CN202771449U

CN202771449U - Open-type radio frequency identification system

Info

Publication number: CN202771449U
Application number: CN 201120326488
Authority: CN
Inventors: 钱国明; 陈涛; 陈毅华; 程玉才; 吴金娇
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-09-02
Filing date: 2011-09-02
Publication date: 2013-03-06
Anticipated expiration: 2021-09-02

Abstract

The utility model discloses an open-type radio frequency identification system composed of an open-type physical layer processing module (1) and an open-type hardware interface module (3). A baseband processing module (101) of the open-type physical layer processing module realizes the conversion between baseband of physical layer signals and intermediate frequency signals. An AD/DA module (102) realizes high-speed analog/digital conversion. A radio frequency transceiving module (103) is divided into a receiver part and a transmitter part. The open-type hardware interface (3) realizes the transmission of data signals and control signals of the open-type radio frequency identification system. The utility model provides the low-cost open-type platform system capable of configuring a systematic bottom level flexibly under different environments for an RFID (Radio Frequency Identification Device).

Description

A kind of open radio-frequency recognition system

Technical field

The utility model relates to radio-frequency recognition system, more specifically, relates to a kind of open type software radio platforms and carries out the REID of communicating by letter and between label and the read write line.

Background technology

REID (RFID, Radio Frequency Identification) formed by RFID label, rfid interrogator and antenna, its course of work is: rfid interrogator produces the electromagnetic wave of characteristic frequency and goes out from antenna transmission by the mode of Space Coupling, when the RFID label enter rfid interrogator read apart from the time, the RFID label receives request signal and the electromagnetic wave that rfid interrogator sends is carried out returning to rfid interrogator after the backscattering coupling.The RFID technology has been widely used in the numerous areas such as logistics and retail trade, Effective Raise the efficiency of management, and greatly saved human cost.But, present rfid interrogator all is the Black-box Testing system, this system only provides limited configuration, the ability that lacks autonomous process information, the top layer information that collects can only be transferred to background process, can not observe or revise MAC layer and the Physical layer of RFID, lack dirigibility, limit range of application.In prior art, " a kind of safe radio frequency identification system " (application number: 201010533310.1) just have such problem that on November 05th, 2010 announced.

In recent years, software and radio technique appears as to address the above problem thinking is provided.Software radio (Software Radio) is also referred to as software defined radio (Software Defined Radio), is based on the wireless communication systems structure of software definition.The basic thought of software radio is by being carried in the opening architecture on universalization, standardization, the modularized hardware, break away from the conventional wireless electricity mentality of designing that relies on hardware towards purposes fully, be that the major function such as air interface, frequency band of communication protocol is determined by software and finished, running parameter has programmable features, and operation is provided, controls, administer and maintain function by software, and need not change hardware fully.

Software radio couples together the formation general-purpose platform with modularization, standardization and unitized hardware cell with bus or exchanged form, by load-on module on this platform, unitized software, realizes various radio communication functions.But desirable software radio should be a kind of all radio of software programming, whole radio frequency able to programme (RF) wave band, channel access mode and Channel Modulation of comprising able to programme, basic thought is positioned as close to radio-frequency antenna with broadband A-D converter (A/D) and digital-to-analog converter (D/A) exactly.Software Radio platform commonly used adopts common hardware (for example: commercial server, common PC) as the platform of signal processing software, the signal of pure software is processed has very large dirigibility, can adopt general higher level lanquage (such as C/C++) to carry out software development, extendability and portable strong.But general hardware platform still less than on-site programmable gate array FPGA and the such specialized hardware of digital signal processor DSP, and mostly is the non-system that increases income aspect processing speed, efficient, volume, power consumption and real-time.Aspect specialized hardware, the relative DSP of FPGA, speed is fast, can better realize parallel processing; Power consumption is lower, has the dirigibility of capable of dynamic configuration, can improve performance and saving resource.

The utility model content

In order to solve the problem that conventional radio frequency identification read write line can not Treated Base information, the utility model proposes a kind of able to programme, radio-frequency recognition system that cost is low, basic thought based on software radio, use the open type software radio platforms, the top layer information that not only can collect is transferred to background process, can also observe or revise MAC layer and the Physical layer of RFID.

For realizing above-mentioned utility model purpose, a kind of open radio-frequency recognition system of the utility model is characterized in that this system is comprised of open physical layer process module, background processor and open hardware interface.

