CN105678352A8 - A kind of remote high speed data transmission system based on ultrahigh frequency RFID - Google Patents

Abstract

The invention discloses a kind of remote high speed data transmission system based on ultrahigh frequency RFID, including: host computer, reader and electronic tag；Described electronic tag includes: DC power supplier, DC-DC module, ADC, fpga chip, modulation-demodulation circuit, antenna；The active ultrahigh frequency electronic label identification distance that the present invention uses is up to hundred meters of magnitudes, realize Long-range Data Transmission, analogue signal in the high-speed data signal that height sensors is inputted by ADC is converted to digital signal, these data are stored in internal SRAM by FPGA, then send the data to reader with relatively low wireless data transmission rate；And reader and employing cycle through reading order mode, one time reading order only reads a small amount of data, after device to be read receives the data of generation, retransmit next reading order and read next group data, until completing the transmission of total data, improve the reliability of data transmission, and be greatly promoted data transmission efficiency.

Description

A long-distance high-speed data transmission system based on UHF RF ID

technical field

[0001] The present invention belongs to the technical field of RFID technology and application system design, in particular to a long-distance high-speed data transmission system based on UHF RFID.

Background technique

Radio frequency identification (Rad1 Frequency Identification, RFID) technology is a non-contact automatic identification technology, and its working principle is the antenna of the RFID reader and the RFID electronic label (also known as electronic label) attached to people or things. The antenna realizes radio frequency communication and information exchange through electromagnetic wave coupling (also known as electromagnetic wave backscattering) or inductive coupling, and the reader automatically collects and identifies the target identity and other information stored in the RFID electronic tag.

[0003] The workflow of the RFID system is to sequentially connect the RFID electronic tags, readers, and host computers/backgrounds in the system to complete the collection, transmission, processing and management of information. First, the RFID reader sends out radio signals through its antenna to form an effective identification range of the reader. When the RFID electronic tag enters this identification range, the RFID electronic tag receives the electromagnetic wave signal from the reader and is activated and performs command analysis. , according to the command instructions, the data information stored in the electronic tag is sent out through its antenna; then the antenna of the reader receives the radio frequency signal from the RFID electronic tag, and the reader demodulates and decodes the signal, through the host computer/background or reading After the writer judges the validity of the received information, it issues different instructions for different settings, such as reading or rewriting the information in the memory of the electronic tag; finally, the reader transmits the processed data information to the host computer/background The system, the host computer/background update the information in real time, and share the information with users.

[0004] After years of research and practice, RFID systems have been implemented in a variety of ways. According to different operating frequencies, RFID systems can be divided into low frequency (Low Frequency, LF), high frequency (High Frequency, HF), ultra-high frequency (Ultra-high Frequency, UHF) and microwave (Microwave, MW) several type. The low-frequency RFID system works in the 30KHz~300KHz frequency band, and the typical operating frequencies are 125KHz, 133KHz and 134.2KHz. The low-frequency electronic tag is generally a passive electronic tag, and can have multiple shapes. Its working energy is obtained by inductive coupling (transformer coupling) between the antenna (coil) of the electronic tag and the antenna (coil) of the reader. When exchanging data with the reader, the electronic tag must be located in the near field area radiated by the reader antenna, that is, the reader antenna and the RFID electronic tag antenna have strong directivity. Due to the high penetration of low-frequency magnetic fields, the identification distance is not affected by the properties of surrounding accessories (except metals). However, compared with passive electronic tags in other frequency bands, the antenna cost is higher, the reading and writing distance is short, the speed is slow, and the anti-collision ability of multi-electronic tags is weak. The high-frequency RFID system works in the 3MHz~30MHz frequency band, and the typical operating frequency is 13.56MHz. Generally, it is also a passive electronic tag. The working principle is exactly the same as that of the low-frequency RFID system. Compared with the low-frequency RFID system, the high-frequency RFID system has improved the data transmission rate and the internal storage space of the electronic tag, but although its identification distance has been improved compared with the low-frequency RFID system, reaching the order of 1 meter, it still cannot meet the long-distance requirements. identification requirements. The UHF RFID system works in the frequency range of 300~1000MHz, and the typical working frequency bands are 433.05MHz~434.79MHz, 840MHz~845MHz, and 860MHz~960MHz. Compared with low-frequency and high-frequency RFID systems, UHF RFID systems have higher data transmission rates and larger storage space for electronic tags, and their anti-collision capabilities have also been significantly improved. Compared with the recognition distance of the high-frequency RFID system of the order of 1 meter, the recognition distance of the UHF RFID system can reach the order of 10 meters, and the recognition distance of the UHF RFID electronic tag with a battery can reach the order of 100 meters; Compared with microwave and millimeter wave RFID systems, UHF RFID systems have stronger anti-interference ability, more mature technology and lower cost. Therefore, it is very suitable for high-speed, long-distance, multi-target RFID system applications.

