WO2011113216A1 - 移动射频装置、射频ic卡及射频存储卡 - Google Patents
移动射频装置、射频ic卡及射频存储卡 Download PDFInfo
- Publication number
- WO2011113216A1 WO2011113216A1 PCT/CN2010/071416 CN2010071416W WO2011113216A1 WO 2011113216 A1 WO2011113216 A1 WO 2011113216A1 CN 2010071416 W CN2010071416 W CN 2010071416W WO 2011113216 A1 WO2011113216 A1 WO 2011113216A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- frequency
- circuit
- low frequency
- card
- mobile radio
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q20/00—Payment architectures, schemes or protocols
- G06Q20/30—Payment architectures, schemes or protocols characterised by the use of specific devices or networks
- G06Q20/32—Payment architectures, schemes or protocols characterised by the use of specific devices or networks using wireless devices
- G06Q20/327—Short range or proximity payments by means of M-devices
- G06Q20/3278—RFID or NFC payments by means of M-devices
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
- G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
- G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
- G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
- G06K19/0723—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
- G06K19/0724—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs the arrangement being a circuit for communicating at a plurality of frequencies, e.g. for managing time multiplexed communication over at least two antennas of different types
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/12—Supports; Mounting means
- H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
- H01Q1/2208—Supports; Mounting means by structural association with other equipment or articles associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q7/00—Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
Definitions
- the present invention relates to the field of communications, and in particular, to a mobile radio frequency device, a radio frequency IC card, and a radio frequency memory card. Background technique
- a radio frequency function (referred to as a radio frequency SIM card) is added to a subscriber identity module SIM (Subscr iber Ident module) card in a mobile terminal, or a short-range communication module is added on a mobile terminal motherboard to implement a mobile terminal near
- SIM Subscriber identity module
- FC Near Field Communication
- the radio frequency SIM card adopts UHF (Ultra tra High Frequency).
- UHF Ultra tra tra High Frequency
- the radio frequency SIM card adopts UHF (Ultra tra High Frequency).
- UHF Ultra tra tra High Frequency
- ISM common frequency band ie industrial, scientific and medical frequency bands
- its operating frequency is very high, the size of the antenna is small, and a small antenna can be placed in the SIM card to transmit A signal of sufficient strength, even if the radio frequency SIM card is embedded in the mobile terminal, the radio frequency signal can still be transmitted from the mobile terminal.
- the industry mainstream RF (Radio Frequency) transceiver chip can be used to receive the receiver without additional amplification.
- the radio frequency signals of most mobile terminals enable the mobile terminal to have short-range communication functions without any structural changes to existing mobile terminals.
- different mobile terminals have great differences in the transmission effect of radio frequency signals due to different internal structures.
- the radio frequency SIM card radio communication distance of a mobile terminal with strong transmission may reach a distance of several meters, and the radio frequency SIM card communication distance of a mobile terminal with weak transmission. Only a few centimeters can be reached.
- NFC Another mobile payment technology, evolved based on the I S014443 standard contactless card technology. The fundamental point is that both transmit signals and energy using a magnetic field of 1.56 MHz. The main problems of NFC technology are:
- the mobile terminal must be modified to achieve reliable two-way data communication.
- the magnetic field line of NFC cannot be integrated into the SIM card or SD card (Secure Di ta ta l Memory Card) /TF (TransFLa sh, flash memory) Cards for mobile terminals such as cards.
- the size of the coupled coil is relatively large.
- NFC requires that the antenna cable in the mobile terminal is sufficiently large, and the size cannot be placed in a card for a mobile terminal such as an SIM card or an SD/TF card, and not only the metal and other conductive materials on the mobile terminal. Objects can seriously interfere with the receiving and load modulation effects of the antenna.
- the mobile phone In order to achieve good communication performance in near field communication, the mobile phone must be customized to optimize the effect of the antenna.
- the retrofit point is, for example, placing the multi-turn antenna of the card on the battery back cover of the mobile terminal, or guiding the antenna from the terminal main board to the back of the battery through a flexible PCB, the area of the antenna is equivalent to the size of the ordinary battery, and the back cover of the mobile phone Cannot be made of metal.
- the 1 56 used by NFC requires calibration to be used for distance control.
- Figure 1 shows the voltage-distance curve of the test in the case where the coil receiving circuit is placed in various mobile terminals and the carrier is kept constant at the same 14443 P0S machine.
- the signal strength value is the necessary amplification of the receiving antenna induced voltage. After the value, the magnification remains constant, just pay attention to the relative change in intensity with distance. It can be seen that the field strength difference received by different terminals is > 30dB, and the field strength change from 1 cm to 10 cm in the same terminal is about 25 dB, and the field strength change caused by the difference in mobile phones has exceeded The field strength changes within the control range of l cm to 10 cm distance, so it is impossible to control the distance of each terminal by the same threshold, that is, the non-calibrated distance control cannot be realized. Summary of the invention
- the technical problem to be solved by the present invention is to provide a mobile radio frequency device such that a mobile terminal provided with the mobile radio frequency device can implement a credit card transaction such as electronic payment.
- the present invention provides a mobile radio frequency device comprising at least one low frequency magnetic induction circuit, at least one low frequency amplifying circuit, at least one threshold determination and demodulation circuit, at least one second main processor, and at least one radio frequency transceiver
- the circuit and the at least one radio frequency antenna, the low frequency magnetic induction circuit, the low frequency amplification circuit, the threshold determination and demodulation circuit, the second main processor, the radio frequency transceiver circuit, and the radio frequency antenna are connected in series; wherein the low frequency magnetic induction circuit and the low frequency
- the low frequency receive link consisting of the amplifying circuit, the threshold decision and the demodulation circuit operates at a frequency below the highest frequency f O of the preselected system without calibration.
- the mobile radio frequency device may further have the following characteristics: the low frequency magnetic induction circuit is a coil, and the product of the conversion gain of the low frequency magnetic induction circuit and the amplification factor of the low frequency amplification circuit is farthest from the system applied by the mobile terminal where the mobile radio device is located.
- the system preset value corresponding to the swipe distance, the volume of the low frequency receiving link depends on the conversion gain of the low frequency magnetic induction circuit and the amplification factor of the low frequency amplifying circuit, and the volume of the low frequency receiving link increases with the conversion gain of the low frequency magnetic induction circuit. Increase, or increase with the decrease of the amplification factor of the low frequency amplification circuit.
- the mobile radio frequency device may further have the following feature: the highest frequency f O of the system without calibration work is in a special low frequency band or a low frequency band or a low frequency band, and the frequency range of the special low frequency band is 300 Hz - 3000 Hz.
- the frequency range of the very low frequency band is 3KHz ⁇ 30KHz, and the frequency range of the low frequency band is 30 KHz ⁇ 300KHz.
- the above mobile radio frequency device may further have the following characteristics: the highest frequency f O of the system without calibration work is in a frequency range of 300 Hz to 50 kHz.
- the above mobile radio frequency device may further have the following characteristics: the highest frequency f O of the system without calibration work is 500 ⁇ , 1 ⁇ , 1 ⁇ 5 ⁇ , 2 ⁇ , 2 ⁇ 5 ⁇ , 3 ⁇ , 4 ⁇ , 5 ⁇ , 10 ⁇ , 20 ⁇ or 30 ⁇ .
- the mobile radio frequency device may further have the following features: the threshold determination and demodulation circuit is composed of a comparison circuit and a decoding circuit connected to each other. Further, the mobile radio frequency device may further have the following features: the threshold determination and demodulation circuit is composed of a sequentially connected comparison circuit, a demodulation circuit, and a decoding circuit.
- the mobile radio frequency device may further have the following features: the second main processor and the processor in the SIM/UIM/USIM/TF/SD/MMC card are the same shared processor.
- the mobile radio frequency device may further have the following characteristics: the mobile terminal is a mobile phone, a personal digital assistant PDA or a notebook computer.
- the present invention also provides a radio frequency IC card comprising the mobile radio frequency device of any of the above.
- the present invention also provides a radio frequency memory card comprising the mobile radio frequency device of any of the above.
- the present invention also provides a method for determining the highest frequency f O of the system in the above mobile radio frequency devices without calibration work, comprising the following steps:
- Step a1 determining a distance control target (Din, Dv) of the system, where the system includes at least one mobile radio device and at least one card reader, wherein Din represents all mobile radios loaded in the range of 0 ⁇ Din
- Din represents all mobile radios loaded in the range of 0 ⁇ Din
- the terminal of the device ensures that the card can be swiped, Dv indicates the range of distance fluctuation, and the distance is allowed to be swiped within the range of Din ⁇ (Din+Dv), and the range of distance greater than Din+Dv is not allowed to be swiped;
- Step a2 determining a fluctuation range ⁇ ⁇ of the detection voltage in the mobile radio frequency device caused by the card reader; step a3, determining a fluctuation range S c of the detection voltage caused by the mobile radio frequency device itself;
- Step a4 testing the voltage distance curve of each typical terminal and obstacle at the f frequency, the f frequency is any frequency in the special low frequency band or the low frequency band or the low frequency band, and the frequency range of the special low frequency band is 300 Hz ⁇ 3000 Hz, the frequency range of the frequency band is 3KHz ⁇ 30KHz, and the frequency range of the low frequency band is 30 KHz - 300KHz;
- Step a5 determining, by the distance control target (Din, Dv), the detected voltage in the mobile radio frequency device
- the fluctuation range ⁇ ⁇ , ⁇ ⁇ is equal to the voltage value corresponding to the Din point on the voltage distance curve with the slope of the average field strength attenuation curve obtained from the voltage distance curve of each typical terminal and obstacle, and the voltage corresponding to the (Din+ Dv ) point Difference in value;
- Step a7 calculating the maximum field strength difference ⁇ at each distance point between each typical terminal and the obstacle in the distance control range. If ⁇ is greater than ⁇ ⁇ , the frequency f is decreased, and step a4 is performed; if ⁇ is smaller than ⁇ ⁇ , then increasing Frequency f, go to step a4; if ⁇ is equal to ⁇ ⁇ , the current test frequency f is equal to the highest frequency f0 of the system without calibration work.
- the present invention also provides a low frequency alternating magnetic field distance control method for a mobile terminal comprising the mobile radio frequency device according to any of the preceding claims, the method comprising the following steps:
- Step b if the electrical signal Vo converted by the low-frequency alternating magnetic field signal is greater than the preset comparison voltage threshold Vt, the ID of the card reader is decoded, the radio frequency communication is entered, and the IDr is coupled to the mobile radio device through the radio frequency channel.
- the unique identification code IDc is transmitted to the card reader while continuously monitoring the low frequency alternating magnetic field signal;
- Step c performing radio frequency communication, splitting the radio frequency communication data into multiple data packets and transmitting and receiving in stages, and checking whether the Vo is greater than Vt every time the radio frequency is received or sent, if yes, continuing the radio frequency communication until the transaction ends, otherwise the transaction is ended.
- RF communication return to step &.
- the low frequency alternating magnetic field distance control method may further have the following features, and the method for determining the magnetoelectric conversion gain in the step a is as follows:
- Step al determining a magnetic induction gain K, selecting a low frequency magnetic induction circuit on the carrier of the mobile radio device, thereby selecting a magnetic induction gain K;
- the gain A of the low frequency amplifying circuit is arbitrarily selected under the following principle: 1) The magnetic induction intensity Br received by the mobile radio frequency device at any position is less than the value required by the system safety specification;
- the mobile radio frequency device is placed in one or more carriers specified by the system, and the signal-to-noise ratio of the magnetic induction signal after the magnetoelectric conversion is greater than the SNR;
- the low frequency alternating magnetic field distance control method may further have the following feature, wherein the signal to noise ratio SNR is greater than 5 in the step a2.
- the low frequency alternating magnetic field distance control method may further have the following characteristics: the low frequency magnetic induction circuit is a line, and the mobile radio frequency device is placed on a SIM card, a UIM card, a USIM card, a TF card, an SD card, or an MMC card. In the middle, the number of turns of the line is 1 ⁇ 20 ⁇ , and the gain A of the frequency amplifying circuit is greater than 100.
- the low frequency alternating magnetic field distance control method may further have the following features.
- the magnetoelectric conversion has an error, that is, Vo has fluctuation, and the fluctuation range is S c (db), and the error S c (db)
- the choice and control method are as follows:
- ⁇ c 2 ⁇ 6dB
- the control method of ⁇ c includes the following steps:
- the attenuation of the standard obstacle in the error control system is ⁇ ⁇ /2.
- Step 601 The standard card reader emits a low-frequency alternating magnetic field signal with a constant amplitude or a constant differential amplitude at a fixed distance and a position, and the magnetic value of the magnetic field after the magnetic field of the amplitude value Bgate or the amplitude value B.RATEgate of the system Is a voltage signal Vo near the amplitude of Vt;
- Step 602 Determine a Vo range (Vt_S cx/2, Vt- ⁇ cx/2), where ⁇ cx ⁇ ⁇ c;
- Step 603 Measure an output electrical signal Vo of the low frequency amplifying circuit in the mobile radio frequency device, if Vo exceeds (Vt- For the range of ⁇ cx/2, Vt- ⁇ cx/2), adjust the amplification factor A of the low-frequency amplifier circuit by software setting until Vo is within the above range;
- Step 604 Set the Vt value of the mobile radio frequency device by software to adjust the input after step A. Power out signal Vo.
- the low frequency alternating magnetic field distance control method may further have the following feature: the voltage threshold V t is replaced by a current threshold corresponding to the voltage threshold V t .
- the mobile radio frequency device of the present invention enables a mobile terminal provided with the mobile radio frequency device to implement a credit card transaction such as electronic payment.
- Figure 1 is a voltage-distance curve tested in the case where the coil receiving circuit is placed in various mobile terminals and the 13.56 MHz carrier is kept constant on the same 14443 P0S machine;
- FIG. 2 is a structural block diagram of a system for selecting a highest frequency f O of a system without calibration work in the short-range communication method of the present invention
- FIG. 3 is a schematic diagram of determining a total received detection voltage fluctuation range ⁇ ⁇ by a distance control target (Din, Dv);
- Figure 4 is a typical terminal and obstacle voltage distance curve and its fluctuation interval ⁇ ;
- Figure 5 is the voltage distance curve of five typical mobile terminals when the frequency f is 3. 3KHz;
- Figure 6 is the non-modulation detected inside the mobile RF device a voltage waveform diagram of a received voltage signal at the time of direct baseband transmission and a received voltage signal at the time of sinusoidal FSK modulation;
- Figure 7 is a schematic diagram of a calculation method of a reference voltage distance curve
- FIG. 8 is a structural diagram of a short-range communication system according to an embodiment of the present invention.
- Figure 9 is a schematic diagram of a low frequency transmitting portion of the card reader.
- FIG. 10 is a schematic diagram of a format of a low frequency data frame of a card reader
- Figure 11 shows the voltage distance curve of the coil receiving circuit placed in various mobile terminals and tested by a signal source through a low frequency transmitting line ⁇ under a constant ⁇ magnetic field;
- FIG. 12 is a structural diagram of a radio frequency IC card according to an embodiment of the present invention.
- Figure 13 is a schematic view showing the structure of a 4 ⁇ pcb copper wire ⁇ antenna applied to a SIM card;
- Figure 14 is a differential Manchester encoding format of 5bi t data 11010 and a waveform diagram of field strength and line ⁇ receiving voltage;
- Figure 15 is a constant amplitude diagram of the s im card received in the mobile terminal of the low frequency magnetic field of Fig.;
- Fig. 16 is a schematic diagram of the structure of the 4 ⁇ pcb coil antenna applied to the TF card;
- Figure ⁇ is a block diagram of the error control system. detailed description
- the terminal appearing in the following text refers to a terminal loaded with a mobile radio device by default, and refers to a terminal that can be moved, that is, a mobile terminal, such as a mobile phone, etc., a distance card reader and a mobile radio device.
- a mobile terminal such as a mobile phone, etc.
- a distance card reader and a mobile radio device.
- the distance between the reader that is, the distance between the card reader and the terminal loaded with the mobile radio device.
- the invention provides a distance control problem for a short-distance transaction between a radio frequency device (especially a radio frequency card built in a terminal, such as a radio frequency SIM card) and a card reader device, and proposes a function of transmitting a low-frequency alternating magnetic field and a radio frequency signal.
- a radio frequency device especially a radio frequency card built in a terminal, such as a radio frequency SIM card
- a short-distance communication system consisting of a transceiver card reader and a mobile radio frequency device with a low-frequency alternating magnetic field induction receiving function and a radio frequency signal transceiving function, and a short-distance communication method corresponding to the system.
- the invention utilizes the characteristics of low-frequency alternating magnetic field penetrating different terminals to reduce the difference of attenuation, and uses the high-frequency radio frequency to effectively penetrate the terminal to complete high-speed two-way communication for transaction.
- the system performs the distance detection and control without calibration by a preset threshold determination method, that is, the card reader transmits the low frequency alternating magnetic field signal according to the preset transmission parameter, and the mobile radio frequency device detects the magnetic field signal at each distance point and Amplifying into a voltage signal having a constant amplitude corresponding to the distance, and further determining whether the terminal enters a preset effective distance interval (the effective distance interval, that is, the range of allowing the card to be swiped) by a preset voltage threshold Vt, the voltage threshold Vt All terminals are identical and no calibration is required.
- the invention combines the low-frequency one-way communication and the RF two-way communication to complete the unique binding of the card reader and the mobile radio device, and after binding, completes the bidirectional high-speed and large-data communication through the radio frequency channel.
- the system of the present invention can realize that the data communication distance (i.e., the transaction distance) of the terminal (e.g., the mobile phone equipped with the radio frequency SIM card) containing the mobile radio device and the card reader is reliably controlled within the specified range, and the terminal need not be calibrated.
- the short-range communication method of the present invention is applied to a short-range communication system including at least one card reader and at least one mobile radio frequency device, and includes the following steps of step &, step b, step c and step d, respectively The steps are specified:
- Step a the card reader transmits a low frequency alternating magnetic field signal according to a preset transmission parameter, where the low frequency alternating magnetic field signal carries the identity identification information of the card reader, wherein the transmitting parameter includes a frequency of the low frequency alternating magnetic field signal,
- the frequency is equal to or less than the highest frequency f O of the system without calibration work;
- the identity information may be an identification code ID.
- the frequency of the low-frequency alternating magnetic field signal in this step refers to the frequency corresponding to the high-end frequency cut-off point of the 3dB bandwidth of the spectrum of the low-frequency alternating signal.
- the frequency point selection system selects the frequency point with a small enough difference to achieve No calibration distance control.
- the low frequency alternating magnetic field signal is transmitted through a standard magnetic field emission line using a standard signal source, and the low frequency alternating magnetic field signal is received inside each typical mobile terminal and obstacle, and the transmission frequency is adjusted until the frequency point f O is found to make the mobile radio frequency device (loaded in the mobile terminal) the received voltage (the voltage is a voltage signal whose amplitude corresponding to the distance obtained by amplifying the low-frequency alternating magnetic field signal is constant) at the same distance from the center point of the plane of the emission line,
- the difference in field strength between different terminals and obstacles is approximately equal to the set fluctuation range ⁇ ⁇ .
- the frequency point f 0 and the frequency band lower than the frequency point f O are the frequency bands in which the system has no calibration work, and do not need to be calibrated in any system.
- the operating frequency ie, the frequency of the low-frequency alternating magnetic field signal mentioned above
- f O the frequency of the low-frequency alternating magnetic field signal mentioned above
- the system needs to be calibrated.
- the more operating frequencies are higher than f O the more terminals need to be calibrated, the more complicated the calibration. high.
- Frequency selection is a one-time job. Once selected, there is no need to change it during use.
- the frequency point selection system is composed of a signal source 505 and a low-frequency magnetic field emission line.
- the 504 is composed of a typical mobile terminal 501 and an obstacle, a signal strength tester 503 (a voltmeter, an oscilloscope, a spectrum analyzer, etc.), and the mobile terminal 501 has a low frequency receiving module 502 therein.
- Signal source 505 accurately produces signals of various frequencies, waveforms, and amplitudes.
- signal source 505 generates a sine wave signal of fixed amplitude frequency f, which is transmitted through transmission line 504, and low frequency receiving module 502 is placed inside selected typical mobile terminal 501 or obstacle, and received low frequency.
- the signal is connected to the signal strength tester 503 through a dedicated signal line, and the signal strength tester 503 tests the received voltage.
- Changing the distance of the mobile terminal can obtain a curve of the detected voltage of the mobile terminal or the obstacle under the condition of the frequency f (hereinafter referred to as a voltage distance curve), and changing the mobile terminal or the obstacle can obtain a curve of the plurality of terminals, changing A different curve can also be obtained for the frequency f.
- step a the highest frequency f O of the system without calibration work is determined by the following steps: Step 101, determining the distance control target (Din, Dv), wherein Din indicates that all terminals in the range of 0 ⁇ Din ensure that the card can be swiped, and Dv represents the distance fluctuation. Range, the distance is Din ⁇ ( Din + Dv ) Swipe is allowed in the circumference, and the distance is greater than the Din+Dv range.
- 5cm, 5 cm means that all terminals below 5 cm ensure that the card can be swiped, 5 cm ⁇ 10 cm allows swiping, and more than 10 cm can not swipe.
- the distance control target is determined by the specific application. (0 ⁇ Din+Dv) is called the distance control range.
- Step 102 Determine a fluctuation range ⁇ ⁇ of the detection voltage in the mobile radio frequency device caused by the card reader; the parameter fluctuation of the low frequency transmission circuit of the card reader forms a fluctuation of the transmission field strength, causing fluctuation of the detection voltage in the mobile radio frequency device, and the parameter includes the transmission.
- Drive voltage fluctuations, line parameter fluctuations, temperature effects, etc. ⁇ ⁇ is controlled by the reader design and production process. This fluctuation can be calibrated in the production process. Since the low frequency transmitting circuit operates at a low frequency, ⁇ ⁇ can usually be well controlled, for example, within 4 dB.
- Step 103 determining a fluctuation range S c of the detection voltage caused by the mobile radio frequency device itself
- S e is controlled by the design and production of the mobile RF device.
- the fluctuation can be calibrated at the production stage. Since the low frequency receiving circuit of the mobile RF device has a low operating frequency, usually s c can be well controlled, for example, within 4 dB.
