CN105634563A - Low frequency communication system and method limiting distance - Google Patents
Low frequency communication system and method limiting distance Download PDFInfo
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Abstract
The present invention is applicable to the field of near field communication technologies, and provides a low frequency communication system and method limiting a distance. The system includes a communication transmit apparatus and a communication receive apparatus. The communication transmit apparatus includes a transmit coil. The communication receive apparatus includes a receive antenna. The communication transmit apparatus includes a coding unit, a modulation unit and a power amplification unit. The communication receive apparatus includes a filter unit, an amplification unit and a decoding unit. The system has a simple circuit structure, is convenient and flexible to configure, and has good adaptability and practicability. The energy transmitted by the system attenuates slowly.
Description
Technical field
The invention belongs to Near Field Communication technical field, particularly relate to the LF communication system and method for a kind of limiting distance.
Background technology
RFID chip is built in mobile phone or mobile phone intelligent card by mobile phone radio frequency identification (RadioFrequencyIdentification, RFID) technology, realizing the integrated of cell-phone function and RFID function, user can realize many closely mobile payments such as mobile payment, financial service, purchase and consumption, by bus service, authentication and apply by brush mobile phone. At present, main flow mobile phone RFID solution can be divided into two big classes according to operating frequency, i.e. 13.56MHz scheme and 2.4GHz scheme, wherein, it is integrated in SIM based on the RFID-SIM of 2.4GHz by radio-frequency technique to be packaged into together the form of SIM, RFID-SIM had both supported the SIM function of standard, it is possible to complete wireless near field communication, was the Typical Representative that combines with noncontact field of smart card techniques.
In a lot of mobile payments are applied, it is thus necessary to determine that payable distance range, and judge mobile phone or pay the distance that SIM entrance pays, thus avoided swiping the card at a distance by mistake. Wherein, Chinese invention patent one near field communication method and system CN201010166226.0 adopt low frequency alternating magnetic field signal to transmit data, namely default emission parameter is adopted to launch low frequency alternating magnetic field signal, the highest frequency f0 of this low frequency alternating magnetic field signal, it is preferable that low frequency alternating magnetic field signal frequency can be 500Hz, 1KHz, 1.5KHz, 2KHz, 2.5KHz, 3KHz, 4KHz, 5KHz, 10KHz, 20KHz or 30KHz.
Existing scheme low frequency alternating magnetic field signal directly adopts baseband signal to be transmitted, and the energy attenuation of transmission is very fast, close together, and for multiple different transfer rates, needing to produce the alternating magnetic field signal of different frequency, circuit controls complex, and cost is higher.
Summary of the invention
Embodiments provide the LF communication system and method for a kind of limiting distance, aim to solve the problem that prior art adopts baseband signal to be transmitted, the energy attenuation of transmission is very fast, close together, and for multiple different transfer rates, needing to produce the alternating magnetic field signal of different frequency, circuit controls complex, the problem that cost is higher.
On the one hand, it is provided that the LF communication system of a kind of limiting distance, described system includes: communication transmitting device and communication receiving device, wherein, described communication transmitting device includes transmitting coil, and described communication receiving device includes reception antenna, and described communication transmitting device includes:
Coding unit, for carrying out Differential Manchester Encoding to data to be sent, it is thus achieved that current signal waveform to be sent;
Modulating unit, it is connected with described coding unit respectively, for adopting default altofrequency clock, control the pulse width within the persistent period of described current signal waveform to be sent or/and impulse density by signaling switch, it is thus achieved that the current signal of preset signals speed;
Power amplification unit, is connected with described modulating unit and transmitting coil respectively, and for described current signal being amplified through the first power amplifier, output afterwards sends to described transmitting coil.
Further, described communication receiving device includes:
Filter unit, the current signal for being received by described reception antenna filters the signal of upper frequency by low pass filter, it is thus achieved that filtering signal;
Amplifying unit, for being amplified described filtering signal by the second power amplifier;
Decoding unit, for carrying out Difference Manchester decoding to the described filtering signal after amplifying, it is thus achieved that the data of described preset signals speed.
Further, described modulating unit includes modulation circuit, and described modulation circuit includes carrier frequency configuration register; The carrier clock being connected with described carrier frequency configuration register outfan; Piecemeal configuration register; The first enumerator being connected with described piecemeal configuration register outfan; First configuration register; The second enumerator being connected with described first configuration register outfan respectively; Second configuration register; The 3rd enumerator being connected with described second configuration register outfan respectively; The output level generator being connected with described first counter output, the second counter output and the 3rd counter output, described second counter output is connected with described first counter input, and described second counter output is connected with described 3rd counter input.
