WO2023138409A1

WO2023138409A1 - Communication method and apparatus based on wireless radio-frequency identification

Info

Publication number: WO2023138409A1
Application number: PCT/CN2023/070947
Authority: WO
Inventors: 赖思佳; 唐宽锋; 闵昊; 贾嘉
Original assignee: 华为技术有限公司
Priority date: 2022-01-19
Filing date: 2023-01-06
Publication date: 2023-07-27
Also published as: CN116502655A

Abstract

Disclosed in the present application are a communication method and apparatus based on wireless radio-frequency identification. The method comprises: a reader sending a first message, wherein the first message is used for identifying a label, the first message comprises indication information, the indication information is used for instructing the label to randomly determine an encoding mode, or determining an encoding mode on the basis of a sequence which is acquired by the label, or determining an encoding mode on the basis of a received signal energy intensity which is acquired by the label; the label receiving the first message; the reader sending a second message, wherein the second message is used for instructing the label to report the sequence; the label receiving the second message; then, the label sending a third message to the reader on the basis of a first encoding mode, wherein the third message comprises a first sequence; and the reader receiving the third message. By means of the method provided in the present application, the access efficiency of a label can be improved.

Description

Communication method and device based on radio frequency identification

This application claims the priority of the Chinese patent application with the application number 202210061629.1 and the application title "Communication Method and Device Based on Radio Frequency Identification" submitted to the China Patent Office on January 19, 2022, the entire contents of which are incorporated in this application by reference.

technical field

The present application relates to the technical field of communication, and in particular to a communication method and device based on radio frequency identification.

Background technique

Radio Frequency Identification (RFID) technology was born in the 1940s. As a typical application of back reflection communication, RFID relies on the sending end (such as a reader) to send out radio waves of a specific frequency, carrying energy and messages. After the receiving end (such as a tag) collects the energy of the radio wave of this specific frequency, it performs rectification and energy storage, and activates its own processing capabilities. The receiving end adjusts its own antenna matching network to absorb or reflect the radio waves emitted by the sending end. Thus, the sending end can observe the "disturbance" of the radio wave emitted by the receiving end. This "disturbance" carries specific information (such as the identification information of the receiving end), and the sending end identifies the receiving end based on the specific information.

When radio frequency identification technology is applied to the Internet of Things (IoT), it can effectively solve the low power consumption requirement in the Internet of Things. Especially for the massive Internet of Things, the reader can effectively manage and identify the massive tags around it, so as to realize the automatic identification of tags and information sharing. Correspondingly, by using low-power tags for managed items or equipment, the problem of battery replacement or plugging in can be effectively improved. Exemplarily, the reader sends out radio waves of a specific frequency, and the tag can activate its own processing capability according to the radio wave of the specific frequency, so as to send relevant information of the tag to the reader.

However, in the above method, the tag access efficiency still needs to be improved.

Contents of the invention

The present application provides an RFID-based communication method and device, which can improve tag access efficiency.

In the first aspect, the embodiment of the present application provides an RFID-based communication method, the method comprising:

The tag receives a first message, the first message is used to identify the tag, and the first message includes indication information, and the indication information is used to instruct the tag to randomly determine an encoding mode, or determine an encoding mode based on a sequence obtained by the tag, or determine an encoding mode based on received signal energy strength obtained by the tag; the tag receives a second message, and the second message is used to indicate the tag to report a sequence; the tag sends a third message to the reader based on the first encoding mode, and the third message includes the first sequence.

In the embodiment of the present application, the encoding method is determined by indicating information, so that the tags located in the same time unit adopt different encoding methods as much as possible, so that the reader can effectively recover messages from different tags, effectively improve the situation of discarding information due to collisions, and improve the utilization rate of time domain resources.

In a possible implementation manner, the method further includes: the tag receives an acknowledgment (acknowledge, ACK) message from the reader, where the ACK message is used to confirm one or more of the first sequences; the tag sends identification information of the tag to the reader based on the first encoding manner.

In this embodiment of the application, the encoding method used by the tag to send the third message is the same as the encoding method used when sending the identification information. Therefore, the tag determines the first encoding method through the indication information, and can send the third message and identification information through the first encoding method.

In a possible implementation manner, the sequence obtained by the tag includes at least one of the following: the first sequence, the second sequence or a reference sequence.

