CN102663330A - Method for radio frequency tag inventory, radio frequency tag card reader and radio frequency tag - Google Patents
Method for radio frequency tag inventory, radio frequency tag card reader and radio frequency tag Download PDFInfo
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Abstract
The invention discloses a method for radio frequency tag inventory, a radio frequency tag card reader and a radio frequency tag. The method comprises the following steps: (a), emitting a radio frequency tag inventory request; (2), receiving a response signal from a radio frequency tag; (c), according to the response signal, determining all conflict bits and load modulation depth ratios of all the conflict bits; (d), determining a maximum value of the load modulation depth ratios of all the conflict bits to obtain the number of mask bits; (e), determining mask bits according to the load modulation depth ratios of all the conflict bits and the number of the mask bits; (f), sending mask bit information; (g), receiving return information from the radio frequency tag according to time slots determined by the mask bits so as to carry out radio frequency tag inventory. According to the method, the radio frequency tag card reader and the radio frequency tag, high-speed inventory of a tag with high capacity can be supported, thereby improving efficiency of tag inventory.
Description
Technical field
The present invention relates to the RF tag recognition system, specifically, relate to method, card reader and RF tag that a kind of RF tag is checked.
Background technology
RF identification (RFID-Radio Frequency Identification) is a kind of automatic identification technology.Compare with traditional automatic identification technologies such as bar code, have a lot of advantages, such as the problem that does not exist optics to block, corrosion resistivity is good, or the like.Particularly adopted after the REID of electronics, single radio frequency identification card reader can once be checked (Anti-collision Inventory) to a plurality of RF tags realization anti-collision automatically.Therefore, RFID becomes the basic device and the technology of Internet of Things, realizes the ubiquitous identification (Ubiquitous Identification) of object.
As receive in two or more the electromagnetic field of RF tag in same card reader card reader check instruction in; These labels are in the time that limits; With unique identifier (UID) form of communication frame according to a preconcerted arrangement of self, almost card reader is given in passback simultaneously.Because the UID of each label is independently, therefore, the data of passback UID can produce conflict at the card reader receiving end.In the card reader receiving course, conflict of qualification is also realized checking of whole addressable labels, is called as anti-collision and checks technology.
To receiving the identification situation of colliding data, can adopt different anti-collision methods according to the card reader end.Can not navigate to concrete data bit such as collision position, then can adopt so-called ALOHA agreement.In the ALOHA agreement, label is receiving that checking inside, instruction back produces random number, and is returning the UID sign indicating number with the random number time slot corresponding.Because the ALOHA agreement can not guarantee all labels of correct identification in the time of confirming, therefore, recognition result is a probability problem.
In the time of the The data Manchester's cde method of sending when RF tag, the card reader receiving end can navigate to concrete data bit with conflict, realizes that anti-collision checks thereby can adopt based on tree (Tree) search technique.Checking representational technology based on the anti-collision of tree is binary tree technology (B-Tree), for example the binary tree type anti-collision searching method of ISO/IEC14443 Type A standard.
It is following to reply traditional recognition principle based on B-Tree:
At first, each all adopts the Manchester's cde scheme reply data of RF tag, and Fig. 1 shows the expression way of Manchester's cde logical signal, according to Fig. 1.The width of the sign indicating number position of each data is all fixed; " 0 " uses a rising edge to express, and just preceding half yard position is low, and back half yard position is high; " 1 " uses negative edge to express, and preceding half yard position is high, and back half yard position is low.
For tag responses with coding " 0001 ", " 0100 " and " 0101 ".Fig. 2 shows Manchester's cde multiple signals sign indicating number bit swiping synoptic diagram; According to Fig. 2; Then when there are " 0 " and " 1 " two kinds of return datas simultaneously in this 2nd and the 4th sign indicating number position; Be encoded to " 0 " that the card reader end can not be distinguished the 2nd and the 4th still is " 1 ", is called in the sign indicating number position the 2nd and has conflict with the 4th, and use X representes.
In order to realize checking of label; The card reader end uses the instruction of checking of band mask, and requirement can be replied for the label of " 0 " such as second (conflict position); If two above-mentioned labels are only arranged in the card reader electromagnetic field, then can realize being numbered checking of " 0001 " label; When accomplishing after second coding all be the label counting of " 0 ", card reader all is that the label of " 1 " carries out identical query script to second coding again.The 4th still existence conflict this moment repeats above-mentioned mask to the 4th conflict position and checks process, discerns earlier " 0100 ", at last identification " 0101 ".
Because any one conflict position all will comprise two branches of " 0 " and " 1 ", so this counting method is called as binary tree and checks process.Here supposition has N to open label, and the communication process of checking each time all comprises the inventory requests of a card reader and replying of a secondary label, and then total process need of checking carries out such communication process of once checking 2*N-1 time.Fig. 3 shows the processing procedure of " 0001/0100/0101 " standard binary tree anti-collision.According to Fig. 3,, 2*3-1=5 time, promptly need the replying of label of inventory requests and 5 times of 5 times card reader for three labels with coding " 0001 ", " 0100 " and " 0101 ".