- Step 104 Test the voltage distance curve of each typical terminal and obstacle at the f frequency, wherein the f frequency is any frequency in the special low frequency band or the low frequency band or the low frequency band, and the frequency range of the special low frequency band is 300 Hz - 3000Hz, the frequency range of the very low frequency band is 3KHz ⁇ 30KHz, and the frequency range of the low frequency band is 30KHz - 300KHz;
- a preparatory work is to be performed, that is, a typical terminal and a typical obstacle are selected.
- the selection principle of a typical terminal is mainly selected according to the number of terminal metals or conductive structures. The more metal, the greater the attenuation. For example, plastic casing, metal casing, thick metal shell, thin metal shell, large-size terminal, small-sized terminal, etc. can be selected.
- the number of typical terminals is not strictly limited.
- the selection of typical terminals can basically cover the attenuation characteristics of the terminal to the low-frequency alternating magnetic field signals.
- the mobile terminal type authentication may be added in the application, and the mobile terminal that needs to support the payment application is attempted to perform a card test to confirm that the attenuation characteristics of the mobile terminal of the model meet the requirements.
- Typical obstacles can be selected from different materials of standard shape plastic, aluminum, copper, iron, stainless steel and other mobile terminal common materials, placed between the card reader and the mobile radio device as an equivalent obstacle measurement attenuation of the mobile terminal effect.
- Step 105 Determine, by the distance control target (Din, Dv), a fluctuation range ⁇ ⁇ of the detection voltage in the mobile radio frequency device, where ⁇ A is equal to a voltage having a slope of the average field strength attenuation curve obtained from a voltage distance curve of each typical terminal and the obstacle The difference between the voltage value corresponding to the Din point on the curve and the voltage value corresponding to the (Din+Dv) point;
- Step 107 Calculate a maximum field strength difference ⁇ (also called a fluctuation interval) at each distance point between each typical terminal and an obstacle in a distance control range. If ⁇ is greater than ⁇ ⁇ , decrease the frequency f, and go to step a4; If ⁇ is smaller than ⁇ ⁇ , the frequency f is increased, and step a4 is turned; if ⁇ is equal to ⁇ ⁇ , the current test frequency f is equal to the highest frequency f0 of the system without calibration work.
- ⁇ also called a fluctuation interval
- Figure 4 shows a typical terminal and obstacle voltage distance curve and its fluctuation interval ⁇ .
- the voltage distance curve corresponding to the maximum attenuation terminal or obstacle is called the maximum attenuation curve.
- the voltage attenuation curve corresponding to the minimum attenuation terminal or obstacle is called the minimum attenuation curve.
- the highest frequency f0 of the system without calibration work is determined.
- the system can adopt the modulation method or the method of directly transmitting the baseband signal.
- the maximum frequency component of the system operation is as long as it is not greater than f0, and the distance control does not need to be calibrated.
- FIG. 5 is a voltage distance curve of five typical mobile terminals at a frequency f of 3.3 kHz.
- the system distance control target is (5cm, 5 cm)
- the system 0 ⁇ 10cm distance range varies by about 40dB
- the transmission parameters may further include a modulation mode, an encoding mode, and a transmitting magnetic induction intensity amplitude Br.
- the basic principle of selecting the transmission parameters is to ensure that the mobile radio frequency device detects and amplifies the low-frequency alternating magnetic field signal emitted by the card reader at various distance points, and the signal is a voltage signal with a constant amplitude corresponding to the distance.
- FIG. 6 is a voltage waveform diagram of a received voltage signal and a received voltage signal when a sinusoidal FSK modulation is detected in a non-modulated direct baseband transmission detected by a mobile radio frequency device, wherein a is a received voltage signal waveform when the baseband is transmitted without modulation.
- Figure, b is a waveform diagram of the received voltage signal when sinusoidal FSK modulation.
- the detection voltage signal is a variable voltage signal including demodulation information, and the signal may be an AC voltage signal without a DC component or a voltage signal having a DC component, and the constant amplitude means that the AC component changes the most. The amplitude is constant between different transmission symbols.
- the modulation mode, coding mode and amplitude of the transmitted magnetic induction intensity in the transmission parameters are selected by the following steps al l to al 3:
- Step al l selecting any encoding method without an average DC component, such as Manchester code, differential Manchester code, return to zero code, etc.;
- Step a2 selecting a carrier modulation mode with no modulation mode or no change in amplitude, and the carrier modulation mode may select any modulation mode with no change in amplitude.
- the carrier may adopt a sine wave, a pulse, a triangular wave, etc.
- the modulation mode may be selected as Key control method (00K), phase shift keying method or frequency shift keying method (FSK); when using no modulation method, the encoded baseband signal is directly transmitted by the transmitting line after being driven by the driving circuit;
- Step a3 selecting the amplitude of the transmitted magnetic induction intensity Br, by: selecting the typical noise terminal and the easy-to-implement magnetic detection in the mobile radio device under the selected operating frequency, modulation mode and coding mode less than f O And the amplified gain parameter, the mobile terminal including the mobile radio device is placed at a distance far from the card reader at a distance far from the control target, that is, Din+Dv, if the mobile radio device uses a Hall device, a giant magnetoresistive device, or the like to detect a magnetic field.
- the magnetic induction signal of the intensity value is received by the card reader, and the card reader emits a magnetic field signal with a constant amplitude of change of the magnetic induction intensity; if the mobile radio frequency device adopts a sensing circuit that detects the rate of change of the magnetic field strength, such as a wire ⁇ , the rate of change of the magnetic induction intensity of the card reader is emitted. (ie, differential amplitude) a constant magnetic field signal, test the inherent noise voltage amplitude Vn of the detected voltage in the mobile radio device without transmitting the low frequency alternating magnetic field signal, and then measure the card reader to transmit the low frequency intersection with the selected modulation and coding method.
- the detection voltage Vr in the radio frequency device is moved, and the emission amplitude value Bgate or framing is selected.
- Value B_RATEgate so Vr / Vn> SNR, SNR is the signal to noise ratio of the mobile RF device.
- the choice of SNR value is usually as large as possible, but too large will cause the reader to send work. The rate is too large, and the difficulty is realized.
- Br is determined by the above method. According to the type of magnetic induction circuit selected by the system, the Br parameter value is divided into two types, the Hall device and the giant magnet.
- the resistive device receiving system is a magnetic induction intensity amplitude threshold Bga te
- the coil receiving system is a magnetic induction intensity change rate amplitude threshold B_RATEga te.
- Step b The mobile radio frequency device receives, detects, and amplifies the low-frequency alternating magnetic field signal at each distance point and amplifies the voltage signal with a constant amplitude corresponding to the distance, and further determines that the movement is loaded by a preset voltage threshold V t Whether the terminal of the radio frequency device enters a preset effective distance interval, and the voltage threshold Vt is the same for all terminals loaded with the mobile radio frequency device;
- step b the preset voltage threshold Vt is determined by the following steps 201 to 203, provided that the card reader transmission and the mobile radio device reception are not fluctuating, or the received detection voltage fluctuation caused by the two is much less than 3 1! and S c:
- Step 201 measuring a voltage distance curve of each typical terminal and obstacle under the selected transmission parameter, wherein the transmission parameter includes a frequency, a modulation mode, a coding mode, and a magnitude of the transmitted magnetic induction intensity Br of the low frequency alternating magnetic field signal;
- Step 202 obtaining a reference voltage distance curve, wherein the reference voltage distance curve is an intermediate value of a typical terminal and an obstacle curve, and the voltage amplitudes of the upper boundary and the lower boundary of the typical terminal curve are both ⁇ ⁇ /2 , as shown in FIG. 7 .
- Step 203 Select a detection voltage threshold value Vt in the mobile radio frequency device, and the Vt value is equal to an intermediate value of the voltage value in dBmV between the voltage values respectively corresponding to the distance control target Din and (Din+Dv).
- the voltage corresponding to Din on the reference voltage distance curve is V5 (dBmV)
- the voltage value corresponding to the (Din+Dv) point is V6 (dBmV)
- Vt V5- (V5- V6) /2 (dBmV) 0 step c, if the voltage signal corresponding to the received low frequency alternating magnetic field signal is greater than or equal to the preset voltage threshold Vt, the terminal loaded with the mobile radio frequency device enters the preset valid swipe interval,
- the mobile radio frequency device acquires the identity identification information of the card reader from the received low frequency alternating magnetic field signal, and transmits the card identification device together with the identity identification information thereof to the card reader through the radio frequency channel;
- the card reader receives the information transmitted by the mobile radio device through the radio frequency channel, and compares whether the identity information of the card reader in the information is consistent with the identity information of the card, and if they are consistent, the identity information and the mobile radio device are The combination of the identification information is used as a combined address, and the mobile radio device performs a credit card transaction through the radio frequency channel.
- the card transaction does not only refer to electronic payment, but also other communication processes through the RF channel, such as recharge, consumption, identity authentication, etc.
- the card transaction in this document refers to communication through the RF channel, especially the communication through the RF channel in short-range communication.
- the frequency of the low frequency alternating magnetic field signal is in the ultra low frequency band or the low frequency band or the low frequency band, wherein the frequency range of the special low frequency band is 300 Hz ⁇ 3000 Hz, and the frequency range of the low frequency band is 3 kHz ⁇ 30 KHz, the low frequency band
- the frequency range is from 30 KHz to 300KHz.
- the frequency of the low frequency alternating magnetic field signal may be 300 Hz to 50 kHz.
- the frequency of the low frequency alternating magnetic field signal may be 500 ⁇ , 1 ⁇ , 1 ⁇ 5 ⁇ , 2 ⁇ , 2 ⁇ 5 ⁇ , 3 ⁇ , 4 ⁇ , 5 ⁇ , 10 ⁇ , 20 ⁇ or 30 ⁇ .
- the short-distance communication method of the invention adopts a combination of low-frequency magnetic field one-way communication and radio frequency electromagnetic field high-speed two-way communication, thereby avoiding the use of the unique 13.56 MHz frequency point bidirectional communication and distance control in the NFC system, and the antenna signal and the terminal signal attenuation difference are large. And other issues.
- the card reader transmits the unique identifier IDr (ie, the foregoing identity information) to the mobile radio device by using the low frequency unidirectional channel, and the mobile radio device attaches its unique identifier I Dc to the IDr through the radio frequency bidirectional channel.
- IDr unique identifier
- I Dc unique identifier
- the card reader compares the correctness of the returned IDr, thereby enabling the unique binding of the card reader to the mobile radio device. After the binding, the card reader and the mobile radio device use the RF bidirectional channel to realize high-speed and large-data communication until the transaction is completed.
- the short-distance communication method of the present invention realizes that the data communication distance (ie, the transaction distance) of the radio frequency communication terminal (such as the mobile phone equipped with the radio frequency SIM card) containing the mobile radio frequency device and the card reader is reliably controlled within a prescribed range, and There is no need to calibrate the terminal.
- the radio frequency communication terminal such as the mobile phone equipped with the radio frequency SIM card
- the near field communication system of the present invention includes at least one card reader and at least one mobile radio frequency device, wherein:
- the card reader is configured to transmit a low frequency alternating magnetic field signal according to a preset transmission parameter, where the low frequency alternating magnetic field signal carries identification information of the card reader, wherein the transmission parameter includes a frequency of the low frequency alternating magnetic field signal, and the frequency is equal to Or the maximum frequency f 0 of the system without calibration work; the card reader is further configured to receive information transmitted by the mobile radio device through the radio frequency channel, and compare whether the identity information of the card reader in the information is consistent with the identity information of the card, if Consistently, the combination of the identity information of the mobile device and the identity information of the mobile radio device is used as a combined address, and the mobile radio device performs a card transaction through the radio frequency channel;
- a mobile radio frequency device for receiving and detecting low frequency alternating magnetic waves emitted by the card reader at various distance points
- the field signal is amplified and converted into a voltage signal having a constant amplitude corresponding to the distance, and further determines whether the terminal loaded with the mobile radio frequency device enters a preset effective distance interval by using a preset voltage threshold Vt, wherein the voltage threshold Vt is loaded All terminals of the mobile radio frequency device are the same;
- the mobile radio frequency device is further configured to receive the low frequency alternating magnetic field signal when the voltage signal corresponding to the received low frequency alternating magnetic field signal is greater than or equal to a preset voltage threshold vt
- the identification information of the card reader is obtained and transmitted to the card reader through the radio frequency channel together with the identity information of the card reader; the mobile radio frequency device is also used for card transaction with the card reader through the radio frequency channel.
- the identity information may be an identifier ID.
- the card reader in the short-range communication system of the present invention has two basic functions of a low-frequency transmitting function and a radio frequency transceiving function. It can also be said that the card reader in the short-range communication system of the present invention has a low-frequency transmitting module and radio frequency transmitting and receiving.
- the module has two basic modules; the mobile radio frequency device in the short-range communication system of the present invention has two basic functions of a low frequency receiving function and a radio frequency transceiving function, and it can also be said that the mobile radio frequency device in the short-range communication system of the present invention has a low frequency receiving module. And two basic modules such as RF transceiver module.
- the card reader includes at least one low frequency transmission line, at least one driving circuit, at least one encoding circuit, at least one first main processor, at least one radio frequency a transceiver circuit and at least one radio frequency antenna, wherein the low frequency transmission line ⁇ , the driving circuit, the encoding circuit, the first main processor, the radio frequency transceiver circuit, the radio frequency antenna, and the serial connection in series;
- the mobile radio frequency device includes at least one low frequency magnetic induction circuit, at least a low frequency amplifying circuit, at least one threshold determining and demodulating circuit, at least one second main processor, at least one radio frequency transceiver circuit and at least one radio frequency antenna, wherein the low frequency magnetic induction circuit, the low frequency amplifying circuit, the threshold determining and demodulating circuit,
- the second main processor, the radio frequency transceiver circuit, and the radio frequency antenna are connected in series in series.
- a modulation circuit may be further
- the low frequency transmission line ⁇ , the driving circuit and the encoding circuit (including the modulation circuit when modulating the circuit) in the card reader can be regarded as a component of the low frequency transmitting module, and the first in the card reader
- the main processor, the RF transceiver circuit and the RF antenna can be considered as components of the RF transceiver module in the card reader;
- the low frequency magnetic induction circuit, the low frequency amplification circuit and the threshold determination and demodulation circuit in the mobile RF device can be regarded as the low frequency receiving module.
- Component, the second main processor, the radio frequency transceiver circuit, and the radio frequency antenna in the mobile radio device can be considered as a mobile radio device
- the components of the frequency transceiver module are described as a mobile radio device.
- the low frequency emission line ⁇ may be an enameled wire ⁇ or a PCB ⁇ .
- the number of turns of the low-frequency emission line ⁇ may be greater than 10 ⁇ .
- the number of turns of the low-frequency emission line 50 is 50 ⁇ 500 ⁇ .
- the low frequency emission line is filled with a ferrite core or a core.
- the cross-sectional area of the area surrounded by the low-frequency emission line ⁇ is wider than the cross-sectional width of the mobile radio frequency terminal.
- the section of the area enclosed by the low-frequency emission line ⁇ includes at least a circular area i of 3 cm in diameter or a square area i of 3 cm * 3 cm.
- the frequency magnetic sensing circuit described above may be a PCB coil, an enamelled wire, a Hall device or a giant magnetoresistive device.
- the mobile radio frequency device may be placed in the mobile terminal, or may be placed in a SIM card, a UIM card, a USIM card, a TF card or an SD card in the mobile terminal.
- the mobile terminal can be a mobile phone, a personal digital assistant PDA or a laptop computer.
- the highest frequency of the system without calibration work f 0 is selected in the content of the short-range communication method described above, and will not be described here;
- the card reader continuously transmits a low-frequency alternating magnetic field signal not higher than the selected frequency f 0 according to the distance control target according to the distance control target, and the data carries the data frame in the manner of modulation or direct baseband transmission.
- the frame contains the unique identifier of the card reader Idr (of course, it can also be other identity information).
- the low frequency alternating magnetic field signal penetrates the terminal to reach the internal mobile radio frequency device, and the mobile radio frequency device detects the magnetic field signal at each distance point and amplifies the distance to the distance
- the receiving voltage threshold value Vt indicates that the terminal enters the predetermined valid card swiping range of the card reader
- the low frequency receiving circuit refers to the aforementioned low frequency magnetic inducting circuit, low frequency amplifying circuit and threshold determining and demodulating circuit
- the mobile radio device access card reader mainly includes the unique binding process of the card reader and the mobile radio device.
- the binding process is illustrated here: the mobile radio device removes the card reader unique identification code IDr from the low frequency signal and transmits it to the second main processing module in the mobile radio device, and the second main processing module moves the radio device.
- the unique identification code IDc is sent to the card reader through the RF transceiver module together with the received IDr. After the card reader receives the IDr (IDc) returned by the mobile radio device, the mobile radio device with the identification code IDc is confirmed to be correct. It returns the IDR of the reader and is the only communication terminal for this transaction.
- the mobile radio device with the ID code IDc confirms that it has unique communication with the card reader whose ID code is IDr.
- the mobile radio device and the card reader implement a unique binding, and the two parties uniquely identify each other through the (IDr, IDc) combined address.
- the binding communication process uses the RF channel to interact without error. After the mobile radio device is successfully accessed, the distance control process is completed, and the subsequent transaction process can be performed on the RF channel until the transaction ends.
- the card reader and the mobile radio device establish a reliable and unique communication link through the RF channel. Based on the link, the two parties can implement the process required for identity authentication and other transactions required for the transaction. All of these processes are performed through a fast RF channel. Since the completion of the aforementioned process ensures that access can only be achieved within a predetermined distance, the entire transaction process is also within a limited range of communication.
- FIG. 8 is a structural diagram of a short-range communication system according to an embodiment of the present invention. As shown in Fig. 8, the system consists of two parts: a card reader device 100 and a mobile radio device 200, which is placed inside the mobile terminal and interacts with the terminal through the mobile terminal communication interface.
- the card reader 100 is composed of the following modules: a first main processor 101, which is responsible for the low frequency and high frequency control of the card reader and other protocol processing, and the first main processor 101 is directly connected to the external communication interface through the interface circuit 102;
- the encoding circuit 108 is responsible for bit-by-bit encoding of the low-frequency frame data, and the modulation circuit 107 is responsible for modulating the encoded-output symbol stream to form a modulated signal to the driving circuit 106, and the encoded signal is directly sent to the driving circuit without modulation.
- the low frequency transmitting module formed by the driving circuit 106, the modulating circuit 107 and the encoding circuit 108 can change and set the transmission field strength value;
- the low frequency transmitting line ⁇ 105 is usually composed of a plurality of turns of a specific shape;
- the RF transmitting and receiving circuit 103. Receive and transmit an RF signal through the RF antenna 104.
- the mobile radio device is composed of the following modules: a second main processor 201, which is responsible for the control of low frequency and radio frequency modules and other protocol processing, and is also responsible for communication with the mobile terminal; S IM/TF/SD card module 202 is a mobile terminal S IM/TF/SD card body module, which module is determined by the card type; low frequency magnetic induction circuit 207, which is composed of PCB wire ⁇ , enamelled wire ⁇ , Hall device or other circuit components capable of sensing magnetic field changes, is responsible for sensing low frequency intersection
- the variable magnetic field signal 301 is converted into an electrical signal;
- the low frequency amplifying circuit 206 is responsible for amplifying the electrical signal detected by the low frequency magnetic induction circuit to obtain a low frequency magnetic detecting voltage signal 303;
- the threshold determining and demodulating circuit 205 is responsible for presetting the low frequency magnetic detecting voltage signal 303
- the threshold Vt is set to determine that the threshold Vt is not demodulated and the card is not allowed to be swiped.
- the threshold Vt is used to demodulate the signal, and the demodulated signal is sent to the second main processor 201.
- the RF transceiver circuit 203 passes through the RF antenna 204. Responsible for RF two-way communication with the RF transceiver module of the card reader.
- the system performs the distance detection and control without calibration by using a preset threshold determination method, that is, the card reader 100 transmits the low frequency alternating magnetic field signal 301 according to the preset transmission parameter, and the mobile radio frequency device 200 receives the magnetic field signal and converts it into a low frequency.
- the magnetic detection voltage signal 303 is used to determine whether the terminal enters a preset effective distance interval by a preset threshold Vt.
- the threshold Vt is the same for all terminals, and does not need to be modified for different terminals (so-called calibration).
- the unique binding of the card reader 100 and the mobile radio device 200 is accomplished by a combination of low frequency one-way communication and RF two-way communication, that is, the card reader 100 transmits its unique identification IDr to the mobile radio device by using the low frequency one-way channel. 200.
- the mobile radio device 200 adds the card's own unique identifier IDc to the IDR through the RF bidirectional channel, and then returns the card ID to the card reader 100.
- the card reader 100 compares the correctness of the IDr, thereby implementing the card reader 100 and the mobile radio frequency.
- the unique binding of device 200 After binding, the two-way high-speed and large-volume communication is completed through the RF channel.
- the specific working process of the short-range communication system is as follows:
- the frequency of the above RF communication usually uses 2400 - 2483MH 2.
- the above method is used to determine the low-frequency uncalibrated operating frequency f o of the system.
- distance control in the range of 0 to 10 cm is required, and the f O frequency point is usually less than ⁇ ⁇ , and the typical value includes 500 Hz , ⁇ , 1. 5KHz, 2KHz, 2. 5KHz, 3KHz, 5KHz, etc.
- the transmission parameters mainly include the modulation mode, the coding mode and the amplitude of the transmitted magnetic induction intensity Br.
- Figure 9 is a schematic diagram of the low frequency transmitting part of the card reader. Referring to FIG. 8, the low frequency transmitting circuit of the card reader is composed of a driving circuit 106, a modulation circuit 107 and an encoding circuit 108, and the low frequency modulation signal driven by the driving circuit 106 is output to the low frequency transmitting line ⁇ 105.
