CN101957923A - Method and reader for reading data from tags in radio frequency identification system - Google Patents

Abstract

The invention discloses a method for reading data from tags in a radio frequency identification system. The radio frequency identification system comprises more than one reader and a group of tags, wherein each tag comprises a piece of data and a group of characteristic description information. The method comprises that: firstly, a first reader or the tags code the characteristic description information by codes with error correction and error detection functions, and write the codes into the tags; secondly, the first reader or a second reader reads the tags, receives the coded characteristic description information and decodes the characteristic description information by the codes; and finally, the first reader or the second reader reads corresponding data according to the decoded characteristic description information. The method has the advantages of effectively helping the readers to master the characteristics of the tags and more accurately reading the stored data from the tags by protecting the characteristic description information in the tags.

Description

Method that in radio-frequency recognition system, label data is read and read write line

Technical field

The present invention relates to radio-frequency (RF) identification (Radio Frequency Identification is called for short RFID) technology, relate in particular to the read write line of a kind of method that in radio-frequency recognition system, label data is read and this method of realization.

Background technology

Recently, UHF radio frequency identification (RFID) technology more and more receives publicity.Because UHF RFID has the ability of hundreds of unique objects of per second identification, it has createed many application chances in the logistics related occasion.Along with the fast development of new technology, for example, the passive label that near field UHF technology, battery are assisted etc., UHF RFID also is regarded as making the potential solution of application scenario (for example leechdom production line operation).Because UHF RFID meets the EPC C1G2 standard (EPC Radio-Frequency Identity Protocols Class-1 Generation-2 UHF RFIDProtocol for Communications at 860MHz-960MHz) of global general-use, have unique advantages such as high speed read/write, compare with HF frequency range solution traditional in the manufacturing application scenario and can obtain more performance.

Yet in making the application scenario, can the reliability of label read/write be moved most important for production line continuously.For these application scenarios, the ultimate challenge that UHF RFID is faced is that the reliability of read/write operation is relatively poor.For all read/write operations, first step is the electronic product code of reading in the EPC C1G2 standard (Electronic ProductCode:EPC).We can say that the EPC reliability of reading will determine the reliability and the speed of whole read/write procedure.

Usually, have three kinds of situations may cause reading EPC failure, be respectively: read write line reads that the RN16 prefix is overtime, read write line reads the overtime and read write line of EPC prefix data and the EPC data are carried out CRC check makes a mistake.As shown in Figure 1, the process that reads EPC can be divided into two stages.At first, read write line (Reader) sends a querying command Query to label (Tag), and label sends 16 random numbers or a pseudo-random data (RN16) as handle and gives read write line then.Next, read write line sends an ACK who has effective handle and orders to label, after label receives this ACK order, and its EPC data of backscattering.Except the EPC code, the EPC data also comprise agreement control bit (ProtocolControl; PC) and cyclic redundancy check (CRC) position (Cyclic Redundancy Check; CRC).If catch the failure of RN16 prefix or EPC prefix data, will cause RN16 overtime overtime respectively with EPC.In addition, the invalid handle that produces owing to label collision also can cause EPC overtime.In addition, read write line only uses CRC to carry out verification in the process owing to read at EPC, crc error takes place when the position of some mistake will cause read write line to carry out CRC check in the EPC transmission, it is to causing EPC to take defeat.

Because label design is very simple, do not require that generally label uses complicated method (for example, information source and chnnel coding) to communicate, to reduce the chance of these three kinds of situations of generation.In the patented claim 200810004983.0 of Siemens Company, a kind of " method and apparatus of energy is provided to passive label in radio-frequency recognition system " proposed, can solve preceding two kinds of failure scenarios preferably.Yet in the application scenario of many UHF RFID, for example make the application scenario, because the simplicity of design of label, a large amount of interference will make read write line correctly receive EPC, and crc error takes place when causing read write line to read the EPC data.But concerning read/write speed had the application scenario of specific (special) requirements, the receiving efficiency and the reliability of EPC data were extremely important for many.

Can't correctly receive EPC to read write line in the prior art, this problem of crc error take place when causing read write line to read the EPC data have some solutions.For example, in the process that receives the EPC data, some read write line (as ALR8800) in a single day makes a mistake when reading the EPC data, and read write line can retransmit confirms order ACK, can't carry out label backscattering EPC data once more under the situation by detection in the EPC data.

But as shown in Figure 2, because the end of signaling is undesirable, read write line is difficult to detect the backscattered end of transmission (EOT) of label.The figure place that read write line can only rely on first byte of the agreement control bit PC in the EPC data to determine the EPC receiving course will to receive (comprise in the PC data of two bytes EPC code, the length of EPC data) in other words.Fig. 3 has shown in the prior art orders ACK to obtain the basic flow sheet of EPC code by retransmitting affirmation.

At first, read write line sends querying command Query to label.After label received querying command Query, the random number R N16 that returns to one 16 of read write lines was as handle.If read write line does not receive random number R N16, then read write line resends querying command Query after after a while.

Secondly, after read write line receives the random number R N16 of label transmission, send one and confirm that order ACK is to label.After label receives the confirmation order ACK, to the prefix of read write line return electron product code EPC data.If read write line does not detect this prefix, then read write line resends querying command Query after after a while.

Once more, read write line receives first byte of agreement control bit PC, and therefrom obtain the length (because the length of agreement control bit PC is fixed, the length of cyclic redundancy check (CRC) is fixed, the length that therefore obtains the EPC code has just obtained the length of whole electronic product code EPC data) of EPC code.

Then, the length that its data bit that will receive of read write line is set to the EPC code adds 32 bits, and prepares to receive data.

After through one period stand-by period, read write line has received the data of electronic product code EPC data.Subsequently, read write line carries out cyclic redundancy check (CRC) to the data that receive.If verification is passed through, then read write line sends next querying command QueryRep to label; If verification is not passed through, then read write line resends and confirms that order ACK gives the prefix of label and testing product code EPC data.

If read write line can correctly detect PC, process then shown in Figure 3 can solve the crc error problem.But if some mistake occurs in the process that receives PC, read write line will be analyzed EPC length mistakenly.To waste a large amount of time subsequently is used to send Next Command, as shown in Figure 4.Figure above Fig. 4 represents the original length of EPC data, and the figure below Fig. 4 represents that read write line fails correctly to receive PC, and therefore the length to the EPC data produces erroneous judgement.In the worst case, the time of waste may reach (496+32-8) * 0.025=13ms.And normal EPC reads only about 2～3ms of required time of process.On the other hand, because label is synchronous and overtime because of losing, so it can not make response to Next Command.Thereby the mistake of PC receives the reliability and the efficient that will influence total system to a great extent.

Summary of the invention

Fundamental purpose of the present invention is to provide the read write line of a kind of method that in radio-frequency recognition system the data in the label is read and this method of realization; can in process, protect the feature description information of label to the label read-write; thereby make read write line correctly detect and receive feature description information, thereby correctly obtain the data in the label.

For achieving the above object, a kind of method that in radio-frequency recognition system, the data in the label is read, described radio-frequency recognition system comprises an above read write line and one group of label, and described each label all comprises one a group of data and a stack features descriptor, and the method includes the steps of:

(1) first read write line or described label use the coding with error correction and error detecing capability, and described feature description information is encoded and described coding is write described label;

(2) described first read write line or second read write line read described label, receive described feature description information after encoded, and by described coding described feature description information are decoded;

(3) described first read write line or second read write line read corresponding data according to decoded feature description information.

As a preferred version, in the described step (1), described coding with error correction and error detecing capability comprises an error-detecting code (EDC) and an error-correcting code (ECC).

According to one embodiment of present invention, the data of described label are the data in electronic product code (EPC) data field, the feature description information of described label is agreement control bit (PC), the length records of the electronic product code (EPC) in described electronic product code (EPC) data field is in described agreement control bit (PC)

In the described step (1), described first read write line uses described error-detecting code (EDC) and described error-correcting code (ECC) that described agreement control bit (PC) is encoded, and described coding is write in described label electronic product code (EPC) data;

In the described step (2), described first read write line or second read write line read the electronic product code in the described label (EPC) data, receive the agreement control bit (PC) behind the described coding, and the agreement control bit (PC) behind the described coding is decoded;

In the described step (3), described first read write line or second read write line according to decoded agreement control bit (PC) will be to be received data bit be provided with and prepare to receive data.