Further, described modulating unit specifically includes:
Computation of Period module, for the ratio according to the default altofrequency clock configured in described carrier frequency configuration register and transmission code rate, it is thus achieved that per bit signal transmits the carrier cycle numerical value S taken;
Pulsewidth acquisition module, for obtaining the N number of pulsewidth modulation of level value in the carrier cycle numerical value S that the transmission of described per bit signal takies, in described N configuration and the first configuration register and export extremely described second enumerator, N is integer, it is necessary to satisfies condition N*N and approximates S;
Cycle registration module, for according to continuing carrier cycle R/ level value N, using its quotient as the first numerical value Q and its remainder as third value R, described Q is configured in described piecemeal configuration register and exports to described first enumerator, described R is configured in described second configuration register and exports to described 3rd enumerator, and Q, R are integer;
Cycle divides module, and for S carrier cycle is divided into Q+1 fritter, wherein, front Q fritter comprises N number of clock cycle, and last fritter comprises R clock cycle;
Pulse width modulation module, in each fritter, according to block value now, the high level of the high level dutycycle or pulse density modulated that control pulsewidth modulation occurs that density linear increases or reduces.
Further, described default altofrequency clock includes 1M, 2M, 4M or 8M.
On the other hand, it is provided that a kind of LF communication method of limiting distance, described method includes:
Data to be sent are carried out Differential Manchester Encoding by described communication transmitting device, it is thus achieved that current signal waveform to be sent;
Described communication transmitting device adopts presets altofrequency clock, controls the pulse width within the persistent period of described current signal waveform to be sent or/and impulse density by signaling switch, it is thus achieved that the current signal of preset signals speed;
Described current signal is amplified by described communication transmitting device through the first power amplifier, and output afterwards sends to described transmitting coil.
Further, described method includes:
The current signal that described reception antenna is received by described communication receiving device filters the signal of upper frequency by low pass filter, it is thus achieved that filtering signal;
Described filtering signal is amplified by described communication receiving device by the second power amplifier;
Described filtering signal after amplifying is carried out Difference Manchester decoding by described communication receiving device, it is thus achieved that the data of described preset signals speed.
Further, described communication transmitting device adopts presets altofrequency clock, controls the pulse width within the persistent period of described current signal waveform to be sent or/and impulse density by signaling switch, it is thus achieved that the current signal of preset signals speed includes:
Ratio according to the default altofrequency clock configured in described carrier frequency configuration register and transmission code rate, it is thus achieved that per bit signal transmits the carrier cycle numerical value S taken;
Obtaining the N number of pulsewidth modulation of level value in the described per bit signal carrier cycle numerical value S that takies of transmission, in described N configuration and the first configuration register and export extremely described second enumerator, N is integer, it is necessary to satisfies condition N*N and approximates S;
According to lasting carrier cycle R/ level value N, using its quotient as the first numerical value Q and its remainder as third value R, described Q is configured in described piecemeal configuration register and exports to described first enumerator, described R is configured in described second configuration register and exports to described 3rd enumerator, and Q, R are integer;
S carrier cycle is divided into Q+1 fritter, and wherein, front Q fritter comprises N number of clock cycle, and last fritter comprises R clock cycle;
In each fritter, according to block value now, the high level of the high level dutycycle or pulse density modulated that control pulsewidth modulation occurs that density linear increases or reduces.
Further, described default altofrequency clock includes 1M, 2M, 4M or 8M.
The embodiment of the present application includes advantages below:
Communication transmitting device carries out Differential Manchester Encoding to sent bit, obtain the current signal waveform that the electric current needed for low frequencies end sends, adopt upper frequency such as 1M, 2M, the clock of 4M or 8M, by the switch of signal, control the pulse width in current duration or impulse density, obtain the current signal of a linear change, this signal rate can be 2K, 4K or 8K, current signal amplifies through power amplifier, and flow through transmitting coil, the alternating electromagnetic field produced by coil is coupled on the reception antenna of communication receiving device, receive signal and filter the signal of upper frequency through low pass filter, and amplify, 2K can be obtained after decoding, the data signal of 4K or 8K, its circuit structure is simple, configure convenient, flexible, the energy attenuation of transmission is slow, possess good adaptability and practicality.
Accompanying drawing explanation
Fig. 1 is the structural representation of the LF communication system of the limiting distance that the embodiment of the present invention one provides;
Fig. 2 is Manchester's code and the Differential Manchester Encoding schematic diagram of the embodiment of the present invention one offer;
Fig. 3 is the structural representation of the modulation circuit that the embodiment of the present invention one provides;
Fig. 4 is the structural representation of the modulating unit that the embodiment of the present invention one provides;
Fig. 5 is the flow chart of the LF communication method of the communication transmitting device that the embodiment of the present invention two provides;
Fig. 6 is the flow chart of the LF communication method of the communication receiving device that the embodiment of the present invention two provides.
Detailed description of the invention
In order to make the purpose of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated. Should be appreciated that specific embodiment described herein is only in order to explain the present invention, is not intended to limit the present invention.
Below in conjunction with specific embodiment, the realization of the present invention is described in detail:
Embodiment one
Fig. 1 illustrates the concrete structure block diagram of the LF communication system of the limiting distance that the embodiment of the present invention one provides, and for the ease of illustrating, illustrate only the part relevant to the embodiment of the present invention. In the present embodiment, the LF communication system of this limiting distance includes: communication transmitting device 1 and communication receiving device 2, and wherein, communication transmitting device 1 includes transmitting coil, and described communication receiving device 2 includes reception antenna.