- the modulation circuit 107 can employ a variety of modulation methods:
- Carrier modulation mode modulation The baseband signal generated by the encoding circuit 108 is modulated by the modulation circuit 107, and the carrier can be a sine wave, a square wave, a triangle wave, etc., and the modulation can be switched frequency shift keying 00K, phase shift keying, frequency Shift keying FSK or the like, the modulated signal is loaded into the low frequency emission line ⁇ 105 through the driving circuit 106;
- Carrierless direct baseband transmission The baseband signal generated by the encoding circuit 108 is directly loaded to the low frequency transmission line ⁇ 105 through the driving circuit 106;
- the encoding circuit 108 can employ a variety of encoding methods:
- Bit 1 is coded as two symbols 01 and bit 0 is coded as 10.
- the process of adjusting Br is actually a process of adjusting parameters such as the number of turns, wire diameter, and shape.
- the card receiving threshold voltage Vt is determined by the aforementioned method.
- Step A100 Distance measurement and control process.
- the first main processor 101 of the card reader 100 generates a data frame containing the unique identification code IDr of the card reader, and sends it to the encoding circuit 108 for encoding.
- the encoded signal is modulated by the modulation circuit 107 or directly sent to the driver without modulation.
- the circuit 106 transmits a modulation voltage to the low-frequency transmission line ⁇ 105.
- the transmission line 105 continuously transmits the specified parameters according to the frame format at the set intensity Br continuously.
- the low frequency alternating magnetic field signal 301 The low frequency alternating magnetic field signal 301.
- the low frequency alternating magnetic field signal 301 penetrates the terminal to reach the internal mobile radio frequency device 200, and the low frequency magnetic induction circuit 207 in the mobile radio frequency device 200 detects the low frequency magnetic signal and converts it into an electrical signal. After being amplified by the low frequency amplifying circuit 206, the low frequency magnetic detecting voltage 303 is obtained.
- the card When the magnitude of the voltage is less than (or greater than) the preset receiving voltage threshold value Vt, the card is not allowed to be swiped; when the magnitude of the voltage is greater than or equal to (or less than or equal to)
- the preset receiving voltage threshold value Vt indicates that the terminal enters the predetermined effective card swipe range of the card reader, and the low frequency receiving circuit starts the decoding process to obtain the unique identification code IDr of the card reader.
- the frame format in step A100 is defined as follows:
- FIG 10 is a schematic diagram of the low-frequency data frame format of the card reader. As shown in Figure 10, the low-frequency data frame of the card reader is divided into: 3 ⁇ 4 ports under i or:
- Sync code 8 bits, usually FFH, for frame synchronization
- Control field 8 bits, used to provide de-frame information of frame data, such as length, data type, etc., may be reserved for expansion;
- IDr N bits, the unique identifier of the reader, specified by the control field;
- CRC For the control domain, the IDr is verified, and the CRC checksum or other methods can be used.
- the frame format described above is only an example and does not limit the frame format actually employed by the present invention.
- any frame format including a card reader that uniquely identifies the card reader can be used.
- the unique identification code may use a random number of sufficient length, or a method in which all readers manually assign a unique code, or an identification code generated by other means.
- Step A2QQ The process of the mobile radio device accessing the card reader:
- the mobile radio device access card reader mainly includes the unique binding process of the card reader 100 and the mobile radio device 200, which actually indicates that the card reader and the mobile radio device are located.
- the internal low frequency receiving circuit of the mobile radio frequency device 200 solves the card reader unique identification code Idr and transmits it to the first main processor 201 in the mobile radio frequency device, and the module adds the unique identification code Idc of the mobile radio frequency device together with the received Idr.
- the card reader 100 And transmitting to the card reader 100 through the RF transceiver circuit 203 and the RF antenna 204 in the mobile radio device, and the internal RF antenna 103 and the RF transceiver circuit 104 of the card reader receive the (IDr, IDc) returned by the mobile radio device, and then transmit the signal to the first A main processor 101 processes, and the first main processor 101 confirms that the mobile radio device whose identification code is IDc correctly returns the card reader IDr, which is the only communication terminal of the transaction. Since the IDr code ensures that the identification codes of other card readers around the card reader are different at this time, the card whose ID is IDc confirms that it has unique communication with the card reader whose ID code is IDr.
- the mobile radio device and the card reader implement a unique binding, and the two parties uniquely identify each other through the (IDr, IDc) combined address.
- the binding communication process uses RF channels for interaction without error. After the mobile radio device is successfully connected to the card reader, the distance control process is completed, and the subsequent transaction process can be performed on the RF channel;
- the mobile radio device unique identification code IDc in step A200 is a unique identification code pre-stored in the non-volatile memory (NVM) in the mobile radio device, or a sufficiently long random number generated in the mobile radio device.
- NVM non-volatile memory
- Step A300 The transaction process.
- the card reader 100 and the mobile radio device 200 establish a reliable unique communication link through the RF channel, on the basis of which the two parties can implement the processes required for identity authentication and other transactions required for the transaction. All of these processes are completed through a fast RF channel until the end of the transaction. Since the completion of the foregoing steps A100-A200 ensures that the mobile radio device 200 can only complete access within a predetermined distance range, the entire transaction process is also within a limited distance to complete the transaction.
- the transaction process is a mature POS processing process, which is not described in detail in the present invention.
- the low frequency signal detecting circuit 207 in the mobile radio frequency device 200 can generally be constructed by using a PCB wire ⁇ , an enameled wire ⁇ or a Hall device. The detecting circuit is not limited to these components, and in principle any magnetic field change can be converted into an electrical signal. Sensors can be used with this module, the only restriction being that it can be placed inside the card.
- the system of the invention realizes the distance detection and control by using the low frequency alternating magnetic field, and realizes the one-way communication between the card reader and the mobile radio frequency device, and realizes the reliable binding of the terminal by using the RF channel combined with the low frequency communication, and simultaneously realizes the card reader by using the RF channel.
- High-speed data communication between mobile radios It has the following characteristics: 1. It is possible to realize reliable two-way distance communication by simply replacing the internal SIM card/TF/SD card in the terminal without replacing the mobile terminal; 2 the card reader transmits low-frequency alternating magnetic field signals, moving The radio frequency device only needs to receive the magnetic field signal.
- the receiving line or other receiving circuit can be miniaturized enough to put the mobile radio device into the SIM card/TF/ In the SD card; 3. Due to the weak received signal, the amplifier circuit needs to be added in the mobile RF device.
- the RF transceiver circuit is placed in the mobile RF device at the same time, and the RF transceiver circuit in the card reader realizes bidirectional high-speed communication. As described above, the antenna of the RF circuit is small and can be easily integrated into the SIM card/TF/SD card. Inside.
- the system does not need to be calibrated to work below the frequency point.
- the system works above the f 0 frequency point, and it is not absolutely impossible, and the possible effect is performance degradation.
- the accuracy of the distance control is reduced, and calibration with the cartridge may be required.
- the near field communication system of the invention realizes that the data communication distance (ie, the transaction distance) of the radio frequency communication terminal (such as the mobile phone equipped with the radio frequency SIM card) containing the mobile radio frequency device and the card reader is reliably controlled within the prescribed range, and Calibrate the terminal.
- the radio frequency communication terminal such as the mobile phone equipped with the radio frequency SIM card
- FIG. 11 shows the voltage distance curve of the coil receiving circuit placed in various mobile terminals and tested by a signal source through a low frequency transmitting line ⁇ under a constant ⁇ magnetic field. As shown in FIG. 11, it is an example of a voltage distance curve of a plurality of typical terminals of the system at a chirp frequency.
- the signal strength value is the value after the necessary amplification of the receiving antenna induced voltage, and the magnification is kept constant, and only the relative change of the intensity with the distance is concerned.
- the field strength difference between the terminals is ⁇ 5dB, and each terminal is at 1 ⁇
- the range of field strength variation in the 10cm range reaches 40dB, regardless of the fluctuation of the field strength of the reader and the error of the detection circuit of the mobile RF device.
- the mobile RF device uses a uniform threshold Vt to determine whether each terminal is within the target distance range.
- the difference in control between the terminals is approximately 1 cm, which fully satisfies the requirements of non-calibrated distance control.
- the mobile radio frequency device is usually an IC card (such as a SIM card, a UIM card, a USIM card, etc.) or a memory card (such as a TF card, an SD card, an MMC (Mul ti Media Card) placed in the mobile terminal.
- IC card such as a SIM card, a UIM card, a USIM card, etc.
- memory card such as a TF card, an SD card, an MMC (Mul ti Media Card) placed in the mobile terminal.
- MMC Media ti Media Card
- FIG. 12 is a structural diagram of a radio frequency IC card according to an embodiment of the present invention.
- the radio frequency IC card 1200 is composed of a mobile radio frequency device and a SIM/UIM/USIM card module (which may be collectively referred to as an IC card module) 1202 and an interface module 1207.
- the mobile radio frequency device includes at least one magnetic frequency magnetic induction circuit 1206, at least one frequency amplifying circuit 1215, at least one comparison circuit 1225, at least one demodulation circuit 1235, at least one decoding circuit 1245, and at least one second main processor.
- the RF transceiver circuit 1203 and the RF antenna 1204 are connected in series in series.
- the comparison circuit 1225, the demodulation circuit 1235 and the decoding circuit 1245 constitute a threshold determination and demodulation circuit of the mobile radio frequency device.
- the threshold determination and demodulation circuit of the mobile radio frequency device may not include the demodulation circuit 1235, but only the comparison circuit 1225 and the decoding circuit 1245.
- the low frequency amplifying circuit 1215, the comparing circuit 1225, the demodulating circuit 1235, and the decoding circuit 1245 constitute a low frequency signal receiving and processing module 1205.
- the second main processor 1201 is the same as the second main processor in the aforementioned mobile radio frequency device.
- the low frequency receiving circuit composed of the low frequency magnetic sensing circuit 1206, the low frequency amplifying circuit 1215, the threshold determining and demodulating circuit (including the comparing circuit 1225, the demodulating circuit 1235 and the decoding circuit 1245) operates in a pre-selected system without calibration work.
- the frequency below the highest frequency f 0 The method for determining the highest frequency f O of the system without calibration work has been previously described, and will not be described here.
- the low-frequency receiving link magnetically converts a low-frequency alternating magnetic field of constant amplitude or constant differential amplitude to obtain a constant amplitude detection voltage with an error of 5 c dB.
- the volume of different low frequency receiving links can be selected by selecting different low frequency magnetic induction circuits and amplification factors of the low frequency amplifying circuits, so that the mobile radio frequency device can be selected to be placed in carriers of different volume requirements. If the low frequency magnetic induction circuit is a line, the volume of the low frequency receiving link depends on the conversion gain of the low frequency magnetic induction circuit and the amplification factor of the low frequency amplification circuit.
- the magnetoelectric conversion gain conversion formula is:
- the product of the conversion gain of the magnetic induction circuit and the amplification factor of the low frequency amplification circuit is a system preset value corresponding to the farthest card swipe distance of the system applied by the mobile terminal, and the farthest swipe distance is the value of the field strength of the reader at the distance.
- Vt and B_RATEga te are values determined by the system, so the K*A value is determined, and the volume of the coil is mainly determined by the K value. The more the number of turns, the larger the K, the larger the volume, the A value.
- the size has little effect on the volume of the low frequency amplifying circuit, so the distribution of the total magnetoelectric conversion gain between K and A will determine the volume of the low frequency receiving link.
- the volume of the coil is easily placed in the range of 1 to 20 ⁇ , so the conversion gain of the magnetic induction circuit is determined first, and then the low frequency amplification circuit is selected. A big gain is enough. If the mobile RF device is placed on the terminal board, this can increase the number of turns and the area, and the amplifier gain can be reduced.
- the advantage is that the signal-to-noise ratio is improved, and the disadvantage is that the low-frequency receiving link becomes larger.
- the magnetic induction circuit is a Hall device or a giant magnetoresistive device, the volume of the low frequency receiving link has little to do with the conversion gain of the low frequency magnetic induction circuit and the amplification factor of the low frequency amplifying circuit.
- the second main processor 1201, the S IM/UIM/US IM card module 1202, the RF transceiver module 1203, the low frequency signal receiving and processing module 1205, and the interface module 1207 may be integrated into an IC (Integrated Circuit).
- the circuit and peripheral passive components are also composed, and can also be combined into different ICs, plus peripheral passive components.
- the RF antenna 1204 cannot be integrated into the IC, and the PCB antenna can be used, which is composed of the copper printed circuit of the PCB.
- the low frequency magnetic induction circuit 1206 is configured to receive the low frequency magnetic field signal, convert the low frequency magnetic field signal into a corresponding voltage signal, and send it to the subsequent low frequency amplifying circuit 1215.
- the low frequency magnetic induction circuit 1206 can be realized by a PCB wire ⁇ , an enameled wire ⁇ , a Hall device, a giant magnetoresistive device, or the like.
- the signal 1302 output by the low frequency magnetic induction circuit 1206 may be a voltage signal or other signal such as a current. In general, the signal 1302 is a voltage signal. If the low frequency magnetic sensing circuit 1206 is constructed using a Hall device or a giant magnetoresistive device, the voltage signal 1302 is proportional to the low frequency magnetic field signal strength 1301.
- the voltage signal 1302 is proportional to the low frequency magnetic field signal strength signal change rate 1301.
- a typical antenna is a ring-shaped differential amplitude constant-sensing antenna composed of the outermost ⁇ pcb copper of the card, and the output is a voltage signal 1302.
- FIG. 1 For example, a structure of a 4 ⁇ pcb copper wire ⁇ antenna applied to a SIM card is shown in FIG.
- the second main processor 1201 implements coordinated control processing of the entire radio frequency IC card 1200, and the second main processor 1201 contains various control hardware, program modules, and memories.
- the second main processor 1201 is implemented by an IC and peripheral passive components, the main functions are implemented by the IC, and the peripheral components only serve as an auxiliary function.
- the SIM/UIM/USIM card module 1202 is coupled to the second main processor 1201 and has application data interaction with the second main processor 1201.
- the SIM/UIM/USIM card module 1202 is mainly implemented by an IC.
- the second host processor can be the same shared processor as the processor in the SIM/UIM/US IM/TF/SD/MMC card. That is, using a shared processor to do the work of the second processor and the processor in the SIM/UIM/USIM/TF/SD/MMC card at the same time.
- the interface module 1207 is connected to the second main processor 1201, and the second main processor 1201 is connected to the communication interface of the mobile terminal through the interface module 1207, and performs data interaction with the mobile terminal.
- the interface module 1207 is implemented by an IC. In general, the second main processor 1201 and the interface module 1207 are integrated in the same IC.
- the SIM/UIM/USIM card module 1202 can perform data interaction with the mobile terminal through the second main processor 1201 and the interface module 1207 to perform the functions that should be performed.
- the low frequency signal receiving and processing module 1205 is coupled to the second main processor 1201 and also to the low frequency magnetic sensing circuit 1206.
- the low frequency signal receiving and processing module 1205 receives the low frequency magnetic induction circuit
- the low frequency signal receiving and processing module 1205 compares whether the signal 1303 is greater than the set threshold Vt and transmits the comparison result to the second main processor 1201.
- the low frequency signal receiving and processing module 1205 also decodes the data information in the signal 1303 and sends it to the second main processor 1201.
- the low frequency signal receiving and processing module 1205 receives the control of the second main processor 1201 and receives control information such as the threshold Vt sent from the second main processor 1201.
- the RF transceiver circuit 1203 is coupled to the second host processor 1201.
- the RF transceiver circuit 1203 is connected to the RF antenna 1204, and the RF signal 400 in the air is transmitted and received through the RF antenna 1204.
- the low frequency magnetic induction circuit 1206 is connected to the low frequency signal receiving and processing module 1205, receives the low frequency magnetic field signal 1301 transmitted by the air card reader, converts it into a low frequency magnetic field signal 1302, and sends it to the low frequency signal receiving and processing module 1205 for processing.
- the low frequency signal receiving and processing module 1205 is composed of a low frequency amplifying circuit 1215, a comparing circuit 1225, a decoding circuit 1245, and an optional demodulating circuit 1235.
- the demodulation circuit 1235 is optional. When the digital signal transmitted by the low frequency magnetic field is only subjected to baseband coding without modulation and demodulation, the demodulation circuit 1235 is not required, otherwise the demodulation circuit 1235 is required.
- the low frequency amplifying circuit 1215 receives the low frequency magnetic field signal 1302 sent from the low frequency magnetic induction circuit 1206, and amplifies the low frequency magnetic field signal 1302 by a factor of A to obtain a signal 1303.
- Signal 1303 is sent to comparison circuit 1225 for processing.
- the signal 1303 is also sent to the demodulation circuit 1235 for processing. If there is no demodulation circuit 1235, the signal 1303 is directly sent to the decoding circuit 1245 for processing.
- the amplification factor A of the low frequency amplifying circuit 1215 can be set by software.
- the comparison circuit 1225 is connected to the second main processor 1201, receives the signal 1303 sent from the low frequency amplifying circuit 1215, and compares whether the signal 1303 exceeds the threshold Vt. If the signal 1303 changes in comparison with the threshold Vt, the information of the change is sent to The second main processor 1201.
- the threshold Vt is set by the second main processor 1201 and stored in the comparison circuit 1225.
- the Vt value can also be set by software.
- the demodulation circuit 1235 is connected to the decoding circuit 1245, receives the signal 1303 sent from the low frequency amplifier circuit 1215, and sends the demodulated baseband signal to the decoding circuit 1245.
- the decoding circuit 1245 is connected to the second main processor 1201, and receives the baseband signal sent by the low frequency amplifying circuit 1215 or the demodulating circuit 1235. After decoding, the information sent by the card reader through the low frequency magnetic field is sent to the second main processor 1201. .
- Decoding circuit 1245 can be implemented using the techniques of a differential Manchester decoder.
- the RF memory card consists of a mobile RF device and a TF/SD/ ⁇ C card module (collectively referred to as a memory card module) and an interface module.
- the RF memory card can be obtained by simply replacing the SIM/UIM/USIM card module 1202 of the RF IC card with the TF/SD/ ⁇ C card module.
- the other parts of the RF memory card are the same as the RF IC card.
- the RF memory card is not mentioned here.
- Figure 16 is a schematic diagram showing the structure of a 4 ⁇ pcb coil antenna applied to a TF card.
- the radio frequency IC card/RF memory card of the present invention can receive data information in a low frequency magnetic field.
- the coded modulation method of the data information can use various existing mature technologies. For example, a differential Manchester coded technique can be used to directly pass the encoded differential Manchester coded baseband signal using the low frequency magnetic field rate of change.
- Fig. 14 is a differential Manchester format of the 5b i t data 11010 and a waveform diagram of the field strength and the line reception voltage. Fig.
- Fig. 14 is a differential Manchester coding format diagram of 5bi t data 11010, b is a field strength map corresponding to a, and c is a corresponding voltage waveform diagram received by the line ⁇ . It can be seen from Fig. 14 that in the differential Manchester code, the difference represents 1 and the same represents 0.
- the low-frequency alternating magnetic field with constant amplitude or constant differential amplitude is magnetically converted to obtain a constant amplitude detection voltage, and the threshold comparison function and the control card function are performed.
- Amplitude constant low-frequency alternating magnetic field is a low-frequency alternating magnetic field with a constant amplitude of change in magnetic induction, such as a square wave and a sine wave.
- the differential amplitude constant low-frequency alternating magnetic field refers to a ⁇ -frequency alternating magnetic field whose amplitude of change in the rate of change of the magnetic induction intensity is constant, such as a triangular wave and a sine wave.
- the voltage signal 1 303 K*A*Br or K*A*dBr/dt.
- the comparison circuit 1225 compares whether the voltage signal 1 303 is greater than Vt and sends the comparison result information to the second main processor 1201.
- the second main processor 1201 determines whether or not the card is allowed to be swiped based on the comparison result information.
- the measurement of the field strength of the low-frequency receiving link of the mobile radio device is errory.
- the error is basically equal to the error of the RF IC card/RF memory card.
- the error comes from the following a) ⁇ e) 5 aspects:
- the amplifier (low frequency amplifying circuit) allows the equivalent input noise figure eN (db);
- the system consisting of a card reader and a mobile terminal with a built-in mobile radio device is configured to achieve the goal of no calibration distance control, and the fluctuation of the detection voltage is distributed in various links in the system, and the fluctuations allowed to be allocated to the mobile radio frequency device itself are called The low frequency detection voltage fluctuation range ⁇ c (db) caused by the mobile radio device.
- the sum of the error factors of the above five mobile RF device RF IC card / RF memory card must be less than the error index ⁇ c (db) assigned by the system to the card. which is:
- the low frequency amplifying circuit 1215 is integrated inside the card chip.
- the amplification factor A of the low-frequency amplifier circuit is determined by the design of the chip design. In theory, there is a large range that can be freely selected, but once Bgate is determined and the sensor determines K, the size of A is determined.
- Vt Vt / Bgate / K
- Vt can take IV
- A can take the value of IV / Bgate / K 0
- the size of A determined by other parameters, but the value range of K can be A wider range is allowed, with the result that the selection of the low frequency magnetic sensing circuit 1206 provides a great deal of flexibility.
- the selection of the low frequency magnetic induction circuit 1206 can have a large degree of freedom, a 4 ⁇ pcb wire which is easy to implement on the card can be selected as the low frequency magnetic induction circuit 1206, as shown in FIG.
- the use of the 4 ⁇ pcb wire ⁇ sensor has the following advantages: 1. It is easy to implement, does not increase the structure on the card, the card itself needs pcb; 2, does not increase the size of the card. Thus the antenna of this solution can be implemented on the card without connecting to an antenna other than the card.
- the error margin of the RF IC card/RF memory card ⁇ c (db) is also an important part of the card design.
- the error margin S c(db) needs to be assigned to the following five factors: a) sensor (low frequency magnetic induction circuit) error ratio eK(db) of transform coefficient K; b) amplifier (low frequency amplifier circuit) Magnification A error ratio eA (db);
- the amplifier (low frequency amplifier circuit) allows the equivalent input noise figure eN(db);
- the error ratio eA of the amplification amplifier A of the low-frequency amplifier circuit is determined by the resistance ratio in the integrated circuit process.
- the present invention proposes a low frequency alternating magnetic field distance control method, which is applied to various mobile terminals including the above mobile radio frequency device, including the following Steps:
- Step a performing magnetoelectric conversion on the received low frequency alternating magnetic field signal Br to convert the low frequency alternating magnetic field signal into an electrical signal Vo.