As a preferred version of the present invention, comprise following steps in the described step (1):

(11) length that write down of described agreement control bit (PC) is set to the length sum of described electronic product code (EPC), error-detecting code (EDC), error-correcting code (ECC);

(12) a protection sign is set on the reserved bit (RFU) of described agreement control bit (PC);

(13) calculate described error-detecting code (EDC) for described agreement control bit (PC);

(14) calculate described error-correcting code (ECC) for described agreement control bit (PC) and described error-detecting code (EDC);

(15) described error-detecting code (EDC) and described error-correcting code (ECC) are stored into the starting position of described electronic product code (EPC).

As a preferred version of the present invention, in the described step (2), described first read write line or second read write line agreement control bit (PC) after with described coding is decoded and is further comprised:

Described first read write line or second read write line carry out error-detecting and correction by described error-correcting code (ECC) to described agreement control bit (PC) and described error-detecting code (EDC);

Described first read write line or second read write line carry out error-detecting by described error-detecting code (EDC) to described agreement control bit (PC), to obtain the length of correct electronic product code (EPC).

As a preferred version of the present invention, if it is wrong that described error-detecting code (EDC) detects described agreement control bit (PC), the length of the electronic product code (EPC) that the described pickup of then described first read write line or second read write line is received is set to the length of the electronic product code (EPC) of previous label.Perhaps, wrong if described error-detecting code (EDC) detects described agreement control bit (PC), the length of the electronic product code (EPC) of then described first read write line or the described reception of second read write line is set to 96 bits.Perhaps, if it is wrong that described error-detecting code (EDC) detects described agreement control bit (PC), then described first read write line or second read write line at first wait the longest described electronic product code to be read (EPC) required time, start a new label subsequently and read process, wherein, the longest described electronic product code (EPC) is 496 bits.

As a preferred version of the present invention, in the described step (3), the length that the data bit that described first read write line or second read write line will receive is set to described electronic product code (EPC) adds 32 bits.

As a preferred version of the present invention, if the length of described electronic product code (EPC) changes, then described first read write line writes described error-detecting code (EDC) and described error-correcting code (ECC) in the described electronic product code data once more.

As a preferred version of the present invention; described step (1) before; further comprising the steps of: described first read write line or second read write line send a protection label select command to being in its label of reading and writing in the zone, are chosen in the label that the interior reserved bit (RFU) in described read-write zone is provided with described protection sign.In addition; described step (3) also comprises afterwards: described first read write line or second read write line label in being in its read-write zone sends a common label select command; be chosen in the common label that described protection sign is not set on the reserved bit (RFU) in the described read-write zone, and the data in the described common label that described protection sign is not set read according to common read step.

As a preferred version of the present invention, also comprise before: a register protected mode classification logotype is set in described first read write line or second read write line, when described register is in first protected mode, continues described step (1) in described step (1).

As a preferred version of the present invention, described first read write line or second read write line select to wait for that receiving the RN16 period receives electronic product code (EPC) data at least one period in the period as strengthening the period with waiting for, described read write line is regulated sending the gain of signal, makes that the carrier signal in the described enhancing period sends with the transmitted power that strengthens.

According to second embodiment of the present invention, the data of described label comprise data in electronic product code (EPC) data field and the data in the user data area, the feature description information of described label is agreement control bit (PC), in the described user data area of described agreement control bit (PC) sign whether valid data are arranged

In the described step (1), described first read write line uses described error-detecting code (EDC) and described error-correcting code (ECC) that described agreement control bit (PC) is encoded, and described coding is write in described label electronic product code (EPC) data;

In the described step (2), described first read write line or second read write line read the electronic product code in the described label (EPC) data, receive the agreement control bit (PC) behind the described coding, and the agreement control bit (PC) behind the described coding is decoded;

In the described step (3), described first read write line or second read write line determine whether initiate data read command according to decoded agreement control bit (PC), and the data in the described user data area are read.

A preferred version according to second embodiment of the present invention comprises following steps in the described step (1):

(11) length that write down of described agreement control bit (PC) is set to the length sum of described electronic product code (EPC), error-detecting code (EDC), error-correcting code (ECC);

(12) a protection sign is set on the reserved bit (RFU) of described agreement control bit (PC);

(13) calculate described error-detecting code (EDC) for described agreement control bit (PC);

(14) calculate described error-correcting code (ECC) for described agreement control bit (PC) and described error-detecting code (EDC);

(15) described error-detecting code (EDC) and described error-correcting code (ECC) are stored into the starting position of described electronic product code (EPC).

According to the 3rd embodiment of the present invention, the data of described label comprise data in electronic product code (EPC) data field and the data in the user data area, the feature description information of described label is agreement control bit (PC) and Extended Protocol control bit (XPC), recalled state after the described label of sign is killed in the described Extended Protocol control bit (XPC)

In the described step (1), described first read write line uses described error-detecting code (EDC) and described error-correcting code (ECC) that described agreement control bit (PC) and described Extended Protocol control bit (XPC) are encoded, and described coding is write in the described label;

In the described step (2), described first read write line or second read write line read described label, receive agreement control bit (PC) and Extended Protocol control bit (XPC) behind the described coding, and agreement control bit (PC) behind the described coding and Extended Protocol control bit (XPC) are decoded;

In the described step (3), described first read write line or second read write line are according to the recalled state of decoded agreement control bit (PC) and Extended Protocol control bit (XPC) decision label.

A preferred version according to the 3rd embodiment of the present invention, in the described step (1), described first read write line uses described error-detecting code (EDC) and described error-correcting code (ECC) that described agreement control bit (PC) and described Extended Protocol control bit (XPC) are encoded, and described coding write in the described label may further comprise the steps:

(11) length that write down of described agreement control bit (PC) is set to the length sum of described electronic product code (EPC), error-detecting code (EDC), error-correcting code (ECC);

(12) a protection sign is set on the reserved bit (RFU) of described agreement control bit (PC);

(13) calculate described error-detecting code (EDC) for described agreement control bit (PC);

(14) calculate described error-correcting code (ECC) for described agreement control bit (PC) and described error-detecting code (EDC);

(15) described error-detecting code (EDC) and described error-correcting code (ECC) are stored in the described label.

According to the preferred version of the 3rd embodiment of the present invention, in the described step (15), described error-detecting code (EDC) and described error-correcting code (ECC) are stored into the starting position of described electronic product code (EPC).Perhaps, in the described step (15), described error-detecting code (EDC) and described error-correcting code (ECC) are stored in the described Extended Protocol control bit (XPC).

The invention allows for the method that another reads the data in the label in radio-frequency recognition system, described radio-frequency recognition system comprises an above read write line and one group of label, described each label all comprises the data in electronic product code (EPC) data field, each described electronic product code (EPC) data comprises agreement control bit (PC), electronic product code (EPC), cyclic redundancy check (CRC) position (CRC), it is characterized in that the method includes the steps of:

(1) read write line and with main frame that described read write line links to each other between interface of definition, by the described main frame of described interface the length of described electronic product code (EPC) is configured to a regular length;

(2) described read write line is stored the length of the electronic product code (EPC) that described main frame disposed in its register;

When (3) described read write line reads the data in the described label, from the register of this read write line, obtain the length of the electronic product code (EPC) of described label;

(4) data bit that described read write line will be to be received is provided with and prepares to receive data.

According to a preferred version of another method, in the described step (4), the length that the data bit that the described read write line or second read write line will receive is set to described electronic product code (EPC) adds 32 bits.

A preferred version according to another method also comprises before in described step (1): a register protected mode classification logotype is set in described read write line, when described register is in second protected mode, continues described step (1).

A preferred version according to another method, described read write line selects to wait for that receiving the RN16 period receives electronic product code (EPC) data at least one period in the period as strengthening the period with waiting for, described read write line is regulated sending the gain of signal, makes that the carrier signal in the described enhancing period sends with the transmitted power that strengthens.

Correspondingly, the present invention proposes a kind of read write line that in radio-frequency recognition system, the data in the label is read, it is characterized in that described read write line comprises:

Coding unit is used to use a coding with error correction and error detecing capability that feature description information is encoded;

Writing unit is used for described coding is write a label;

Reading unit is used for the data of described label are read, and receives described feature description information after encoded;

Decoding unit is used for by described coding described feature description information being decoded;

Receiving element is used for according to decoded feature description information corresponding data being read.