Wherein, described communication transmitting device 1 includes:
Coding unit 11, for carrying out Differential Manchester Encoding to data to be sent, it is thus achieved that current signal waveform to be sent;
Wherein, first data to be sent are carried out Differential Manchester Encoding by communication transmitting device, and coding waveforms is as shown in Figure 2. There is a saltus step each centre of Manchester's code, and saltus step from low to high represents 0, and saltus step from high to low represents 1; Also definition that can be contrary, saltus step from low to high represents 1, and saltus step from high to low represents 0. Differential Manchester Encoding based on Manchester's code, in code stream with previous jump along in the same direction be data 0, reverse is data 1.
Modulating unit 12, it is connected with described coding unit respectively, for adopting default altofrequency clock, control the pulse width within the persistent period of described current signal waveform to be sent or/and impulse density by signaling switch, it is thus achieved that the current signal of preset signals speed;
Preferably, described default altofrequency clock includes 1M, 2M, 4M or 8M.
In the present embodiment, described modulating unit 12 includes modulation circuit, as it is shown on figure 3, described modulation circuit includes carrier frequency configuration register; The carrier clock being connected with described carrier frequency configuration register outfan; Piecemeal configuration register; The first enumerator being connected with described piecemeal configuration register outfan; First configuration register; The second enumerator being connected with described first configuration register outfan respectively; Second configuration register; The 3rd enumerator being connected with described second configuration register outfan respectively; The output level generator being connected with described first counter output, the second counter output and the 3rd counter output, described second counter output is connected with described first counter input, and described second counter output is connected with described 3rd counter input.
Wherein, the clock of the second enumerator and R counting is carrier clock, and configuration is provided by N configuration register and R configuration register respectively. When system initialization, the value of N and the three enumerator is 0. After proceeding by signal modulation, when the value of the second enumerator is become Configuration Values N ' from 0, produce a pulse signal and be sent to the first enumerator; When the value of the 3rd enumerator is become Configuration Values R ' from 0, produce a pulse signal and be sent to the first enumerator. The configuration numerical value of N and R provides according to method as described above. The value of N and the three enumerator is all input in output level generator.
First enumerator represents the count value of current piecemeal. In piecemeal configuration register, the Q-value of storage is provided by hereafter civilian described method. During system initialization, Q-value is 0. After proceeding by signal modulation, after the first enumerator often receives the pulse that second enumerator is sent, the value of the first enumerator adds 1. When the value of the first enumerator is equal to piecemeal configuration register preset value Q ', and after receiving a pulse signal from the 3rd enumerator, Q-value saltus step is 0, and represents that a bit signal is sent.
Output level generator produces the low and high level of output, and in each fritter, the value according to the first enumerator, density occurs in the high level of the corresponding high level dutycycle controlling PWM or PDM so that in this N carrier cycle, the dutycycle of high level is Q/N. When the value of the first enumerator is equal to the preset value Q ' of piecemeal configuration register, now high level dutycycle is 1, and the lasting carrier cycle time is R.
Further, as shown in Figure 4, described modulating unit 12 specifically includes:
Computation of Period module 121, for the ratio according to the default altofrequency clock configured in described carrier frequency configuration register and transmission code rate, it is thus achieved that per bit signal transmits the carrier cycle numerical value S taken;
Pulsewidth acquisition module 122, for obtaining the N number of pulsewidth modulation of level value in the carrier cycle numerical value S that the transmission of described per bit signal takies, in described N configuration and the first configuration register and export extremely described second enumerator, N is integer, it is necessary to satisfies condition N*N and approximates S;
Cycle registration module 123, for according to continuing carrier cycle R/ level value N, using its quotient as the first numerical value Q and its remainder as third value R, described Q is configured in described piecemeal configuration register and exports to described first enumerator, described R is configured in described second configuration register and exports to described 3rd enumerator, and Q, R are integer;
Cycle divides module 124, and for S carrier cycle is divided into Q+1 fritter, wherein, front Q fritter comprises N number of clock cycle, and last fritter comprises R clock cycle;
Pulse width modulation module 125, in each fritter, according to block value now, the high level of the high level dutycycle or pulse density modulated that control pulsewidth modulation occurs that density linear increases or reduces.
Power amplification unit 13, is connected with described modulating unit and transmitting coil respectively, and for described current signal being amplified through the first power amplifier, output afterwards sends to described transmitting coil.