[0005] UHF RFID electronic tags have two types of passive and active, and the difference is mainly in that the energy supply methods of the RFID electronic tags are different, and the identification distances are different. There is no power supply inside the passive sticky note. When working, the radio frequency signal emitted by the reader is rectified into DC energy to supply the corresponding circuit, and the radio frequency signal is demodulated at the same time, and the memory data of the electronic tag is backscattered. Modulate the radio frequency carrier from the reader way to transmit to the reader. Since electronic tags can only extract energy from radio frequency signals, the identification distance is limited. Active RFID electronic tags have a built-in power supply, and their working energy comes from the built-in power supply. It does not need to return data through a backscatter modulation mechanism, and can actively initiate radio frequency communication. Compared with passive electronic tags, active electronic tags have a longer distance. Identify distance and communication reliability.

[0006] However, the existing RFID technology generally only has the function of identification, and there are problems such as single function and narrow application field. In addition, although the existing technology has developed to the combination of RFID and sensor technology, it is limited by the data rate regulations of RFID international standards. The existing technology generally combines RFID with low-speed sensors, and RFID and high-speed sensors have not yet appeared. combined technology.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the present invention proposes a kind of long-distance high-speed data transmission system based on UHF RFID, combined with the technology of UHF RFID and wireless high-speed long-distance data transmission, applied to high-speed sensor information wireless transmission It has greatly expanded the functions and application fields of the RFID system.

Technical scheme of the present invention is: a kind of long-distance high-speed data transmission system based on UHF RFID, comprising: reading system and electronic label, described reading system comprises: upper computer and reader; Described upper computer controls The reader sends a sensor information collection command to the electronic tag; the electronic tag collects and quantifies the high-speed sensor data according to the sensor information collection command sent by the reader, and the electronic tag sends the quantified data to the reader through wireless transmission , the reader transmits the data to the upper computer for display.

Further, described electronic label comprises: DC power module, DC-DC module, VGA input module, ADC module, FPGA chip, modulation and demodulation circuit, antenna, described DC power module converts AC power into DC voltage , the DC-DC module is used to generate a first voltage and a second voltage, the first voltage is used to power the ADC module, the second voltage is used to power the FPGA chip and the modulation and demodulation circuit, the ADC The module converts the analog signal into a digital signal under the control of the FPGA chip, and transmits the digital signal to the FPGA chip. The FPGA chip stores the digital signal transmitted by the ADC module in the internal SRAM unit, and the antenna is in the FPGA chip. The digital signal is sent to the reader under the control of the

[0010] Further, the reader adopts the mode of cyclically sending read commands.

Further, the process of reader identification electronic tag is: reader/writer sends Select order to electronic tag, sets electronic tag attribute and sign; Reader sends Query order to electronic tag, electronic tag returns RN16, electronic tag The state changes to Reprint state; the reader sends an ACK command to the electronic tag, and the electronic tag returns EPC to the reader.