In the RF tag and card reading system of reality, the UID of RF tag has specifications such as 64bit, 96bit and 128bit, and the quantity of a label counting is also individual from several to thousands of not to be waited.In order to realize checking of high capacity label quickly, the researchist on above-mentioned technical foundation, has proposed combination B-Tree/ time slot (CN 101069193A) again, and based on anti-collision counting methods such as UID field segmentations.
Summary of the invention
The present invention proposes a kind of method that RF tag is checked in radio-frequency recognition system, card reader and radio frequency mark, this method, card reader and label can be supported the jumbo label of checking at a high speed, thereby improve the efficient of label counting.
According to an aspect of the present invention, proposed a kind of RF tag counting method, having comprised:
A) emission RF tag inventory requests;
B) reception is from the response signal of RF tag;
C) confirm the load-modulate depth ratio of all conflict positions and each conflict position according to response signal;
D) confirm the maximal value of the load-modulate depth ratio of all conflict positions, obtain masked bits quantity;
E) according to the load-modulate depth ratio of above-mentioned each conflict position, and the quantity of masked bits, confirm masked bits;
F) send masked bits information;
G) time slot of confirming according to masked bits receives the return message from RF tag, thereby checks RF tag.
According to another aspect of the present invention, proposed a kind of RF tag counting method, comprised
Receive the label counting request;
Send the response signal of label;
Receive masked bits information;
According to the data of the corresponding masked bits of label self, in time slot corresponding, send signal.
According to a further aspect of the invention, proposed a kind of RF tag card reader, having comprised:
Transmitter module is configured to launch the RF tag inventory requests;
Receiver module is configured to receive the response signal from RF tag;
Processing module comprises:
Load-modulate depth ratio determination module is configured to confirm according to response signal the load-modulate depth ratio of all conflict positions and each conflict position,
Masked bits quantity determination module is configured to confirm the maximal value of the load-modulate depth ratio of all conflict positions obtain masked bits quantity, and
The masked bits determination module is configured to the load-modulate depth ratio according to above-mentioned each conflict position, and the quantity of masked bits, confirms masked bits;
Wherein, said transmitter module also is configured to send masked bits information; Said processing module also is configured to receive the return message from RF tag, thereby check RF tag according to the definite time slot of masked bits.
According to a further aspect of the invention, proposed a kind of RF tag, comprised
Receiver module is configured to receive the label counting request;
Sending module, the response signal that is configured to send label;
Control module is configured to receive masked bits information in response to receiver module, and according to the data of the corresponding masked bits of label self, the indication control module is sent signal in time slot corresponding.
Description of drawings
Through the more detailed description to illustrated embodiments of the invention mode in the accompanying drawing, above-mentioned and other purpose, characteristic and advantage of the present invention will become more obvious, and wherein, identical reference number is represented the same parts in the illustrated embodiments of the invention mode usually.
Fig. 1 shows the expression way of Manchester's cde logical signal;
Fig. 2 shows Manchester's cde multiple signals sign indicating number bit swiping synoptic diagram;
Fig. 3 shows the processing procedure of " 0001/0100/0101 " standard binary tree anti-collision;
Fig. 4 shows the Manchester's cde list carrier load of different pieces of information in the RF identification and modulates corresponding simulating signal;
Fig. 5 shows in the RF identification the corresponding mould signal of subcarrier load-modulate under the bit swiping of Manchester's cde sign indicating number;
Fig. 6 shows in the RF identification Manchester's cde sign indicating number position has conflict/nothing conflict dark strength difference of subcarrier load-modulate down;
Fig. 7 shows the corresponding simulating signal of double frequency Manchester's cde subcarrier load-modulate of different pieces of information in the RF identification;
Fig. 8 shows in the RF identification the corresponding simulating signal of subcarrier load-modulate under the bit swiping of double frequency Manchester's cde sign indicating number;
Fig. 9 shows in the RF identification double frequency Manchester's cde sign indicating number position has conflict/nothing conflict dark strength difference of subcarrier load-modulate down;
Figure 10 shows a kind of method flow of RF tag counting method;
Figure 11 shows the workflow of the label of counting method;
Figure 12 shows the instance that adopts RF identification anti-collision of the present invention to check;
Figure 13 shows the structured flowchart of card reader of the present invention; And
Figure 14 shows the structured flowchart of label of the present invention.
Embodiment
To describe preferred implementation of the present invention in further detail with reference to accompanying drawing, show the preferred embodiments of the present invention in the accompanying drawings.Yet the present invention can should not be construed by the embodiment that sets forth here with the various forms realization and limit.On the contrary, it is in order to make the present invention thorough more and complete that these embodiment are provided, and, fully scope of the present invention is conveyed to those skilled in the art.
For radio-frequency recognition system, when RF tag is large numbers of, such as greater than 1000, because the time overhead and the number of tags of traditional B-Tree method are directly proportional, checking needs the time of consumption just to become unacceptable.