In the embodiment of the present application, the tag can determine the coding method based on the sequence that it can obtain, so that each tag can determine the coding method based on the sequence that it can obtain as much as possible. Furthermore, tags that select the same time unit use different encoding methods to send the third message or identification information as much as possible, so as to further improve the utilization rate of time domain resources.

In a possible implementation manner, the indication information used to indicate that the encoding method is determined based on the sequence obtained by the tag includes: the indication information is used to indicate that the encoding method is determined based on the m-th bit and the n-th bit in the first sequence, the m is not equal to the n, the m and the n are both less than or equal to the length of the first sequence, and the x and the y are positive integers; The length of the second sequence, the i and the j are positive integers; or, the indication information is used to indicate that the encoding method is determined based on the p-th bit and the q-th bit in the reference sequence, the p is not equal to the q, the p and the q are both less than or equal to the length of the reference sequence, and the p and the q are positive integers; or, the indication information is used to indicate that the encoding method is determined based on the x-th bit and the y-th bit in the comparison result of the second sequence and the reference sequence, the x is not equal to the y, and the x and the y are both less than or equal to the length of the comparison result, Said x and said y are positive integers.

In a possible implementation manner, the indication information used to indicate that the encoding method is determined based on the received signal energy strength acquired by the tag includes: the indication information is used to indicate that the encoding method is determined based on a comparison result between the received signal energy intensity of the second message and a preset threshold.

In a possible implementation manner, the first encoding manner is determined based on any of the following:

The first encoding method is determined based on the mth bit and the nth bit in the first sequence, the m is not equal to the n, the m and the n are both less than or equal to the length of the first sequence, the m and the n are positive integers; the first encoding method is determined based on the i bit and the j bit in the second sequence, the i is not equal to the j, the i and the j are both less than or equal to the length of the second sequence, and the i and the j are positive integers; the first encoding method is based on the p bit and the q bit in the reference sequence It is determined that the p is not equal to the q, the p and the q are both less than or equal to the length of the reference sequence, the p and the q are positive integers; the first encoding method is determined based on the xth bit and the yth bit in the comparison result of the second sequence and the reference sequence, the x is not equal to the y, the x and the y are both less than or equal to the length of the comparison result, and the x and the y are positive integers; the first encoding method is determined based on the comparison result of the received signal energy strength of the second message and a preset threshold;

In a possible implementation manner, determining the first coding method based on a comparison result between the received signal energy strength of the second message and a preset threshold includes: when the received signal energy strength of the second message is greater than or equal to a first threshold, the first coding method includes a Miller coding method of M=8; or, when the received signal energy strength of the second message is smaller than the first threshold and greater than or equal to a second threshold, the first coding method includes a Miller coding method of M=4, and the first threshold is greater than the second threshold; In the case where the received signal energy strength is less than the second threshold and greater than or equal to the third threshold, the first coding method includes a Miller coding method with M=2, and the second threshold is greater than the third threshold; or, when the received signal energy strength of the second message is smaller than the third threshold, the first coding method includes a Miller coding method with M=1.

In a possible implementation manner, the first message further includes at least one of start position information, length information, or a second sequence, the start position information and the length information are used to determine a reference sequence, the reference sequence is used to compare with the second sequence, and a comparison result between the reference sequence and the second sequence is used to identify the tag.

In a possible implementation manner, the first message further includes start position information, length information, and a second sequence, the start position information and the length information are used to determine a reference sequence, the reference sequence is used to compare with the second sequence, and a comparison result between the reference sequence and the second sequence is used to identify the tag.

In a possible implementation manner, the first encoding manner includes any of the following: M=1 Miller encoding manner, M=2 Miller encoding manner, M=4 Miller encoding manner, M=8 Miller encoding manner.

In a second aspect, the embodiment of the present application provides a communication method based on radio frequency identification RFID, the method comprising:

The reader sends a first message, the first message is used to identify the tag, and the first message includes indication information, and the indication information is used to instruct the tag to randomly determine the encoding mode, or determine the encoding mode based on the sequence obtained by the tag, or determine the encoding mode based on the received signal energy strength obtained by the tag; the reader sends a second message, and the second message is used to indicate the sequence reported by the tag; the reader receives a third message from the tag, the third message includes the first sequence, and the encoding mode of the third message includes the first encoding mode.