Wherein, preset altofrequency clock as carrier wave using 8M, the preset signals speed of transmission 2K be example to describe modulated process:
(1) ratio S, the S=16M/2K=4000 that preset altofrequency clock and preset signals speed are calculated, i.e. 4000 carrier cycle one bit signals of transmission;
(2) design one is total to pulsewidth modulation (PWM, PulseWidthModulation) or the pulse density modulated (PDM, PulseDensityModulation) of N number of grade, and N is integer, it is necessary to satisfies condition N*N and approximates S. According to above-mentioned condition, it is possible to try to achieve N equal to 64;
(3) calculating R/N and try to achieve quotient Q and remainder R, in this example, Q is 62, R is 32;
(4) being divided into Q+1 fritter the S cycle, wherein, front Q fritter comprises N number of clock cycle, and last fritter comprises R clock cycle. In these row, 4000 cycles are divided into 63 fritters, front 62 every piece comprise 64 clock cycle, last fritter remaining only comprises 32 clock cycle;
(5) in each fritter, according to block value now, the high level of the corresponding high level dutycycle controlling PWM or PDM occurs that density does following linear change, from 0/N, 1/N, 2/N, 3/N, 4/N, ... ... (N-3)/N, (N-2)/N, (Q-1)/N, R/R. Wherein, dutycycle or high level density are 0/64,1/64,2/64,3/64 ... ... 61/64,32/32, the wherein full width level of last 32,/32 32 clock cycle of expression;
By the way, the electric current that macroscopically current intensity linearly increases gradually can be obtained, similar method, there is density R/R in the following order in the high level dutycycle of PWM or the high level of PDM, (Q-1)/N ... ... 1/N, 0/N can obtain the current signal that current intensity linearly reduces.
Further, described communication receiving device 2 includes:
Filter unit 21, the current signal for being received by described reception antenna filters the signal of upper frequency by low pass filter, it is thus achieved that filtering signal;
Amplifying unit 22, for being amplified described filtering signal by the second power amplifier;
Decoding unit 23, for carrying out Difference Manchester decoding to the described filtering signal after amplifying, it is thus achieved that the data of described preset signals speed.
Wherein, in the code stream of Differential Manchester Encoding with previous jump along in the same direction be data 0, reverse is data 1. Signal based on Differential Manchester Encoding can be sampled by decoding unit 23 according to the default sampling interval, then the amplitude versus time feature of each sampled point obtained is converted into temporal characteristics; Or level signal is converted into triangular signal by the method adopting accumulated counts, by triangular wave gate method, it is judged that crest and trough, obtains clock signal and intermediate data, thus completing manchester decoder. The signal of communication receiving device 2 is produced by the induced voltage of reception antenna, and induced voltage is proportional to the rate of change of receiving coil magnetic flux, i.e. V=d ��/dt. When receiving coil area one timing, magnetic flux and magnetic field intensity are directly proportional. For communication transmitting device, coil transmissions, to the magnetic field intensity in space, is be directly proportional with electric current, and magnetic field intensity calculates formula: H=N*I/Le, and in formula, H is magnetic field intensity, and unit is A/m; N is the number of turn of transmitting antenna coil, and I is exciting current, and Le is the effective magnetic circuit length of measuring samples, and unit is m. According to expression above it was determined that if communication receiving device senses low and high level as shown in Figure 2, then communication transmitting device electric current needs to meet V=K*di/dt, and wherein K is proportionality constant. Communication transmitting device coil current linear change can meet requirement.
The present embodiment, communication transmitting device carries out Differential Manchester Encoding to sent bit, obtain the current signal waveform that the electric current needed for low frequencies end sends, adopt upper frequency such as 1M, 2M, the clock of 4M or 8M, by the switch of signal, control the pulse width in current duration or impulse density, obtain the current signal of a linear change, this signal rate can be 2K, 4K or 8K, current signal amplifies through power amplifier, and flow through transmitting coil, the alternating electromagnetic field produced by coil is coupled on the reception antenna of communication receiving device, receive signal and filter the signal of upper frequency through low pass filter, and amplify, 2K can be obtained after decoding, the data signal of 4K or 8K, its circuit structure is simple, configure convenient, flexible, the energy attenuation of transmission is slow, possess good adaptability and practicality.
Embodiment two
What Fig. 5 illustrated the LF communication method of the communication transmitting device that the embodiment of the present invention two provides realizes flow process, and details are as follows:
What deserves to be explained is, the LF communication system of limiting distance includes communication transmitting device and communication receiving device, and wherein, described communication transmitting device includes transmitting coil, and described communication receiving device includes reception antenna.
In step S501, data to be sent are carried out Differential Manchester Encoding by communication transmitting device, it is thus achieved that current signal waveform to be sent.
In the present embodiment, wherein, first data to be sent are carried out Differential Manchester Encoding by communication transmitting device, and coding waveforms is as shown in Figure 2. There is a saltus step each centre of Manchester's code, and saltus step from low to high represents 0, and saltus step from high to low represents 1; Also definition that can be contrary, saltus step from low to high represents 1, and saltus step from high to low represents 0. Differential Manchester Encoding based on Manchester's code, in code stream with previous jump along in the same direction be data 0, reverse is data 1.
In step S502, described communication transmitting device adopts presets altofrequency clock, controls the pulse width within the persistent period of described current signal waveform to be sent or/and impulse density by signaling switch, it is thus achieved that the current signal of preset signals speed.