Inventor of the present invention finds: according to Fig. 2, current anti-collision counting method based on B-Tree all is the method for after digital signal interface, implementing.That is to say that the data that receive all are the Manchester's cdes that recovers through after simulation amplification, shaping, the filtering.Manchester's cde is a kind of phase encoding, on the narrow sense, jumps to high level presentation logic " 0 " with low level, otherwise, jump to low level presentation logic " 1 " from high level; Broadly, can use the switching between the two states to represent logical zero and " 1 ".This is a kind of expression mode of digital signal; And in fact; Be the digital signal that adopts carrier wave to express between card reader and the label, when forming Manchester's cde, these information more specifically in carrier wave have been lost; If can utilize these information, just the time that the label anti-collision is checked can further be reduced.
Specifically, Fig. 4 shows the corresponding simulating signal of Manchester's cde subcarrier load-modulate of different pieces of information in the RF identification.According to Fig. 4, what the card reader termination was received is the simulation load modulation signal, and this is an am signals that is similar to simulation.For the data " 0 " of label, simulating signal adopts the carrierfree preceding half yard position of adjusting and later half each yard position that subcarrier-modulated is arranged to express; There is subcarrier-modulated the preceding half yard position of data " 1 ", and back half yard position does not have subcarrier-modulated.
Fig. 5 shows under the situation of Manchester's cde sign indicating number bit swiping in the RF identification, the corresponding mould signal of subcarrier load-modulate.According to Fig. 5, when when the card reader termination is received a plurality of label, replying, the card reader termination is received is actually the stack that these subcarrier load-modulate have/do not have.For comprise " 0001 ", reply " 0100 " and " 0101 " three; The simulating signal that the RF identification card reader terminates in the correspondence code position 2 with the position of sign indicating number position 4, no matter preceding half yard position, still back half yard position; The subcarrier load-modulate is all arranged, just have the load-modulate degree of depth.The load-modulate degree of depth can be expressed with the changes in amplitude of carrier wave, and for example, carrier amplitude originally is 60V, because the label return signal causes the signal fluctuation of 1V, then available above-mentioned 1V is used as the load-modulate degree of depth.
The inventor is through examining the signal that these return; Find that there are not conflict in sign indicating number position 1 and sign indicating number position 3; All replying all is not have the subcarrier load-modulate in preceding half yard position, and there is subcarrier-modulated in back half yard position, in these positions; The changes in amplitude of carrier wave is maximum, so its load-modulate degree of depth is the maximal value of the load-modulate degree of depth of all.In fact, the load-modulate degree of depth possibly be that logical zero causes, or logical one causes; Or the two causes jointly; When for the two when causing jointly, be exactly to have a sign indicating number bit swiping, Fig. 6 shows all difference of carrier load depth of modulation of Manchester's cde sign indicating number position in the RF identification; According to Fig. 6; In the sign indicating number position two with sign indicating number position four because the quantity of " 0 " and " 1 " that same bit swiping comprises there are differences, the preceding half yard position of a sign indicating number position and the subcarrier load-modulate degree of depth of back half yard position are also inequality.In other words, the maximum conflict position of " 0 " that comprises and the quantity variance of " 1 " has the maximal value of load-modulate ratio.
Fig. 7 and Fig. 8 are the another kind of modes that common Manchester's cde is represented in RF identification, and wherein, Fig. 7 shows the corresponding simulating signal of double frequency Manchester's cde subcarrier load-modulate of different pieces of information in the RF identification; Fig. 8 shows in the RF identification subcarrier-modulated that the first half of the corresponding simulating signal of subcarrier load-modulate a sign indicating number position under the bit swiping of double frequency Manchester's cde sign indicating number uses a kind of frequency; Use the subcarrier-modulated of another kind of frequency at latter half.In the mode that this Manchester's cde is represented, switch to frequency 2 expressions " 0 " from frequency 1; Otherwise, switch to frequency 1 expression " 1 " from frequency 2.The mode that exist/does not exist subcarrier to express is similar with using: for the position that does not have yard bit swiping, the load-modulate radio-frequency component of any half yard position is single, and the maximum load-modulate degree of depth is arranged; For the sign indicating number position that has conflict, all there is the subcarrier of two frequencies in any half yard position, but different with the ratio of " 1 " according to data " 0 ", and two frequency corresponding load depth of modulation are different.Accordingly, Fig. 9 shows in the RF identification double frequency Manchester's cde sign indicating number position has conflict/nothing conflict dark strength difference of subcarrier load-modulate down.
Radio-frequency recognition system for a reality; It is fully possible that all there is conflict in all positions of RF tag UID coding to be visited; But the whole frame form of swap data comprises frame head, data, checking data and postamble between card reader and the RF tag, and the information that all labels return has identical frame head and postamble.Therefore; If take the suitable technique means; The load-modulate degree of depth of the maximum load depth of modulation (signal of frame head and postamble) of measurement and quantification RF tag return data, preceding half yard position of each position of conflicting and the load-modulate depth information of back half yard position, thus each situation that is 0 or 1 distribution of conflicting distinguished, just can be for further checking the information that provides extra; Thereby further reduce the time overhead of checking, realize card reader quick identification high capacity RF tag.
