent from the CRC generation and addition 1402 into FM0 data and outputs it to the preamble addition 1404. Preamble addition 1404 adds a preamble to FM0 data sent from FMO data encoding 1403.

  FIG. 10 shows a communication sequence between the active RFID master and the slave. This communication sequence is a so-called beacon mode sequence in which an active RFID master fixed at a certain location notifies its presence to an active RFID slave carried by a person. The active RFID master periodically transmits its own ID. The active RFID slave receives periodically whether there is an active RFID master. When the active RFID slave moves closer to the active RFID master, it receives the ID of the active RFID master.

  Information other than the ID can be obtained by linking the received ID to the position on the map, store information, and the like.

(Embodiment 2)
The first embodiment is a one-way communication mode in active RFID master / slave communication. FIG. 11 shows an example of bidirectional communication between the active RFID master / slave.

  The active RFID master 1 sends a Query1 command. When the slave 1, 2, 3, 4,... N in the area that can receive the transmission of the active master 1 receives the Query1 command, it tries to transmit its ID to the master 1. Considering the case where there are multiple slaves, each slave should set the transmission timing after receiving the Query command with a random number, and the waiting time until transmission will not be transmitted from the master 1 command. Continue to receive Master 1 to confirm

  In FIG. 11, the response to Query 1 from Master 1 is the first response by Slave 2, and the response to the Query 1 command (slave 2 ID) is transmitted. The master 1 sends a Req_RN command because it has received a response from the slave 2. Thereafter, when the memory information other than the ID of the slave 2 is to be read or written to the memory, the master 1 transmits a Read command or a Write command. When the master 1 receives a response from the slave to each command, the master 1 transmits a Req_RN command indicating that the command has been received.

  When communication with the slave 2 is completed, the master 1 transmits a Query2 command to perform communication with the next slave. At this time, the slave 2 may not respond to the Query2 command depending on the setting value of the parameter RF_OFF in the Query1 command of the master 1 communicated earlier. In FIG. 11, the slave 3 responds to the Query2 command. Thereafter, the same communication with the slave 2 described above is also performed in the slave 1.

(Embodiment 3)
Since the passive RFID reader / writer function and the active RFID function can be made into one chip and one module, the memory used by each function can be shared.

  For example, when operating as a passive RFID reader / writer, in order to prevent frequency interference with other wireless devices, carrier sense is performed to determine at which frequency radio waves are emitted. And it communicates with passive RFID using the unused frequency. At this time, by storing the carrier sensed result in the memory, it is possible to determine the communication frequency by referring to the carrier sense result in the passive RFID reader / writer first when the active RFID is operated next time.

  A specific control flow is shown in FIG. When reading passive RFID using the passive RFID reader / writer function (communication start 1501), first, data in a designated area of the passive and active shared memory is read (memory read 1502). When the memory is read, it is determined whether there is write data in the specified area (write data presence / absence 1503), and if there is no write data, other wireless devices are not emitting radio waves in the frequency band to be used For example, the frequencies f1 to fn are scanned (frequency scan 1504). As a result of the frequency scan, the presence / absence of an empty frequency is determined (presence / absence of empty frequency 1505). If there is no empty frequency, the frequency scan 1504 is performed again. If there is a free frequency, the free frequency is written to the designated memory area (write the free frequency to memory 1506), and then communication is performed using one of the free frequencies (communication with free frequency 1507). When communication is completed, the communication is started.

  Next, it is assumed that active RFID communication is started (communication start 1501). When the memory read 1502 is performed, since the empty frequency in the passive RFID reader / writer was previously written in the memory, it is determined that there is write data based on the presence / absence of write data 1503. Then, one free frequency is selected from the data in which the free frequency is written, carrier sense is performed (fx, which is one of the free frequencies, is carrier sense 1508), and it is determined whether the free frequency is available ( Free? 1509). If it is an empty frequency, communication is performed at the empty frequency (communication 1510 at frequency fx). Is it free after communication is completed? In 1509, it is determined whether it is not empty (NO determination was not made) (NO in 1509? 1511), and if NO, there is a communication start waiting state. If there is NO, the designated memory area is cleared (no write data is set) (memory clear 1512), and a communication start waiting state is entered.

  As described above, by sharing the memory between the passive RFID reader / writer function and the active communication function, it becomes possible to quickly find a vacant frequency and accelerate the start of communication.