In the present embodiment, described default altofrequency clock includes 1M, 2M, 4M or 8M. Described modulating unit includes modulation circuit, as it is shown on figure 3, described modulation circuit includes carrier frequency configuration register; The carrier clock being connected with described carrier frequency configuration register outfan; Piecemeal configuration register; The first enumerator being connected with described piecemeal configuration register outfan; First configuration register; The second enumerator being connected with described first configuration register outfan respectively; Second configuration register; The 3rd enumerator being connected with described second configuration register outfan respectively; The output level generator being connected with described first counter output, the second counter output and the 3rd counter output, described second counter output is connected with described first counter input, and described second counter output is connected with described 3rd counter input.
Wherein, the clock of the second enumerator and R counting is carrier clock, and configuration is provided by N configuration register and R configuration register respectively. When system initialization, the value of N and the three enumerator is 0. After proceeding by signal modulation, when the value of the second enumerator is become Configuration Values N ' from 0, produce a pulse signal and be sent to the first enumerator; When the value of the 3rd enumerator is become Configuration Values R ' from 0, produce a pulse signal and be sent to the first enumerator. The configuration numerical value of N and R provides according to method as described above. The value of N and the three enumerator is all input in output level generator.
First enumerator represents the count value of current piecemeal. In piecemeal configuration register, the Q-value of storage is provided by hereafter civilian described method. During system initialization, Q-value is 0. After proceeding by signal modulation, after the first enumerator often receives the pulse that second enumerator is sent, the value of the first enumerator adds 1. When the value of the first enumerator is equal to piecemeal configuration register preset value Q ', and after receiving a pulse signal from the 3rd enumerator, Q-value saltus step is 0, and represents that a bit signal is sent.
Output level generator produces the low and high level of output, and in each fritter, the value according to the first enumerator, density occurs in the high level of the corresponding high level dutycycle controlling PWM or PDM so that in this N carrier cycle, the dutycycle of high level is Q/N. When the value of the first enumerator is equal to the preset value Q ' of piecemeal configuration register, now high level dutycycle is 1, and the lasting carrier cycle time is R.
Further, described communication transmitting device adopts presets altofrequency clock, controls the pulse width within the persistent period of described current signal waveform to be sent or/and impulse density by signaling switch, it is thus achieved that the current signal of preset signals speed specifically includes:
Ratio according to the default altofrequency clock configured in described carrier frequency configuration register and transmission code rate, it is thus achieved that per bit signal transmits the carrier cycle numerical value S taken;
Obtaining the N number of pulsewidth modulation of level value in the described per bit signal carrier cycle numerical value S that takies of transmission, in described N configuration and the first configuration register and export extremely described second enumerator, N is integer, it is necessary to satisfies condition N*N and approximates S;
According to lasting carrier cycle R/ level value N, using its quotient as the first numerical value Q and its remainder as third value R, described Q is configured in described piecemeal configuration register and exports to described first enumerator, described R is configured in described second configuration register and exports to described 3rd enumerator, and Q, R are integer;
S carrier cycle is divided into Q+1 fritter, and wherein, front Q fritter comprises N number of clock cycle, and last fritter comprises R clock cycle;
In each fritter, according to block value now, the high level of the high level dutycycle or pulse density modulated that control pulsewidth modulation occurs that density linear increases or reduces.
Wherein, preset altofrequency clock as carrier wave using 8M, the preset signals speed of transmission 2K be example to describe modulated process:
Ratio S, the S=16M/2K=4000 of S11, the default altofrequency clock of calculating and preset signals speed, i.e. 4000 carrier cycles one bit signals of transmission;
The pulsewidth modulation (PWM, PulseWidthModulation) of S12, design one N number of grade altogether or pulse density modulated (PDM, PulseDensityModulation), N is integer, it is necessary to satisfies condition N*N and approximates S. According to above-mentioned condition, it is possible to try to achieve N equal to 64;
S13, calculating R/N try to achieve quotient Q and remainder R, and in this example, Q is 62, R is 32;
S14, being divided into Q+1 fritter the S cycle, wherein, front Q fritter comprises N number of clock cycle, and last fritter comprises R clock cycle. In these row, 4000 cycles are divided into 63 fritters, front 62 every piece comprise 64 clock cycle, last fritter remaining only comprises 32 clock cycle;
S15, in each fritter, according to block value now, the high level of the corresponding high level dutycycle controlling PWM or PDM occurs that density does following linear change, from 0/N, 1/N, 2/N, 3/N, 4/N, ... ... (N-3)/N, (N-2)/N, (Q-1)/N, R/R. Wherein, dutycycle or high level density are 0/64,1/64,2/64,3/64 ... ... 61/64,32/32, the wherein full width level of last 32,/32 32 clock cycle of expression;
By the way, the electric current that macroscopically current intensity linearly increases gradually can be obtained, similar method, there is density R/R in the following order in the high level dutycycle of PWM or the high level of PDM, (Q-1)/N ... ... 1/N, 0/N can obtain the current signal that current intensity linearly reduces.
In step S503, described communication transmitting device adopts presets altofrequency clock, controls the pulse width within the persistent period of described current signal waveform to be sent or/and impulse density by signaling switch, it is thus achieved that the current signal of preset signals speed.