As a preferred version of the present invention, the said write unit further comprises:

The unit is set, the length that is used for described label agreement control bit (PC) is set to the length sum of electronic product code (EPC), error-detecting code (EDC), error-correcting code (ECC), and a protection sign is set on the reserved bit (RFU) of described agreement control bit (PC);

Computing unit is used to described agreement control bit (PC) to calculate described error-detecting code (EDC), and is that described agreement control bit (PC) calculates described error-correcting code (ECC) with described error-detecting code (EDC);

Storage unit is used for described error-detecting code (EDC) and described error-correcting code (ECC) are stored into the starting end of described electronic product code (EPC).

As a preferred version of the present invention, described read write line comprises that also an order sends module, be used for sending a protection label select command, be chosen in the label that the interior reserved bit (RFU) in described read-write zone is provided with described protection sign to being in its label of reading and writing in the zone; Perhaps the label in being in its read-write zone sends a common label select command; be chosen in the common label that described protection sign is not set on the reserved bit (RFU) in the described read-write zone, and the data in the described common label that described protection sign is not set read according to common read step.

Corresponding to another method that in radio-frequency recognition system, the data in the label is read, the invention allows for a kind of read write line, described read write line comprises:

Interface unit, be used for read write line and with main frame that described read write line links to each other between interface of definition, by the described main frame of described interface the length of described electronic product code (EPC) is configured to a regular length;

Storage unit is used for the length at the register storage electronic product code (EPC) that described main frame disposed of described read write line;

Reading unit is used for when the data to described label read, and obtains the length of the electronic product code (EPC) of described label from the depositing of this read write line;

Receiving element is used for data bit to be received is provided with and prepares to receive data.

Adopt the method and apparatus that in radio-frequency recognition system, the data in the label is read of the present invention to have the following advantages:

At first, the present invention is by protecting the feature description information in the label, thereby the aiding in literacy device is grasped the feature of label, the storage data of reading tag more exactly effectively.By method provided by the present invention, read write line can be searched correct EPC length before receiving the EPC position.Read write line will be synchronous well with label, can not spend the unnecessary time to wait for label response, thereby can raise the efficiency.On the other hand, because good synchronously, read write line can send the ACK order in the correct time, and to ask EPC once more, this will greatly improve reliability.

Secondly, read write line can increase power soon and catch the T2R preamble by providing energy to label.The inventive method provides the method for energy to combine with above-mentioned to label, can further improve reliability, and can not produce bigger interference to other equipment.Based on these two advantages, method provided by the present invention is highly suitable for disturbing greatly and has the occasion of a plurality of read write lines, for example makes the application scenario.

In addition, the enforcement of the inventive method only needs the read write line slightly modified, and because this method meets the EPCC1G2 standard fully, so can implement the inventive method easily in present employed label and read write line, provides cost savings.

Description of drawings

Below in conjunction with accompanying drawing the specific embodiment of the present invention is described in further detail, wherein:

Fig. 1 has provided that read write line carries out contingent wrong synoptic diagram in the process of reading to label in the prior art;

The done state of signal when Fig. 2 has provided label backscattering in the prior art;

Fig. 3 has provided the process flow diagram of determining the EPC data length in the prior art according to first byte of agreement control bit PC;

Fig. 4 has provided and has occurred in the receiving course to agreement control bit PC in the prior art that some is wrong and cause read write line to analyze the synoptic diagram of EPC length mistakenly;

Fig. 5 has provided the synoptic diagram of agreement control bit and Extended Protocol control bit;

Fig. 6 has provided the structure that read write line writes an error-detecting code EDC and error-correcting code ECC the electronic product code EPC data after the label electronic product code EPC data;

Fig. 7 has provided preceding 5 the EPC length of coming identification (RFID) tag at the use agreement control bit, perhaps when the 6th of use agreement control bit comes whether valid data to be arranged in the identifying user data field, a concrete error-detecting code EDC and a concrete error-correcting code ECC among Fig. 6;

Fig. 8 has provided the process that the length of shielded electronic product code EPC code is write agreement control bit PC;

Fig. 9 has provided the read process of read write line to the shielded label of agreement control bit PC;

When Figure 10 has provided REC position in using the Extended Protocol control bit and has come recalled state after identification (RFID) tag is killed, a concrete error-detecting code EDC and a concrete error-correcting code ECC among Fig. 6;

Figure 11 has provided and has existed common label and agreement control bit PC to be protected label classified inquiry synoptic diagram under the situation of label;

Figure 12 has provided read write line to the process that reads of the shielded label of agreement control bit PC and the process that reads of common label;

Figure 13 has provided and has selected two at least one that strengthen in the period to regulate the synoptic diagram of transmission signal gain among the embodiment three to embodiment five;

Figure 14 has provided the synoptic diagram of the interface that defines between read write line and the main frame that is attached thereto;

Figure 15 has provided read write line the data in the label of fixed product code bit EPC has been carried out process of reading;

Figure 16 has provided the setting of the true manufacturing application scenario that is used to simulate interference source in the test;

Figure 17 has provided the contrast relationship figure of BER performance and jamming power;

Figure 18 has provided the overtime number percent of RN16 and the contrast relationship figure of jamming power;

Figure 19 has provided time interval Tinit and the TEPCRetry in the read-write process;

Figure 20 has provided the time of normally reading single label and has utilized the present invention program to read the time comparison diagram of single label, and wherein, the BER scope is (1e-4 is to 1e-2);

Figure 21 has provided the time of normally reading single label and has utilized the present invention program to read the time comparison diagram of single label, and wherein, the BER scope is (1e-2 is to 5e-2);

Figure 22 has provided according to the method that under the fixing situation of electronic product code EPC code of the present invention label is read and according to the resulting reading reliability of method that provides energy to label that is write down in Siemens Company's patented claim 200810004983.0 relatively;

Figure 23 has provided according to the method that under the fixing situation of electronic product code EPC code of the present invention label is read and according to the resulting reading rate of method that provides energy to label that is write down in Siemens Company's patented claim 200810004983.0 relatively.

Embodiment

In radio-frequency recognition system, store data in the label.These data can be divided into two classes, and class data are the data that really will use in radio-frequency recognition system; Another kind of data are data that the data that front one class really will be used are described, and these data are called as the feature description information of label.In more detail, the total data in the label is stored in three zones (Bank), and these three zones are respectively: label identifier (TagID) district, electronic product code (EPC) data field, user data (User Memory) district.Wherein, the feature description information spinner of label will be stored in the front end of electronic product code data field EPC, and removes these feature description information, and the remaining data that are arranged in described three zones are exactly the data that radio-frequency recognition system really will use.

If the feature description information spinner of label defines by agreement control bit PC and Extended Protocol control bit XPC (XPC defines in up-to-date UHF RFID standard), as shown in Figure 5.In Fig. 5, agreement control bit PC is made up of two bytes, and wherein the definition of each bit is referring to lower-left figure.And Extended Protocol control bit XPC comprises W1 part and W2 part, and each is made up of each part two bytes.Some bits among the W1 are defined at present, referring to bottom-right graph, the bit of its meta 0 is a reservation bit; W2 part then as reserve bytes, is not defined wherein any bit at present.

Feature description information is mainly used to the aiding in literacy device and grasps the feature of label so that the storage data of more effective reading tag.For example, preceding 5 bits of agreement control bit PC are used for the length of EPC code in the electronic product code data field of identification (RFID) tag, the length when read write line can read according to this information setting EPC.Again for example, the 6th bit in the agreement control bit can be used in the user data area User Memory of identification (RFID) tag whether valid data being arranged, and whether read write line can initiate data read command according to this information decision.Also have, REC position in the Extended Protocol control bit the recalled state (Recommissioning) after (Kill) of can identification (RFID) tag being killed, read write line can determine the recalled state of label according to this information, thereby the lock condition of judgement user data area is to take different tactful reading of data.In a word, this category feature descriptor has very big influence to the efficient of read write line read write tag, may cause whole read-write procedure failure if make a mistake in transmission course, therefore how to transmit these information reliably and becomes very crucial.