- K is the magnetic induction circuit gain, A low frequency amplification circuit gain, A*K is the magnetoelectric conversion gain, the gain is preset, and there is no need to change during use; there is error in magnetoelectric conversion, that is, Vo has fluctuation, and the fluctuation range is S c (db) ;
- Step b if the electric signal Vo converted by the low frequency magnetic induction magnetic signal is greater than the preset comparison voltage signal threshold Vt, the IDID of the card reader is decoded, the radio frequency communication is entered, and the IDr is coupled to the mobile device itself through the radio frequency channel.
- the identification code IDc is transmitted to the card reader while continuously monitoring the low frequency magnetic induction signal;
- Step c performing radio frequency communication, splitting the radio frequency communication data into multiple data packets and transmitting and receiving in stages, and checking whether the Vo is greater than Vt every time the radio frequency is received or sent out, if yes, continuing the radio frequency communication until the transaction ends, otherwise the transaction is ended.
- RF communication return to step &.
- the method for determining the magnetoelectric conversion gain in step a is as follows:
- Step al determining the magnetic induction gain. Selecting a magnetic induction circuit, such as a coil, a Hall device, and a giant magnetoresistive device, which are easily implemented on the carrier of the mobile RF device, thereby selecting a magnetic induction gain K;
- a magnetic induction circuit such as a coil, a Hall device, and a giant magnetoresistive device, which are easily implemented on the carrier of the mobile RF device, thereby selecting a magnetic induction gain K;
- Step a2 arbitrarily selecting the gain of the low frequency amplifying circuit under the following principle
- the mobile device is placed in one or more carriers (such as mobile terminals) designated by the system, and the signal-to-noise ratio of the magnetic induction signal after the magnetoelectric conversion is greater than the distance that the system requires to control the target farthest receivable distance SNR.
- SNR usually 5;
- the frequency magnetic induction circuit is a line
- the mobile RF device is placed in the S IM, UIM card, US IM card, TF card, SD card or MMC card
- the number of turns of the line can be 1 ⁇ 20 ⁇
- the amplifier gain A is greater than 100
- the low-frequency magnetic induction circuit is a coil
- the mobile device is placed in the mobile terminal, and under the condition that the above-mentioned magnetoelectric conversion gain selection method is satisfied, the number of turns is not limited, and the gain A of the low-frequency amplifier circuit is not limited.
- step a the selection and control method of the fluctuation range ⁇ c of the detection voltage of the mobile radio device is as follows:
- ⁇ c is a system composed of a card reader and a mobile terminal with a built-in mobile radio frequency device.
- the fluctuation of the detection voltage is distributed in various links in the system, and is allocated to
- the allowable fluctuation of the mobile radio frequency device itself is called the low frequency detection voltage fluctuation range ⁇ c (db) caused by the mobile radio frequency device.
- the fluctuation range of the card can be determined to be relatively small, for example 2 to 6 dB.
- the control method of ⁇ c is as follows: To solve the problem of the difference in detected field strength between a plurality of mobile radio frequency devices, the present invention proposes an error control method based on the error control system shown in Fig. 17, which is applied to the above mobile radio frequency device.
- the transmission line 504 in the standard card reader 505 transmits a low frequency magnetic field signal having a constant amplitude or a constant differential amplitude to the mobile radio device 501 at a fixed distance and the standard obstacle 502 at a fixed position.
- the mobile radio device 501 is connected to the PC via a device 503 that communicates with the card.
- the control method of ⁇ c includes the following steps:
- the attenuation of the standard obstacle in the error control system is ⁇ ⁇ / 2
- the effect of the obstacle is to make the movement
- the attenuation of the low frequency alternating magnetic field received by the radio frequency device is the intermediate value of various terminal attenuations.
- Step 601 As shown in FIG. 17, the standard card reader transmits a low-frequency alternating magnetic field signal with a constant amplitude or a constant differential amplitude at a fixed distance and position, and the amplitude value Bga te or the amplitude value of the system is lower.
- the voltage value of the B.RATEgate magnetic field after magnetoelectric conversion should be the voltage signal Vo near the amplitude Vt;
- Step 603 Measure the output electrical signal Vo of the low frequency amplifying circuit in the mobile radio frequency device. If Vo exceeds the range of (Vt - ⁇ cx/2, Vt - ⁇ cx/2), adjust the amplification factor A of the low frequency amplifying circuit by software setting. Until Vo is within the above range;
- Step 604 Set the Vt value of the mobile radio frequency device by software to adjust the output electric signal Vo after step A to 603.
- the invention can realize the payment of the mobile terminal without calibration, and the method and the process for realizing the payment of the mobile terminal without calibration are specifically described below with reference to the examples.
- the implementation process has the following prerequisites:
- Prerequisites 1 The strength of the low-frequency magnetic field signal emitted by the matched card reader has been adjusted, and the spatial distribution of the field strength has met the requirements of distance control;
- the magnetic field signal having a constant differential amplitude allows the magnetic intensity change rate of the gate intensity threshold Bgate of the card to be ⁇ 26500 A/m/s (26500 amps per meter per second). If it is a 2 kHz magnetic field signal, the peak value of the magnetic induction intensity is ⁇ 3.32A/m, the peak-to-peak magnetic induction is 6.64A/m. If it is a magnetic field signal of ⁇ , the peak value of magnetic induction is ⁇ 6.64A/m, and the peak-to-peak magnetic induction is 13.28A/m;
- Prerequisites 2 The RF IC card/RF memory card is set with the appropriate threshold voltage Vt before leaving the factory.
- the threshold voltage Vt corresponds to the required swipe operation distance.
- the threshold voltage Vt corresponds to the magnetic intensity change rate of the gate strength threshold Bgate of the card swiping is ⁇ 26500 A/m/s
- the peak-to-peak voltage Vt of the output voltage 1302 of the low-frequency magnetic induction circuit is IV;
- Precondition 3 RF IC card/RF memory card and card reader The communication and credit card agreement between the two has been stipulated;
- the data bit stream between the RF IC card/RF memory card and the card reader can be transmitted using a differential Manchester coded baseband signal of 2K baud rate.
- Data information in data frames The unit performs transmission, and the data frame bi t stream is encoded as follows: Each frame of data has a sync header of 9b it, the sync header is 1 of 8bi t , and the latter is 0. In the data information behind the synchronization header, a row of 1 is followed by a bit of 0 to distinguish the data information and the synchronization header;
- Prerequisites 4 The RF IC card/RF memory card has been installed in the mobile terminal and is ready for card swipe operation;
- the card reader is ready to continuously transmit the low frequency magnetic field signal carrying the digital frame information of the reader data frame Idr;
- the data frame information Idr includes channel information of the RF module of the card reader; further, the channel information of the RF module of the card reader is a channel between 2480 MHz and 2843 MHz;
- Precondition 6 Frequency of low frequency operation f O has been determined according to the aforementioned steps;
- Prerequisites 7 The amplification factor of the low-frequency amplifier circuit of the RF IC card/RF memory card A and the threshold Vt have been set according to the aforementioned error control method.
- the RF IC card/RF memory card implementing the method is as described above.
- the low frequency magnetic induction circuit 1206 of the RF IC card/RF memory card converts the low frequency magnetic field signal 1301 at the position into the low frequency magnetic field voltage signal 1302.
- the low frequency magnetic induction circuit 1206, the low frequency amplifier circuit 1215 and the comparison circuit 1225 are low power consumption modules, and the power supply current consumption during operation is less than 300 uA.
- the low frequency magnetic induction circuit 1206, the low frequency amplifying circuit 1215 and the comparison circuit 1225 can operate continuously and affect.
- the other modules in the RF IC card/RF memory card are in a sleep state for most of the time, and basically do not consume the power supply current;
- the low frequency magnetic induction circuit 1206 sends the low frequency magnetic field voltage signal 1302 to the low frequency amplifying circuit 1215 in the low frequency signal receiving and processing module 1205, and the amplified voltage signal 1303 of the low frequency amplifying circuit 1215 is supplied to the comparing circuit 1225 and the decoding circuit 1245.
- the low frequency magnetic induction circuit 1206 is composed of 4 pc along the pcb line s of the s im card frame, such a low frequency magnetic induction circuit 1206 is In a magnetic field with a constant differential amplitude of ⁇ 26500 A/m/s, a peak voltage signal of ⁇ 50 uV will be sensed with a peak-to-peak value of l OOuV;
- the comparison circuit 1225 compares the voltage signal 1303 with the threshold voltage Vt and compares The result is sent to the second main processor 1201. If the comparison result is greater than Vt, the other modules of the wake-up card work together, otherwise, the other modules continue to sleep;
- the second main processor 1201 controls the decoding circuit 1245 to decode the received voltage signal 1303 to obtain digital information of the card reader Idr.
- the decoding circuit 1245 sends the decoded digital information of the card reader Idr to the second main processor 1201;
- the second main processor 1201 finds the channel information CH, and controls the RF transceiver circuit 1203 to communicate with the card reader through the RF antenna 1204 on the channel CH, and establishes only the current card reader and
- the RF IC card/RF memory card can communicate with the RF communication channel CH, and the received card reader Idr is sent to the card reader through the RF communication channel;