In a possible implementation manner, the receiving the third message from the tag by the reader includes: receiving the third message sent by at least two tags by the reader, and at least two of the tags use different encoding methods when sending the third message.

In a possible implementation manner, the method further includes: the reader sends an acknowledgment ACK message, where the ACK message is used to confirm one or more of the first sequences; and the reader receives the identification information of the tag.

Optionally, the reader may send an ACK message to a tag, and the ACK message includes a first sequence. Optionally, the reader may send ACK messages to at least two tags respectively, where the ACK messages are used to confirm multiple first sequences. When the reader sends ACK messages to at least two tags, the reader can respectively receive the identification information sent by the at least two tags.

In a possible implementation manner, the indication information used to indicate that the encoding method is determined based on the sequence obtained by the tag includes: the indication information is used to indicate that the encoding method is determined based on the m-th bit and the n-th bit in the first sequence, the m is not equal to the n, the m and the n are both less than or equal to the length of the first sequence, and the m and the n are positive integers; The length of the second sequence, the i and the j are positive integers; or, the indication information is used to indicate that the encoding method is determined based on the p-th bit and the q-th bit in the reference sequence, the p is not equal to the q, the p and the q are both less than or equal to the length of the reference sequence, and the p and the q are positive integers; or, the indication information is used to indicate that the encoding method is determined based on the x-th bit and the y-th bit in the comparison result of the second sequence and the reference sequence, the x is not equal to the y, and the x and the y are both less than or equal to the length of the comparison result, Said x and said y are positive integers.

In a possible implementation manner, determining the encoding method based on a comparison result between the received signal energy strength of the second message and a preset threshold includes: when the received signal energy strength of the second message is greater than or equal to a first threshold, the encoding method determined by the tag includes a Miller encoding method of M=8; or, when the received signal energy strength of the second message is smaller than the first threshold and greater than or equal to a second threshold, the encoding method determined by the tag includes a Miller encoding method of M=4, and the first threshold is greater than the second threshold; When the received signal energy strength of the second message is less than the second threshold and greater than or equal to the third threshold, the encoding method determined by the tag includes a Miller encoding method with M=2, and the second threshold is greater than the third threshold; or, when the received signal energy strength of the second message is less than the third threshold, the encoding method determined by the tag includes a Miller encoding method with M=1.

In a possible implementation manner, the encoding manner determined by the tag includes any of the following: M=1 Miller encoding manner, M=2 Miller encoding manner, M=4 Miller encoding manner, M=8 Miller encoding manner.

In a third aspect, the embodiment of the present application provides a second communication device, configured to execute the method in the first aspect or any possible implementation manner of the first aspect. The second communication device includes a unit for performing the method in the first aspect or any possible implementation manner of the first aspect.

In this embodiment of the present application, the second communication device may include a tag.

In a fourth aspect, the embodiment of the present application provides a first communication device, configured to execute the method in the second aspect or any possible implementation manner of the second aspect. The first communication device includes a unit for performing the method in the second aspect or any possible implementation manner of the second aspect.

In the embodiment of the present application, the first communication device may include a reader or a chip or a chip system disposed in the reader.

In a fifth aspect, the embodiment of the present application provides a second communication device, where the second communication device includes a processor, configured to execute the method described in the first aspect or any possible implementation manner of the first aspect. Alternatively, the processor is used to execute a program stored in the memory, and when the program is executed, the method shown in the first aspect or any possible implementation manner of the first aspect is executed.

In a possible implementation manner, the memory is located outside the second communication device.

In a possible implementation manner, the memory is located in the second communication device.

In the embodiment of the present application, the processor and the memory may also be integrated into one device, that is, the processor and the memory may also be integrated together.

In a possible implementation manner, the second communication device further includes a transceiver, where the transceiver is configured to receive a signal or send a signal.

In a sixth aspect, the embodiment of the present application provides a first communication device, where the first communication device includes a processor, configured to execute the method described in the second aspect or any possible implementation manner of the second aspect. Alternatively, the processor is used to execute the program stored in the memory, and when the program is executed, the method shown in the above second aspect or any possible implementation manner of the second aspect is executed.

In a possible implementation manner, the memory is located outside the first communication device.

In a possible implementation manner, the memory is located in the first communication device.

In a possible implementation manner, the first communication device further includes a transceiver, where the transceiver is configured to receive a signal or send a signal.