Core concept of the present invention just is by these feature description information are protected, thereby improves the label data reliability of reading, comprises following steps in the concrete scheme:

At first, first read write line or label use the coding with error correction and error detecing capability, and feature description information is encoded and coding is write label.

Secondly, first read write line or second read write line read label, receive the feature description information after encoded, and by coding feature description information are decoded.

At last, first read write line or second read write line read corresponding data according to decoded feature description information.

Be that example illustrates the specific embodiment of the present invention with the radio-frequency recognition system of forming by read write line and label below.

In radio-frequency recognition system, read write line depends on to a great extent that to the label reliability of reading read write line catches the RN16 prefix, catches data (hereinafter referred to as the EPC data) prefix in the EPC data field and revise the ability of crc error in the process that the data to the electronic product code data field receive.The EPC data comprise agreement control bit PC, EPC code and cyclic redundancy check (CRC) code CRC; and wherein the length information of EPC code is extremely important for read write line is understood the backscattered end of EPC; in following embodiments of the invention one, will specifically describe at read write line and how at first the length information of EPC code to be protected; read write line receives the length information of shielded EPC code then, thereby correctly the EPC data is received.

The radio-frequency recognition system of embodiments of the invention one comprises an above read write line and one group of label, and wherein each label all contains the EPC data, and the EPC data further comprise agreement control bit PC, EPC code, cyclic redundancy check (CRC) position CRC.Wherein, the length of agreement control bit PC is 16 bits, and the length of EPC code can change between 96 to 496 bits, and the length of cyclic redundancy check (CRC) position CRC is 16 bits.The length records of EPC code is in described agreement control bit PC.

Read write line uses an error-detecting code (Error Detection Code when for the first time a label being read; EDC) and an error-correcting code (Error Correction Code; ECC) agreement control bit PC is encoded, and coding is write in the label electronic product code EPC data field.Fig. 6 has provided the structure that writes the EPC data behind the coding.Wherein, the foremost is agreement control bit PC, and its length is 16 bits, and is convenient for subsequent calculations, is designated as the N1 bit herein.Agreement control bit PC writes down the length of EPC code usually with five bits in first byte.Remove outside above-mentioned five bits, agreement control bit PC also has some reserved bit (Reserved for Future Use; RFU), read write line is provided with a protection sign with two bits among these reserved places RFU, and the length information that identifies the EPC code of this label is protected.After agreement control bit PC, be the protection bit of Npro bit, comprise an error-detecting code EDC and an error-correcting code ECC.Described N1 bit and Npro bit sum are designated as the Np bit.Next be the EPC code, its length is designated as the N2 bit between 96 bit to 496 bits.Be cyclic redundancy check (CRC) position CRC at last, its length is 16 bits.

Fig. 7 has provided a concrete error-detecting code EDC and the concrete error-correcting code ECC among Fig. 6, wherein error-detecting code EDC chooses the cyclic redundancy check (CRC) code CRC of 5 bits, error-correcting code ECC chooses BCH (31,21) sign indicating number, wherein 21 expressions length to be encoded is 21 bits, and promptly the agreement control bit PC of 16 bits adds the cyclic redundancy check (CRC) code CRC as error-detecting code of 5 bits; BCH code length behind 31 presentation codes is 31 bits, therefore can learn that the length of error-correcting code ECC is 10 bits (being the 31-16-5=10 bit) herein.In other words, the length sum of error-detecting code EDC and error-correcting code ECC is Npro=15 bit (a 5+10=15 bit) herein.

Fig. 8 has provided the process that the length of shielded EPC code is write agreement control bit PC, comprises following steps:

At first, in using, open loop determines to change the length (just changing the length of whole EPC data) of EPC code.So-called herein open loop is used, and is meant that label may use in a plurality of links, for example all can use this label in links such as processing, logistics, retail trader, retailer, users.For instance, for a retail trader, it may receive from different local next various labels, and these are from the different local labels that receive, and the length of its EPC code may be different.And then can learn that for each link in the above-mentioned link, the length of the EPC code of the label that receives from last link all may be different, therefore need protect the label of the length variations of these EPC codes.

Secondly, the length that read write line agreement control bit PC is write down is set to the length sum of EPC code, error-detecting code EDC, error-correcting code ECC.That is to say, the length of error-detecting code EDC, error-correcting code ECC is used as the part of EPC code.

Once more, read write line is provided with a protection sign on the reserved bit RFU of agreement control bit PC, and the length information that identifies the EPC code of this label is protected.For example, can utilize last two conduct protection signs of the agreement control bit PC of 16 bits.

Then, read write line is agreement control bit PC computing faults in checking codes EDC.This calculation procedure is a prior art, repeats no more herein.

Then, read write line is agreement control bit PC and error-detecting code EDC miscount correcting code ECC.The same with last step, this calculation procedure is a prior art.

At last, store error-detecting code EDC and error-correcting code ECC the starting end of EPC code into, its position such as above-mentioned Fig. 6 and shown in Figure 7.After this read write line just can begin to carry out normal read step.

Read write line just carries out the operation of above-mentioned steps when for the first time label being read, that is to say, through after the above-mentioned steps, the length information of the EPC code of this label just has been subjected to protection.If the length of EPC code changes, for example foregoing in open loop is used the application scenario variation has taken place, then read write line needs once more error-detecting code EDC and error-correcting code ECC are write in the electronic product code EPC data field.

Above-mentioned ablation process is finished by a read write line, and still, this ablation process is also nonessential to be finished by read write line, and label itself also can be finished the ablation process of above-mentioned coding.

When the read write line of above-mentioned write error error detecting code EDC and error-correcting code ECC or another one read write line read the data in the electronic product code EPC data field in this label; the read write line that reads has also just obtained the length of correct EPC code by the information that the decoding agreement control bit PC that just can obtain to be protected is write down.Read write line to the process that reads of the shielded label of agreement control bit PC as shown in Figure 9.

At first, read write line sends querying command Query to label.After label received querying command Query, the random number R N16 that returns to one 16 of read write lines was as handle.If read write line does not receive random number R N16, then read write line resends querying command Query after after a while.

Secondly, after read write line receives the random number R N16 of label transmission, send one and confirm that order ACK is to label.After label receives the confirmation order ACK, to the prefix of read write line return electron product code EPC data.If read write line does not detect this prefix, then read write line resends querying command Query after after a while.

Once more, if read write line detects the prefix of electronic product code EPC data, then read write line reads the data in the electronic product code EPC data field in the label, receives agreement control bit PC, error-detecting code EDC, error-correcting code ECC.

Then, read write line carries out error-detecting and correction by error-correcting code ECC to agreement control bit PC and error-detecting code EDC.That is to say that if error-correcting code ECC detects and wrong and capable among agreement control bit PC and the error-detecting code EDC this mistake corrected, then error-correcting code ECC corrects this mistake.

Then, read write line carries out error-detecting by error-detecting code EDC to agreement control bit PC.Make mistakes if detect agreement control bit PC, then read write line can take one of following three kinds of modes to handle:

First kind, the length of EPC code to be received is set to the length of the EPC code of previous label.This is that this label of supposition and previous label all belong to a kind of label.

Second kind, the length of EPC code to be received is set to 96 bits.96 bits are EPC

The third, read write line at first waits the longest described EPC code required time to be read, and the longest here described EPC code is 496 bits, starts a new label subsequently and reads process, and promptly read write line resends querying command Query and gives label.

When read write line carries out mistake by error-detecting code EDC to agreement control bit PC, do not make mistakes, mean that read write line has obtained the length of correct EPC code if detect agreement control bit PC; Perhaps after above-mentioned first kind of detecting that agreement control bit PC makes mistakes and second kind of processing mode, suppose that read write line has obtained the length of correct EPC code.Therefore, the length that its data bit that will receive of read write line is set to the EPC code adds 32 bits, and prepares to receive data.

After through one period stand-by period, read write line has received electronic product code EPC data.Subsequently, read write line carries out cyclic redundancy check (CRC) to the data that receive.If verification is passed through, then read write line sends next querying command QueryRep to label, and gives the main frame that links to each other with this read write line with received EPC data report.And the EPC data that report to main frame here do not comprise error-correcting code ECC and error-detecting code EDC.If verification is not passed through, then read write line resends and confirms that order ACK gives the prefix of label and testing product code EPC data.