For achieving the above object; The invention provides a kind of method and card reader of system, classification and a plurality of labels of identification of RF identification card reader; The present invention is based on the distribution method of conflict position generation time slot; According to the conflict position that the load-modulate intensity decision of conflict position produces time slot, overcome the defective of random number time slot, effectively reduce the degree of depth of binary tree search again.
In the B-Tree method, in fact card reader only checks at every turn whether a position exists conflict, that is to say, has only a bitmask position.In the present invention; Consider to use at least one masked bits; And what masked bits are the maximal value through all conflict position load-modulate depth ratios need to confirm; In case confirmed the quantity of masked bits, and utilized the value of all conflict position load-modulate depth ratios to confirm that which position sends to label as masked bits simultaneously.The data that label is corresponding according to masked bits and self masked bits can the definite response time slot, and replys at this time slot.Card reader just can be confirmed number of tags according to the time slot of replying of label.
Specifically, Figure 10 shows the method step of this method, and this method step is a step of bringing in execution from card reader one.According to Figure 10,
In step 1001, the request of launching dart label counting;
In step 1002, receive the response signal of label;
In step 1003, confirm the load-modulate depth ratio of all conflict positions and each conflict position according to response signal;
In step 1004, confirm the maximal value of the load-modulate depth ratio of all conflict positions, obtain masked bits quantity;
In the load-modulate depth ratio of step 1005 according to above-mentioned each conflict position, and the quantity of masked bits, confirm masked bits;
In step 1006, send masked bits information;
In step 1007, the time slot according to masked bits is confirmed receives the return message of label, thereby checks label.
Wherein, step 1001 with 1002 with prior art in the method used of label counting method be identical, repeat no more here.In step 1003, confirm that according to response signal the load-modulate depth ratio of all conflict positions and each conflict position has multiple implementation method.
In one embodiment, the position of can at first conflicting is detected, then to the definite load-modulate depth ratio in detected conflict position.Wherein, the conflict position detecting method that can use prior art is detected in the conflict position.For confirming of load-modulate depth ratio; Need at first to confirm the logical zero of conflict position and the load-modulate degree of depth of logical one, the load-modulate depth ratio can use the load-modulate degree of depth big in the load-modulate degree of depth of logical zero and logical one divided by the little load-modulate degree of depth.
The load-modulate depth ratio can also be used the maximum load depth of modulation information of frame head, postamble correspondence; Divided by the less data of the load-modulate degree of depth of the logical zero of conflict position and logical one, the result is subtracted result after 1 as the load-modulate depth ratio of correspondence conflict.And the confirming of the maximum load-modulate degree of depth, because the international standard of relevant RF identification, for example ISO14443; After regulation such as ISO15693 and ISO18000-3 card reader is sent and is checked instruction; Label must be replied in the time of appointment, and replys and must begin with unified frame head, can be with the total signal of all labels; For example the load-modulate degree of depth of frame head and postamble is a foundation, just can obtain the maximum load-modulate degree of depth.Therefore, above-mentioned frame head, postamble load-modulate depth information is actual is exactly maximum load depth of modulation information.
Definite about the load-modulate degree of depth of the logical zero of conflict position and logical one; If the RF tag answer signal adopts the single-frequency subcarrier; The load-modulate degree of depth that at first logical zero is caused is separated with the load-modulate degree of depth that logical one causes; Promptly measure the load-modulate degree of depth of preceding half yard position or back half yard position, the load-modulate degree of depth can use analog to digital converter (ADC) that the envelope detected result directly is converted to; If the RF tag answer signal adopts the double frequency subcarrier; Need be on analog-to-digital basis to envelope signal; Analog to digital conversion result to preceding half yard position or back half yard position carries out amplitude-frequency relation that Fourier transform obtains two and half yards position signals then; Wherein, frequency is exactly the frequency of two number of sub-carrier, and the mean value of any one or the two in two corresponding amplitudes is exactly the load-modulate degree of depth.For the system of double frequency subcarrier, the sign indicating number position of arbitrary existence conflict, put upside down half yard in front and back position of the amplitude of two frequency components, and the amplitude of just preceding half yard bit frequency 1 equals the amplitude of the frequency 2 of back half yard position, and vice versa.For same conflict position, use big amplitude divided by little amplitude.
According to above-mentioned load-modulate depth ratio, can obtain each conflict position and have " 0 " perhaps relative populations relation of " 1 ".Such as: adopt the single-frequency subcarrier for the RF tag answer signal, if the load-modulate deep equality of preceding half yard position and back half yard position or approximate representes that then the quantity of " 0 " and " 1 " that this conflict position exists is close; If the load-modulate degree of depth of preceding half yard position is big more than the load-modulate degree of depth of back half yard position, represent that then the quantity of this yard position " 1 " is more than the quantity of " 0 ", otherwise then " 0 " is more than " 1 ".Adopt the double frequency subcarrier for the RF tag answer signal, if two frequency component signal amplitudes of any half yard position are close, then " 0 " and " 1 " quantity of conflict sign indicating number position is close, otherwise perhaps " 0 " is more than " 1 ", and perhaps " 1 " is more than " 0 ".