In a seventh aspect, the embodiment of the present application provides a second communication device, the second communication device includes a logic circuit and an interface, the logic circuit is coupled to the interface; the interface is used to input the first message and the second message; the interface is also used to output the third message.

In a possible implementation manner, the interface is further configured to input an ACK message and output identification information of the second communication device.

It can be understood that the logic circuit is configured to obtain the third message according to the input first message and the second message. Optionally, the logic circuit is further configured to acquire identification information according to the input ACK message.

In an eighth aspect, the embodiment of the present application provides a first communication device, the first communication device includes a logic circuit and an interface, the logic circuit is coupled to the interface; the interface is used to output a first message and a second message, and the interface is also used to input a third message.

It can be understood that the logic circuit can be used to acquire the first message and the second message.

In a possible implementation manner, the interface is further configured to output an ACK message and input tag identification information.

It can be understood that the logic circuit can be used to obtain the ACK message.

In the ninth aspect, the embodiment of the present application provides a computer-readable storage medium, which is used to store a computer program, and when it is run on a computer, the method shown in the above-mentioned first aspect or any possible implementation manner of the first aspect is executed.

In a tenth aspect, the embodiment of the present application provides a computer-readable storage medium, which is used to store a computer program, and when it is run on a computer, the method shown in the above-mentioned second aspect or any possible implementation of the second aspect is executed.

In the eleventh aspect, the embodiment of the present application provides a computer program product, the computer program product includes a computer program or computer code, and when it is run on a computer, the method shown in the above first aspect or any possible implementation of the first aspect is executed.

In a twelfth aspect, an embodiment of the present application provides a computer program product, the computer program product includes a computer program or computer code, and when it is run on a computer, the method shown in the above second aspect or any possible implementation of the second aspect is executed.

In a thirteenth aspect, an embodiment of the present application provides a computer program. When the computer program is run on a computer, the method shown in the above-mentioned first aspect or any possible implementation manner of the first aspect is executed.

In a fourteenth aspect, an embodiment of the present application provides a computer program. When the computer program is run on a computer, the method shown in the second aspect or any possible implementation manner of the second aspect is executed.

In a fifteenth aspect, the embodiment of the present application provides a wireless communication system, the wireless communication system includes a tag and a reader, the tag is used to execute the method shown in the first aspect or any possible implementation of the first aspect, and the reader is used to execute the method shown in the second aspect or any possible implementation of the second aspect.

Description of drawings

FIG. 1 is a schematic structural diagram of a radio frequency identification system provided by an embodiment of the present application;

Fig. 2a is an interactive schematic diagram of an RFID-based communication method provided by an embodiment of the present application;

Fig. 2b is an interactive schematic diagram of another RFID-based communication method provided by the embodiment of the present application;

FIG. 3 is an interactive schematic diagram of an RFID-based communication method provided by an embodiment of the present application;

Figure 4a and Figure 4b are schematic diagrams of a coding method provided by the embodiment of the present application;

Fig. 4c is a schematic diagram between a coding method and a carrier frequency provided by an embodiment of the present application;

FIG. 5 is an interactive schematic diagram of another RFID-based communication method provided by the embodiment of the present application;

6 to 8 are schematic structural diagrams of a communication device provided by an embodiment of the present application.

Detailed ways

In order to make the purpose, technical solution and advantages of the application clearer, the application will be further described below in conjunction with the accompanying drawings.

The terms "first" and "second" in the specification, claims and drawings of the present application are only used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other inherent steps or units for these processes, methods, products, or devices.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The occurrences of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is understood explicitly and implicitly by those skilled in the art that the embodiments described herein can be combined with other embodiments.

In the present application, "at least one (item)" refers to one or more, "multiple" refers to two or more, "at least two (items)" refers to two or three and more than three, "and/or" is used to describe the association relationship of associated objects, indicating that there may be three kinds of relationships. The character "/" generally indicates that the contextual objects are an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items. For example, at least one item (unit) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c".