Open physical layer process module (1) comprises baseband processing module (101), AD/DA module (102), radio-frequency (RF) receiving and transmission module (103) and clock module (104).Baseband processing module (101) adopts fpga chip, and intermediate-freuqncy signal through becoming baseband signal after digital down converter and the stacked comb filter, becomes intermediate-freuqncy signal behind the baseband signal process pectination interpolater successively.AD/DA module (102) employing complex sampling, two groups of plural numbers are inputted and two groups of plural number outputs are matched to obtaining, for the conversion of finishing at different protocol and standards between high-frequency digital signal and the intermediate-freuqncy signal.Radio-frequency (RF) receiving and transmission module (103) is divided into receiver section and transmitter section, the two-way orthogonal local oscillation that transmitter is sent modulus of complex number analog signal into mixting circuit and phase circuit generation carries out exporting the amplification of rear class rf power amplifier to after mixing, the summation, request signal passes through aerial radiation the most at last, receive information that function returns the backscattering of RFID label successively by obtaining the I/Q complex base band signal behind two-stage variable gain amplifier, frequency mixer and the independent I/Q passage variable gain amplifier, be demodulated to simulating signal.Clock module (104) can use active crystal oscillator, perhaps passive crystal oscillator, perhaps pulse producer clocking is delivered to radio-frequency module in order to local oscillations to be provided with clock signal by the MMCX interface, and delivers to baseband processing module and AD/DA module in order to carry out clock synchronous.Data-signal in open physical layer process module (1) inside and control signal are transmitted by serial peripheral equipment bus interface and chip chamber serial transmission bus interface.Must use E2PROM to indicate between baseband processing module (101) and the radio-frequency (RF) receiving and transmission module (103) and match, and a plurality of E2PROM need to distinguish by the address when using simultaneously.

Background processor is realized configuration and control to described open physical layer process module, and the label information of RFID is back to gui interface, shows simultaneously the information of MAC layer and Physical layer.

Further, the information that radio-frequency (RF) receiving and transmission module in the open physical layer process module is returned the backscattering of RFID label receives, MAC layer and the PHY layer of inciting somebody to action by open hardware interface feed back to background processor, and the result is shown by gui interface.The user can pass through gui interface, recognizes intuitively MAC layer and PHY layer, and further improves on this basis accuracy rate and the reading speed of radio-frequency (RF) identification.

The utility model provides one powerful configurable open platform for the research of radio-frequency (RF) identification, open physical layer process module and background processor provide powerful arithmetic capability; The reconfigurability of open baseband processing module, open interface module and background processor provides stronger configurability, can analyze improvement to radio-frequency recognition system, improves accuracy rate and reading speed.

Description of drawings

Fig. 1 is a kind of embodiment theory diagram of the present utility model.

Fig. 2 is program flow diagram of the present utility model.

Fig. 3 is tag state transition diagram of the present utility model.

Embodiment

Below in conjunction with accompanying drawing embodiment of the present utility model is described, so that those skilled in the art understands the utility model better.What need to point out especially is that in the following description, when perhaps the detailed description of known function and design can desalinate main contents of the present utility model, these were described in here and will be left in the basket.

Embodiment 1, as shown in Figure 1, is a kind of embodiment theory diagram of the present utility model, is comprised of open physical layer process module 1, background processor 2 and open hardware interface 3.

Open physical layer process module 1 comprises baseband processing module 101, AD/DA module 102, overlaps radio-frequency (RF) receiving and transmission module 103 and clock module 104 more.

Baseband processing module 101 is a slice high-performance FPGA, extracts required narrow band signal from the digital intermediate frequency signal of input, and data rate is reduced so that data can pass on the background processor by open hardware interface.In real time signal processing, the data processing amount of bottom is larger, and processing speed is had relatively high expectations, and the signal bandwidth after the intermediate frequency process reaches tens MHz simultaneously, and the FPGA that therefore has the powerful processing power of high speed is the desirable device that carries out the software radio Base-Band Processing.On RX path, the FPGA digital signal that sampling obtains to ADC is carried out Digital Down Convert DDC, and data is carried out the extraction of variable bit rate by stacked comb filter CIC.On transmit path, what FPGA carried out data is the pectination interpolation, and Digital Up Convert DUC carries out 102 li of AD/DA modules.Fpga chip uses the Cyclone ITEP2C50 of ALTERA company, and the equivalent gate number is 2,150,000.In the situation of the communication system of finishing same effect, use EP2C50 can effectively reduce cost.

The radiofrequency signal that AD/DA module 102 will be got off from antenna reception again down coversion outputting analog signal is up-converted into radiofrequency signal to general AD module input with the intermediate-freuqncy signal of DA module output terminal, and goes out by antenna transmission.Must have higher sampling rate, enough bandwidth and higher sampling precision for the utility model ADC and DAC.In addition, in order to adapt to complicated electromagnetic environment, also larger dynamic range to be arranged.Process chip adopts the AD9963 of ADI company, it comprises 2 tunnel 12 high-speed AD converter (ADC, 100MS/s), 2 tunnel 12 high-speed A/D converter (DAC, 170MS/s) and auxiliary frequency converter, wave filter, amplifier, have 66.5dB signal to noise ratio (S/N ratio) (SNR), the advantage such as the lower 425mW super low-power consumption of sampling and outstanding phase place and amplitude balance at full speed.