In embodiments of the invention two, the 6th bit of protection agreement control bit PC, this bit can be used in the user data area User Memory of identification (RFID) tag whether valid data being arranged, and read write line determines whether initiating data read command according to this information.

Because writing down preceding 5 bits of EPC code length, being used for of will protecting among the 6th bit will protecting and the embodiment one all be positioned at agreement control bit PC, thus similar among protection process and the embodiment one.Wherein, can use with embodiment one in identical error-detecting code EDC and error-correcting code ECC agreement control bit PC is encoded, and coding is write in the label electronic product code EPC data field.Employed error-detecting code EDC and error-correcting code ECC use step that error-detecting code EDC and error-correcting code ECC encode to agreement control bit PC as shown in Figure 8 as shown in Figure 7.Read write line reads the electronic product code EPC data in the label, receives the agreement control bit PC behind the coding, and the agreement control bit PC after will encoding decodes, and its process as shown in Figure 9.After decoding, obtain agreement control bit PC, whether initiate data read command by the 6th bit decision of this agreement control bit, the data in the described user data area are read.

In embodiments of the invention three; the REC bit of protection Extended Protocol position XPC; this bit recalled state (Recommissioning) after (Kill) of can identification (RFID) tag being killed; read write line can determine the recalled state of label according to this information, thereby the lock condition of judgement user data area is to take different tactful reading of data.Its protection process and above-mentioned two embodiment are similar, and the difference part is:

At first; because the REC bit is the W1 part that is stored in Extended Protocol position XPC; therefore what will protect in this embodiment three is the W1 part of agreement control bit PC and Extended Protocol control bit XPC, this moment employed error-detecting code EDC with error-correcting code ECC with last two different.When Figure 10 (a) has provided REC position in using the Extended Protocol control bit and has come recalled state after identification (RFID) tag is killed, a concrete error-detecting code EDC and a concrete error-correcting code ECC among Fig. 6.Wherein, error-detecting code EDC chooses the cyclic redundancy check (CRC) code CRC of 5 bits, and error-correcting code ECC chooses BCH (63,39) sign indicating number.

Secondly, use step that error-detecting code EDC and error-correcting code ECC encode to agreement control bit PC as shown in Figure 8, just the agreement control bit PC among Fig. 8 is become the W1 part of agreement control bit PC and Extended Protocol control bit XPC.In addition, error-detecting code EDC and error-correcting code ECC are stored in the label.Different with preceding two embodiment is, coding can be stored in the different local of label herein, and Figure 10 (b) and Figure 10 (c) have provided this two kinds of storage modes respectively.Because at present the W2 of Extended Protocol control bit XPC partly be a reserve part, so in Figure 10 (b), error-detecting code EDC and error-correcting code ECC are stored into the W2 part of Extended Protocol control bit XPC.In Figure 10 (c), then error-detecting code EDC and error-correcting code ECC are stored into the starting position of EPC code.

Read write line reads the electronic product code EPC data in the label, receives agreement control bit PC and Extended Protocol control bit XPC behind the coding, and the agreement control bit PC after will encoding and Extended Protocol control bit XPC decode, and its process and Fig. 9 are similar.After decoding, obtain agreement control bit PC and Extended Protocol control bit XPC, by the recalled state of the REC bit of Extended Protocol position XPC decision label, thereby the lock condition of judging user data area is to take different tactful reading of data.

As replenishing of embodiment one to embodiment three, in the read-write zone of read write line, the label that may both exist agreement control bit PC to be protected, the common label that also exists agreement control bit PC not to be protected.Figure 11 has provided and has existed common label and agreement control bit PC to be protected label classified inquiry synoptic diagram under the situation of label.In this case, read write line at first sends a select command Select to all labels in its read-write zone, selects those reserved bit RFU to be provided with the label of protection sign.Start the process that reads of the shielded label of agreement control bit PC shown in Figure 9 then for these labels.Then; the label of read write line in its read-write zone sends a select command Select again; be chosen in the common label that the protection sign is not set on the reserved bit RFU in the read-write zone, according to common read step the data in the described common label that described protection sign is not set read then.

Figure 12 has provided above-mentioned said read write line to the process that reads of the shielded label of agreement control bit PC and the process that reads of common label.

Certainly, read write line also can be selected earlier the data in the common label are read, and selects the data in the shielded label of agreement control bit PC are read again.

In addition, in embodiment one, mainly be that any one bit in the EPC data makes a mistake in transmission course and makes the scheme that read write line generation CRC check mistake is solved in the process that receives electronic product code EPC data.Mention in background technology, exist three kinds of situations may cause reading the EPC data failure, be respectively: read write line reads that the RN16 prefix is overtime, read write line reads the overtime and read write line of EPC prefix data and carries out CRC check and make a mistake.In the patented claim 200810004983.0 of Siemens Company, proposed to have proposed solution at preceding two kinds of situations.In order further to improve the reliability of read write line comprehensively to the data read in the label; a kind of improvement project as embodiments of the invention one; read write line is when using the scheme that the length of EPC code is protected of the present invention; select to wait for and receive the RN16 period as strengthening the period; strengthening in the period; read write line is regulated sending the gain of signal, makes to send with the transmitted power that strengthens in the carrier signal that strengthens in the period.

Another kind of improvement project as embodiments of the invention one; read write line is when using the scheme that the length of EPC code is protected of the present invention; select to wait for and receive the electronic product code EPC data period as strengthening the period; strengthening in the period; read write line is regulated sending the gain of signal, makes to send with the transmitted power that strengthens in the carrier signal that strengthens in the period.

Another improvement project as embodiments of the invention one; read write line is when using the scheme that the length of EPC code is protected of the present invention; select wait reception RN16 period, wait to receive these two periods of electronic product code EPC data period as strengthening the period; strengthen in the period at these two; read write line is regulated sending the gain of signal, makes to send with the transmitted power that strengthens in the carrier signal that strengthens in the period.Figure 13 has provided and has selected two at least one that strengthen in the period to regulate the synoptic diagram of transmission signal gain among the embodiment three to embodiment five.

The foregoing description and improvement project thereof all are to use example of the present invention at the open loop application scenario.But except open loop is used, the situation that also exists closed loop to use under many circumstances.In closed loop was used, label only circulated an internal system usually, for example, and the label that in a process, circulates.This class label can not enter into follow-up intermediate links usually, and generally can reclaim use owing to be in the occasion of sealing.For the label in these closed loops application, the EPC code of label is changeless.Purpose at read the EPC code reliably under the closed loop applicable cases the present invention proposes another solution.

In embodiments of the invention four, radio-frequency recognition system comprises an above read write line and one group of label, wherein each label all comprises electronic product code EPC data, and the EPC data further comprise agreement control bit PC, EPC code, cyclic redundancy check (CRC) position CRC.Wherein, the length of agreement control bit PC is 16 bits, and the length of EPC code immobilizes, and can be fixed as the some bits between 96 to 496 bits, and the length of cyclic redundancy check (CRC) position CRC is 16 bits.The length records of EPC code is in described agreement control bit PC.

According to the present invention program, at first, interface of definition between read write line and the main frame that is attached thereto.Main frame is configured to a regular length n with the length of EPC code _EPC, by this interface the length of product code position EPC is passed to read write line then.

Secondly, after read write line receives the length of product code position EPC, the length n of this EPC code of storage in its register _EPCFigure 14 has provided the synoptic diagram of the interface that defines between read write line and the main frame that is attached thereto.

After having carried out above-mentioned configuration and storage, read write line just can read the data in the label of fixed product code bit EPC.Figure 15 has provided read write line the data in the label of fixed product code bit EPC has been carried out process of reading.

At first, read write line sends querying command Query to label.After label received querying command Query, the random number R N16 that returns to one 16 of read write lines was as handle.If read write line does not receive random number R N16, then read write line resends querying command Query after after a while.

Secondly, after read write line receives the random number R N16 of label transmission, send one and confirm that order ACK is to label.After label receives the confirmation order ACK, to the prefix of read write line return electron product code EPC data.If read write line does not detect this prefix, then read write line resends querying command Query after after a while.