- the card reader determines whether the Idr received from the RF communication channel is the Idr that it sends out from the low frequency magnetic field signal. If not, the communication is rejected. If it is correct, the subsequent communication with the card is initiated until the required card swipe operation is completed.
- the RF IC card/RF memory card and the card reader require multiple RF communications. During each RF communication process, the card must determine whether the voltage signal 1303 is less than the threshold voltage Vt. If it is less than Vt, it will end immediately. RF communication, ending the card-free operation that has not yet been completed. If the RF IC card/RF memory card interacts with the mobile terminal during the card operation, it can be implemented through the interface module 1207.
- the modules other than the low frequency magnetic induction circuit 1206, the low frequency amplifying circuit 1215, and the comparison circuit 1225 in the low frequency signal receiving and processing module 1205 continue to sleep until the voltage 1303 corresponding to the next low frequency magnetic field signal is less than Vt.
- the implementation of the credit card operation function of the mobile terminal payment is redundantly performed by the second main processor 1201, the SIM/UIM/USIM/TF/SD/MMC card module, the RF transceiver circuit 1203, and the RF antenna 1204. ;
- the SIM/UIM/USIM/TF/SD/MMC card module performs its intended function. When implementing its function, it interacts with the mobile terminal through the second main processor 1201 and the interface module 1207.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Business, Economics & Management (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Accounting & Taxation (AREA)
- Strategic Management (AREA)
- General Business, Economics & Management (AREA)
- Near-Field Transmission Systems (AREA)
Description
移动射频装置、 射频 IC卡及射频存储卡
技术领域
本发明涉及通信领域, 尤其涉及一种移动射频装置、 射频 IC卡及射频 存储卡。 背景技术
随着移动终端的普及, 利用移动终端进行移动终端支付的应用需求非常 迫切, 目前已经有多种实现方案, 但各有缺点。 当前,已经出现了在移动终 端中的用户识别模块 SIM ( Subscr iber Ident i ty Module )卡上增加射频功 能(称为射频 SIM卡 )或者在移动终端主板上增加近距离通信模块来实现移 动终端近距离通信的方法,后者称为 FC (Near Field Communicat ion,近场通 信),这些方法的出现使得移动终端成为一个可以充值、 消费、 交易及身份认 证的超级智能终端, 极大地满足了市场的迫切需求。
其中, 基于射频 SIM卡的移动终端近距离解决方案以其筒单、 无需更改 移动终端等优势得到广泛的关注, 在该方案中, 射频 S IM卡采用 UHF ( Ul tra High Frequency, 超高频)技术, 由于 UHF特别是采用 2. 4GHz ISM公共频 段(即工业, 科学和医用频段)的射频 SIM卡, 其工作频率很高, 天线的尺寸 很小, 在 SIM卡内放置小型的天线就能发射足够强度的信号, 即使射频 SIM 卡嵌入在移动终端内部射频信号仍然可以从移动终端中透射出来,在读卡器 中采用业界主流的 RF (Radio Frequency,射频)收发芯片即可无需额外放大 可靠接收到绝大多数移动终端的射频信号,从而实现不必对现有的移动终端 进行任何结构改变就可使移动终端具备近距离通信功能。 但是, 不同移动终 端由于内部结构不同造成射频信号透射效果存在很大的差异,透射强的移动 终端其射频 SIM卡射频通信距离可能达到几米远的距离,透射弱的移动终端 其射频 SIM卡通信距离只可以达到几厘米。射频 SIM卡为了避免不同移动终 端对 RF信号衰减的巨大差异, 必须对移动终端进行校准, 也就是在使用前 必须将移动终端的衰减参数记录到卡中。需要校准是射频 S IM卡的主要问题。
另外一种移动支付的技术 NFC基于 I S014443标准的非接触卡技术演化 而来, 两者根本点在于都采用 1 3. 56MHz的磁场传送信号和能量。 NFC技术的 主要问题有:
1.必须改造移动终端才能实现可靠的双向数据通讯, NFC的磁场线圏不 能集成到 S IM 卡或 SD 卡(Secure Di g i ta l Memory Card,安全数字存储 卡) /TF (TransFLa sh,闪存)卡等移动终端用的卡内。
在 1 3. 56MHz频点下, 读卡器和卡之间采用电感线圏耦合的方式交互信 号及传送能量,读卡器到卡的方向需要同时传递能量和 1 3. 56MHz调幅信号, 对卡上接收线圏的尺寸面积均有较高要求; 卡到读卡器的方向, 卡依靠短路 和开路卡上线圏的负载调制方式而不是依靠外部能量直接发送场强的方式 向读卡器传递信息, 由于负载调制信号要求卡线圏和读卡器线圏的耦合系数 越高越利于读卡器解码卡传送的信息, 这种方式进一步提高了对卡上天线尺 寸和面积的要求。 另外一方面, 由于 1 3. 56MHz频点较低, 耦合线圏的尺寸 相对较大。 综合上述因素, NFC要求移动终端内的天线线圏足够大, 该尺寸 大小完全不能放入 S IM卡或 SD/TF卡等移动终端用的卡内, 不但如此, 移动 终端上的金属及其它导电物体会严重干扰天线的接收和负载调制效果, 为了 达到近场通讯良好的通讯效果, 必须对手机进行定制化的改造, 使天线的效 果达到最佳。 改造点例如, 将卡的多匝天线放到移动终端的电池后盖上, 或 者通过柔性 PCB从终端主板上将天线引到电池背面, 天线的面积和普通电池 尺寸相当, 另外, 手机的后盖不能为金属材质。
2. NFC所使用的 1 3. 56MHz频点需要校准才能用于距离控制。
即使有一种 NFC 的天线能够更换到任何移动终端中, 由于其使用 1 3. 56MHz频点,该频点信号在遇到金属和其它导电物体会形成强烈的涡流效 应, 信号强度会随着移动终端结构而变化, 从而在 NFC卡接收天线上形成场 强的巨大波动, 无法进行无校准的距离控制。
图 1为线圏接收电路放入各种移动终端内, 在同一 14443 P0S机上保持 1 3. 56MHz 载波恒定的情况下测试的电压-距离曲线,其中信号强度值是接收 天线感应电压经过必要的放大后的值, 放大倍数保持恒定, 只需关注强度随 距离的相对变化。 可以看出, 不同终端接收到的场强差异 > 30dB , 同一终端 从 l cm到 10cm的场强变化为 25dB左右,手机差异造成的场强变化已经超过
终端在 l cm到 1 0cm距离控制范围内的场强变化, 因此无法采用同一门限对 各终端进行距离控制, 也就是无法实现无校准距离控制。 发明内容
本发明所要解决的技术问题是提供一种移动射频装置,使得设置有该移 动射频装置的移动终端能够实现电子支付等刷卡交易。
为解决上述技术问题, 本发明提出了一种移动射频装置, 包括至少一个 低频磁感应电路、 至少一个低频放大电路、 至少一个门限判断及解调电路、 至少一个第二主处理器、 至少一个射频收发电路和至少一个射频天线, 所述 低频磁感应电路、 低频放大电路、 门限判断及解调电路、 第二主处理器、 射 频收发电路、 射频天线顺次串联连接; 其中, 所述低频磁感应电路、 低频放 大电路、 门限判断及解调电路组成的低频接收链路工作于预先选定的***无 校准工作的最高频率 f O以下的频率。
进一步地, 上述移动射频装置还可具有以下特点, 所述低频磁感应电 路为线圏,低频磁感应电路转换增益与低频放大电路的放大倍数的乘积为与 移动射频装置所在移动终端所应用的***最远刷卡距离对应的***预设值, 所述低频接收链路的体积取决于所述低频磁感应电路转换增益及低频放大 电路的放大倍数,低频接收链路的体积随低频磁感应电路转换增益的增大而 增大, 或者随低频放大电路放大倍数的减少而增大。
进一步地, 上述移动射频装置还可具有以下特点, 所述***无校准工作 的最高频率 f O处于特低频频段或甚低频频段或低频频段,所述特低频频段的 频率范围为 300 Hz - 3000Hz, 所述甚低频频段的频率范围为 3KHz ~ 30KHz, 所述低频频段的频率范围为 30 KHz ~ 300KHz。
进一步地, 上述移动射频装置还可具有以下特点, 所述***无校准工作 的最高频率 f O所处的频率范围为 300Hz ~ 50KHz。
进一步地, 上述移动射频装置还可具有以下特点, 所述***无校准工作 的最高频率 f O为 500Ηζ、 1ΚΗζ、 1 · 5ΚΗζ、 2ΚΗζ、 2· 5ΚΗζ、 3ΚΗζ、 4ΚΗζ、 5ΚΗζ、 1 0ΚΗζ、 20ΚΗζ或 30ΚΗζ。
进一步地, 上述移动射频装置还可具有以下特点, 所述门限判断及解调 电路由相互连接的比较电路和解码电路组成。
进一步地, 上述移动射频装置还可具有以下特点, 所述门限判断及解调 电路由顺次相连的比较电路、 解调电路和解码电路组成。
进一步地, 上述移动射频装置还可具有以下特点, 所述低频磁感应电路 为 PCB线圏、 漆包线线圏、 霍尔器件或巨磁阻器件。
进一步地, 上述移动射频装置还可具有以下特点, 所述移动射频装置置 于移动终端中。
进一步地, 上述移动射频装置还可具有以下特点, 所述移动射频装置置 于移动终端内的 SIM卡、 UIM卡、 USIM卡、 TF卡、 SD卡或 MMC卡中。
进一步地, 上述移动射频装置还可具有以下特点, 所述第二主处理器与 SIM/UIM/USIM/TF/SD/MMC卡中的处理器为同一共用处理器。
进一步地,上述移动射频装置还可具有以下特点,所述移动终端为手机、 个人数字助理 PDA或笔记本电脑。
为解决上述技术问题, 本发明还提出了一种射频 IC卡, 包括上述任一 项所述的移动射频装置。
为解决上述技术问题, 本发明还提出了一种射频存储卡, 包括上述任一 项所述的移动射频装置。
为解决上述技术问题, 本发明还提出了一种确定上述各项移动射频装置 中***无校准工作的最高频率 f O的方法, 包括如下步骤:
步骤 al , 确定***的距离控制目标(Din, Dv ), 所述***中包含至少一 个移动射频装置和至少一个读卡器, 其中 Din表示距离为 0 ~ Din的范围内 所有装载有所述移动射频装置的终端确保可刷卡, Dv表示距离波动范围,距 离为 Din ~ ( Din+Dv )的范围内均允许刷卡, 距离大于 Din+Dv的范围不允许 刷卡;
步骤 a2 , 确定读卡器导致的移动射频装置内检测电压的波动范围 δ κ; 步骤 a3 , 确定移动射频装置本身导致的检测电压的波动范围 S c;
步骤 a4 , 在 f 频率下测试各典型终端及障碍物的电压距离曲线,所述 f 频率为处于特低频频段或甚低频频段或低频频段中的任一频率,所述特低频 频段的频率范围为 300 Hz ~ 3000Hz, 所述甚 频频段的频率范围为 3KHz ~ 30KHz,所述低频频段的频率范围为 30 KHz - 300KHz;
步骤 a5 , 由距离控制目标(Din, Dv )确定移动射频装置内检测电压的
波动范围 δΑ, δ Α等于由各典型终端及障碍物的电压距离曲线得到的具有平 均场强衰减曲线斜率的电压距离曲线上 Din点所对应的电压值与 (Din+ Dv ) 点所对应的电压值之差;
步骤 a6, 确定由终端导致的移动射频装置内检测电压的波动范围 δτ, δτ表示终端衰减特性造成的移动射频装置内检测电压波动范围, δ τ= δ A- δ R- δ c;
步骤 a7,计算各典型终端及障碍物间在距离控制范围内各距离点上的最 大场强差异 δ , 若 δ 大于 δτ, 则降低频率 f, 转步骤 a4; 若 δ 小于 δτ, 则提高频率 f, 转步骤 a4; 若 δ 等于 δτ, 则当前测试频率 f 等于***无校 准工作的最高频率 f0。
为解决上述技术问题, 本发明还提出了一种低频交变磁场距离控制方 法, 应用于包括前述任一项所述的移动射频装置的移动终端,该方法包括如 下步骤:
步骤 a,对接收到的低频交变磁场信号 Br进行磁电转换,将低频交变磁 场信号转换为电信号 Vo, 若 Br为幅度恒定的低频交变磁场信号, 则磁电转 换公式为 Vo=A*K*Br; 若 Br为 分幅度恒定的低频交变磁场信号, 则磁电转 换公式为 Vo=A*K*dBr/dt, 其中 K为低频磁感应电路增益, A低频放大电路 增益, A*K为磁电转换增益, 该增益预先设定;
步骤 b,若低频交变磁场信号转换的电信号 Vo大于预设的比较电压信号 门限 Vt, 则解码出读卡器的身份识别标识 IDr, 进入射频通讯, 通过射频通 道将 IDr连同移动射频装置本身的唯一识别码 IDc—同传送给读卡器, 同时 持续监控低频交变磁场信号;
步骤 c, 进行射频通讯, 将射频通讯数据拆分为多个数据包分次收发, 每次射频收包或发包都检查 Vo是否大于 Vt, 若是则继续射频通讯直至交易 结束, 否则结束本次交易的射频通讯, 返回步骤&。
进一步地, 上述低频交变磁场距离控制方法还可具有以下特点, 所述步 骤 a中磁电转换增益的确定方法如下:
步骤 al, 确定磁感应增益 K, 选定移动射频装置所在载体上的低频磁感 应电路, 从而选定了磁感应增益 K;
步骤 a2, 在下述原则下任意选定低频放大电路的增益 A:
1 )移动射频装置在任意位置处接收到的磁感应强度 Br小于***安全规 范要求的值;
2 )移动射频装置放置于***指定的一种或多种载体中, 并在***要求 的距离控制目标最远可接收距离处,磁感应信号经过磁电转换后的信号 信噪比大于 SNR;
3)若磁感应电路为霍尔器件或巨磁阻器件: A*K = Vt/Bgate,其中 Bgate 为磁感应强度门限; 若磁感应电路为线圏: A*K = Vt/B_RATEgate, 其中 B.RATEgate 为磁感应强度变化率的门限值, 磁感应强度变化率 B_RATE=dBr/dt0
进一步地, 上述低频交变磁场距离控制方法还可具有以下特点, 所述步 骤 a2中信噪比 SNR大于 5。
进一步地, 上述低频交变磁场距离控制方法还可具有以下特点, 所述低 频磁感应电路为线圏, 所述移动射频装置放置在 SIM卡、 UIM卡、 USIM卡、 TF卡、 SD卡或 MMC卡中, 则所述线圏的匝数为 1 ~ 20匝, 频放大电路的 增益 A大于 100。
进一步地, 上述低频交变磁场距离控制方法还可具有以下特点, 所述步 骤 a中, 所述磁电转换存在误差, 即 Vo存在波动, 波动范围为 S c(db),误 差 S c(db) 的选择及控制方法如下:
δ c的范围为 2 ~ 6dB;
δ c的控制方法包括如下步骤:
假设移动射频装置所应用的各种移动终端对低频交变磁场信号的衰减 的最大波动范围为 δ Τ, 则所述误差控制***中标准障碍物的衰减为 δΤ/2。
步骤 601: 标准读卡器在固定距离及位置上发射幅度恒定或微分幅度恒 定的低频交变磁场信号, 该***下幅度值 Bgate或 分幅度值 B.RATEgate 的磁场经过磁电转换后的电压值为幅度为 Vt附近的电压信号 Vo;
步骤 602: 确定 Vo范围 (Vt_S cx/2, Vt- δ cx/2) , 其中 δ cx< δ c; 步骤 603: 测量移动射频装置中低频放大电路的输出电信号 Vo,如果 Vo 超出(Vt- δ cx/2, Vt- δ cx/2)范围, 则通过软件设置调整低频放大电路的放 大倍数 A, 直到 Vo在上述范围内;
步骤 604:通过软件设置移动射频装置的 Vt值为步骤 603调整 A后的输
出电信号 Vo。
进一步地, 上述低频交变磁场距离控制方法还可具有以下特点, 所述电 压门限 V t用与该电压门限 V t对应的电流门限替代。
本发明的移动射频装置, 能够使设置有该移动射频装置的移动终端实现 电子支付等刷卡交易。 附图说明
图 1为线圏接收电路放入各种移动终端内, 在同一 14443 P0S机上保持 13. 56MHz载波恒定的情况下测试的电压 -距离曲线;
图 2为本发明近距离通信方法中***无校准工作的最高频率 f O的选择 ***结构框图;
图 3为由距离控制目标( Din, Dv )确定***总的接收检测电压波动范围 δ Α的示意图;
图 4为典型终端及障碍物电压距离曲线及其波动区间 δ示意图; 图 5为频率 f 为 3. 3KHz时 5种典型移动终端的电压距离曲线; 图 6为移动射频装置内部检测到的无调制直接基带发射时的接收电压信 号和正弦波 FSK调制时的接收电压信号的电压波形图;
图 7为基准电压距离曲线的计算方法示意图;
图 8为本发明实施例中近距离通信***的结构图;
图 9为读卡器低频发射部分示意图;
图 10为读卡器低频数据帧格式示意图;
图 11 为线圏接收电路放入各种移动终端内, 用信号源通过低频发射线 圏发射恒定 ΙΚΗζ磁场条件下测试的电压距离曲线;
图 12为本发明实施例中射频 IC卡的结构图;
图 13为应用于 SIM卡的 4匝 pcb铜皮线圏天线结构示意图;
图 14为 5bi t数据 11010的差分曼切斯特编码格式以及场强、 线圏接收 电压波形图;
图 15为 ΙΚΗζ的低频磁场移动终端内 s im卡接收到的幅度恒定图; 图 16为应用于 TF卡的 4匝 pcb线圏天线结构示意图;
图 Π为误差控制***框图。
具体实施方式
在此首先说明, 以下本文中所出现的终端在默认情况下指装载有移动射 频装置的终端, 而且指能够移动的终端, 即移动终端, 如手机等, 距离指读 卡器与移动射频装置之间的距离,也即读卡器与装载有移动射频装置的终端 之间的距离。
本发明针对射频装置(尤其是内置于终端中的射频卡, 如射频 SIM卡) 与读卡器装置近距离交易的距离控制问题,提出了一种由带有低频交变磁场 发射功能及射频信号收发功能的读卡器和与之对应的带有低频交变磁场感 应接收功能及射频信号收发功能的移动射频装置组成的近距离通信***, 以 及与该***对应的近距离通信方法。本发明利用低频交变磁场穿透不同终端 衰减差异小的特点进行距离控制, 利用高频射频能有效穿透终端来完成高速 双向通讯进行交易。 ***通过预先设定好的门限判定方法来完成无需校准的 距离检测和控制, 即读卡器按照预设的发射参数发射低频交变磁场信号, 移 动射频装置在各距离点上检测该磁场信号并放大为与距离对应的幅度恒定 的电压信号, 进而通过预先设定的电压门限 Vt来判断终端是否进入预先设 定的有效距离区间(有效距离区间也即允许刷卡的范围), 该电压门限 Vt对 所有终端相同, 无需校准。 本发明通过低频单向通讯和 RF双向通讯结合的 方法来完成读卡器和移动射频装置的唯一绑定, 绑定之后通过射频通道来完 成双向的高速大数据量的通讯。本发明***可以实现含有移动射频装置的终 端 (如装有射频 SIM卡的手机)与读卡器的数据通信距离 (也即交易距离) 可靠地控制在规定范围内, 并且无需对终端进行校准。
以下结合附图对本发明的原理和特征进行描述, 所举实例只用于解释本 发明, 并非用于限定本发明的范围。
本发明的近距离通信方法,应用于包括至少一个读卡器和至少一个移动 射频装置的近距离通信***, 包括如下的步骤 &、 步骤 b、 步骤 c和步骤 d 四个步骤, 下面分别对各个步骤进行具体说明:
步骤 a , 读卡器按照预设的发射参数发射低频交变磁场信号, 该低频交 变磁场信号中携带该读卡器的身份标识信息, 其中, 发射参数包括低频交变 磁场信号的频率, 该频率等于或小于***无校准工作的最高频率 f O; 其中,
身份标识信息可以是识别码 ID。
这里需要说明的是, 本步骤中低频交变磁场信号的频率是指所述低频交 变信号的频谱上 3dB带宽的高端频率截止点所对应的频率。
低频交变磁场频率越低, 穿过各种类型的终端后衰减的差异越小,利用 该特性, 在频点选择***(如图 2所示) 中选定差异足够小的频点, 以实现 无校准距离控制。采用标准信号源通过标准的磁场发射线圏发送低频交变磁 场信号, 在各个典型的移动终端及障碍物内部接收该低频交变磁场信号, 调 整发射频率直到找到频点 f O , 使移动射频装置(装载在移动终端中)接收到 的电压(该电压是由低频交变磁场信号经放大后得到的与距离对应的幅度恒 定的的电压信号)在距离发射线圏平面中心点相同距离条件下, 不同终端及 障碍物间的场强差异大致等于设定的波动范围 δ τ,该频点 f 0及低于该频点 f O的频段是***无校准工作的频段, 不需要校准任何***中的任何终端, 工 作频点(即前述的低频交变磁场信号的频率)高于 f O , ***需要校准, 通常 工作频点高于 f O越多, 需要校准的终端越多, 校准的复杂度越高。 频点选 定是一次性工作, 一旦选定, 在使用中无需更改。
图 2为本发明近距离通信方法中***无校准工作的最高频率 f O的选择 ***结构框图,如图 2所示,频点选择***的组成为:发送***由信号源 505 和低频磁场发射线圏 504组成, 接收***由典型移动终端 501及障碍物、 信 号强度测试仪 503 (电压表、 示波器、 频谱仪等)组成, 移动终端 501内部 具有低频接收模块 502。 信号源 505可以精确的产生各种频率、 波形和幅度 的信号。 频点选择的原理是: 信号源 505产生固定幅度频率为 f 的正弦波信 号, 通过发射线圏 504发送, 低频接收模块 502放置在选定的典型移动终端 501或障碍物内部, 接收到的低频信号通过专用信号线接到信号强度测试仪 503 , 信号强度测试仪 503测试接收到的电压。 改变移动终端的距离可以得 到该移动终端或障碍物在频率 f 条件下的检测电压随距离变化的曲线(以下 称为电压距离曲线), 更换移动终端或障碍物可以得到多个终端的曲线, 改 变频率 f也可以得到不同的曲线。
步骤 a中, ***无校准工作的最高频率 f O通过下述步骤确定: 步骤 101 , 确定距离控制目标(Din, Dv ), 其中 Din表示 0 ~ Din范围内 所有终端确保可刷卡, Dv表示距离波动范围, 距离为 Din ~ ( Din+Dv )的范
围内均允许刷卡, 距离大于 Din+Dv范围不允许刷卡;
例如(5cm, 5 cm)表示 5 cm以下所有终端确保可刷卡, 5 cm ~ 10 cm允许 刷卡, 超过 10cm不能刷卡。 距离控制目标由具体的应用确定。 (0 ~Din+Dv) 称为距离控制范围。
步骤 102, 确定读卡器导致的移动射频装置内检测电压的波动范围 δκ; 读卡器低频发射电路参数波动形成发射场强的波动,造成移动射频装置 内检测电压的波动, 该参数包括发射驱动电压波动、 线圏参数波动、 温度影 响等。 δκ由读卡器设计及生产环节来控制, 该波动可以在生产环节校准, 由于低频发射电路工作频率很低, 通常 δ κ可以被控制得很好, 例如 4dB以 内。
步骤 103, 确定移动射频装置本身导致的检测电压的波动范围 Sc;
移动射频装置本身低频接收电路参数波动造成的最终检测输出电压的 波动, 该参数包括接收天线误差、 放大器增益误差、 比较器或 AD误差、 温 度影响及噪声等。 Se由移动射频装置设计及生产环节来控制, 该波动可以 在生产环节校准, 由于移动射频装置低频接收电路工作频率很低, 通常 s c 可以被控制得很好, 例如 4dB以内。
步骤 104,在 f 频率下测试各典型终端及障碍物的电压距离曲线,其中 f 频率为处于特低频频段或甚低频频段或低频频段中的任一频率,特低频频段 的频率范围为 300 Hz - 3000Hz, 甚低频频段的频率范围为 3KHz ~ 30KHz,低 频频段的频率范围为 30 KHz - 300KHz;