DESCRIPTION OF SYMBOLS 100 ... Passive RFID reader / writer 101 ... Passive RFID reader / writer main body 102 ... Antenna 103 ... RF (Radio Frequency) and Logic (logic) circuit 104 ... CPU (Central Processing Unit)
105 ... Memory 110 ... Electromagnetic wave (unmodulated wave or modulated wave),
120 ・ ・ ・ Passive RFID
121 ... IC chip 122 ... antenna 200 ... forklift 210 ... article 220 ... gate etc. for attaching a passive RFID reader / writer antenna 230 ... passive RFID reader / writer antenna 300 ... belt conveyor 310 ... Article 320 ... Passive RFID reader / writer main body 330 ... Passive RFID reader / writer antenna 400 ... Mobile phone 410 ... Module 1201 having both a passive RFID reader / writer function and a short-range wireless function LNA (Low Noise Amplifier)
1202 .. Mixer 1203 .. Filter 1204 .. ADC (Analog-to-Digital Converter)
1205 ·· Logic circuit 1206 · · DAC (Digital-to-Analog Converter)
1207-Filter 1208-Mixer 1209-Transmission amplifier 1210-VCO (Voltage-Controlled Oscillator)
1211 ··· Reception data detection block 1211 · · Transmission data generation block 1301 · · Preamble detection block 1302 · · FM0 data decoding block 1303 · · Data length · CRC check block 1304 · · Response recognition block 1401 · · Command generation block 1402 CRC generation and addition block 1403 FM0 data encoding block 1404 Preamble addition block 1501 Communication start function 1502 Memory read function 1503 Write data presence / absence determination function 1504 Frequency scan function 1505・ Availability determination function 1506 ・ ・ Write function 1507 to memory with free frequency ・ ・ Communication function 1508 with free frequency ・ ・ Function 1509 for carrier sensing one of the free frequencies ・ ・ Free Function 1510 for determining frequency 15 ··· Function 1512 for determining NO in communication function 1511 ·· 1509 at free frequency ··· Memory clear function

Claims (11)

  An RFID wireless device that has two functions: a reader / writer function for communicating with a passive RFID and an active RFID function for communicating as an active RFID. The reader / writer function is an RFID of the international standard ISO / IEC 18000-6 Type C. An RFID radio apparatus comprising: a communication means based on a communication connection procedure of the international standard ISO / IEC 18000-6 Type C. The RFID wireless device is
2. The RFID wireless device according to claim 1, wherein communication is performed as a passive RFID reader / writer or an active RFID.   2. The RFID radio apparatus according to claim 1, wherein a communication frequency band in a reader / writer function communicating with a passive RFID and a communication frequency band in an active RFID function communicating as an active RFID are the same. In the RFID wireless device,
2. The RFID wireless device according to claim 1, wherein a reader / writer function for communicating with a passive RFID and an active RFID function for communicating as an active RFID are formed as one chip.   3. The RFID wireless device according to claim 2, wherein the active RFID function has two functions: a master function for starting communication and a slave function for starting communication in accordance with an instruction from the active RFID master. In the active RFID master and slave functions,
6. The RFID wireless device according to claim 5, wherein the RFID wireless device has a communication frame format for identifying a master or a slave by transmission data transmitted from an active RFID master or slave. In the active RFID master and slave functions,
6. The RFID wireless device according to claim 5, further comprising a communication control procedure that enables communication between one active RFID master wireless device and one to a plurality of active RFID slave wireless devices.   The RFID wireless device that has two functions, the reader / writer function for communicating with the passive RFID and the active RFID function for communicating as the active RFID, shares the data memory contents as the passive RFID reader / writer and the data memory contents as the active RFID. The RFID wireless device according to claim 1, wherein the RFID wireless device is used.   It has two functions: a reader / writer function that has means to communicate with passive RFID that has communication means based on the international standard ISO / IEC 18000-6 Type C communication connection procedure, and an active RFID function that communicates as active RFID. An RFID system characterized by constructing a wireless network using a plurality of RFID wireless devices. RFID wireless devices
A first means having a reader / writer function for communicating with a passive RFID;
A second means having an active RFID function for communicating as an active RFID,
The communication frequency band in the reader / writer function is the same as the communication frequency band in the active RFID function,
The second means includes a master function that starts communication and a means that operates as a slave function that starts communication according to an instruction from the active RFID master,
The second means includes means for communicating using a communication frame format for identifying the master or slave by transmission data transmitted from the active RFID master or slave,
An RFID wireless device comprising means for sharing and storing data memory contents for operating as the reader / writer and data memory contents for operating as the active RFID. An active RFID communication control method in an RFID wireless device having a first means having a reader / writer function for communicating with a passive RFID and a second means having an active RFID function for communicating as an active RFID,
The communication frequency band in the reader / writer function and the communication frequency band in the active RFID function are set to be the same,
The second means operates either a master function for starting communication or a slave function for starting communication according to an instruction from the active RFID master,
The second means communicates using a communication frame format for identifying the master or slave by transmission data transmitted from the active RFID master or slave,
An active RFID communication control method characterized in that a data memory content for operating as the reader / writer and a data memory content for operating as the active RFID are shared and stored.

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