In other a kind of embodiment, can at first obtain the load-modulate degree of depth of all, confirm the conflict position according to all the load-modulate degree of depth that obtains then, at last the load-modulate depth ratio is confirmed in the conflict position of confirming.In fact, in this embodiment, the conflict position is to confirm through the load-modulate degree of depth of all, and the load-modulate degree of depth of all and load-modulate depth ratio preparation method are identical with the method for top embodiment.
In step 1004, confirm the maximal value of the load-modulate depth ratio of all conflict positions, thereby obtain masked bits quantity; The maximal value of the load-modulate depth ratio of all conflict positions has been reacted certain conflict label for logical one and has been the number of tags ratio situation (otherwise perhaps) of logical zero with the conflict position, and the quantity that can get masked bits is floor (log
2(maximal value of load-modulate depth ratio+1)), wherein, floor representes rounding operation.
In step 1005, according to the load-modulate depth ratio of above-mentioned each conflict position, and the quantity of masked bits, confirm masked bits.Wherein, can get an above-mentioned masked bits quantity conflict position successively near 1 situation,, get all if remaining conflict position does not have above-mentioned masked bits quantity individual according to the load-modulate depth ratio.
In step 1006, send masked bits information; Can an above-mentioned masked bits quantity conflict position all be sent to label as mask.
In step 1007, the time slot according to masked bits is confirmed receives the return message of label, thereby checks label.According to masked bits, from the coding of label from a high position to the low level, otherwise perhaps, form binary number by masked bits and confirm the used time slot of label echo reply signal.
In one embodiment, in response to the time slot of confirming according to masked bits, receive the return message of label; Find also to exist the conflict position; Then repeated execution of steps S1003-S1007 finishes until whole label countings, and just there is not the conflict position in label echo reply signal.
In the said method implementation, the counting method of label itself is also wanted corresponding change.Figure 11 shows the workflow of the label of counting method, according to Figure 11,
In step 1101, receive the label counting request;
In step 1102, send the response signal of label;
In step 1103, receive masked bits information;
In step 1104,, in time slot corresponding, send signal according to the data of the corresponding masked bits of label self.
In one embodiment, label continues to receive masked bits information, and continues the data according to the corresponding masked bits of label self, in time slot corresponding, sends signal.
Below use the further method of the above-mentioned label counting of explanation of an example, Figure 12 shows the instance that adopts RF identification anti-collision of the present invention to check, referring to Figure 12, wherein
For label: 000001,100010,100100,100110,101000,101010, adopt traditional B-Tree method, then need to check for 2*6-1=11 time, check replying of the request that comprises a card reader and label at every turn.If adopt system and method for the present invention:
Original tag: 000001
1?0?0?0?1?0
1?0?0?1?0?0
1?0?0?1?1?0
1?0?1?0?0?0
1?0?1?0?1?0
Conflict position situation: X0XXXX
Here use the actual load conflict of ratio simulation of simple conflict bit quantity; Then the 1st, 3,4,5,6 load-modulate depth ratio is respectively: 5,2,2,1,5; According to computing formula, can obtain masked bits quantity is 2, at first gets the 4th and the 5th masked bits as time slot; All labels return the UID of oneself respectively in 00,01,10,11 (scale-of-two) time slot corresponding, then first pass can obtain:
X0X00X ( comprise 000001 and 101000, conflict is arranged), 10X010 ( comprise 100010 and 101010, conflict is arranged), 100100 (not having conflict) and 100110 (not having conflict).
X0X00X is continued to use said method, and the 1st, 3 and 6 load-modulate depth ratio is about 1, appoints and gets a conflict position, as the time slot mask, then in two time slots that link to each other, returns 000001 and 101000 (not having conflict) such as the conflict position of getting most significant digit respectively.Use same flow process for 10X010, can finish the process of checking.
See that from whole process the communication of checking between card reader and the label has only been carried out 3 times and just can be finished, comprised 3 card reader inventory requests and 8 secondary label and replied.Compare traditional B-Tree method, saved 8 card reader requests and 3 secondary label and replied.When number of labels was more, the superiority of this method was then more obvious.
For the low occasion of number of labels, the said method of the present invention is superior to traditional B-Tree method equally.With two labels is example, for having 8 codings:
01010101
10101010
All positions all exist conflict: XXXXXXXX, traditional B-Tree method to need to check for 2*2-1=3 time.The load-modulate that method of the present invention can determine each conflict position is balanced, and the load-modulate depth ratio of each conflict position approaches 1.According to masked bits quantity Calculation formula, get 1.Therefore, card reader only need once be checked, and gets the load-modulate degree of depth near the time slot position as tag responses, any conflict position of 1, once realizes checking of whole labels.Compare with the B-Tree method, practiced thrift the card reader inventory requests 1 time.
This method is defined as the time slot masked bits because working load depth of modulation information is definite with a plurality of conflicts position; Thereby effectively reduce a B-Tree conflict position expense of checking one by one traditionally; And the time slot masked bits information that produces is confirmed; Eliminated the uncertainty of time slot at random, thereby the efficient that RF identification is checked improves greatly.