Generally speaking, both ends of the transceiver are active (such as plug-in or battery) devices. However, for back reflection communication, it generally means that one of the two ends of the transceiver is passive and the other is active. For example, the sending end is active and the receiving end is passive. For example, a transmitter can be used to transmit radio waves to activate a receiver so that the receiver can transmit a signal. For another example, the transmitting end transmits radio frequency energy by transmitting a radio frequency carrier, thereby activating the receiving end. The activated receiving end can continue to receive the downlink message sent by the sending end, and make an uplink response (such as sending its own identification information to the sending end). For another example, after the receiving end is activated, the sending end still continues to transmit the radio frequency carrier, and the receiving end adjusts its antenna impedance to produce a state of matching or not matching with the radio frequency carrier. As a result, the radio frequency carriers transmitted by the sending end may be absorbed or reflected by different receiving ends, so that the sending end can obtain the fluctuation in the size of the echo signal caused by the absorption or reflection of the receiving end in the echo signal, and this change can carry uplink messages (such as uplink messages including RN16 or uplink messages including EPC, etc.). Through the above method, the sending end and the receiving end can complete a round of uplink and downlink interaction process. The communication method shown above can be called back reflection communication.

In the embodiment of the present application, the sending end may include a reader (also called an RFID reader), and the receiving end includes a tag (also called an RFID tag). It can be understood that the back reflection communication shown above is also applicable to the radio frequency identification technology, and the radio frequency identification technology will not be described in detail here.

Fig. 1 is a schematic structural diagram of a radio frequency identification system provided by an embodiment of the present application. As shown in FIG. 1 , the RFID system includes a reader 101 and a tag 102. The reader 101 may be an active device, and the tag 102 may be a passive device, a semi-active device or an active device. Exemplarily, a passive tag can be understood as the tag does not include a radio frequency processor, and sends an uplink message through back reflection communication. A semi-active tag can be understood as the tag does not include a radio frequency processor, but includes a power supply or plug-in, etc., and sends uplink messages through back reflection communication. An active tag can be understood as the tag includes a radio frequency processor, including a power supply or plug-in, etc., and sends uplink messages through back reflection communication. Compared with semi-active tags, active tags can increase the power of the transmitted signal. Alternatively, the power of the transmitted signal of an active tag may be boosted relative to a passive tag. In the embodiment of the present application, the direction in which the reader sends signals to the tags is called downlink, and the direction in which the tags send signals to the readers is called uplink.

Fig. 1 only exemplarily shows three labels, but it should not be understood as a limitation to the embodiment of the present application. Exemplarily, the label 102 may include a chip, a bus card, a bank card, a printed label, or a work card, etc. The embodiment of the present application does not limit the specific product form of the label. It can be understood that the label shown in the embodiment of the present application can also be directly embedded in the paper, so that the paper can be pasted on the item, so as to facilitate identification or management of the item by the reader.

As shown in FIG. 1 , the reader 101 activates the tag 102 by transmitting a radio frequency signal. After the tag 102 is activated, it sends an uplink message to the reader 101 according to the downlink message it receives. It can be understood that for specific descriptions of downlink messages and uplink messages, reference may be made to the following, and details will not be described here. It can be understood that the radio frequency signal shown here may also be called a radio frequency carrier, carrier wave, electromagnetic wave, or radio wave, and the specific name of the radio frequency signal is not limited in this embodiment of the present application.

Exemplarily, the reader 101 can automatically identify the tag 102 through a radio frequency signal, and obtain relevant information. For another example, the reader 101 may be used to manage and/or identify surrounding tags 102 . For another example, the reader 101 can be used to report the relevant information it receives from the tag 102 (such as the identification information of the tag 102, etc.) to a central server or database (the central server or database can be used to store the relevant information of the tag or identify the location of the tag, etc.). For another example, the reader 101 may automatically identify or share information on the tag 102 according to the relevant information it receives from the tag 102 . Instructions on readers and tags are not listed here.

The radio frequency identification system shown in FIG. 1 can be applied to the Internet of Things, the narrowband Internet of Things, the Internet of Vehicles, etc., and the embodiment of the present application does not limit the specific application of the radio frequency identification system. For example, the radio frequency identification system shown in Figure 1 can be applied to logistics management, manufacturing, airline luggage handling, express package handling, document tracking, library management, animal identification, sports timing, access control (such as electronic ticket control), automatic road toll collection, etc., and will not be listed here.

The following describes the interaction process between the reader and the tag in detail.