在进行本步骤 104之前先要做个准备工作, 即选定典型终端及典型障碍 物。 典型终端的选取原则主要依据终端金属或导电结构的多少来选取, 金属 越多, 衰减越大, 例如可以选取塑料外壳、金属外壳、厚金属壳、 薄金属壳、 大尺寸终端、 小尺寸终端等, 典型终端的数量不严格限制, 典型终端的选取 基本可以覆盖终端对低频交变磁场信号的衰减特点。 为了避免个别移动终端 差异太大, 可以在应用中加入移动终端型号认证, 对每种需要支持支付应用 的移动终端尝试做刷卡测试, 确认该型号的移动终端衰减特性符合要求。 典 型障碍物可以选择不同材质的标准形状的塑料、 铝、 铜、 铁、 不锈钢等移动 终端常见材料,放置在读卡器和移动射频装置之间作为移动终端衰减特性的 一种等效障碍物测量衰减效果。
步骤 105, 由距离控制目标(Din, Dv)确定移动射频装置内检测电压的 波动范围 δΑ, δ A等于由各典型终端及障碍物的电压距离曲线得到的具有平 均场强衰减曲线斜率的电压距离曲线上 Din点所对应的电压值与 (Din+ Dv ) 点所对应的电压值之差;
图 3为由距离控制目标(Din,Dv)确定***总的接收检测电压波动范围 δΑ的示意图。 如图 3所示, (Din+ Dv)点所对应的电压值为 V2, Din点所 对应的电压值为 VI,则 SA=V1-V2。
步骤 106, 确定由终端导致的移动射频装置内检测电压的波动范围 δτ, 参数 δτ表示终端衰减特性造成的移动射频装置内检测电压波动范围, δ τ= δ Α_ δ R_ δ c;
步骤 107, 计算各典型终端及障碍物间在距离控制范围内各距离点上的 最大场强差异 δ (又称为波动区间), 若 δ 大于 δτ, 则降低频率 f, 转步 骤 a4; 若 δ 小于 δτ, 则提高频率 f, 转步骤 a4; 若 δ 等于 δ τ, 则当前测 试频率 f 等于***无校准工作的最高频率 f0。
图 4为典型终端及障碍物电压距离曲线及其波动区间 δ示意图。 如图 4 所示, 最大衰减终端或障碍物对应的电压距离曲线称为最大衰减曲线, 最小 衰减终端或障碍物对应的电压距离曲线称为最小衰减曲线, 最大及最小衰减 曲线包围的区域称为典型终端及障碍物电压距离曲线分布区间, 任意距离 D 在最小衰减曲线上对应的电压为 V3, 在最大衰减曲线上对应的电压为 V4, 则 5=V3-V4。
至此, 在限定距离控制目标的情况下, ***无校准工作的最高频率 f0 就确定下来了。 ***可以采用调制的方式, 也可以采用直接发送基带信号的 方式, ***工作的主要频率分量最高只要不大于 f0, 距离控制就无需校准。
举例说明 f0的确定过程。 图 5为频率 f 为 3.3KHz时 5种典型移动终端 的电压距离曲线。 如图 5所示, ***距离控制目标为(5cm, 5 cm), *** 0~ 10cm距离区间电压的变化范围约为 40dB, 读卡器和移动射频装置导致的移 动射频装置内检测电压波动均为 4dB, 即 SR=Sc=4dB, δΑ=20άΒ , ST=SA_SR_Sc=12dB。 假设 5种终端可以代表***所使用的所有终端, 检查 曲线在各距离点上的最大波动约等于 12dB,因此该***无校准工作的最高频 率 f0可确定为 f0=3.3KHz。
步骤 a中, 发射参数还可以包括调制方式、 编码方式及发射磁感应强度 幅值 Br。发射参数选定的基本原则是保证移动射频装置在各距离点上对读卡 器所发射的低频交变磁场信号检测并放大后的信号是与距离对应的幅度恒 定的电压信号。 图 6为移动射频装置内部检测到的无调制直接基带发射时的 接收电压信号和正弦波 FSK调制时的接收电压信号的电压波形图, 其中, a 为无调制直接基带发射时的接收电压信号波形图, b为正弦波 FSK调制时的 接收电压信号波形图。 如图 6所示, 检测电压信号是包含解调信息的变化电 压信号, 该信号可以为无直流分量的交流电压信号, 也可以是有直流分量的 电压信号, 幅度恒定是指交流分量的变化最大幅度在不同传输符号间恒定。
发射参数中的调制方式、 编码方式及发射磁感应强度幅值 Br通过下述 步骤 al l至步骤 al 3选定:
步骤 al l ,选定任意一种无平均直流分量的编码方式,例如曼彻斯特码, 差分曼彻斯特码, 归零码等;
步骤 al 2 , 选择无调制方式或幅度无变化的载波调制方式, 载波调制方 式可以选定任意一种幅度无变化的调制方式, 例如载波可以采用正弦波、 脉 沖、 三角波等, 调制方式可以选为开关键控法(00K )、 相移键控法或频移键 控法 (FSK )等; 采用无调制方式时, 编码后的基带信号直接经驱动电路驱 动由发射线圏发射;
步骤 al 3 , 选定发射磁感应强度幅值 Br , 方法为: 在选定的小于 f O的 工作频率、 调制方式及编码方式下, 先选定典型噪声终端及易于实现的移动 射频装置内磁检测及放大的增益参数,将包含移动射频装置的移动终端放置 在离读卡器为距离控制目标最远处即 Din+Dv距离处, 如果移动射频装置采 用霍尔器件、 巨磁阻器件等检测磁场强度值的磁感应电 妻收, 则读卡器发 射磁感应强度变化幅度恒定的磁场信号; 如果移动射频装置采用线圏等检测 磁场强度变化率的感应电路接收, 则读卡器发射磁感应强度变化率幅度(即 微分幅度)恒定的磁场信号, 测试读卡器未发送低频交变磁场信号条件下移 动射频装置内检测电压的固有噪声电压幅度 Vn,然后测量读卡器用选定的调 制编码方式发送低频交变磁场信号时移动射频装置内的检测电压 Vr ,选择发 射幅度值 Bgate或 分幅度值 B_RATEgate, 使 Vr/Vn>SNR, SNR为移动射频 装置的信噪比。 SNR值的选择通常越大越好, 但是太大会造成读卡器发送功
率过大, 实现困难, 典型值可选择 SNR=10.当 SNR确定, Br通过上述方式便 确定了, 根据***选择的磁感应电路类型不同, Br参数值分为两种, 霍尔器 件及巨磁阻器件接收***为磁感应强度幅值门限 Bga te , 线圏接收***为磁 感应强度变化率幅值门限 B_RATEga t e。
步骤 b , 移动射频装置在各距离点上接收、 检测所述低频交变磁场信号 并放大为与距离对应的幅度恒定的的电压信号,进而通过预设的电压门限 V t 判断装载有所述移动射频装置的终端是否进入了预设的有效距离区间,所述 电压门限 Vt对装载有所述移动射频装置的所有终端相同;
步骤 b中, 预设的电压门限 Vt通过下述步骤 201至步骤 203确定, 前 提是, 确定读卡器发射及移动射频装置接收是无波动的, 或者两者引起的接 收检测电压波动远小于 3 1!及 S c:
步骤 201 , 在选定的发射参数下, 测量各典型终端和障碍物的电压距离 曲线, 其中, 发射参数包括低频交变磁场信号的频率、 调制方式、 编码方式 及发射磁感应强度幅值 Br ;
步骤 202 , 求取基准电压距离曲线, 基准电压距离曲线是典型终端及障 碍物曲线的中间值, 其距离典型终端曲线的上边界及下边界的电压幅度都为 δ τ/2 , 如图 7所示;
步骤 203 ,选定移动射频装置内检测电压门限值 Vt , Vt值等于距离控制 目标 Din与 (Din+Dv )分别对应的电压值之间以 dBmV为单位的电压值的中 间值。 如图 7所示, 在基准电压距离曲线上对应于 Din的电压为 V5 ( dBmV ), 对应于 (Din+Dv ) 点的电压值为 V6 ( dBmV ), 则 Vt=V5- (V5- V6) /2 ( dBmV )0 步骤 c , 若与接收到的低频交变磁场信号对应的电压信号大于或等于预 设的电压门限 Vt , 则装载有移动射频装置的终端进入了预设的有效刷卡区 间,移动射频装置从接收到的低频交变磁场信号中获取读卡器的身份标识信 息, 并将其连同自身的身份标识信息一起通过射频通道传送给读卡器;
步骤 d , 读卡器接收移动射频装置通过射频通道传送的信息, 比较该信 息中读卡器的身份标识信息是否同自身的身份标识信息一致, 若一致则以自 身的身份标识信息和移动射频装置的身份标识信息的结合作为组合地址, 与 移动射频装置通过射频通道进行刷卡交易。此处,刷卡交易不单指电子支付, 还可以是其他通过射频通道进行的通讯过程, 比如充值、消费、身份认证等,
本文中的刷卡交易泛指通过射频通道进行的通信,尤其指近距离通信中通过 射频通道进行的通信。
本发明中,低频交变磁场信号的频率处于特低频频段或甚低频频段或低 频频段,其中, 特低频频段的频率范围为 300 Hz ~ 3000Hz, 甚低频频段的频 率范围为 3KHz ~ 30KHz,低频频段的频率范围为 30 KHz ~ 300KHz。 优选地, 低频交变磁场信号的频率可以为 300Hz ~ 50KHz。优选地,低频交变磁场信号 的频率可以为 500Ηζ、 1ΚΗζ、 1 · 5ΚΗζ、 2ΚΗζ、 2· 5ΚΗζ、 3ΚΗζ、 4ΚΗζ、 5ΚΗζ、 10ΚΗζ、 20ΚΗζ或 30ΚΗζ。
本发明近距离通信方法采用低频磁场单向通讯和射频电磁场高速双向 通讯的结合, 从而避免了 NFC***中采用唯一 1 3. 56MHz频点双向通讯及距 离控制带来天线问题及终端信号衰减差异大等问题。 本方法中, 读卡器利用 低频单向通道将自身唯一标识 IDr (即前述的身份标识信息)传给移动射频 装置,移动射频装置通过射频双向通道将自身唯一标识 I Dc附加在 IDr后回 传给读卡器, 读卡器比较回传的 IDr的正确性, 进而实现了读卡器与移动射 频装置的唯一绑定。绑定后读卡器与移动射频装置采用射频双向通道实现高 速大数据量的通讯, 直至本次交易完成。
本发明近距离通信方法实现了含有移动射频装置的射频通信终端(如装 有射频 S IM卡的手机)与读卡器的数据通信距离 (也即交易距离 )可靠地控 制在规定范围内, 并且无需对终端进行校准。
为了实现上述的近距离通信方法,本发明还提出了一种近距离通信系 统。本发明的近距离通信***包括至少一个读卡器和至少一个移动射频装置, 其中:
读卡器用于按照预设的发射参数发射低频交变磁场信号, 该低频交变磁 场信号中携带该读卡器的身份标识信息, 其中, 发射参数包括低频交变磁场 信号的频率,该频率等于或小于***无校准工作的最高频率 f 0;读卡器还用 于接收移动射频装置通过射频通道传送的信息, 比较该信息中读卡器的身份 标识信息是否同自身的身份标识信息一致,若一致则以自身的身份标识信息 和移动射频装置的身份标识信息的结合作为组合地址, 与移动射频装置通过 射频通道进行刷卡交易;
移动射频装置, 用于在各距离点上接收、检测读卡器发射的低频交变磁
场信号并放大为与距离对应的幅度恒定的的电压信号, 进而通过预设的电压 门限 Vt判断装载有该移动射频装置的终端是否进入了预设的有效距离区间, 其中, 电压门限 Vt对装载有该移动射频装置的所有终端相同; 移动射频装 置还用于在与接收到的低频交变磁场信号对应的电压信号大于或等于预设 的电压门限 v t 时, 从接收到的低频交变磁场信号中获取读卡器的身份标识 信息, 并将其连同自身的身份标识信息一起通过射频通道传送给读卡器; 移 动射频装置还用于与读卡器通过射频通道进行刷卡交易。
其中, 身份标识信息可以为识别码 ID。
由上述可见,本发明近距离通信***中的读卡器具有低频发射功能和射 频收发功能这样两个基本功能,也可以说本发明近距离通信***中的读卡器 具有低频发射模块和射频收发模块这样两个基本模块; 本发明近距离通信系 统中的移动射频装置具有低频接收功能和射频收发功能这样两个基本功能, 也可以说本发明近距离通信***中的移动射频装置具有低频接收模块和射 频收发模块这样两个基本模块。
进一步地, 上述的近距离通信***可以由如下的具体电路来实现: 读卡 器包括至少一个低频发射线圏、 至少一个驱动电路、 至少一个编码电路、 至 少一个第一主处理器、 至少一个射频收发电路和至少一个射频天线, 其中, 低频发射线圏、 驱动电路、 编码电路、 第一主处理器、 射频收发电路、 射频 天线、 顺次串联连接; 移动射频装置包括至少一个低频磁感应电路、 至少一 个低频放大电路、 至少一个门限判断及解调电路、 至少一个第二主处理器、 至少一个射频收发电路和至少一个射频天线, 其中, 低频磁感应电路、 低频 放大电路、 门限判断及解调电路、 第二主处理器、 射频收发电路、 射频天线 顺次串联连接。 优选地, 在上述具体实现电路中, 读卡器的驱动电路和编码 电路之间还可以设有调制电路。
在上述具体实现电路中, 读卡器中的低频发射线圏、 驱动电路和编码电 路(带调制电路时,还包括调制电路 )可以认为是低频发射模块的组成部分, 读卡器中的第一主处理器、射频收发电路和射频天线可以认为是读卡器中射 频收发模块的组成部分; 移动射频装置中的低频磁感应电路、 低频放大电路 和门限判断及解调电路可以认为是低频接收模块的组成部分,移动射频装置 中的第二主处理器、 射频收发电路、 射频天线可以认为是移动射频装置中射
频收发模块的组成部分。
优选地 ,在上述具体实现电路中,低频发射线圏可以为漆包线线圏或 PCB 线圏。 进一步地, 低频发射线圏的匝数可以大于 10 圏。 优选地, 低频发射 线圏的匝数为 50 ~ 500圏。 优选地, 低频发射线圏内填塞有铁氧体磁芯或铁 芯。 优选地, 低频发射线圏所包围面积的截面最宽处大于移动射频终端的截 面宽度。 优选地, 低频发射线圏所包围面积的截面至少包含直径 3cm的圓形 区 i或或者 3cm* 3cm的方形区 i或。
优选地, 上述的 频磁感电路可以为 PCB线圏、 漆包线线圏、 霍尔器件 或巨磁阻器件。
本发明中, 移动射频装置可以置于移动终端中, 也可以置于移动终端内 的 SIM卡、 UIM卡、 USIM卡、 TF卡或 SD卡中。 其中, 移动终端可以为手机、 个人数字助理 PDA或笔记本电脑等。
下面对本发明近距离通信***的原理进行说明:
1、 ***无校准工作的最高频率 f 0的选定方法及装置在前述近距离通信 方法的内容中已有阐述, 此处不再赘述;
2、 距离测量和控制实现原理如下:
读卡器根据距离控制目标, 以设定的发射参数持续不断的循环发送不高 于选定频率 f 0的低频交变磁场信号,该信号中以调制或直接基带传送的方式 携带数据帧, 数据帧内包含读卡器的唯一识别码 Idr (当然也可以是其他身 份标识信息)。 当装载有移动射频装置的移动终端置于读卡器周围, 低频交 变磁场信号穿透该终端到达其内部的移动射频装置,移动射频装置在各距离 点上检测该磁场信号并放大为与距离对应的幅度恒定的的电压信号, 当电压 的幅度低于卡内预设的接收电压门限值 Vt ,表示终端未进入有效刷卡距离范 围, 不允许刷卡; 当电压的幅度高于卡内预设的接收电压门限值 Vt , 表示终 端进入读卡器预定的有效刷卡范围, 移动射频装置内的低频接收电路(指前 述的低频磁感应电路、低频放大电路和门限判断及解调电路)启动解码过程, 得到读卡器的唯一标识码 IDr。 另一方面, 移动射频装置内磁场转换后的电 压信号与读卡器和移动射频装置之间的距离存在一一对应关系,该关系由电 压距离变化曲线确定, 根据该对应关系, 可以由该电压确定移动射频装置与 读卡器之间的距离,从而间接的确定了移动终端与读卡器的距离。 Vt和发射
参数的设定是一次工作, 一旦设定在使用中无需更改。
3、 移动射频装置接入读卡器的过程原理:
移动射频装置接入读卡器主要包含读卡器和移动射频装置的唯一绑定 过程。 这里举例说明该绑定过程: 移动射频装置中从低频信号中解出读卡器 唯一识别码 IDr后传送到移动射频装置内的第二主处理模块, 该第二主处理 模块将移动射频装置的唯一识别码 IDc连同收到的 IDr—起, 通过 RF收发 模块发送给读卡器, 读卡器收到移动射频装置返回的(IDr, IDc)后, 确认识 别码为 IDc的移动射频装置正确的返回了读卡器的识别码 IDr , 是本次交易 的唯一通讯终端。 由于 IDr编码保证了该读卡器周围其它读卡器的识别码在 该时刻不相同, 因此识别码为 IDc的移动射频装置确认了其与识别码为 IDr 的读卡器建立了唯一的通讯。至此,移动射频装置和读卡器实现了唯一绑定, 双方通过 ( IDr, IDc )组合地址唯一的识别对方。 绑定后的通讯过程采用 RF 通道进行交互不会产生错误。移动射频装置接入成功后,距离控制过程完成, 可在 RF通道上进行后续的交易过程, 直至交易结束。
4、 交易过程:
读卡器和移动射频装置通过 RF通道建立了可靠的唯一通讯链路, 在该 链路基础上, 双方可以实现交易所需的身份认证及其他交易所需的过程。 所 有这些过程均通过快速的 RF通道完成, 由于前述过程的完成保证了只能在 预定的距离范围内完成接入, 因此整个交易过程也是在限定范围内的近距离 通讯。
下面通过实施例对本发明作进一步说明。
图 8为本发明实施例中近距离通信***的结构图。 如图 8所示, 该*** 由 2部分组成: 读卡器装置 100和移动射频装置 200 , 该移动射频装置 200 放在移动终端内部, 并通过移动终端通讯接口与终端交互。
读卡器 100由下述模块组成: 第一主处理器 101 , 负责读卡器低频及高 频的控制及其他协议处理, 第一主处理器 101通过接口电路 102或直接连接 到外部通讯接口; 编码电路 108 , 负责将低频帧数据进行逐比特编码, 调制 电路 107负责将编码输出的符号流对载波进行调制形成调制信号送给驱动电 路 106 , 不需要调制时编码后的信号直接送给驱动电路 106; 驱动电路 106 , 负责驱动低频发射线圏 105 , 产生低频交变磁场 301 ; 由低频发射线圏 105、
驱动电路 106、 调制电路 1 07及编码电路 108构成的低频发射模块, 其发射 场强值可更改并设定;低频发射线圏 105通常由较多匝数特定形状的线圏构 成; RF收发电路 103 , 通过 RF天线 104接收及发射 RF信号。
移动射频装置由下述模块组成: 第二主处理器 201 , 负责低频及射频模 块的控制及其他协议处理,也负责和移动终端的通讯; S IM/TF/SD卡模块 202 为移动终端的 S IM/TF/SD卡本体模块, 具体何种模块由卡类型确定; 低频磁 感应电路 207 , 由 PCB线圏、 漆包线线圏、 霍尔器件或其他能感应磁场变化 的电路元件构成, 负责感应低频交变磁场信号 301并转换为电信号; 低频放 大电路 206负责放大低频磁感应电路检测到的电信号得到低频磁检测电压信 号 303; 门限判断及解调电路 205 , 负责对低频磁检测电压信号 303按照预 设的门限 Vt进行判决, 未达到门限 Vt不解调也不允许刷卡, 达到门限 Vt 对信号进行解调, 解调后的信号送给第二主处理器 201 ; RF收发电路 203 通过 RF天线 204负责与读卡器的 RF收发模块完成 RF双向通讯。
***通过预先设定好的门限判定方法来完成无需校准的距离检测和控 制, 即读卡器 100按照预设的发射参数发射低频交变磁场信号 301 , 移动射 频装置 200接收该磁场信号转换为低频磁检测电压信号 303 , 并通过预先设 定的门限 Vt来判断终端是否进入预先设定的有效距离区间, 该门限 Vt对所 有终端相同, 无需针对不同终端修改(即所谓校准)。 通过低频单向通讯和 RF双向通讯结合的方法来完成读卡器 1 00和移动射频装置 200的唯一绑定, 即读卡器 1 00利用低频单向通道将自身唯一标识 IDr传给移动射频装置 200 , 移动射频装置 200通过射频双向通道将卡自身唯一标识 IDc附加在 IDr后回 传给读卡器 100 ,读卡器 100比较回传 IDr的正确性,进而实现了读卡器 100 与移动射频装置 200的唯一绑定。绑定之后通过射频通道来完成双向的高速 大数据量的通讯。
本实施例中, 近距离通信***的具体工作流程如下:
(一)首先, 选定***工作的基本参数, 包括 RF频点, 无校准低频频点 f 0 , 读卡器发射参数, 移动射频装置的接收电压门限 Vt。
1. RF频点选择
上述 RF通讯的频点通常采用 2400 - 2483MH 2. 4G I SM频段, 以实现高 速的通讯和对终端的良好穿透性, 也可以采用其它频点, 例如 433MHz ,
900MHz , 5GHz等。
2.无校准低频频点 f 0选择
采用前述方法确定***低频无校准工作频点 f O ,对于典型的 GSM移动通 讯终端, 要实现 0 ~ 10cm范围的距离控制, f O频点通常小于 Ι ΟΚΗζ , 典型值 包括 500Hz , ΙΚΗζ , 1. 5KHz , 2KHz , 2. 5KHz , 3KHz, 5KHz等。
3.读卡器发射参数的选择
发射参数主要包括调制方式、 编码方式及发射磁感应强度幅值 Br。 图 9为读卡器低频发射部分示意图。 参见图 8 , 读卡器低频发射电路由 驱动电路 106、 调制电路 1 07及编码电路 108构成的, 驱动电路 1 06驱动的 低频调制信号输出到低频发射线圏 1 05。
调制电路 107可以采用多种调制方式:
1)载波调制方式调制: 编码电路 108产生的基带信号通过调制电路 107对载波进行调制, 载波可以为正弦波、 方波及三角波等, 调制可以 采用开关频移键控 00K、 相移键控、 频移键控 FSK等, 调制后的信号通 过驱动电路 106加载到低频发射线圏 105上;
2)无载波直接基带发射: 编码电路 108产生的基带信号, 通过驱动 电路 106直接加载到低频发射线圏 105上;
3)其他调制方式: 由于本发明***采用门限判断的方式进行距离控 制, 因此调制方式不宜采用幅度调制, 凡是发送过程中能够保持移动射 频装置内检测电压幅度基本恒定的调制方式均可以用于本发明的近距 离通信***;
编码电路 108可以采用多种编码方式:
1)曼彻斯特编码: 比特 1编码为两个符号 01 , 比特 0编码为 10。
2)差分曼彻斯特编码: 有两种比特符号序列: 01及 10 , 比特 1编码为 与上一符号序列不同, 比特 0则相同, 或者反过来编码亦可。
3)其他编码方式: 由于本发明***采用门限判断的方式进行距离控制, 因此低频调制信号必须保持均值稳定, 编码后的序列不能含有直流分 量,凡是编码后平均直流分量为零的编码方式均可以用于本发明的近距 离通信***。
确定好调制方式和编码方式后, 采用前述方法, 确定读卡器发射磁感应
强度幅值 Br。 调整 Br的过程实际上是调整线圏匝数, 线径, 形状等参数的 过程。
4. 移动射频装置接收电压门限 Vt的选择
采用前述方法确定卡接收门限电压 Vt。
上述参数的选定是一次性的, 一旦选定, 工作中无需改变。
(二)其次, 工作参数确定后的***工作流程如下:
步骤 A100:距离测量和控制过程。读卡器 100的第一主处理器 101产生 包含读卡器的唯一识别码 IDr的数据帧, 送给编码电路 108完成编码, 编码 后的信号通过调制电路 107调制或不经调制直接送给驱动电路 106 , 调制电 压送给低频发射线圏 105发射, 通过预先设定好帧格式、 调制编码方式及驱 动能力, 发射线圏 105以设定的强度 Br持续不断的按照上述帧格式循环发 送指定参数的低频交变磁场信号 301。 当移动终端置于读卡器周围, 低频交 变磁磁场信号 301穿透该终端到达内部的移动射频装置 200 , 移动射频装置 200内的低频磁感应电路 207检测到低频磁信号, 转换为电信号后经低频放 大电路 206放大后得到低频磁检测电压 303 , 当电压的幅度小于 (或大于) 于预设的接收电压门限值 Vt , 不允许刷卡; 当电压的幅度大于等于于(或小 于等于)预设的接收电压门限值 Vt ,表示终端进入读卡器预定的有效刷卡范 围, 低频接收电路启动解码过程, 得到读卡器的唯一标识码 IDr。 另一方面, 所述移动射频装置内磁场转换后的电压信号与读卡器和移动射频装置之间 的距离存在——对应关系, 该关系由电压-距离变化曲线确定, 根据该对应 关系, 可以由该电压确定移动射频装置与读卡器的距离, 从而间接的确定了 移动终端与读卡器的距离。 上述门限值 Vt对所有终端均相同, 无需针对每 个终端修正, 也就是无需知道校准, 从而上述过程是一种无需校准的距离测 量及控制过程;
步骤 A100中的帧格式定义如下:
图 10为读卡器低频数据帧格式示意图, 如图 10所示, 读卡器低频数据 帧每帧分为: ¾口下 i或:
同步码: 8比特, 通常为 FFH, 用于帧同步;
控制域: 8比特, 用于提供帧数据的解帧信息, 如长度, 数据类型等, 可留保留位用于扩展;
IDr: N比特, 读卡器唯一识别码, 由控制域指定;
CRC: 对控制域, IDr进行校验, 可采用 CRC校验和或其他方式。
上面所述帧格式仅作为一种示例, 不限制本发明实际采用的帧格式, 原 则上任何包含能唯一识别读卡器的帧格式均可使用。唯一识别码可采用足够 长度的随机数, 也可采用所有读卡器人工分配唯一码的方式, 或其他方式产 生的识别码。
步骤 A2QQ: 移动射频装置接入读卡器的过程: 移动射频装置接入读卡器 主要包含读卡器 100和移动射频装置 200的唯一绑定过程, 实际上表示读卡 器和移动射频装置所在移动终端的唯一绑定过程。移动射频装置 200内部低 频接收电路解出读卡器唯一识别码 Idr后传送到移动射频装置内第一主处理 器 201 ,该模块将移动射频装置自身的唯一识别码 Idc连同收到的 Idr—起, 通过移动射频装置内 RF收发电路 203和 RF天线 204发送给读卡器 100 , 读 卡器内部 RF天线 103和 RF收发电路 104收到移动射频装置返回的(IDr , IDc) 后, 传送给第一主处理器 101处理, 第一主处理器 101确认识别码为 IDc的 移动射频装置正确的返回了读卡器 IDr , 是本次交易的唯一通讯终端。 由于 IDr编码保证了该读卡器周围其它读卡器的识别码在该时刻不相同, 因此识 别码为 IDc的卡确认了其与识别码为 IDr的读卡器建立了唯一的通讯。至此, 移动射频装置和读卡器实现了唯一绑定, 双方通过(IDr,IDc )组合地址唯 一的识别对方。 绑定后的通讯过程采用 RF通道进行交互不会产生错误。 移 动射频装置成功接入读卡器后, 距离控制过程完成, 可在 RF通道上进行后 续的交易过程;