Under same inventive concept, the invention also discloses a kind of RF tag card reader, Figure 13 shows the structured flowchart of card reader of the present invention.According to Figure 13, this card reader comprises: transmitter module 1301 is configured to launch the RF tag inventory requests; Receiver module 1302 is configured to receive the response signal from RF tag; Processing module 1303 comprises:
Load-modulate depth ratio determination module 1304 is configured to confirm according to response signal the load-modulate depth ratio of all conflict positions and each conflict position,
Masked bits quantity determination module 1305 is configured to confirm the maximal value of the load-modulate depth ratio of all conflict positions obtain masked bits quantity, and
Masked bits determination module 1306 is configured to the load-modulate depth ratio according to above-mentioned each conflict position, and the quantity of masked bits, confirms masked bits;
Wherein, said transmitter module also is configured to send masked bits information; Said processing module also is configured to receive the return message from RF tag, thereby check RF tag according to the definite time slot of masked bits.
In a kind of embodiment, transmitter module comprises the transmission data encoder, and the data that are configured to the transmission of reading card device processing module are encoded the transmission data-signal behind the output encoder; Modulation and amplification module are configured to the transmission data-signal behind the coding is modulated and amplified, the output modulation and amplify after the transmission data-signal, antenna, be configured to send modulation and amplify after the transmission data-signal, and receive signal from label.Antenna not only belongs to transmitter module, also belongs to receiver module.
In one embodiment, receiver module comprises that signal demodulator receives and amplification module, is configured to the signal from label of antenna reception carried out the signal demodulator reception and amplifies, the label signal after output detection and the amplification; A decoding and a conflict position detection module, be configured to detection with amplify after label signal decode and the position of conflicting is detected, obtain the decoding and a conflict information of label signal; And load-modulate intensity detection module, be configured to the label signal after detection and the amplification is carried out the load-modulate intensity detection.
In another embodiment, signal demodulator receives and amplification module, is configured to the signal from label of antenna reception carried out the signal demodulator reception and amplifies, the label signal after output detection and the amplification; Load-modulate intensity detection module is configured to detection and the label signal after amplifying carries out the load-modulate intensity detection; Wherein, the load-modulate intensity that card reader processing module basis obtains from load-modulate intensity detection module, the load-modulate strength ratio of the conflict position information of the label signal of acquisition and conflict position, thus label is checked.
Card reader possibly single job can not all be checked label; Therefore; Can repeatedly check, that is: processing module receives the return message from RF tag in response to the time slot of confirming according to masked bits; Indication transmitter module and receiver module transmit and receive information, until confirm not exist the conflict position according to response signal.
In one embodiment, load-modulate depth ratio determination module comprises: conflict position detection module, and the position that is configured to conflict is detected; And first determination module, be configured to the definite load-modulate depth ratio in detected conflict position.
In another embodiment, load-modulate depth ratio determination module comprises: obtain module, be configured to obtain the load-modulate degree of depth of all; Second determination module is configured to first and confirms the conflict position according to all the load-modulate degree of depth that obtains; First determination module is configured to the load-modulate depth ratio is confirmed in the conflict position of confirming.
In above-mentioned two kinds of embodiments, first determination module uses one of two kinds of methods of following method to obtain the load-modulate depth ratio, and the first method step is: confirm the logical zero of conflict position and the load-modulate degree of depth of logical one; Use then the load-modulate degree of depth big in the load-modulate degree of depth of logical zero and logical one divided by the little load-modulate degree of depth as the load-modulate depth ratio.The second method step is: use frame head, postamble maximum load depth of modulation information, divided by less that of the load-modulate degree of depth of the logical zero of conflict position and logical one, the result deducts the 1 load-modulate depth ratio that obtains conflicting.Confirm that wherein the logical zero of conflict position and the load-modulate depth step of logical one adopt different subcarriers to card reader; Use diverse ways; For example adopt the single-frequency subcarrier in response to the RF tag answer signal; Measure the load-modulate degree of depth of preceding half yard position or back half yard position, select one of them or the two mean value as the load-modulate degree of depth.For example adopt the double frequency subcarrier again, to the envelope signal analog to digital conversion in response to the RF tag answer signal; Envelope signal analog to digital conversion result to preceding half yard position or back half yard position carries out amplitude-frequency relation that Fourier transform obtains two and half yards position signals then; Wherein, the mean value of any or the two in corresponding two amplitudes of two of said double frequency subcarrier frequencies is exactly the load-modulate degree of depth.
In the above method, the load-modulate degree of depth can use analog to digital converter that the envelope detected result directly is converted to.
In one embodiment, state in the masked bits quantity determination module, the quantity of masked bits is floor (log
2(maximal value of load-modulate depth ratio+1)), wherein, floor representes rounding operation.In further embodiment, in the masked bits determination module, can get an above-mentioned masked bits quantity conflict position successively as masked bits near 1 situation according to the load-modulate depth ratio.Perhaps the conflict position in response to remainder does not have above-mentioned masked bits quantity individual, gets whole conflicts position as masked bits.