What Fig. 6 illustrated the LF communication method of the communication receiving device that the embodiment of the present invention two provides realizes flow process, and details are as follows:
In step S503, the current signal that described reception antenna is received by described communication receiving device filters the signal of upper frequency by low pass filter, it is thus achieved that filtering signal.
In step S503, described filtering signal is amplified by described communication receiving device by the second power amplifier.
In step S503, the described filtering signal after amplifying is carried out Difference Manchester decoding by described communication receiving device, it is thus achieved that the data of described preset signals speed.
In the present embodiment, in the code stream of Differential Manchester Encoding with previous jump along in the same direction be data 0, reverse is data 1. According to the default sampling interval, the signal based on Differential Manchester Encoding can be sampled, then the amplitude versus time feature of each sampled point obtained is converted into temporal characteristics. Or level signal is converted into triangular signal by the method adopting accumulated counts, by triangular wave gate method, it is judged that crest and trough, obtains clock signal and intermediate data, thus completing manchester decoder. The signal of communication receiving device is produced by the induced voltage of reception antenna, and induced voltage is proportional to the rate of change of receiving coil magnetic flux, i.e. V=d ��/dt. When receiving coil area one timing, magnetic flux and magnetic field intensity are directly proportional. For communication transmitting device, coil transmissions, to the magnetic field intensity in space, is be directly proportional with electric current, and magnetic field intensity calculates formula: H=N*I/Le, and in formula, H is magnetic field intensity, and unit is A/m; N is the number of turn of transmitting antenna coil, and I is exciting current, and Le is the effective magnetic circuit length of measuring samples, and unit is m. According to expression above it was determined that if communication receiving device senses low and high level as shown in Figure 2, then communication transmitting device electric current needs to meet V=K*di/dt, and wherein K is proportionality constant. Communication transmitting device coil current linear change can meet requirement.
The present embodiment, communication transmitting device carries out Differential Manchester Encoding to sent bit, obtain the current signal waveform that the electric current needed for low frequencies end sends, adopt upper frequency such as 1M, 2M, the clock of 4M or 8M, by the switch of signal, control the pulse width in current duration or impulse density, obtain the current signal of a linear change, this signal rate can be 2K, 4K or 8K, current signal amplifies through power amplifier, and flow through transmitting coil, the alternating electromagnetic field produced by coil is coupled on the reception antenna of communication receiving device, receive signal and filter the signal of upper frequency through low pass filter, and amplify, 2K can be obtained after decoding, the data signal of 4K or 8K, its circuit structure is simple, configure convenient, flexible, the energy attenuation of transmission is slow, possess good adaptability and practicality.
The LF communication method of the limiting distance that the embodiment of the present invention provides can be applied in the system embodiment one of aforementioned correspondence, and details, referring to the description of above-described embodiment one, do not repeat them here.
It should be noted that in said apparatus embodiment, included unit is carry out dividing according to function logic, but is not limited to above-mentioned division, as long as being capable of corresponding function; It addition, the concrete title of each functional unit is also only to facilitate mutually distinguish, it is not limited to protection scope of the present invention.
Each embodiment in this specification all adopts the mode gone forward one by one to describe, and what each embodiment stressed is the difference with other embodiments, between each embodiment identical similar part mutually referring to.
Those skilled in the art are it should be appreciated that the embodiment of the embodiment of the present application can be provided as method, controller or computer program. Therefore, the embodiment of the present application can adopt the form of complete hardware embodiment, complete software implementation or the embodiment in conjunction with software and hardware aspect. And, the embodiment of the present application can adopt the form at one or more upper computer programs implemented of computer-usable storage medium (including but not limited to disk memory, CD-ROM, optical memory etc.) wherein including computer usable program code.
The embodiment of the present application is to describe with reference to flow chart and/or the block diagram according to the method for the embodiment of the present application, terminal unit (system) and computer program. It should be understood that can by the combination of the flow process in each flow process in computer program instructions flowchart and/or block diagram and/or square frame and flow chart and/or block diagram and/or square frame. These computer program instructions can be provided to produce a machine to the processor of general purpose computer, special-purpose computer, Embedded Processor or other programmable data processing terminal equipment so that the instruction performed by the processor of computer or other programmable data processing terminal equipment is produced for realizing the controller of function specified in one flow process of flow chart or multiple flow process and/or one square frame of block diagram or multiple square frame.
These computer program instructions may be alternatively stored in and can guide in the computer-readable memory that computer or other programmable data processing terminal equipment work in a specific way, the instruction making to be stored in this computer-readable memory produces to include the manufacture of instruction control unit, and this instruction control unit realizes the function specified in one flow process of flow chart or multiple flow process and/or one square frame of block diagram or multiple square frame.
These computer program instructions also can be loaded on computer or other programmable data processing terminal equipment, make on computer or other programmable terminal equipment, to perform sequence of operations step to produce computer implemented process, thus the instruction performed on computer or other programmable terminal equipment provides for realizing the step of function specified in one flow process of flow chart or multiple flow process and/or one square frame of block diagram or multiple square frame.