Radio-frequency (RF) receiving and transmission module 103 is divided into receiver section and transmitter section, finishes the modulation of radio frequency identification signal, request signal is transmitted in the space, and receives the information that the backscattering of RFID label is returned, and is demodulated to simulating signal.

Clock module 104 serviceability temperature offset-type quartz crystal oscillator clockings, and deliver to baseband processing module and radio-frequency (RF) receiving and transmission module by clock bus.

Background processor 2 is realized configuration and control to described open physical layer process module, and the label information of RFID is back to the GUI interface, shows simultaneously the information of MAC layer and Physical layer.Adopt common PC to realize, realize programming and the modification of communication protocol with C Plus Plus, finish gui interface with wxPython.

Open hardware interface 3 uses USB, SPI, I in the utility model ²General total toe-in such as C, GPIO is realized data-signal in open physical layer process module and background processor and the open physical layer process inside modules and the transmission of control signal.

Embodiment 2, as shown in Figure 2, are program flow diagrams of the present utility model.Background processor 2 sends configuration information according to user instruction to baseband processing module 101, by open hardware interface 3 parameters such as channel width, Training, pulse width (PW), depth of modulation is transferred to modules.Baseband processing module 101 carries out Signal coding subsequently, and data stream is sent into AD/DA module 102, become the I/Q complex signal and send into radio-frequency (RF) receiving and transmission module 103 and finish intermediate-freuqncy signal to the conversion of radiofrequency signal, and by antenna transmission in the space.

On reverse path, RFID label in the aerial radiation scope is sensed the continuous wave (CW) that sends, mode by the backscattering coupling is back to read write line with label information, deliver to baseband processing module 101 by twice down coversion and DA conversion, and obtain correct label information by decoding, CRC check.By open hardware interface 3 label information is fed back to background processor 2 at last, and show by gui interface.

Embodiment 3, as shown in Figure 3, are tag state transition diagrams of the present utility model.Label is total " power down ", " preparation ", " identification " and " data interaction " one of four states in the course of the work.Label enters the working range of reader, and " power down " state enters " preparation " state from leaving the theatre.Reader allows all or part label that is in " preparation " state enter " identification " state by selection instruction.When the label that enters " identification " state during more than, will realize by the collision arbitration effective identification of label.

Above-described embodiment is used for the utility model of explaining; rather than the utility model limited; in the protection domain of spirit of the present utility model and claim, any modification and change to the utility model is made all fall into protection domain of the present utility model.

Claims

1. open radio-frequency recognition system, it is characterized in that, comprise open physical layer process module (1) and open hardware interface (3), open physical layer process module comprises baseband processing module (101), AD/DA module (102), radio frequency transceiver module (103) and clock module (104).

2. a kind of open radio-frequency recognition system according to claim 1, it is characterized in that, described baseband processing module (101) adopts fpga chip, intermediate-freuqncy signal through becoming baseband signal after digital down converter and the stacked comb filter, becomes intermediate-freuqncy signal behind the baseband signal process pectination interpolater successively.

3. a kind of open radio-frequency recognition system according to claim 1, it is characterized in that, described radio-frequency (RF) receiving and transmission module (103) is divided into receiver section and transmitter section, the two-way orthogonal local oscillation that transmitter is sent modulus of complex number analog signal into mixting circuit and phase circuit generation carries out mixing, exporting the rear class rf power amplifier after the summation to amplifies, request signal passes through aerial radiation the most at last, the information that the reception function is returned the backscattering of RFID label is passed through the two-stage variable gain amplifier successively, obtain the I/Q complex base band signal behind frequency mixer and the independent I/Q passage variable gain amplifier, be demodulated to simulating signal.

4. a kind of open radio-frequency recognition system according to claim 1 is characterized in that, described AD/DA module (102) adopts complex sampling, and two groups of plural numbers are inputted and two groups of plural number outputs are matched to obtaining.

5. a kind of open radio-frequency recognition system according to claim 1, it is characterized in that, described clock module can use active crystal oscillator, perhaps passive crystal oscillator, perhaps pulse producer clocking, clock signal is delivered to radio-frequency module in order to local oscillations to be provided by the MMCX interface, and deliver to baseband processing module and AD/DA module in order to carry out clock synchronous.

6. a kind of open radio-frequency recognition system according to claim 1, it is characterized in that, the data-signal in described open physical layer process module (1) inside and control signal are transmitted by serial peripheral equipment bus interface and chip chamber serial transmission bus interface.