Under same inventive concept, the invention also discloses a kind of RF tag, adapt with above-mentioned card reader; Figure 14 shows the structured flowchart of this RF tag; According to Figure 14, this RF tag comprises: receiver module 1401 is configured to receive the label counting request; Sending module 1402, the response signal that is configured to send label; Control module 1403 is configured to receive masked bits information in response to receiver module, and according to the data of the corresponding masked bits of label self, the indication control module is sent signal in time slot corresponding.In one embodiment, control module also continues to receive masked bits information in response to said receiver module, continues the data according to the corresponding masked bits of label self, indicates said control mould in time slot corresponding, to send signal.
Above-described specific embodiment has carried out further explain to the object of the invention, technical scheme and beneficial effect.Institute it should be understood that the above is merely specific embodiment of the present invention, is not limited to the present invention, and is all within spirit of the present invention and principle, any modification of being made, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (20)
1. RF tag counting method comprises:
A) emission RF tag inventory requests;
B) reception is from the response signal of RF tag;
C) confirm the load-modulate depth ratio of all conflict positions and each conflict position according to response signal;
D) confirm the maximal value of the load-modulate depth ratio of all conflict positions, obtain masked bits quantity;
E) according to the load-modulate depth ratio of above-mentioned each conflict position, and the quantity of masked bits, confirm masked bits;
F) send masked bits information;
G) time slot of confirming according to masked bits receives the return message from RF tag, thereby checks RF tag.
2. method according to claim 1 wherein also comprises:
In response to the time slot of confirming according to masked bits, receive return message, repeating step c from RF tag)-g), until confirm not exist the conflict position according to response signal.
3. method according to claim 1 and 2, wherein saidly confirm that according to response signal the load-modulate depth ratio step of all conflict positions and each conflict position comprises one of following method:
Method one: the position of conflicting is detected, then to the definite load-modulate depth ratio in detected conflict position;
Method two: obtain the load-modulate degree of depth of all, confirm the conflict position according to all the load-modulate degree of depth that obtains then, at last the load-modulate depth ratio is confirmed in the conflict position of confirming.
4. method according to claim 3, wherein use one of following method to obtain the load-modulate depth ratio:
Method one: confirm the logical zero of conflict position and the load-modulate degree of depth of logical one, use then the load-modulate degree of depth big in the load-modulate degree of depth of logical zero and logical one divided by the little load-modulate degree of depth as the load-modulate depth ratio;
Method two: use frame head, postamble maximum load depth of modulation information, divided by the less load-modulate degree of depth in the load-modulate degree of depth of the logical zero of conflict position and logical one, the result deducts 1, a load-modulate depth ratio that obtains conflicting.
5. method according to claim 4, the logical zero of wherein said definite conflict position and the load-modulate degree of depth of logical one comprise:
Adopt the single-frequency subcarrier in response to the RF tag answer signal, measure the load-modulate degree of depth of preceding half yard position or back half yard position, select one of them or the two mean value as the load-modulate degree of depth;
Adopt the double frequency subcarrier in response to the RF tag answer signal; To the envelope signal analog to digital conversion; Envelope signal analog to digital conversion result to preceding half yard position or back half yard position carries out amplitude-frequency relation that Fourier transform obtains two and half yards position signals then; Wherein, the mean value of any or the two in corresponding two amplitudes of two of said double frequency subcarrier frequencies is exactly the load-modulate degree of depth.
6. according to the described method of one of claim 1-5, the wherein said maximal value of confirming the load-modulate depth ratio of all conflict positions obtains in the masked bits quantity, and the quantity of masked bits is floor (log
2(maximal value of load-modulate depth ratio+1)), wherein, floor representes rounding operation.
7. according to the described method of one of claim 1-6; Wherein said load-modulate depth ratio according to above-mentioned each conflict position; And the quantity of masked bits, confirm in the masked bits, get an above-mentioned masked bits quantity conflict position successively as masked bits according to the load-modulate depth ratio near 1 situation.
8. method according to claim 7, wherein individual less than above-mentioned masked bits quantity in response to the conflict bit quantity of remainder, get whole conflicts position as masked bits.
9. a RF tag counting method comprises
Receive the label counting request;
Send the response signal of label;
Receive masked bits information;
According to the data of the corresponding masked bits of label self, in time slot corresponding, send signal.
10. method according to claim 13 wherein continues to receive masked bits information in response to label, continues the data according to the corresponding masked bits of label self, in time slot corresponding, sends signal.
11. a RF tag card reader comprises:
Transmitter module is configured to launch the RF tag inventory requests;
Receiver module is configured to receive the response signal from RF tag;
Processing module comprises:
Load-modulate depth ratio determination module is configured to confirm according to response signal the load-modulate depth ratio of all conflict positions and each conflict position,
Masked bits quantity determination module is configured to confirm the maximal value of the load-modulate depth ratio of all conflict positions obtain masked bits quantity, and
The masked bits determination module is configured to the load-modulate depth ratio according to above-mentioned each conflict position, and the quantity of masked bits, confirms masked bits;
Wherein, said transmitter module also is configured to send masked bits information; Said processing module also is configured to receive the return message from RF tag, thereby check RF tag according to the definite time slot of masked bits.