Although having been described for the preferred embodiment of the embodiment of the present application, but those skilled in the art are once know basic creative concept, then these embodiments can be made other change and amendment. So, claims are intended to be construed to include preferred embodiment and fall into all changes and the amendment of the embodiment of the present application scope.
Finally, it can further be stated that, in this article, the relational terms of such as first and second or the like is used merely to separate an entity or operation with another entity or operating space, and not necessarily requires or imply the relation that there is any this reality between these entities or operation or sequentially. And, term " includes ", " comprising " or its any other variant are intended to comprising of nonexcludability, so that include the process of a series of key element, method, article or terminal unit not only include those key elements, but also include other key elements being not expressly set out, or also include the key element intrinsic for this process, method, article or terminal unit. When there is no more restriction, statement " including ... " key element limited, it is not excluded that there is also other identical element in including the process of described key element, method, article or terminal unit.
LF communication system and method to a kind of limiting distance provided herein above, it is described in detail, principle and the embodiment of the application are set forth by specific case used herein, and the explanation of above example is only intended to help and understands the present processes and core concept thereof; Simultaneously for one of ordinary skill in the art, according to the thought of the application, all will change in specific embodiments and applications, in sum, this specification content should not be construed as the restriction to the application.
Claims (9)
1. a LF communication system for limiting distance, including communication transmitting device and communication receiving device, wherein, described communication transmitting device includes transmitting coil, and described communication receiving device includes reception antenna, it is characterised in that described communication transmitting device includes:
Coding unit, for carrying out Differential Manchester Encoding to data to be sent, it is thus achieved that current signal waveform to be sent;
Modulating unit, it is connected with described coding unit respectively, for adopting default altofrequency clock, control the pulse width within the persistent period of described current signal waveform to be sent or/and impulse density by signaling switch, it is thus achieved that the current signal of preset signals speed;
Power amplification unit, is connected with described modulating unit and transmitting coil respectively, and for described current signal being amplified through the first power amplifier, output afterwards sends to described transmitting coil.
2. the LF communication system of the limiting distance according to described claim 1, it is characterised in that described communication receiving device includes:
Filter unit, the current signal for being received by described reception antenna filters the signal of upper frequency by low pass filter, it is thus achieved that filtering signal;
Amplifying unit, for being amplified described filtering signal by the second power amplifier;
Decoding unit, for carrying out Difference Manchester decoding to the described filtering signal after amplifying, it is thus achieved that the data of described preset signals speed.
3. the LF communication system of the limiting distance according to described claim 1, it is characterised in that described modulating unit includes modulation circuit, and described modulation circuit includes carrier frequency configuration register; The carrier clock being connected with described carrier frequency configuration register outfan; Piecemeal configuration register; The first enumerator being connected with described piecemeal configuration register outfan; First configuration register; The second enumerator being connected with described first configuration register outfan respectively; Second configuration register; The 3rd enumerator being connected with described second configuration register outfan respectively; The output level generator being connected with described first counter output, the second counter output and the 3rd counter output, described second counter output is connected with described first counter input, and described second counter output is connected with described 3rd counter input.
4. the LF communication system of the limiting distance according to described claim 3, it is characterised in that described modulating unit specifically includes:
Computation of Period module, for the ratio according to the default altofrequency clock configured in described carrier frequency configuration register and transmission code rate, it is thus achieved that per bit signal transmits the carrier cycle numerical value S taken;
Pulsewidth acquisition module, for obtaining the N number of pulsewidth modulation of level value in the carrier cycle numerical value S that the transmission of described per bit signal takies, in described N configuration and the first configuration register and export extremely described second enumerator, N is integer, it is necessary to satisfies condition N*N and approximates S;
Cycle registration module, for according to continuing carrier cycle R/ level value N, using its quotient as the first numerical value Q and its remainder as third value R, described Q is configured in described piecemeal configuration register and exports to described first enumerator, described R is configured in described second configuration register and exports to described 3rd enumerator, and Q, R are integer;
Cycle divides module, and for S carrier cycle is divided into Q+1 fritter, wherein, front Q fritter comprises N number of clock cycle, and last fritter comprises R clock cycle;
Pulse width modulation module, in each fritter, according to block value now, the high level of the high level dutycycle or pulse density modulated that control pulsewidth modulation occurs that density linear increases or reduces.
5. the LF communication system of the limiting distance according to described claim 1 or 4, it is characterised in that described default altofrequency clock includes 1M, 2M, 4M or 8M.
6. a LF communication method for limiting distance, including communication transmitting device and communication receiving device, wherein, described communication transmitting device includes transmitting coil, and described communication receiving device includes reception antenna, it is characterised in that described method includes:
Data to be sent are carried out Differential Manchester Encoding by described communication transmitting device, it is thus achieved that current signal waveform to be sent;
Described communication transmitting device adopts presets altofrequency clock, controls the pulse width within the persistent period of described current signal waveform to be sent or/and impulse density by signaling switch, it is thus achieved that the current signal of preset signals speed;
Described current signal is amplified by described communication transmitting device through the first power amplifier, and output afterwards sends to described transmitting coil.