Further, reader after identifying electronic label, reader sends Req_RN order to electronic label, makes electronic label enter open or protection state, reader receives the RN16 that electronic label returns simultaneously, and RN16 is used as handle Included in the Sensor_collect command and sent to the electronic tag.

Beneficial effect of the present invention: a kind of long-distance high-speed data transmission system based on UHF RFID of the present invention, comprises: upper computer, reader and electronic label; Described electronic label comprises: DC power module, DC- DC module, ADC module, FPGA chip, modulation and demodulation circuit, and antenna; the active ultra-high frequency electronic label used in the present invention has a recognition distance of up to 100 meters, and realizes long-distance data transmission. The analog signal in the signal is converted into a digital signal, the FPGA stores the data in the internal SRAM, and then sends the data to the reader at a relatively low wireless data transmission rate; and the reader sends the read command cyclically, once The read command only reads a small amount of data. After the reader receives the generated data, it sends the next read command to read the next group of data until the transmission of all data is completed, which improves the reliability of data transmission and improves the reliability of data transmission. Greatly improve data transmission efficiency.

Description of drawings

[0014] FIG. 1 is a schematic diagram of the system structure provided by the present invention.

[0015] Fig. 2 is a flow chart of the communication processing between the reader and the tag provided by the present invention.

[0016] FIG. 3 is the sensor information collection provided by the present invention, the interaction process of the reader and the label.

[0017] FIG. 4 is an electronic label system architecture provided by the present invention.

detailed description

Below in conjunction with accompanying drawing and specific embodiment, the present invention will be further described:

As shown in Figure 1, a kind of long-distance high-speed data transmission system based on UHF RFID of the present invention comprises: upper computer, reader and electronic label; Described electronic label comprises: DC power module, DC- DC module, ADC module, FPGA chip, modulation and demodulation circuit, antenna; control the reader to send the sensor information collection command through the host computer, after the electronic tag receives the sensor information collection command, the FPGA controls the ADC to sample and quantify, and the ADC The output data is stored in the internal SRAM of the FPGA, the reader sends a command to read the electronic tag information, and the electronic tag sends the sensor data stored in the SRAM to the reader wirelessly, and uploads the data to the host computer for display. The electronic chip used in the present invention is an ultra-high frequency RFID chip.

The present invention realizes digital control logic by FPGA chip, and FPGA chip is used to realize ISO18000-6C agreement and self-defined data transmission and processing order, be specially: satisfy the digital baseband processing circuit of relevant standard and the collection to ADC high-speed data , processing and sending control. The internal SRAM memory of the FGPA chip has a read and write speed of not less than 100Mb/s, meeting the storage requirements for high-speed data. FPGA is used for

[0021] The analysis/processing of the relevant standard commands by the digital control logic and the collection/processing flow of the ADC output data are shown in Figure 2. When the reader sends the inventory command, the electronic tag processes the command and returns the corresponding data; when the reader sends the sensor information collection command Sensor_collect, the digital baseband circuit controls the ADC to sample and quantify the high-speed sensor information to realize the analog signal in the high-speed sensor. Converted to a digital signal, the digital baseband circuit stores the digital signal obtained after ADC quantization into the internal SRAM memory of the FPGA chip. The reader sends the READ command to read the sensor information stored in the memory, the electronic tag sends the sensor data to the reader through the air interface, that is, wirelessly, and the FPGA transfers the digital signal to the data at a relatively low wireless data transmission rate. sent to the reader.

Before the reader sends the sensor information collection command Sensor_col Iect to the electronic tag, the reader should first send a series of inventory commands to identify the electronic tag, specifically the Select-Query-RNie-ACK-EPC interaction shown in Figure 3 In the process, when the electronic tag returns to the EPC, the reader recognizes the electronic tag chip, and the electronic tag chip switches to the confirmation state at the same time. After the reader recognizes the electronic tag, it needs to send the Req_RN command to make the electronic tag enter the open or protected state. At the same time, it receives the RN16 returned by the electronic tag and sends it as a handle into the Sensor_collect command. Here, the RN16 is included as a handle in the Sensor_collect command. The command is the communication mechanism stipulated by the IS018000-6C protocol. It is an existing technology and will not be described in detail here. After the electronic tag receives this command, it will notify the ADC to sample and quantify the analog signal in the high-speed sensor, complete information collection, Save and send process.