步骤 A200中的移动射频装置唯一识别码 IDc,是预先存储在移动射频装 置内非易失存储器内 (NVM ) 的唯一识别码, 或者是由移动射频装置内产生 的足够长的的随机数。
步骤 A300:交易过程。读卡器 100和移动射频装置 200通过 RF通道建立 了可靠的唯一通讯链路, 在该链路基础上, 双方可以实现交易所需的身份认 证及其他交易所需的过程。 所有这些过程均通过快速的 RF通道完成, 直至 本次交易结束。 由于前述步骤 A100 ~ A200 的完成保证了移动射频装置 200 只能在预定的距离范围内完成接入, 因此整个交易过程也是在限定距离范围 内才能完成交易。交易过程是成熟的 P0S机处理流程,本发明不做详细描述。
移动射频装置 200中低频信号检测电路 207通常可以用 PCB线圏、漆包 线线圏或霍尔器件构成, 该检测电路并不仅限于用这几种元件, 原则上任何 能将磁场变化转变为电信号的传感器都可以用于该模块,唯一的限制是能放 入卡内部。
本发明***利用低频交变磁场实现距离检测和控制,并实现读卡器和移 动射频装置的单向通讯, 利用 RF通道结合低频通讯实现终端的可靠绑定, 同时利用 RF通道实现读卡器和移动射频装置之间高速的数据通讯。 其具有 如下特点点: 1.可以无需改造移动终端, 只需更换终端内部的 S IM卡 /TF/SD 卡, 即可实现可靠的双向距离通讯; 2读卡器发射低频交变磁场信号, 移动 射频装置只需接收该磁场信号, 由于是单向通讯, 并且无需读卡器通过磁场 提供能量, 因此可以将接收线圏或其他接收电路小型化, 足以将移动射频装 置放入 SIM卡 /TF/SD卡内; 3.由于接收信号较弱,移动射频装置内需要增加 放大电路。 另外移动射频装置内同时放置 RF收发电路, 与读卡器内的 RF收 发电路实现双向高速通讯, 如前面所述, RF电路的天线很小, 可以轻易的集 成到 S IM卡 /TF/SD卡内。
依照本发明所述方法选定的频点 f 0 , ***在该频点以下工作无需校准, 作为一种扩展, ***工作在 f 0频点以上, 也不是绝对不行, 可能的效果是 性能降低, 距离控制的精度降低, 同时可能需要辅以筒单的校准, 这些应用 并不与本发明所述原则从根本上沖突, 只是一种性能改变的延伸应用。
本发明近距离通信***实现了含有移动射频装置的射频通信终端(如装 有射频 SIM卡的手机)与读卡器的数据通信距离 (也即交易距离 )可靠地控 制在规定范围内, 并且无需对终端进行校准。
采用本发明所述的***和方法, 选择合适的无校准工作的最高频点 f 0 , 用低于 f O 的低频交变磁场进行距离测量和控制, 移动终端间结构差异的影 响可以减小到距离控制目标所要求的波动范围之内,从而实现无校准距离控 制。 图 11 为线圏接收电路放入各种移动终端内, 用信号源通过低频发射线 圏发射恒定 ΙΚΗζ磁场条件下测试的电压距离曲线。 如图 11所示, 为***在 ΙΚΗζ频率下多个典型终端的电压距离曲线实例。其中信号强度值是接收天线 感应电压经过必要的放大后的值, 放大倍数保持恒定, 只需关注强度随距离 的相对变化。从图 11可以看出, 终端之间的场强差异 <5dB, 而各终端在 1 ~
10cm范围的场强变化范围达到 40dB, 不考虑读卡器发射场强波动及移动射 频装置检测电路的误差, 移动射频装置端采用统一的门限 Vt来判断各终端 是否在目标距离范围之内,距离控制的误差在终端之间的差异大致为 1cm范 围, 完全满足无校准距离控制的要求。 射频 IC卡、 射频存储卡
作为近距离通信的一方, 移动射频装置通常是置于移动终端内的 IC卡 (例如 SIM卡、 UIM卡、 USIM卡等)或存储卡(例如 TF卡、 SD卡、 MMC ( Mul t i Media Card , 多媒体卡)卡等) 中, 我们将置有移动射频装置的 IC卡和存 储卡分别称为射频 IC卡和射频存储卡。
图 12为本发明实施例中射频 IC卡的结构图。 如图 12所示, 本实施例 中, 射频 IC卡 1200由移动射频装置和 SIM/UIM/USIM卡模块(可以统称为 IC卡模块) 1202以及接口模块 1207组成。 图 12中, 移动射频装置包括至 少一个氏频磁感应电路 1206、 至少一个氏频放大电路 1215、 至少一个比较 电路 1225、 至少一个解调电路 1235、 至少一个解码电路 1245、 至少一个第 二主处理器 1201、至少一个 RF (射频)收发电路 1203和至少一个 RF (射频) 天线 1204 ,其中低频磁感应电路 1206、低频放大电路 1215、 比较电路 1225、 解调电路 1235、 解码电路 1245、 第二主处理器 1201、 RF收发电路 1203、 RF 天线 1204顺次串联连接。 其中, 比较电路 1225、解调电路 1235和解码电路 1245 组成了移动射频装置的门限判断及解调电路。 在本发明的其他实施例 中,移动射频装置的门限判断及解调电路中也可以不包括解调电路 1235 , 而 只由比较电路 1225和解码电路 1245组成。 图 12中, 低频放大电路 1215、 比较电路 1225、解调电路 1235和解码电路 1245组成低频信号接收及处理模 块 1205。 其中, 第二主处理器 1201与前述的移动射频装置中的第二主处理 器是相同的。 其中, 低频磁感应电路 1206、 低频放大电路 1215、 门限判断 及解调电路 (包括比较电路 1225、 解调电路 1235和解码电路 1245 )组成的 低频接收链路工作于预先选定的***无校准工作的最高频率 f 0以下的频率。 ***无校准工作的最高频率 f O 的确定方法前面已有阐述, 此处不再赘述。 低频接收链路将恒定幅度或微分幅度恒定的低频交变磁场经过磁电转换得 到幅度恒定的检测电压, 该幅度的误差为 5c dB。
通过选择不同的低频磁感应电路及低频放大电路的放大倍数可以选择 不同的低频接收链路的体积,从而移动射频装置可以选择放入不同体积要求 的载体中。 若低频磁感应电路为线圏, 则低频接收链路的体积取决于低频磁 感应电路转换增益及低频放大电路的放大倍数。 磁电转换增益转换公式为:
K*A=Vt/B_RATEga te , 其中 B_RATEga t e为磁感应强度变化率的门限值, 磁感 应强度变化率 B_RATE=dBr/dt , A为低频放大电路的放大倍数, K为低频磁感 应电路转换增益; 低频磁感应电路转换增益与低频放大电路的放大倍数的乘 积为与移动终端所应用的***最远刷卡距离对应的***预设值, 最远刷卡距 离即在该距离处读卡器发射场强参数值为 B_RATEga te ,同时移动装置内部检 测电压刚好为门限值 Vt ,此时允许刷卡,超过该距离发射场强持续衰减并小 于 B_RATEga te , 移动装置内部检测电压小于 Vt , 不允许刷卡。 上述关系式 中 Vt及 B_RATEga te是由***确定的值, 因此 K*A值确定, 线圏的体积主要 由 K值确定, 线圏匝数越多, K越大, 体积越大, A值的大小对低频放大电 路的体积基本无影响, 因此磁电转换总增益在 K和 A之间的分配将决定低频 接收链路的体积。 例如, 如果移动射频装置放置到 S IM卡中, 选择线圏匝数 在 1 ~ 20匝范围内容易放置进入卡内的线圏体积, 因此先确定了磁感应电路 转换增益, 再选择低频放大电路较大的增益即可。 若移动射频装置放置在终 端主板上, 这可以增大线圏匝数及面积, 放大器增益可降低, 好处是信噪比 有提升, 坏处是低频接收链路体积变大。 低频磁感应电路为线圏时, 低频接 收链路的磁电转换增益 A*K为预设值的情况下, 改变 A和 K的增益分配, 可 以改变低频接收链路的体积及接收信号的信噪比,增大 K,减小 Α,体积增大, 信噪比增大; 减小 Κ , 增大 Α, 体积减小, 信噪比减小。
若磁感应电路为霍尔器件或巨磁阻器件,则低频接收链路的体积与所述 低频磁感应电路转换增益及低频放大电路的放大倍数关系不大。
图 12中, 第二主处理器 1201、 S IM/UIM/ US IM卡模块 1202、 RF收发模 块 1203、 低频信号接收及处理模块 1205、 接口模块 1207可以由集成到一个 IC (集成电路) 内部的电路及***无源器件组成, 也可以任意组合进不同的 IC内部后, 加上***无源器件组成。
其中, RF天线 1204 , 不能集成到 IC内部, 可以使用 PCB天线, 由 PCB 的铜皮印制线路组成。
低频磁感应电路 1206用于接收低频磁场信号, 将低频磁场信号变换为 对应的电压信号后送给后面的低频放大电路 1215。 低频磁感应电路 1206可 以由 PCB线圏、 漆包线线圏、 霍尔器件、 巨磁阻器件等实现。 一般情况下, 低频磁感应电路 1206输出的信号 1302与其所处环境的低频磁场信号强度信 号 1301 或者低频磁场信号强度信号变化率 1301 之间是固定的线性比例关 系, 即 1302= 1301 *K,其中 Κ是常数, Κ取决于低频磁感应电路 1206的特性 参数。 低频磁感应电路 1206输出的信号 1302可以是电压信号, 也可以是电 流等其他信号,一般情况下信号 1302是电压信号。如果低频磁感应电路 1206 使用霍尔器件或巨磁阻器件构成, 电压信号 1302与低频磁场信号强度 1301 成正比。 如果低频磁感应电路 1206使用 PCB线圏或漆包线线圏构成, 电压 信号 1302与低频磁场信号强度信号变化率 1301成正比。典型的天线为沿卡 片的最外圏 Ν匝 pcb铜皮组成的环状微分幅度恒定感应天线,输出的是电压 信号 1302。 例如, 应用于 SIM卡的 4匝 pcb铜皮线圏天线的一种结构如图 13所示。
第二主处理器 1201实现整个射频 IC卡 1200的协调控制处理, 第二主 处理器 1201里面含有各种控制硬件、 程序模块以及存储器。 第二主处理器 1201由 IC及***无源元件实现,主要功能由 IC实现,***元件只起辅助作 用。
SIM/UIM/ USIM卡模块 1202与第二主处理器 1201连接, 与第二主处理 器 1201之间有应用数据的交互。 SIM/UIM/ USIM卡模块 1202主要由 IC实现。 第二主处理器可以与 SIM/UIM/US IM/TF/SD/MMC卡中的处理器为同一共用处 理器。即用一个共用的处理器同时做第二处理器和 SIM/UIM/USIM/TF/SD/MMC 卡中的处理器所要做的工作。
接口模块 1207与第二主处理器 1201连接, 第二主处理器 1201通过接 口模块 1207与移动终端的通讯接口相连, 并与移动终端进行数据交互。 接 口模块 1207由 IC实现, 一般情况下第二主处理器 1201和接口模块 1207集 成在同一片 IC内部。 SIM/UIM/ USIM卡模块 1202可以通过第二主处理器 1201 以及接口模块 1207与移动终端进行数据交互, 完成应有的功能。
低频信号接收及处理模块 1205与第二主处理器 1201连接,也与低频磁 感应电路 1206连接。低频信号接收及处理模块 1205接收从低频磁感应电路
1206传送过来的低频磁场信号 1302,将低频磁场信号 1302放大 A倍后得到 信号 1303, 即信号 1303=A*信号 302。低频信号接收及处理模块 1205比较信 号 1303是否大于设定的门限 Vt,并将比较结果发送给第二主处理器 1201。 低频信号接收及处理模块 1205还将信号 1303中数据信息解码出来,送给第 二主处理器 1201。 低频信号接收及处理模块 1205接受第二主处理器 1201 的控制, 接收第二主处理器 1201送过来的门限 Vt等控制信息。
RF收发电路 1203与第二主处理器 1201连接。 RF收发电路 1203与 RF 天线 1204连接, 通过 RF天线 1204收发空中的射频信号 400。 RF收发模块 1203和 RF天线 1204—起在第二主处理器 1201的控制下, 完成与读卡器的 射频数据通讯。
低频磁感应电路 1206与低频信号接收及处理模块 1205连接,接收空中 读卡器发射的低频磁场信号 1301, 变换为低频磁场信号 1302, 送给低频信 号接收及处理模块 1205进行处理。
低频信号接收及处理模块 1205由低频放大电路 1215、 比较电路 1225、 解码电路 1245、 以及可选的解调电路 1235组成。 解调电路 1235可选, 当对 低频磁场传递的数字信号只进行基带编码而不进行调制解调时, 不需要使用 解调电路 1235, 否则需要使用解调电路 1235。
低频放大电路 1215 接收低频磁感应电路 1206 送来的低频磁场信号 1302,将低频磁场信号 1302放大 A倍后得到信号 1303。信号 1303送给比较 电路 1225进行处理。 信号 1303还送给解调电路 1235进行处理, 如果没有 解调电路 1235,信号 1303直接送给解码电路 1245进行处理。允许刷卡的磁 感应强度门限 Bgate或磁感应强度变化率门限 B_RATEgate、低频磁感应电路 1206的传感系数 K,低频放大电路 1215的放大倍数 A,设置的门限电压信号 Vt之间必须满足下列关系, 即 Bgate*K*A = Vt或 B_RATEgate*K*A = Vt。 其中, 低频放大电路 1215的放大倍数 A是可以通过软件设置的。
比较电路 1225与第二主处理器 1201连接, 接收从低频放大电路 1215 送过来的信号 1303, 比较信号 1303是否超过门限 Vt, 如果信号 1303与门 限 Vt比较发生变化, 就将变化情况的信息发送给第二主处理器 1201。 门限 Vt由第二主处理器 1201设置, 并存储在比较电路 1225内。 比较电路 1225 将信号 1303与 Vt进行比较时, Vt值也是可以通过软件设置的。
解调电路 1235与解码电路 1245连接, 接收从低频放大电路 1215送来 的信号 1303 , 解调后的基带信号送给解码电路 1245。
解码电路 1245与第二主处理器 1201连接, 接收低频放大电路 1215或 者解调电路 1235送来的基带信号, 解码后得到读卡器通过低频磁场发送过 来的信息, 送给第二主处理器 1201。 解码电路 1245可以使用差分曼切斯特 解码器的技术来实现。
射频存储卡由移动射频装置和 TF/SD/匪 C卡模块(可以统称为存储卡模 块) 以及接口模块组成。 在图 12中, 只需将射频 IC卡的 SIM/UIM/ USIM卡 模块 1202更换为 TF/SD/匪 C卡模块即可得到射频存储卡。 射频存储卡的其 他部分与射频 IC卡一致, 此处对射频存储卡不再赘述。 图 16为应用于 TF 卡的 4匝 pcb线圏天线结构示意图。
利用上述的射频 IC卡 /射频存储卡, 可以实现下面的功能:
1、 低频磁场单向数据通讯功能
本发明的射频 IC卡 /射频存储卡, 可以接收低频磁场中的数据信息。 数 据信息的编码调制方式可以使用现有的各种成熟技术。例如可以使用差分曼 切斯特编码技术,使用低频磁场变化率直接传递编码后的差分曼切斯特编码 基带信号。
每一个固定时间长度的周期传送一个数据 bi t (比特) , 在一个 b i t的 传送期间的中间时刻,电平必须发生变化,但两个不同 bi t传送的分界时刻, 电平可以变化, 也可以不变化。 所以, 一个 bi t传送期间的中间时刻的码字 只有两个: 01 , 10。 发送比特 1 , 采用和上一个码字不同的码字。 发送比 特 0 , 采用和上一个码字相同的码字。 图 14为 5b i t数据 11010的差分曼切 斯特编码格式以及场强、 线圏接收电压波形图。 图 14中为 5bi t数据 11010 的差分曼切斯特编码格式图, b为 a对应的场强图, c为线圏接收到的对应 的电压波形图。 由图 14可见, 差分曼切斯特编码中, 不同代表 1 , 相同代表 0。
2、 将幅度恒定或微分幅度恒定的低频交变磁场经过磁电转换得到幅度 恒定的检测电压, 并进行门限比较功能以及控制刷卡功能
幅度恒定低频交变磁场是磁感应强度变化幅度恒定的低频交变磁场,例 如方波及正弦波。
微分幅度恒定低频交变磁场是指磁感应强度的变化率的变化幅度恒定 的氐频交变磁场, 例如三角波及正弦波。
幅度恒定(或微分幅度恒定)信号 1 301经低频磁感应电路块 1206变换 为低频磁场电压信号 1 302 , 设 1 301磁感应强度为 Br,磁感应电路接收灵敏 度为 K;则电压信号 1 302= K*Br或 K*dBr/dt 0
低频放大电路 1215将电压信号 1 302放大 A倍,得到电压信号 1 303 ,则: 电压信号 1 303=A*电压信号 1 302。
所以, 电压信号 1 303 = K*A*Br或 K*A*dBr/dt。
只要测得电压信号 1 303就可以换算为对应的幅度恒定(或微分幅度恒 定)信号 1 301。
比较电路 1225比较电压信号 1 303是否大于 Vt , 并将比较结果信息送 给第二主处理器 1201。 第二主处理器 1201根据比较结果信息确定是否允许 刷卡。
而移动射频装置的低频接收链路测量场强是有误差的,该误差基本等于 射频 IC卡 /射频存储卡的误差, 误差来源于下述 a ) ~ e ) 5个方面:
a)传感器(低频磁感应电路) 变换系数 K的误差比率 eK (db) ; b)放大器(低频放大电路)放大倍数 A的误差比率 eA (db);
c)比较器 (比较电路 )误差比率 eO (db);
d)放大器(低频放大电路)允许等效输入噪声系数 eN (db) ;
e)其他误差 eC (db);
这 5个误差均已包含由于温度, 电压等工作环境因素引起的误差。
由读卡器及内置移动射频装置的移动终端所构成的***为了达到无校 准距离控制的目标, 对检测电压的波动在***中的各个环节分配, 分配到移 动射频装置本身可允许的波动称为移动射频装置引起的低频检测电压波动 范围 δ c (db)。 上述五个移动射频装置射频 IC卡 /射频存储卡的误差因子的 总和必须小于***分配给卡的误差指标 δ c (db)。 即:
eK (db) + eA (db) + eO (db) + eN (db) + eC (db) < δ c (db)
低频放大电路 1215集成在卡芯片内部, 一般情况下芯片内部的工作电 源电压为 1伏的数量级, 所以, 以幅度恒定检测电路为例, 对应的 Vt应该 在 1 伏的数量级, 那么, Bga te *κ*Α应该约为 IV, 这样要求 K*A = Vt/
Bgate=l伏 / Bgate。 而低频放大电路的放大倍数 A, 是由芯片设计时设计确 定的, 理论上可以有很大的范围可以自由选择, 但是一旦 Bgate确定以及传 感器确定 K也就确定后, A的大小也就确定了, A = Vt/ Bgate/K,一般情况 下 Vt可以取 IV,则 A可以取值为 IV/ Bgate/K0 这样一来, A的大小, 由其 他参数确定, 但 K的取值范围就可以允许一个较宽的范围, 其结果是低频磁 感应电路 1206的选择就有了很大的灵活性。
由于低频磁感应电路 1206的选择可以有较大的自由度, 因此可以选择在 工程上易于在卡上实现的 4匝 pcb线圏作为低频磁感应电路 1206, 见图 13。 当 然也可以选择其他参数的传感器。 使用 4匝 pcb线圏传感器有以下优点: 1、 易于实现, 不增加卡上的结构, 卡上本来就需要 pcb; 2、 不增加卡的体积。 从而这个方案的天线可以在卡上实现, 不需要连接到卡以外的天线上。
射频 IC卡 /射频存储卡的误差余量 δ c (db)的分配设计也是卡的一个重 要内容。 使用本方案的设计, 误差余量 S c(db)需要分配到下列 5个因素中: a)传感器(低频磁感应电路) 变换系数 K的误差比率 eK(db) ; b)放大器(低频放大电路)放大倍数 A的误差比率 eA(db);
c)比较器 (比较电路 )误差比率 eO (db);
d)放大器(低频放大电路)允许等效输入噪声系数 eN(db);
e)其他误差 eC(db) 。
比如,如果最远允许刷卡距离 Dmax要求为 10cm,最近必须刷卡距离 Dmin 为 5cm, 那么从图 15中可以看出 10cm的最强信号为 12db, 5cm最弱信号为 28db, 那么总的误差余量有 28-12=16db, 其中只分配 4db的误差余量给卡, 那么 δ c(db) =4db0 eK(db) , eA (db) , eO (db) , eO (db) , eC(db)平均分配的 话, 每一个都有 0.8db。 而低频磁感应电路 1206使用 4匝 pcb线圏的话, 由 于 PCB生产工艺已经非常成熟, 其尺寸误差在 0.1匪以内, 而其 K值误差主 要决定于线圏的面积误差, 可以计算出 K 的百分数误差约为 0.1匪 *0.1匪 /25mm/ 15mm, 大概为 2.67*10-5, 换算为 db 数为 201og ( 1+2.67*10-5 ) =0.0023dbo 其数值远远小于 0.8db。 低频放大电路放大倍数 A的误差比率 eA决定于集成电路工艺中的电阻比值, 其比值的误差, 现有工艺条件下, 很 容易就可以做到 1%以下, 换算为 db数应该为 201og ( 1+0.01 ) =0.086db , 也远远小于 0.8db。 比较电路误差以及其他误差不再分析。 以上误差分配及
分析说明, 使用本方案可以容易的实现距离控制的目标。
为 了 达到 不 更改移动终端 , 只 需 更换移动终端 内 的
SIM/UIM/USIM/SD/TF/匪 C卡, 实现电子支付等刷卡交易,本发明提出了一种 低频交变磁场距离控制方法,应用于包含上述移动射频装置的各种移动终端, 包括如下步骤:
前提:移动装置工作于预先选定的***无校准工作频点 f O以下的频点。 步骤 a ,对接收到的低频交变磁场信号 Br进行磁电转换,将低频交变磁 场信号转换为电信号 Vo。 若 Br为幅度恒定的低频磁场信号, 则磁电转换公 式为 Vo=A*K*Br; 若 Br为微分幅度恒定的低频磁场信号, 则磁电转换公式为 Vo=A*K*dBr/dt , 其中 K为磁感应电路增益, A低频放大电路增益, A*K为磁 电转换增益, 该增益预先设定, 使用中无需更改; 磁电转换存在误差, 也就 是 Vo存在波动, 波动范围为 S c (db) ;
步骤 b,若低频磁感应磁信号转换的电信号 Vo大于预设的比较电压信号 门限 Vt , 则解码出读卡器的身份识别标识 IDr , 进入射频通讯, 通过射频通 道将 IDr连同移动装置本身的唯一识别码 IDc—同传送给读卡器, 同时持续 监控低频磁感应信号;
步骤 c , 进行射频通讯, 将射频通讯数据拆分为多个数据包分次收发, 每次射频收包或发包都检查 Vo是否大于 Vt若是则继续射频通讯直至交易结 束, 否则结束本次交易的射频通讯, 返回步骤&。
步骤 a中磁电转换增益的确定方法如下:
步骤 al , 确定磁感应增益 选定移动射频装置所在载体上易于工程实 现的磁感应电路, 如线圏, 霍尔器件及巨磁阻器件, 从而选定了磁感应增益 K;
步骤 a2 , 在下述原则下任意选定低频放大电路的增益 A
1)移动装置在任意位置处接收到的磁感应强度 Br 小于***安全规范要 求的值;
2)移动装置放置于***指定的一种或多种载体(比如移动终端) 中, 并 在***要求的距离控制目标最远可接收距离处,磁感应信号经过磁电转换后 的信号信噪比大于 SNR。 通常 SNR>5 ;
3)若低频磁感应电路为霍尔器件或巨磁阻器件, 用于检测幅度恒定的低
频交变磁场信号: A*K = Vt/Bga te , 其中 Bga te为磁感应强度门限; 若磁感 应电路为线圏, 用于检测微分幅度恒定的低频交变磁场信号: A*K = Vt/B_RATEga te , 其中 B_RATEga te为磁感应强度变化率的门限值, 磁感应强 度变化率 B_RATE=dBr/dt。
若^ 频磁感应电路为线圏, 移动射频装置放置在 S IM、 UIM卡、 US IM卡、 TF卡、 SD卡或 MMC卡中, 线圏的匝数可以为 1 ~ 20匝, 放大器增益 A大于 100 ; 若低频磁感应电路为线圏, 移动装置放置在移动终端中, 在满足上述 磁电转换增益选择方法的条件下, 线圏匝数无限制, 低频放大电路的增益 A 无限制。
步骤 a中,移动射频装置检测电压的波动范围 δ c的选择及控制方法如 下:
δ c的选择方法如下: δ c是由读卡器及内置移动射频装置的移动终端 所构成的***为了达到无校准距离控制的目标,对检测电压的波动在***中 的各个环节分配, 分配到移动射频装置本身可允许的波动称为移动射频装置 引起的低频检测电压波动范围 δ c (db)。由于低频接收链路的工作频点很低, 造成检测电压波动的因素: 低频磁感应电路增益误差, 低频放大器放大倍数 误差, 比较电路误差, 电路噪声, 电路温度系数引起的误差等影响很小, 因 此卡的波动范围可以确定的比较小, 例如 2 ~ 6 dB。
δ c的控制方法如下:为解决多个移动射频装置间检测场强的差异问题, 本发明提出了基于如图 17所示误差控制***的误差控制方法, 应用于上述 的移动射频装置。 图 17中, 标准读卡器 505中的发射线圏 504向处于固定 距离的移动射频装置 501及处于固定位置的标准障碍物 502发射幅度恒定或 微分幅度恒定的低频磁场信号。 移动射频装置 501通过与卡通讯的装置 503 和 PC机相连。 δ c的控制方法包括如下步骤:
假设移动装置所应用的各种移动终端对低频交变磁场信号的衰减的最 大波动范围为 δ Τ, 则误差控制***中标准障碍物的衰减为 δ Τ/ 2,该障碍物 的作用是使移动射频装置收到的低频交变磁场的衰减是各种终端衰减的中 间值。
步骤 601 : 如图 17 , 标准读卡器在固定距离及位置上发射幅度恒定或微 分幅度恒定的低频交变磁场信号, 该***下幅度值 Bga te 或 分幅度值