7. the LF communication method of the limiting distance according to described claim 6, it is characterised in that described method includes:
The current signal that described reception antenna is received by described communication receiving device filters the signal of upper frequency by low pass filter, it is thus achieved that filtering signal;
Described filtering signal is amplified by described communication receiving device by the second power amplifier;
Described filtering signal after amplifying is carried out Difference Manchester decoding by described communication receiving device, it is thus achieved that the data of described preset signals speed.
8. the LF communication method of the limiting distance according to described claim 6, it is characterized in that, described communication transmitting device adopts presets altofrequency clock, the pulse width within the persistent period of described current signal waveform to be sent is controlled or/and impulse density, it is thus achieved that the current signal of preset signals speed includes by signaling switch:
Ratio according to the default altofrequency clock configured in described carrier frequency configuration register and transmission code rate, it is thus achieved that per bit signal transmits the carrier cycle numerical value S taken;
Obtaining the N number of pulsewidth modulation of level value in the described per bit signal carrier cycle numerical value S that takies of transmission, in described N configuration and the first configuration register and export extremely described second enumerator, N is integer, it is necessary to satisfies condition N*N and approximates S;
According to lasting carrier cycle R/ level value N, using its quotient as the first numerical value Q and its remainder as third value R, described Q is configured in described piecemeal configuration register and exports to described first enumerator, described R is configured in described second configuration register and exports to described 3rd enumerator, and Q, R are integer;
S carrier cycle is divided into Q+1 fritter, and wherein, front Q fritter comprises N number of clock cycle, and last fritter comprises R clock cycle;
In each fritter, according to block value now, the high level of the high level dutycycle or pulse density modulated that control pulsewidth modulation occurs that density linear increases or reduces.
9. the LF communication method of the limiting distance according to described claim 6 or 8, it is characterised in that described default altofrequency clock includes 1M, 2M, 4M or 8M.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106067802A (en) * | 2016-06-24 | 2016-11-02 | 桂林航天电子有限公司 | Microwave isolation solid-state relay and operation method thereof |
| CN107437961A (en) * | 2017-07-03 | 2017-12-05 | 宜昌市瑞磁科技有限公司 | A kind of magnetostatic communication system and its method |
| CN110692220A (en) * | 2017-05-22 | 2020-01-14 | 住友电气工业株式会社 | In-vehicle communication device, in-vehicle communication system, communication control method, and communication control program |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101977019A (en) * | 2010-10-29 | 2011-02-16 | 中国兵器工业集团第二一四研究所苏州研发中心 | H-bridge motor controller supporting unipolar and bipolar pulse width modulation control |
| CN102196605A (en) * | 2010-03-15 | 2011-09-21 | 国民技术股份有限公司 | Mobile radio frequency device, radio frequency IC (Integrated Circuit) card and radio frequency storage card |
| CN103714375A (en) * | 2013-09-26 | 2014-04-09 | 斯凯瑞利（北京）科技有限公司 | Active tag and radio frequency front-end chip thereof |
| CN104158305A (en) * | 2014-07-30 | 2014-11-19 | 华南理工大学 | Energy and information synchronous transmission system based on self-adaptive magnetic coupling resonance matching |
| CN104935087A (en) * | 2015-05-28 | 2015-09-23 | 天津工业大学 | Wireless electric energy and signal synchronous transmission system based on magnetic coupling resonance |
-
2015
- 2015-12-22 CN CN201510967649.5A patent/CN105634563B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102196605A (en) * | 2010-03-15 | 2011-09-21 | 国民技术股份有限公司 | Mobile radio frequency device, radio frequency IC (Integrated Circuit) card and radio frequency storage card |
| CN101977019A (en) * | 2010-10-29 | 2011-02-16 | 中国兵器工业集团第二一四研究所苏州研发中心 | H-bridge motor controller supporting unipolar and bipolar pulse width modulation control |
| CN103714375A (en) * | 2013-09-26 | 2014-04-09 | 斯凯瑞利（北京）科技有限公司 | Active tag and radio frequency front-end chip thereof |
| CN104158305A (en) * | 2014-07-30 | 2014-11-19 | 华南理工大学 | Energy and information synchronous transmission system based on self-adaptive magnetic coupling resonance matching |
| CN104935087A (en) * | 2015-05-28 | 2015-09-23 | 天津工业大学 | Wireless electric energy and signal synchronous transmission system based on magnetic coupling resonance |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106067802A (en) * | 2016-06-24 | 2016-11-02 | 桂林航天电子有限公司 | Microwave isolation solid-state relay and operation method thereof |
| CN110692220A (en) * | 2017-05-22 | 2020-01-14 | 住友电气工业株式会社 | In-vehicle communication device, in-vehicle communication system, communication control method, and communication control program |
| CN110692220B (en) * | 2017-05-22 | 2022-04-01 | 住友电气工业株式会社 | In-vehicle communication device, in-vehicle communication system, communication control method, and communication control program |
| CN107437961A (en) * | 2017-07-03 | 2017-12-05 | 宜昌市瑞磁科技有限公司 | A kind of magnetostatic communication system and its method |
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|---|---|
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