The Select-Query-RNie-ACK-EPC interaction process shown in Fig. 3 is specifically: reader-writer sends Select order to electronic tag, sets electronic tag attribute and sign; Reader-writer sends Query order to electronic tag, The electronic tag returns to RN16, and the electronic tag status changes to the Reply state; the reader sends an ACK command to the electronic tag, and the electronic tag returns EPC to the reader.

In the described reader system, the reader is mainly realized by the data transmission command that can support self-definition by configuring the relevant standard reader/writer, and adopts the cyclic transmission reading command mode, and a reading command only reads a small amount of After the reader receives the generated data, it sends the next read command to read the next group of data until the transmission of all data is completed.

Electronic tag realizes wireless communication by antenna and RFID reader; demodulation circuit demodulates the reader/writer signal from the radio frequency signal received by antenna in the mode of diode detection; modulation circuit converts electronic tag with backscatter modulation mode The returned data is modulated into the radio frequency band.

[0026] This example will further illustrate the content and effect of the present invention by applying a kind of long-distance high-speed data transmission system based on UHF RFID of the present invention in the wireless transmission of data information in the VGA signal line.

[0027] In this embodiment, the following functions are mainly realized: a radio frequency identification function, which can obtain the identity information of the target object from a long distance. The electronic tag is used to collect the image data information of the R line in the VGA signal line with a resolution of 640*480, and the real-time acquisition of the data in the VGA signal line is realized through the wireless high-speed data transmission between the reader and the electronic tag. The wireless transmission standard conforms to the IS018000-6C UHF RFID standard, and the wireless data transmission rate is not less than 250Kbps.

[0028] FIG. 4 is the system architecture of the RFID electronic label, which is composed of a DC power supply module, a DC-DC module, an ADC, an FPGA, a modulation and demodulation circuit and an antenna. The DC power module converts the 220V AC power into a 12V DC voltage, and then generates 3.3 V and 5 V through the DC-DC module to supply power to the ADC, FPGA and modulation and demodulation circuits respectively; the electronic tag is realized by an antenna and an RF ID reader Wireless communication; the demodulation circuit demodulates the reader signal from the radio frequency signal received by the antenna in the way of diode detection; the modulation circuit modulates the data returned by the electronic tag to the radio frequency band in the way of backscatter modulation; the ADC converts the VGA signal The analog signal in the line R line is converted into a 5-bit digital signal, and the FPGA stores the data in the internal SRAM, and then sends the data to the reader at a relatively low wireless data transmission rate, and uploads the data to the host computer for display.

Traditional RFID system can only transmit low-speed data and external low-speed sensor (such as temperature sensor, data rate <1Mbps), the present invention can handle high-speed sensor (data rate>30Mbps), high-speed sensor data transmission clock is 25.175MHz, and The wireless data rate of the RFID system is 40-640kbps. Through the design of the present invention, a relatively low-speed RFID system is adopted to solve the problem of wireless transmission of high-speed sensor information.

[0030] The analog signal R from the high-speed sensor and the horizontal synchronization signal and the vertical synchronization signal are transmitted to the ADC through the VGA signal line. Since the module is composed of analog circuits, it is easy to generate noise, so the interface device should be placed as close as possible to the ADC. In this system, the resolution of the VGA signal is 640*480, the refresh rate is 60Hz, the line frequency is 31.5KHz, and the amount of R component data corresponding to one frame of image is 1.5M bits.