Once more, if read write line detects the prefix of electronic product code EPC data, then read write line obtains the length n of the EPC code stored from its register _EPCThat is to say, in the present embodiment, although the length records of EPC code is in described agreement control bit PC, but in actual use, it is not the length information that from agreement control bit PC, obtains the EPC code, but from its register, obtain the length information of EPC code by read write line, and make a mistake even can guarantee the bit that in the process that reads the EPC data, writes down the EPC code length information among the agreement control bit PC like this, also can obtain the length of EPC code.

Then, its data bit that will receive of read write line is set to the length n of EPC code _EPCAdd 32 bits, and prepare to receive data.

After through one period stand-by period, read write line has received electronic product code EPC data.Subsequently, read write line carries out cyclic redundancy check (CRC) to the data that receive.If verification is passed through, then read write line sends next querying command QueryRep to label, and gives the main frame that links to each other with this read write line with received EPC data report.If verification is not passed through, then read write line resends and confirms that order ACK gives the prefix of label and testing product code EPC data.

Similar with the improvement project of embodiment one, embodiment four also can combine with the patented claim 200810004983.0 of Siemens Company, further improves the reliability of read write line to the data read in the label comprehensively.A kind of improvement project as embodiment four, read write line is when using the scheme that the fixing label of the length of EPC code is read of the present invention, select to wait for and receive the RN16 period as strengthening the period, strengthening in the period, read write line is regulated sending the gain of signal, makes to send with the transmitted power that strengthens in the carrier signal that strengthens in the period.

Another kind of improvement project as embodiment four, read write line is when using the label fixing to the length of EPC code of the present invention, select to wait for and receive the electronic product code EPC data period as strengthening the period, strengthening in the period, read write line is regulated sending the gain of signal, makes to send with the transmitted power that strengthens in the carrier signal that strengthens in the period.

Another improvement project as embodiment four, read write line is when using the label fixing to the length of EPC code of the present invention, select wait reception RN16 period, wait to receive these two periods of electronic product code EPC data period as strengthening the period, strengthen in the period at these two, read write line is regulated sending the gain of signal, makes to send with the transmitted power that strengthens in the carrier signal that strengthens in the period.

As previously mentioned, embodiment one and improvement project thereof are the schemes that in open loop is used label is read, and embodiment four and improvement project thereof are the schemes that in closed loop is used label is read.In fact, read write line is that label under the divided ring situation reads in order to distinguish, and still the label under the closed-loop case is read, and the situation that a model selection mode is used to distinguish open loop and closed loop can be set on this read write line.When the model selection mode identifies first kind of pattern of read write line use, use the scheme that under the open loop case label is read, i.e. the scheme that the length of EPC code is protected.When the model selection mode identifies second kind of pattern of read write line use, use the scheme that under the closed-loop case label is read, promptly the length at the EPC code is the scheme that under the situation of fixing label is read.

Corresponding with the method for in the embodiment of the invention one length of EPC code being protected, the present invention also proposes a kind of read write line that in radio-frequency recognition system the data in the label is read, and this read write line comprises:

Coding unit is used to use a coding with error correction and error detecing capability that feature description information is encoded;

Writing unit is used for described coding is write a label;

Reading unit is used for the data of described label are read, and receives described feature description information after encoded;

Decoding unit is used for by described coding described feature description information being decoded;

Receiving element is used for according to decoded feature description information corresponding data being read.

Wherein, the said write unit further comprises:

The unit is set, and the length that is used for described label agreement control bit PC is set to the length sum of EPC code, error-detecting code EDC, error-correcting code ECC, and a protection sign is set on the reserved bit RFU of described agreement control bit PC;

Computing unit is used to described agreement control bit PC to calculate described error-detecting code EDC, and calculates described error-correcting code ECC for described agreement control bit PC and described error-detecting code EDC;

Storage unit is used for described error-detecting code EDC and described error-correcting code ECC are stored into the starting end of described EPC code.

In addition, read write line comprises that also an order sends module, the label that is used in being in its read-write zone sends a protection label select command, be chosen in the label that the interior reserved bit RFU in read-write zone is provided with the protection sign, the method for protecting according to the length to the EPC code among the present invention reads the data in the shielded label then; Perhaps the label in being in its read-write zone sends a common label select command; be chosen in the common label that the protection sign is not set on the reserved bit RFU in the read-write zone, and the data in the common label that described protection sign is not set read according to common read step.

Corresponding for the method that under the fixing situation label is read with the length of EPC code in the embodiment of the invention four, the present invention proposes another read write line that in radio-frequency recognition system the data in the label is read, and described read write line comprises:

Interface unit, be used for read write line and with main frame that described read write line links to each other between interface of definition, by this interface main frame the length of EPC code is configured to a regular length;

Storage unit is used for the length of the EPC code that the register storage host at read write line disposed;

Reading unit is used for when the data to label read, and obtains the length of the EPC code of label from the depositing of this read write line;

Receiving element is used for data bit to be received is provided with and prepares to receive data.

In order further to prove the advantage of method provided by the present invention, carried out following test.These tests all have the true manufacturing application scenario of interference source based on simulation.The setting of carrying out in the test as shown in figure 16.Two read write lines among Figure 16 are all based on Indy R1000 platform.Be displayed in Table 1 the setting of test parameter.

The setting of table 1 measurement parameter

The power of the read write line that reads	20dBm
		Backscatter power from the label to the read write line	-58dBm
Disturb the power of read write line	-45dBm is to-30dBm
		The carrier frequency of the read write line that reads	915.75MHz
Disturb the carrier frequency of read write line	(915.75MHz cochannel)
		Error-detecting code	CRC-5
Error-correcting code	BCH(31，21)

The read write line that reads will be operated according to the listed link parameter of table 2.

The link parameter of the read write line that table 2 reads

Modulation system	Tari(us)	x	Coded system	LF(kHz)	Data rate (kbps)
						DSB-ASK	6.25	0.5	FM0	400	400

Figure 17 has provided the contrast relationship figure of BER performance and jamming power.From Figure 17 we as can be seen, BER increases fast along with the increase of jamming power.The inventive method is to use below 0.1 at BER usually.Figure 18 has provided the overtime number percent of RN16 and the contrast relationship figure of jamming power.As can be seen from Fig. 18, in the zone of bigger BER, there has been the overtime situation of many RN16 to take place.

In order to study in normal read-write process and the inventive method reading speed for single label, will be relatively and simulation based on the time of reading single label in these two kinds of read methods.

For reading process normally, can user's formula (1) calculate the time of reading single label.

$P_e=1-{(1-P_b)}^{({\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="H2009101600596E0000012.png"\; state="\{\{state\}\}">N</figure-callout>}}_1+N_2)}$

$P_{\mathrm{PC}}=1-{(1-P_b)}^{{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="H2009101600596E0000012.png"\; state="\{\{state\}\}">N</figure-callout>}}_1}$

$P_{\mathrm{EPC}}=1-{(1-P_b)}^{{\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="H2009101600596E0000142.png,H2009101600596E0000151.png"\; state="\{\{state\}\}">N</figure-callout>}}_2}$

$T=T_{\mathrm{init}}+T_{\mathrm{EPCRetry}}+\frac{P_e}{1-P_e}\&times;\frac{P_{\mathrm{PC}}\&times;T_{\mathrm{PCRETRY}}+P_{\mathrm{EPC}}\&times;T_{\mathrm{EPCRETRY}}}{P_{\mathrm{PC}}+P_{\mathrm{EPC}}}+T_{\mathrm{QueryRep}}---\left(1\right)$

Wherein, P _bBe BER; P _eBe the PER of agreement control bit PC+EPC code+cyclic redundancy check (CRC) position CRC16 bag transmission; P _PCIt is the probability of agreement control bit PC mistake; P _EPCIt is the probability that electronic product code EPC data make a mistake; T is based on basic procedure and reads the employed time of single label.The number of times of in the formula (1) ACK being retransmitted does not limit.T _InitAnd T _EPCRetryBe at the employed time interval of the different phase of agreement among Figure 19.

, encode by protection agreement control bit PC and then correctly obtain the scheme of EPC code for of the present invention, can use formula (2) to calculate by reading the time of single label under the present invention program with CRC-5, BCH (31,21).