12. card reader according to claim 11; Wherein said processing module is in response to the time slot of confirming according to masked bits; Reception is from the return message of RF tag, and indication transmitter module and receiver module transmit and receive information, until confirm not exist the conflict position according to response signal.
13. according to claim 11 or 12 described card reader, wherein said load-modulate depth ratio determination module comprises one of following composition module:
First forms module: comprising: conflict position detection module, and the position that is configured to conflict is detected; And first determination module, be configured to the definite load-modulate depth ratio in detected conflict position;
Second forms module, comprising: obtain module, be configured to obtain the load-modulate degree of depth of all; Second determination module is configured to first and confirms the conflict position according to all the load-modulate degree of depth that obtains; And first determination module, be configured to the load-modulate depth ratio is confirmed in the conflict position of confirming.
14. card reader according to claim 13, wherein said first determination module use one of following method to obtain the load-modulate depth ratio:
Method one: confirm the logical zero of conflict position and the load-modulate degree of depth of logical one; Use then the load-modulate degree of depth big in the load-modulate degree of depth of logical zero and logical one divided by the little load-modulate degree of depth as the load-modulate depth ratio;
Method two: use frame head, postamble maximum load depth of modulation information, divided by the less load-modulate degree of depth in the load-modulate degree of depth of the logical zero of conflict position and logical one, the result deducts 1, a load-modulate depth ratio that obtains conflicting.
15. card reader according to claim 14, the logical zero of said definite conflict position of wherein said first determination module and the load-modulate depth step of logical one comprise:
Adopt the single-frequency subcarrier in response to the RF tag answer signal, measure the load-modulate degree of depth of preceding half yard position or back half yard position, select one of them or the two mean value as the load-modulate degree of depth;
Adopt the double frequency subcarrier in response to the RF tag answer signal; To the envelope signal analog to digital conversion; Envelope signal analog to digital conversion result to preceding half yard position or back half yard position carries out amplitude-frequency relation that Fourier transform obtains two and half yards position signals then; Wherein, the mean value of any or the two in corresponding two amplitudes of two of said double frequency subcarrier frequencies is exactly the load-modulate degree of depth.
16. according to the described card reader of one of claim 11-15, in the wherein said masked bits quantity determination module, the quantity of masked bits is floor (log
2(maximal value of load-modulate depth ratio+1)), wherein, floor representes rounding operation.
17., in the wherein said masked bits determination module, get an above-mentioned masked bits quantity conflict position successively as masked bits near 1 situation according to the load-modulate depth ratio according to the described card reader of one of claim 11-16.
18. card reader according to claim 17 is individual less than above-mentioned masked bits quantity in response to the conflict position of remainder in the wherein said masked bits determination module, gets whole conflicts position as masked bits.
19. a RF tag comprises
Receiver module is configured to receive the label counting request;
Sending module, the response signal that is configured to send label;
Control module is configured to receive masked bits information in response to receiver module, and according to the data of the corresponding masked bits of label self, the indication control module is sent signal in time slot corresponding.
20. RF tag according to claim 19; Wherein said control module also continues to receive masked bits information in response to said receiver module; Continuation indicates said control mould in time slot corresponding, to send signal according to the data of the corresponding masked bits of label self.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012100871906A CN102663330A (en) | 2012-03-29 | 2012-03-29 | Method for radio frequency tag inventory, radio frequency tag card reader and radio frequency tag |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2012100871906A CN102663330A (en) | 2012-03-29 | 2012-03-29 | Method for radio frequency tag inventory, radio frequency tag card reader and radio frequency tag |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104573586A (en) * | 2014-02-27 | 2015-04-29 | 深圳市金溢科技股份有限公司 | Non-contact IC (integrated circuit) card counting equipment and non-contact IC card counting method |
| CN108596298A (en) * | 2018-04-25 | 2018-09-28 | 京东方科技集团股份有限公司 | For the device of electronic tag management, the method for electronic tag management |
| CN112615650A (en) * | 2019-10-04 | 2021-04-06 | 恩智浦有限公司 | Detecting NFC inductive IC card (PICC) during wireless charging |
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2012
- 2012-03-29 CN CN2012100871906A patent/CN102663330A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104573586A (en) * | 2014-02-27 | 2015-04-29 | 深圳市金溢科技股份有限公司 | Non-contact IC (integrated circuit) card counting equipment and non-contact IC card counting method |
| CN104573586B (en) * | 2014-02-27 | 2018-09-04 | 深圳市金溢科技股份有限公司 | Non-contact IC card checks the counting method of equipment and non-contact IC card |
| CN108596298A (en) * | 2018-04-25 | 2018-09-28 | 京东方科技集团股份有限公司 | For the device of electronic tag management, the method for electronic tag management |
| CN108596298B (en) * | 2018-04-25 | 2023-08-04 | 京东方科技集团股份有限公司 | Device and method for electronic tag management |
| CN112615650A (en) * | 2019-10-04 | 2021-04-06 | 恩智浦有限公司 | Detecting NFC inductive IC card (PICC) during wireless charging |
| CN112615650B (en) * | 2019-10-04 | 2024-02-09 | 恩智浦有限公司 | Detecting NFC inductive IC card (PICC) during wireless charging |
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