Adopt the ADC module specially facing VGA signal conversion in this example, this module adopts the chip that collects RGB image signal specially, output pixel clock range can be from 12MHz to 140MHz simultaneously, the user only needs to provide the power supply of 3.3v, whole module firstly The sampled line frequency and field frequency are determined from the synchronization signal, and then the pixel clock is determined by the line frequency and internal registers. The internal PLL of the ADC module generates the pixel clock, converts the analog signal R input by the VGA signal line into a 5-bit digital video signal, and adjusts the sampling effect of the image through a series of registers. The resolution of the VGA signal to be processed by the system developed for this example is 640*480, the refresh rate is 60Hz, the corresponding ADC output signal is 5 bits, and its pixel clock frequency is 25.175MHz.

[0032] A standard reader read command can only read a maximum of about 3K bits of data packets at a time. However, due to environmental interference, long-distance wireless transmission of 3K bits data packets has a high error rate. The amount of sensor data in this system is far greater than 3Kbits, and the standard reading commands cannot meet the application requirements of this system. For example, in this embodiment, the amount of sensor data is 1.5M bits, and the standard read command cannot meet the application requirements of this example. Therefore, the method of cyclically sending read commands is adopted here. One read command only reads 32bytes of data. After the reader receives 32bytes of data, it sends the next read command to read the next 32bytes of data until all 1.5M data is completed. The transmission of bits data improves the reliability of data transmission and improves the efficiency of data transmission in this way.

The present invention realizes high-speed long-distance data transmission based on UHF RFID technology, will greatly expand the function and application range of UHF RFID system, and fully satisfy the long-distance identification and data collection of important equipment in military and civil fields. It can significantly improve the management efficiency of important assets and equipment.

Those of ordinary skill in the art will appreciate that the embodiments described herein are to help readers understand the principles of the present invention, and it should be understood that the protection scope of the present invention is not limited to such special statements and embodiments . Various modifications and variations of the present invention are possible for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims (5)

1. a long-distance high-speed data transmission system based on UHF RFID, is characterized in that, comprises: reading system and electronic label, described reading system comprises: upper computer and reader; Described upper computer controls reader to electronic The tag sends a sensor information collection command; the electronic tag collects and quantifies high-speed sensor data according to the sensor information collection command sent by the reader, and the electronic tag sends the quantified data to the reader through wireless transmission, and the reader will The data is sent to the upper computer for display. 2. a kind of long-distance high-speed data transmission system based on UHF RFID according to claim 1, is characterized in that, described electronic label comprises: DC power module, DC-DC module, ADC module, FPGA chip, modulation and demodulation The DC power supply module converts the AC power supply into a DC voltage, the DC-DC module is used to generate a first voltage and a second voltage, the first voltage is used to power the ADC module, the first voltage The second voltage is used to power the FPGA chip and the modulation and demodulation circuit. The ADC module converts the analog signal output by the high-speed sensor into a digital signal under the control of the FPGA chip, and transmits the digital signal to the FPGA chip. The FPGA chip The digital signal transmitted by the ADC module is stored in the internal SRAM unit, and the antenna sends the digital signal to the reader under the control of the FPGA chip. 3. a kind of long-distance high-speed data transmission system based on UHF RFID according to claim 1, described reader adopts the mode of cyclically sending read command. 4. a kind of long-distance high-speed data transmission system based on UHF RFID according to right 1, the process of reader identification electronic label is: reader/writer sends Select order to electronic label, sets electronic label property and sign; The reader sends a Query command to the electronic tag, the electronic tag returns to RN16, and the electronic tag status changes to the Reply state; the reader sends an ACK command to the electronic tag, and the electronic tag returns EPC to the reader. 5. a kind of long-distance high-speed data transmission system based on UHF RFID according to claim 4, after the reader identifies the electronic tag, the reader sends the Req_RN command to the electronic tag, so that the electronic tag enters an open or protected state, At the same time, the reader receives the RN16 returned by the electronic tag, and incorporates RN16 as a handle into the Sensor_collect command and sends it to the electronic tag.