$P_{\mathrm{PC}}=1-{(1-P_b)}^{N_p}-N_p{P}_b{(1-P_b)}^{(N_p-1)}-\frac{N_p(N_p-1)}{2}\&times;{\mathrm{<figure-callout\; id="2"\; label="P\; b"\; filenames="H2009101600596E0000142.png,H2009101600596E0000151.png"\; state="\{\{state\}\}">P</figure-callout>}}_b^{}\&times;{(1-P_b)}^{(N_p-2)}$

$P_{\mathrm{EPC}}=1-{(1-P_b)}^{{\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="H2009101600596E0000142.png,H2009101600596E0000151.png"\; state="\{\{state\}\}">N</figure-callout>}}_2}$

P _e＝1-(1-P _PC)(1-P _EPC)

$T=T_{\mathrm{init}}+T_{\mathrm{EPCRetry}}+\frac{P_e}{1-P_e}\&times;\frac{P_{\mathrm{PC}}\&times;T_{\mathrm{PCRETRY}}+P_{\mathrm{EPC}}\&times;T_{\mathrm{EPCRETRY}}}{P_{\mathrm{PC}}+P_{\mathrm{EPC}}}+T_{\mathrm{QueryRep}}---\left(2\right)$

Wherein, N _PBe the figure place of agreement control bit PC, the same formula of the implication of other parts (1).

The time of normally reading the time of single label and utilize the present invention program to read single label is compared result such as Figure 20 and shown in Figure 21.

According to analog result, can draw to draw a conclusion: when BER hour, utilize the process of the present invention program's reading tag, its performance similar to the performance of normal processes (because the use redundant digit, the present invention program is more a little bit poorer a little than normal processes).(BER＞=1e-3), utilize the advantage highly significant of the process of the present invention program's reading tag when BER is big.

(for example, when BER=0.05, utilizing the process of the present invention program's reading tag can save time for reading over half).Therefore, the present invention program can solve read write line effectively and carries out the problem that cyclic redundancy check (CRC) makes a mistake.

In addition, in order to assess the overall performance of method provided by the present invention, that implements to be write down in the method that under the fixing situation of EPC code of the present invention label read and the Siemens Company's patented claim 200810004983.0 on Indy R1000 platform provides the method for energy to label, perhaps implements the combination of described method.Be specially: normally read (1);

(2) under the situation that adopts EPC code of the present invention to fix label is read; (3) under the situation that adopts EPC code of the present invention to fix label is read, and select to wait for that receiving the RN16 period provides energy as strengthening the period to label; (4) under the situation that adopts EPC code of the present invention to fix label is read, and select to wait for that receiving the electronic product code EPC data period provides energy as strengthening the period to label; (5) under the situation that adopts EPC code of the present invention to fix label is read, and selection is waited for the reception RN16 period, is waited for that these two periods of reception electronic product code EPC data period provide energy as the enhancing period to label.The reading reliability of these five kinds of methods and the comparative result of reading rate are respectively as Figure 22 and shown in Figure 23.From this two width of cloth figure as can be seen:

At first, RN16 is overtime, EPC is overtime and crc error owing to reduced, and has greatly improved the success ratio of read write line reading tag data.When the interfering frequency scope be-9dBm is during to-5dBm, compares with the method that normally reads in the method provided by the present invention, the ratio that reads 1000 successes is approximately greater than 40%.Especially, when interfering frequency be-during 9dBm, the ratio that uses method provided by the present invention to read 1000 successes is about 90%, shows that reliability of reading is very high.And the normal read access method reads the ratio of 1000 successes only is 50%.

Secondly, read write line is to the reading speed that can reach higher that reads of label.As shown in figure 23, when the interfering frequency scope be-5dBm is during to-9dBm, method provided by the present invention can be got 25 labels than normal read access method mutiread.Especially, the reading speed of method provided by the present invention can reach 100 labels of per second, and this can satisfy the requirement that most of RFID use.

At last, method provided by the present invention has a little interference to other equipment.Reason is that read write line only increases power at short notice for obtaining better reading speed, but its power can recover normal level immediately.

In sum, the method that the feature description information of label in the radio-frequency recognition system is protected provided by the present invention can reach higher reading speed and the reliability of Geng Gao.According to measurement result, particularly under noise circumstance, adopt the present invention can greatly improve the reading reliability and the speed of label.So this method is highly suitable for improving read/write operation reliability and the efficient in the application scenario (for example, making the application scenario) that has noise circumstance.On the other hand, the enforcement of this scheme only need be revised read-write machine firmware and get final product, and is very easy.And this method meets EPC C1G2 standard fully, therefore can implement like a cork in current label and read write line.

The above only is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (29)

1. method that in radio-frequency recognition system, the data in the label is read, described radio-frequency recognition system comprises an above read write line and one group of label, described each label all comprises one a group of data and a stack features descriptor, it is characterized in that the method includes the steps of:

(1) first read write line or described label use the coding with error correction and error detecing capability, and described feature description information is encoded and described coding is write described label;

(2) described first read write line or second read write line read described label, receive described feature description information after encoded, and by described coding described feature description information are decoded;

(3) described first read write line or second read write line read corresponding data according to decoded feature description information.

2. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 1, it is characterized in that: in the described step (1), described coding with error correction and error detecing capability comprises an error-detecting code (EDC) and an error-correcting code (ECC).

3. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 2, it is characterized in that: the data of described label are the data in electronic product code (EPC) data field, the feature description information of described label is agreement control bit (PC), the length records of the electronic product code (EPC) in described electronic product code (EPC) data field is in described agreement control bit (PC)

In the described step (1), described first read write line uses described error-detecting code (EDC) and described error-correcting code (ECC) that described agreement control bit (PC) is encoded, and described coding is write in described label electronic product code (EPC) data;

In the described step (2), described first read write line or second read write line read the electronic product code in the described label (EPC) data, receive the agreement control bit (PC) behind the described coding, and the agreement control bit (PC) behind the described coding is decoded;

In the described step (3), described first read write line or second read write line according to decoded agreement control bit (PC) will be to be received data bit be provided with and prepare to receive data.

4. a kind of method that in radio-frequency recognition system the data in the label is read according to claim 3 is characterized in that: comprise following steps in the described step (1):

(11) length that write down of described agreement control bit (PC) is set to the length sum of described electronic product code (EPC), error-detecting code (EDC), error-correcting code (ECC);

(12) a protection sign is set on the reserved bit (RFU) of described agreement control bit (PC);

(13) calculate described error-detecting code (EDC) for described agreement control bit (PC);

(14) calculate described error-correcting code (ECC) for described agreement control bit (PC) and described error-detecting code (EDC);

(15) described error-detecting code (EDC) and described error-correcting code (ECC) are stored into the starting position of described electronic product code (EPC).

5. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 3, it is characterized in that: in the described step (2), described first read write line or second read write line agreement control bit (PC) after with described coding is decoded and is further comprised:

Described first read write line or second read write line carry out error-detecting and correction by described error-correcting code (ECC) to described agreement control bit (PC) and described error-detecting code (EDC);

Described first read write line or second read write line carry out error-detecting by described error-detecting code (EDC) to described agreement control bit (PC), to obtain the length of correct electronic product code (EPC).

6. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 5, it is characterized in that: wrong if described error-detecting code (EDC) detects described agreement control bit (PC), the length of the electronic product code (EPC) that the described pickup of then described first read write line or second read write line is received is set to the length of the electronic product code (EPC) of previous label.

7. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 5, it is characterized in that: wrong if described error-detecting code (EDC) detects described agreement control bit (PC), the length of the electronic product code (EPC) of then described first read write line or the described reception of second read write line is set to 96 bits.

8. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 5, it is characterized in that: wrong if described error-detecting code (EDC) detects described agreement control bit (PC), then described first read write line or second read write line at first wait the longest described electronic product code to be read (EPC) required time, start a new label subsequently and read process.

9. a kind of method that in radio-frequency recognition system the data in the label is read according to claim 8, it is characterized in that: the longest described electronic product code (EPC) is 496 bits.

10. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 3, it is characterized in that: in the described step (3), the length that the data bit that described first read write line or second read write line will receive is set to described electronic product code (EPC) adds 32 bits.

11. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 3, it is characterized in that: if the length of described electronic product code (EPC) changes, then described first read write line writes described error-detecting code (EDC) and described error-correcting code (ECC) in the described electronic product code data once more.