B.RATEgate的磁场经过磁电转换后的电压值应当为幅度为 Vt附近的电压信 号 Vo;
步骤 602: 确定一个合理的 Vo范围值 =(Vt_ δ cx/2, Vt- δ cx/2) , 其中 δ οχ< δ ο, 这是因为 S C包含多种波动因素, 为筒化误差控制***及方法, 部分因素不能完全测量, 例如温度误差等;
步骤 603: 测量移动射频装置中低频放大电路的输出电信号 Vo,如果 Vo 超出(Vt- δ cx/2, Vt- δ cx/2)范围, 则通过软件设置调整低频放大电路的放 大倍数 A, 直到 Vo在上述范围内;
步骤 604:通过软件设置移动射频装置的 Vt值为步骤 603调整 A后的输 出电信号 Vo。
应用本发明能够实现无校准的移动终端支付,下面结合实例具体说明实 现无校准的移动终端支付的方法和过程。
实现过程有以下几个前提条件:
前提条件 1: 配套的读卡器发射的低频磁场信号强度已经调整好, 其场 强空间分布已经符合距离控制的要求;
进一步地, 微分幅度恒定的磁场信号, 允许刷卡的场强门限 Bgate的磁 感应强度变化率为 ±26500A/m/s (26500安每米每秒),如果是 2KHz的磁场信 号, 磁感应强度的峰值为 ±3.32A/m, 其峰峰值磁感应强度是 6.64A/m, 如果 是 ΙΚΗζ的磁场信号, 磁感应强度的峰值为 ±6.64A/m, 其峰峰值磁感应强度 是 13.28A/m;
前提条件 2: 射频 IC卡 /射频存储卡在出厂前, 设置有合适的门限电压 Vt, 该门限电压 Vt对应于需要限定的刷卡操作距离;
进一步地, 门限电压 Vt对应于允许刷卡的场强门限 Bgate的磁感应强 度变化率为 ±26500A/m/s时, 低频磁感应电路的输出电压 1302放大后的峰 峰值电压 Vt为 IV; 磁感应强度变化率为 ±26500A/m/s时, 低频磁感应电路 的输出电压峰峰值为 lOOuV, 则放大倍数 A=Vt/100uV = 1V/100UV=10000; 前提条件 3: 射频 IC卡 /射频存储卡和读卡器之间的通讯和刷卡协议已 经规定好;
进一步地,射频 IC卡 /射频存储卡和读卡器之间的数据比特流可以使用 2K波特率的差分曼切斯特编码基带信号进行数据传送。数据信息以数据帧为
单位进行传送, 数据帧 bi t流的编码方式如下: 每帧数据有 9b i t的同步头, 同步头为 8bi t的 1 , 后面一个 0。 同步头后面的数据信息中, 连续 7个 1后 面添加一位 0 , 用于区分数据信息和同步头;
前提条件 4: 射频 IC卡 /射频存储卡已经安装于移动终端内, 并且已经 准备好做刷卡操作;
前提条件 5 :读卡器已经准备好,连续发射携带有读卡器数据帧信息 Idr 数字信息的低频磁场信号;
进一步地, 数据帧信息 Idr中含有读卡器的 RF模块的信道信息; 进一 步地,读卡器的 RF模块的信道信息是 2480MHz到 2483MHz之间的一个信道; 前提条件 6: 低频工作的频点 f O已经按照前述步骤确定好;
前提条件 7: 射频 IC卡 /射频存储卡的低频放大电路的放大倍数 A和门 限 Vt已经按照前述误差控制的方法设置好。
实现该方法的射频 IC卡 /射频存储卡如前所述。
实现刷卡操作的过程如下:
1、 装有前述射频 IC卡 /射频存储卡的移动终端靠近读卡器时, 射频 IC 卡 /射频存储卡的低频磁感应电路 1206将所处位置的低频磁场信号 1301变 换为低频磁场电压信号 1302。 低频磁感应电路 1206、 低频放大器电路 1215 以及比较电路 1225是低耗电模块,其工作时的电源电流消耗小于 300uA。低 频磁感应电路 1206、 低频放大电路 1215以及比较电路 1225可以连续工作, 影响。 射频 IC卡 /射频存储卡中的其它模块大部分时间处于休眠状态, 基本 不消耗电源电流;
2、 低频磁感应电路 1206将低频磁场电压信号 1302送给低频信号接收 及处理模块 1205中的低频放大电路 1215 ,低频放大电路 1215放大后的电压 信号 1303送给比较电路 1225和解码电路 1245。 进一步, 如果是射频 s im 卡, 其形状为长方形, 其尺寸大小为 25匪 *15匪, 低频磁感应电路 1206由 4 匝沿 s im卡外框的 pcb线圏组成, 这样的低频磁感应电路 1206在微分幅度 恒定为 ± 26500A/m/s 的磁场中, 将会感应到 ± 50uV的峰值电压信号, 峰峰 值为 l OOuV;
3、 比较电路 1225将电压信号 1303与门限电压 Vt进行比较, 并将比较
结果送给第二主处理器 1201。 如果比较结果大于 Vt , 则唤醒卡的其它模块 一起工作, 否则, 其它模块继续休眠;
4、 如果电压信号 1303大于门限电压 Vt , 第二主处理器 1201控制解码 电路 1245对收到的电压信号 1303进行解码, 得到读卡器 Idr数字信息。 解 码电路 1245将解码出的读卡器 Idr数字信息送给第二主处理器 1201 ;
5、第二主处理器 1201收到有效的读卡器 Idr后,从中找出信道信息 CH, 控制 RF收发电路 1203通过 RF天线 1204以信道 CH与读卡器通讯, 建立只 有当前读卡器和射频 IC卡 /射频存储卡可以通讯的 RF通讯信道 CH , 将收到 的读卡器 Idr通过 RF通讯信道发送给读卡器;
6、读卡器判断从 RF通讯信道收到的 Idr是否为自己从低频磁场信号中 发送出去的 Idr , 如果不是, 拒绝通讯, 如果正确, 启动后续与卡的通讯直 至完成所需的刷卡操作。刷卡操作过程射频 IC卡 /射频存储卡与读卡器需要 多次的 RF通讯, 在每次进行 RF通讯过程中, 卡都要去判断电压信号 1303 是否小于门限电压 Vt ,若小于 Vt则立即结束 RF通讯,结束还没有完成的刷 卡操作。 刷卡操作过程中如果射频 IC卡 /射频存储卡与移动终端交互数据, 可以通过接口模块 1207 实现。 刷卡操作完成后, 除低频信号接收及处理模 块 1205中的低频磁感应电路 1206、 低频放大电路 1215以及比较电路 1225 外的模块继续睡眠, 一直持续到下次低频磁场信号对应的电压 1303从小于 Vt到大于 Vt的变化后的刷卡操作。
7、移动终端支付的刷卡操作功能的实现由第二主处理器 1201、SIM/UIM/ USIM /TF/SD/MMC卡模块、 RF收发电路 1203以及 RF天线 1204—起配合读 卡器来冗成;
8、 SIM/UIM/ USIM /TF/SD/MMC卡模块完成其应有的功能, 在实现其功 能时, 要通过第二主处理器 1201和接口模块 1207与移动终端交互数据。
采用本发明, 能够实现无需校准的近距离通信, 比如电子支付等。
以上所述仅为本发明的较佳实施例, 并不用以限制本发明, 凡在本发明 的精神和原则之内, 所作的任何修改、 等同替换、 改进等, 均应包含在本发 明的保护范围之内。
Claims
1. 一种移动射频装置, 其特征在于, 包括至少一个低频磁感应电路、 至少一个低频放大电路、 至少一个门限判断及解调电路、 至少一个第二主处 理器、 至少一个射频收发电路和至少一个射频天线, 所述低频磁感应电路、 低频放大电路、 门限判断及解调电路、 第二主处理器、 射频收发电路、 射频 天线顺次串联连接;
其中, 所述低频磁感应电路、 低频放大电路、 门限判断及解调电路组成 的低频接收链路工作于预先选定的***无校准工作的最高频率 f o 以下的频 率。
2. 根据权利要求 1所述的移动射频装置,其特征在于, 所述低频磁感应 电路为线圏,低频磁感应电路转换增益与低频放大电路的放大倍数的乘积为 与移动射频装置所在移动终端所应用的***最远刷卡距离对应的***预设 值, 所述低频接收链路的体积取决于所述低频磁感应电路转换增益及低频放 大电路的放大倍数,低频接收链路的体积随低频磁感应电路转换增益的增大 而增大, 或者随低频放大电路放大倍数的减少而增大。
3. 根据权利要求 1所述的移动射频装置,其特征在于, 所述***无校准 工作的最高频率 f 0处于特低频频段或甚低频频段或低频频段,所述特低频频 段的频率范围为 300 Hz ~ 3000Hz, 所述甚 频频段的频率范围为 3KHz ~ 30KHz,所述低频频段的频率范围为 30 KHz ~ 300KHz。
4. 根据权利要求 3所述的移动射频装置,其特征在于, 所述***无校准 工作的最高频率 f 0所处的频率范围为 300Hz ~ 50KHz。
5. 根据权利要求 4所述的移动射频装置,其特征在于, 所述***无校准 工作的最高频率 f 0为 500Ηζ、 1ΚΗζ、 1 · 5ΚΗζ、 2ΚΗζ、 2· 5ΚΗζ、 3ΚΗζ、 4ΚΗζ、 5ΚΗζ、 1 0ΚΗζ、 20ΚΗζ或 30ΚΗζ。
6. 根据权利要求 1所述的移动射频装置,其特征在于, 所述门限判断及 解调电路由相互连接的比较电路和解码电路组成。
7. 根据权利要求 1所述的移动射频装置,其特征在于, 所述门限判断及 解调电路由顺次相连的比较电路、 解调电路和解码电路组成。
8. 根据权利要求 1所述的移动射频装置,其特征在于, 所述低频磁感应 电路为 PCB线圏、 漆包线线圏、 霍尔器件或巨磁阻器件。
9. 根据权利要求 1所述的移动射频装置,其特征在于, 所述移动射频装 置置于移动终端中。
10.根据权利要求 9所述的移动射频装置,其特征在于, 所述移动射频装 置置于移动终端内的 SIM卡、 UIM卡、 USIM卡、 TF卡、 SD卡或 MMC卡中。
11.根据权利要求 10所述的移动射频装置,其特征在于, 所述第二主处 理器与 SIM/UIM/USIM/TF/SD/MMC卡中的处理器为同一共用处理器。
12.根据权利要求 9所述的移动射频装置,其特征在于, 所述移动终端为 手机、 个人数字助理 PDA或笔记本电脑。
13.一种射频 IC卡, 其特征在于, 包括权利要求 1至 12任一项所述的 移动射频装置。
14.一种射频存储卡, 其特征在于, 包括权利要求 1至 12任一项所述的 移动射频装置。
15.一种确定权利要求 1至 14任一项中所述的移动射频装置中***无校 准工作的最高频率 fO的方法, 其特征在于, 包括如下步骤:
步骤 al, 确定***的距离控制目标(Din, Dv), 所述***中包含至少一 个移动射频装置和至少一个读卡器, 其中 Din表示距离为 0~Din的范围内 所有装载有所述移动射频装置的终端确保可刷卡, Dv表示距离波动范围,距 离为 Din~ (Din+Dv)的范围内均允许刷卡, 距离大于 Din+Dv的范围不允许 刷卡;
步骤 a2, 确定读卡器导致的移动射频装置内检测电压的波动范围 δκ; 步骤 a3, 确定移动射频装置本身导致的检测电压的波动范围 Sc;
步骤 a4, 在 f 频率下测试各典型终端及障碍物的电压距离曲线,所述 f 频率为处于特低频频段或甚低频频段或低频频段中的任一频率,所述特低频 频段的频率范围为 300 Hz ~ 3000Hz, 所述甚 频频段的频率范围为 3KHz ~ 30KHz,所述低频频段的频率范围为 30 KHz - 300KHz;
步骤 a5, 由距离控制目标(Din, Dv )确定移动射频装置内检测电压的 波动范围 δΑ, δΑ等于由各典型终端及障碍物的电压距离曲线得到的具有平 均场强衰减曲线斜率的电压距离曲线上 Din点所对应的电压值与 (Din+ Dv ) 点所对应的电压值之差; 步骤 a6 , 确定由终端导致的移动射频装置内检测电压的波动范围 δ τ, δ τ表示终端衰减特性造成的移动射频装置内检测电压波动范围, δ τ= δ Α_ δ R_ δ c;
步骤 a7 ,计算各典型终端及障碍物间在距离控制范围内各距离点上的最 大场强差异 δ , 若 δ 大于 δ τ, 则降低频率 f , 转步骤 a4; 若 δ 小于 δ τ, 则提高频率 f , 转步骤 a4 ; 若 δ 等于 δ τ, 则当前测试频率 f 等于***无校 准工作的最高频率 f 0。
16.—种低频交变磁场距离控制方法, 其特征在于, 应用于包含权利要 求 1至 12任一项所述的移动射频装置的移动终端,该方法包括如下步骤: 步骤 a ,对接收到的低频交变磁场信号 Br进行磁电转换,将低频交变磁 场信号转换为电信号 Vo, 若 Br为幅度恒定的低频交变磁场信号, 则磁电转 换公式为 Vo=A*K*Br; 若 Br为微分幅度恒定的低频交变磁场信号, 则磁电转 换公式为 Vo=A*K*dBr/dt , 其中 K为低频磁感应电路增益, A低频放大电路 增益, A*K为磁电转换增益, 该增益预先设定;
步骤 b,若低频交变磁场信号转换的电信号 Vo大于预设的比较电压信号 门限 Vt , 则解码出读卡器的身份识别标识 IDr , 进入射频通讯, 通过射频通 道将 IDr连同移动射频装置本身的唯一识别码 IDc—同传送给读卡器, 同时 持续监控低频交变磁场信号;
步骤 c , 进行射频通讯, 将射频通讯数据拆分为多个数据包分次收发, 每次射频收包或发包都检查 Vo是否大于 Vt , 若是则继续射频通讯直至交易 结束, 否则结束本次交易的射频通讯, 返回步骤&。
17.根据权利要求 16所述的低频交变磁场距离控制方法, 其特征在于, 所述步骤 a中磁电转换增益的确定方法如下:
步骤 al , 确定磁感应增益 K, 选定移动射频装置所在载体上的低频磁感 应电路, 从而选定了磁感应增益 K;
步骤 a2 , 在下述原则下任意选定低频放大电路的增益 A:
1)移动射频装置在任意位置处接收到的磁感应强度 Br 小于***安全规 范要求的值;
2)移动射频装置放置于***指定的一种或多种载体中, 并在***要求的 距离控制目标最远可接收距离处,磁感应信号经过磁电转换后的信号信噪比 大于 SNR;
3)若磁感应电路为霍尔器件或巨磁阻器件: A*K = Vt/Bgate,其中 Bgate 为磁感应强度门限; 若磁感应电路为线圏: A*K = Vt/B_RATEgate, 其中 B.RATEgate 为磁感应强度变化率的门限值, 磁感应强度变化率 B_RATE=dBr/dt0
18.根据权利要求 17所述的低频交变磁场距离控制方法, 其特征在于, 所述步骤 a2中信噪比 SNR大于 5。
19.根据权利要求 17所述的低频交变磁场距离控制方法, 其特征在于, 所述低频磁感应电路为线圏,所述移动射频装置放置在 SIM卡、 UIM卡、 USIM 卡、 TF卡、 SD卡或匪 C卡中, 则所述线圏的匝数为 1 ~20匝, 低频放大电 路的增益 A大于 100。
20.根据权利要求 16所述的低频交变磁场距离控制方法, 其特征在于, 所述步骤 a中,所述磁电转换存在误差,即 Vo存在波动,波动范围为 δ c (db), 误差 S c(db) 的选择及控制方法如下:
S c的范围为 2~6dB;
δ c的控制方法包括如下步骤:
假设移动射频装置所应用的各种移动终端对低频交变磁场信号的衰减 的最大波动范围为 δ Τ, 则所述误差控制***中标准障碍物的衰减为 δΤ/2。
步骤 601: 标准读卡器在固定距离及位置上发射幅度恒定或微分幅度恒 定的低频交变磁场信号, 该***下幅度值 Bgate或 分幅度值 B.RATEgate 的磁场经过磁电转换后的电压值为幅度为 Vt附近的电压信号 Vo;
步骤 602: 确定 Vo范围 (Vt_S cx/2, Vt- δ cx/2) , 其中 δ cx< δ c; 步骤 603: 测量移动射频装置中低频放大电路的输出电信号 Vo,如果 Vo 超出(Vt- δ cx/2, Vt- δ cx/2)范围, 则通过软件设置调整低频放大电路的放 大倍数 A, 直到 VO在上述范围内;
步骤 604:通过软件设置移动射频装置的 Vt值为步骤 603调整 A后的输 出电信号 Vo。
21.根据权利要求 16所述的低频交变磁场距离控制方法, 其特征在于, 所述电压门限 Vt用与该电压门限 Vt对应的电流门限替代。
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2010101243271 | 2010-03-15 | ||
CN201010124327.1A CN102196605B (zh) | 2010-03-15 | 2010-03-15 | 移动射频装置、射频ic卡及射频存储卡 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2011113216A1 true WO2011113216A1 (zh) | 2011-09-22 |
Family
ID=44603802
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/CN2010/071416 WO2011113216A1 (zh) | 2010-03-15 | 2010-03-30 | 移动射频装置、射频ic卡及射频存储卡 |
Country Status (3)
Country | Link |
---|---|
CN (1) | CN102196605B (zh) |
AR (1) | AR080399A1 (zh) |
WO (1) | WO2011113216A1 (zh) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110210268A (zh) * | 2019-06-05 | 2019-09-06 | 北京京投信安科技发展有限公司 | 基于landmarc算法的rfid高精度定位技术 |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103187984B (zh) * | 2011-12-29 | 2016-09-14 | 国民技术股份有限公司 | 一种移动终端、移动终端***及移动终端信号传输方法 |
CN103187938B (zh) * | 2011-12-27 | 2017-07-25 | 国民技术股份有限公司 | 一种用于低频信号检测及传输***的差分模拟前端装置 |
CN103186873A (zh) * | 2011-12-31 | 2013-07-03 | 国民技术股份有限公司 | 射频ic卡、移动终端以及银行卡业务*** |
TWI502808B (zh) * | 2012-06-19 | 2015-10-01 | Wistron Corp | 行動通訊裝置 |
CN103034824B (zh) * | 2012-11-22 | 2016-06-08 | 深圳市新国都技术股份有限公司 | 一种非接触式ic卡通讯装置 |
CN104050561A (zh) * | 2014-06-20 | 2014-09-17 | 成都联星微电子有限公司 | 一种基于rfid的金融支付*** |
DE102014213217A1 (de) * | 2014-07-08 | 2016-01-14 | Continental Teves Ag & Co. Ohg | Körperschallentkopplung an mit Geberfeldern arbeitenden Sensoren |
US9742443B2 (en) * | 2015-09-08 | 2017-08-22 | Nxp B.V. | Pulse shaping for radio frequency transmitters |
CN105634563B (zh) * | 2015-12-22 | 2018-03-09 | 武汉瑞纳捷电子技术有限公司 | 一种限制距离的低频通信***及方法 |
CN114610079B (zh) * | 2022-03-09 | 2022-10-18 | 国机传感科技有限公司 | 一种基于极低频磁传感的二维控制方法及*** |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN201017339Y (zh) * | 2007-03-13 | 2008-02-06 | 深圳市远望谷信息技术股份有限公司 | 有源通用电子标签 |
CN101329717A (zh) * | 2008-05-19 | 2008-12-24 | 深圳市中兴集成电路设计有限责任公司 | 分阶段控制其信号收发强度的射频读卡器及其实现方法 |
CN101330334A (zh) * | 2008-03-04 | 2008-12-24 | 深圳市中兴集成电路设计有限责任公司 | 一种用于校准射频sim卡通信距离的装置及方法 |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4098489B2 (ja) * | 2001-05-01 | 2008-06-11 | 並木精密宝石株式会社 | 電磁誘導型アクチュエータを搭載する携帯端末機 |
CN101354739B (zh) * | 2008-08-25 | 2010-12-29 | 国民技术股份有限公司 | 借助标签识别控制射频sim卡通信距离的方法及通信*** |
-
2010
- 2010-03-15 CN CN201010124327.1A patent/CN102196605B/zh active Active
- 2010-03-30 WO PCT/CN2010/071416 patent/WO2011113216A1/zh active Application Filing
-
2011
- 2011-03-14 AR ARP110100802A patent/AR080399A1/es not_active Application Discontinuation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN201017339Y (zh) * | 2007-03-13 | 2008-02-06 | 深圳市远望谷信息技术股份有限公司 | 有源通用电子标签 |
CN101330334A (zh) * | 2008-03-04 | 2008-12-24 | 深圳市中兴集成电路设计有限责任公司 | 一种用于校准射频sim卡通信距离的装置及方法 |
CN101329717A (zh) * | 2008-05-19 | 2008-12-24 | 深圳市中兴集成电路设计有限责任公司 | 分阶段控制其信号收发强度的射频读卡器及其实现方法 |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110210268A (zh) * | 2019-06-05 | 2019-09-06 | 北京京投信安科技发展有限公司 | 基于landmarc算法的rfid高精度定位技术 |
Also Published As
Publication number | Publication date |
---|---|
CN102196605B (zh) | 2014-02-26 |
CN102196605A (zh) | 2011-09-21 |
AR080399A1 (es) | 2012-04-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US10019611B2 (en) | Communication device and system | |
WO2011113216A1 (zh) | 移动射频装置、射频ic卡及射频存储卡 | |
WO2011091622A1 (zh) | 近距离通信方法及*** | |
WO2011140732A1 (zh) | 一种近距离通信方法及*** | |
US8630584B2 (en) | RF SIM card, card reader, and communication method | |
KR101492948B1 (ko) | 조절가능 이득을 갖는 근거리 무선 통신 장치 | |
WO2011113215A1 (zh) | 一种读卡器 | |
US9292782B2 (en) | Adaptive NFC transceivers | |
CN102810144B (zh) | 距离可控的移动支付方法及装置 | |
CN102769483B (zh) | 一种通信***及方法 | |
CN102768722B (zh) | 一种通信***及方法 | |
US8954005B2 (en) | Apparatus for low-frequency signal detection and transmission | |
CN102769474B (zh) | 一种低频交变磁场距离控制方法 | |
TWI501575B (zh) | 行動射頻裝置、射頻ic卡及射頻存儲卡 | |
TWI509522B (zh) | 射頻裝置、射頻讀取器及相關通訊系統和方法 | |
TWI549063B (zh) | 讀卡器 | |
CN203054898U (zh) | 一种采用磁场控制距离检测的rf-sim卡 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 10847685 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
32PN | Ep: public notification in the ep bulletin as address of the adressee cannot be established |
Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205 DATED 21/11/2012) |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 10847685 Country of ref document: EP Kind code of ref document: A1 |