The reader can transmit a radio frequency signal to the outside world, and transmit the radio frequency energy contained in the radio frequency signal to the tag to activate the tag, thereby enabling the tag to communicate with the reader. Fig. 2a is an interactive schematic diagram of an RFID-based communication method provided by an embodiment of the present application. As shown in Fig. 2a, the reader sends out a downlink message for activating the tag, and the downlink message may also be called a downlink message frame or the like. The frame header of the downlink message frame includes a blank carrier, which is used to activate the tag. After the tag is activated, its internal circuits and chips start to work, such as decoding the downlink message frame it receives. After the tag completes the downlink reception, the reader still continues to send blank carrier waves to maintain the energy supply of the tag, and enables the tag to modulate the uplink message prepared by itself onto the carrier wave continuously sent by the reader, so as to send it out through back reflection. After receiving the uplink message from the tag, the reader sends an acknowledgment message to the tag, so that after the tag decodes the acknowledgment message, it sends the tag's identification information to the reader. Thus, the reader can identify or manage the tag according to the identification information of the tag.

Take the electronic product code generation-2 ultra high frequency (EPC-Gen2 UHF) protocol widely used in radio frequency identification systems as an example. This protocol defines the RFID link and media access layer standards of 860MHz to 920MHz. The EPC-Gen2 UHF protocol uses a dynamic time unit to enable tag access. That is, there is a polling communication process between the reader and the tag. Since the time unit shown in the embodiment of the present application may include a slot, the above dynamic time unit may also be called a dynamic framed slotted Aloha (DFSA).

Fig. 2b is an interactive schematic diagram of another RFID-based communication method provided by the embodiment of the present application.

Optionally, before the reader sends the inquiry message, the reader may send a select message in the form of broadcast, and the select message may be used to select a tag with certain characteristics, so that the reader communicates with the tag with certain characteristics. That is, the selection message can be used to identify the tag. For example, the tag can know whether it interacts with the reader through the selection message.

Exemplarily, the content of the selection message may be as shown in Table 1.

Table 1

Exemplarily, the instruction field is used to indicate the frame type of the selection message, for example, the frame type of the selection message may be 1010 . The target field is used to indicate inventoried. For example, when the value of the target field is 000, it means that the selected marked disk is S0. For another example, when the value of the target field is 001, it means that the selected marked disk is S1. For another example, when the value of the target field is 010, it means that the selected marked disk is S2. For another example, when the value of the target field is 011, it means that the selected marked disk is S3. For another example, when the value of the target field is 100, it means that the selected marked disk is SL. For another example, when the value of the target field is any one of 101, 110 or 111, it means that the value of the target field in the selection message is reserved as a bit (reserved for use, RFU) available in the future. When the value of the target field in the selection message is any one of 101, 110 or 111, it means that the selection message is no longer used. That is, the tag can ignore or discard the selection message.

Exemplarily, the action (action) field is used to indicate whether the matching tag confirms or cancels the SL flag, or indicates whether to set the disked flag. The membank field is used to indicate that a mask (may also be referred to as a mask) is applied to electronic product code (electronic product code, EPC), tag identification (tagidentification, TID), text type or a single text. Exemplarily, when the value of the storage body field is 00, it may indicate that the memory content that the tag subsequently searches for is a text type (file type). For another example, when the value of the storage body field is 01, it may indicate that the memory content to be searched by the tag subsequently is EPC. For another example, when the value of the storage body field is 10, it may indicate that the memory content to be searched by the tag subsequently is TID. As another example, when the value of the storage body field is 11, it may indicate that the memory content that the tag subsequently searches for is a single text (such as file_0). The pointer (pointer) field is used to indicate the starting position of the data intercepted by the tag. According to the pointer field and the storage body field, the tag can start to intercept data from the content indicated by the storage body field from the starting position indicated by the pointer field. The length (length) field is used to indicate the length of data intercepted from the starting position indicated by the pointer field. According to the storage body field, the pointer field and the length field, the tag can intercept data of length length from the memory content indicated by the storage body field according to the starting position indicated by the pointer field. Exemplarily, the mask (mask) field is used to indicate the mask sequence set by the reader, and the mask sequence is used for comparison with the data intercepted by the tag, thereby generating a comparison result of length. When the comparison result meets a certain condition, it means that the tag is the tag selected by the reader. It can be understood that the certain condition shown above may be set by the reader, and the embodiment of the present application does not limit the specific content of the certain condition. For example, the memory field can be used to instruct the tag to find its memory content, so as to compare its memory content with the sequence indicated by the mask field. The comparison method is to start from the position indicated by the pointer field, take the length indicated by the length field, and compare the extracted sequence with the sequence indicated by the mask field. When the comparison result meets certain conditions, it means that the tag is selected by the selection message.