12. a kind of method that in radio-frequency recognition system the data in the label is read according to claim 3 is characterized in that: described step (1) is before, and is further comprising the steps of:

Described first read write line or second read write line send a protection label select command to being in its label of reading and writing in the zone, are chosen in the label that the interior reserved bit (RFU) in described read-write zone is provided with described protection sign.

13. a kind of method that in radio-frequency recognition system the data in the label is read according to claim 12 is characterized in that: described step (3) also comprises afterwards:

Described first read write line or second read write line label in being in its read-write zone sends a common label select command; be chosen in the common label that described protection sign is not set on the reserved bit (RFU) in the described read-write zone, and the data in the described common label that described protection sign is not set read according to common read step.

14. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 3, it is characterized in that: also comprise before: a model selection mode is set in described first read write line or second read write line in described step (1), when described read write line is chosen described model selection mode, begin described step (1).

15. according to claim 3 or 4 described a kind of methods that in radio-frequency recognition system, the data in the label read, it is characterized in that: described first read write line or second read write line select to wait for that receiving the RN16 period receives electronic product code (EPC) data at least one period in the period as strengthening the period with waiting for, described read write line is regulated sending the gain of signal, makes that the carrier signal in the described enhancing period sends with the transmitted power that strengthens.

16. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 2, it is characterized in that: the data of described label comprise data in electronic product code (EPC) data field and the data in the user data area, the feature description information of described label is agreement control bit (PC), in the described user data area of described agreement control bit (PC) sign whether valid data are arranged

In the described step (1), described first read write line uses described error-detecting code (EDC) and described error-correcting code (ECC) that described agreement control bit (PC) is encoded, and described coding is write in described label electronic product code (EPC) data;

In the described step (2), described first read write line or second read write line read the electronic product code in the described label (EPC) data, receive the agreement control bit (PC) behind the described coding, and the agreement control bit (PC) behind the described coding is decoded;

In the described step (3), described first read write line or second read write line determine whether initiate data read command according to decoded agreement control bit (PC), and the data in the described user data area are read.

17. a kind of method that in radio-frequency recognition system the data in the label is read according to claim 16 is characterized in that: comprise following steps in the described step (1):

(11) length that write down of described agreement control bit (PC) is set to the length sum of described electronic product code (EPC), error-detecting code (EDC), error-correcting code (ECC);

(12) a protection sign is set on the reserved bit (RFU) of described agreement control bit (PC);

(13) calculate described error-detecting code (EDC) for described agreement control bit (PC);

(14) calculate described error-correcting code (ECC) for described agreement control bit (PC) and described error-detecting code (EDC);

(15) described error-detecting code (EDC) and described error-correcting code (ECC) are stored into the starting position of described electronic product code (EPC).

18. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 2, it is characterized in that: the data of described label comprise data in electronic product code (EPC) data field and the data in the user data area, the feature description information of described label is agreement control bit (PC) and Extended Protocol control bit (XPC), recalled state after the described label of sign is killed in the described Extended Protocol control bit (XPC)

In the described step (1), described first read write line uses described error-detecting code (EDC) and described error-correcting code (ECC) that described agreement control bit (PC) and described Extended Protocol control bit (XPC) are encoded, and described coding is write in the described label;

In the described step (2), described first read write line or second read write line read described label, receive agreement control bit (PC) and Extended Protocol control bit (XPC) behind the described coding, and agreement control bit (PC) behind the described coding and Extended Protocol control bit (XPC) are decoded;

In the described step (3), described first read write line or second read write line are according to the recalled state of decoded agreement control bit (PC) and Extended Protocol control bit (XPC) decision label.

19. a kind of method that in radio-frequency recognition system the data in the label is read according to claim 18 is characterized in that: described step may further comprise the steps in (1):

(11) length that write down of described agreement control bit (PC) is set to the length sum of described electronic product code (EPC), error-detecting code (EDC), error-correcting code (ECC);

(12) a protection sign is set on the reserved bit (RFU) of described agreement control bit (PC);

(13) calculate described error-detecting code (EDC) for described agreement control bit (PC);

(14) calculate described error-correcting code (ECC) for described agreement control bit (PC) and described error-detecting code (EDC);

(15) described error-detecting code (EDC) and described error-correcting code (ECC) are stored in the described label.

20. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 19, it is characterized in that: in the described step (15), described error-detecting code (EDC) and described error-correcting code (ECC) are stored into the starting position of described electronic product code (EPC).

21. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 19, it is characterized in that: in the described step (15), described error-detecting code (EDC) and described error-correcting code (ECC) are stored in the described Extended Protocol control bit (XPC).

22. method that in radio-frequency recognition system, the data in the label is read, described radio-frequency recognition system comprises an above read write line and one group of label, described each label all comprises the data in electronic product code (EPC) data field, each described electronic product code (EPC) data comprises agreement control bit (PC), electronic product code (EPC), cyclic redundancy check (CRC) position (CRC), it is characterized in that the method includes the steps of:

(1) read write line and with main frame that described read write line links to each other between interface of definition, by the described main frame of described interface the length of described electronic product code (EPC) is configured to a regular length;

(2) described read write line is stored the length of the electronic product code (EPC) that described main frame disposed in its register;

When (3) described read write line reads the data in the described label, from the register of this read write line, obtain the length of the electronic product code (EPC) of described label;

(4) data bit that described read write line will be to be received is provided with and prepares to receive data.

23. a kind of method that in radio-frequency recognition system, the data in the label is read according to claim 22, it is characterized in that: in the described step (4), the length that the data bit that the described read write line or second read write line will receive is set to described electronic product code (EPC) adds 32 bits.

24. according to claim 22 or 23 described a kind of methods that in radio-frequency recognition system, the data in the label read, it is characterized in that: also comprise before: a model selection mode is set in described first read write line or second read write line in described step (1), when described read write line is chosen described model selection mode, begin described step (1).

25. according to claim 22 or 23 described a kind of methods that in radio-frequency recognition system, the data in the label read, it is characterized in that: described read write line selects to wait for that receiving the RN16 period receives electronic product code (EPC) data at least one period in the period as strengthening the period with waiting for, described read write line is regulated sending the gain of signal, makes that the carrier signal in the described enhancing period sends with the transmitted power that strengthens.

26. a read write line that in radio-frequency recognition system the data in the label is read is characterized in that, described read write line comprises:

Coding unit is used to use a coding with error correction and error detecing capability that feature description information is encoded;

Writing unit is used for described coding is write a label;

Reading unit is used for the data of described label are read, and receives described feature description information after encoded;

Decoding unit is used for by described coding described feature description information being decoded;

Receiving element is used for according to decoded feature description information corresponding data being read.

27. a kind of read write line that in radio-frequency recognition system the data in the label is read according to claim 26, it is characterized in that: the said write unit further comprises:

The unit is set, the length that is used for described label agreement control bit (PC) is set to the length sum of electronic product code (EPC), error-detecting code (EDC), error-correcting code (ECC), and a protection sign is set on the reserved bit (RFU) of described agreement control bit (PC);

Computing unit is used to described agreement control bit (PC) to calculate described error-detecting code (EDC), and is that described agreement control bit (PC) calculates described error-correcting code (ECC) with described error-detecting code (EDC);

Storage unit is used for described error-detecting code (EDC) and described error-correcting code (ECC) are stored into the starting end of described electronic product code (EPC).

28. a kind of read write line that in radio-frequency recognition system, the data in the label is read according to claim 27, it is characterized in that: described read write line comprises that also an order sends module, be used for sending a protection label select command, be chosen in the label that the interior reserved bit (RFU) in described read-write zone is provided with described protection sign to being in its label of reading and writing in the zone; Perhaps the label in being in its read-write zone sends a common label select command; be chosen in the common label that described protection sign is not set on the reserved bit (RFU) in the described read-write zone, and the data in the described common label that described protection sign is not set read according to common read step.

29. a read write line that in radio-frequency recognition system the data in the label is read is characterized in that, described read write line comprises:

Interface unit, be used for read write line and with main frame that described read write line links to each other between interface of definition, by the described main frame of described interface the length of described electronic product code (EPC) is configured to a regular length;

Storage unit is used for the length at the register storage electronic product code (EPC) that described main frame disposed of described read write line;

Reading unit is used for when the data to described label read, and obtains the length of the electronic product code (EPC) of described label from the depositing of this read write line;

Receiving element is used for data bit to be received is provided with and prepares to receive data.

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