Exemplarily, the truncate (truncate) field is used to indicate whether the EPC returned by the tag is a truncated EPC. A cyclic redundancy check (CRC) may be used to verify the selection message. For example, the bit length of the CRC in the selection message may be 16 bits.

It can be understood that, when the reader does not send the selection message, all tags that receive the query message can interact with the reader.

Exemplarily, at the beginning of a polling process, a random parameter is set by the reader, such as the random parameter can be represented by Q, and the Q can be used to indicate the number of time units included in the polling process, such as including 2 ^Q -1 time units. The Q can also be used to indicate the number of polls between the reader and the tag, for example, 2 ^Q −1 polls are included. It can be understood that the polling shown in the embodiment of the present application refers to the completion of the interaction process between the reader and the tag as shown in Figure 2a through polling, and/or the completion of the interaction process within a time unit between the reader and the tag as shown in Figure 2b through polling. It can be understood that the embodiment of the present application does not limit the duration of one time unit. A time unit may also be called a time slot or a time unit, and the specific name of the time unit is not limited in this embodiment of the present application.

As shown in FIG. 2b, the reader may send a query message in the form of broadcast (the query message is represented by query in FIG. 2b), and the query message includes random parameters. Exemplarily, the content of the inquiry message may be as shown in Table 2a.

Table 2a

Wherein, the command (command) field is used to indicate the frame type of the inquiry message, for example, the frame type of the inquiry message may be 1000. The division ratio (division ratio, DR) is used to indicate the connection frequency of the tag and reader communication. M is used to indicate the coding mode and information rate adopted by the tag when sending the uplink message. It can be understood that M can also be used to represent the number of cycles in each symbol (eg, bit). The above coding methods include: M=1 Miller coding method, M=2 Miller coding method, M=4 Miller coding method, M=8 Miller coding method. It can be understood that the Miller coding method with M=1 may also be called a bi-phase space coding (bi-phase space coding, FM0) method. The M occupies 2 bits. For example, when the value of M is 00, it means that the tag can use the FM0 method; for another example, when the value of M is 01, it means that the tag can use the Miller coding method of M=2; for another example, when the value of M is 10, it means that the tag can use the Miller coding method of M=4; The label extension field is used to indicate whether the uplink preamble of the label includes pilot frequency. The TRext occupies 1 bit. For example, when the value of TRext is 0, it means that the pilot is not used; for another example, when the value of TRext is 1, it means that the pilot is used. It can be understood that the tag extension field may also be called a TRext field, or a tag response extend field, etc. The embodiment of the present application does not limit the English name of the tag extension field. The selection field is used to select the tag set that responds to the inquiry message, and occupies 2 bits. The session field is used to indicate the session type participating in the polling process tag, occupying 2 bits. For example, when the value of the call field is 00, it indicates that the call type is S0. For another example, when the value of the call field is 01, it indicates that the call type is S1. For another example, when the value of the call field is 10, it indicates that the call type is S2. For another example, when the value of the call field is 11, it indicates that the call type is S3. The target (target) field is used to indicate that the disked flag of the tag participating in the polling process is A or B, and occupies 1 bit. Q represents the number of polling time units, and the Q occupies 4 bits, and the 4 bits can be used to indicate any one of 0-15. A cyclic redundancy check (CRC) occupies 5 bits.

When the tag obtains the query message broadcast by the reader, the tag can determine the total number of time units according to the value of Q, randomly generate a sequence, and randomly select a time unit among 2 ^Q -1 time units. Exemplarily, the tag can randomly generate a sequence with a bit length of 16, for example, the sequence can include a 16-bit random number (random number 16, RN16) (RN16 as shown in Figure 2b, or RN16 as shown in Table 3). It can be understood that the RN16 shown above may also be called a pseudo-random number. It can be understood that, when multiple tags receive the query message, each of the multiple tags can randomly generate a sequence, and randomly select a time unit among 2 ^Q −1 time units. It can be understood that Fig. 2b only exemplarily shows two tags, such as a first tag and a second tag, and the number of tags shown in Fig. 2b should not be construed as limiting the embodiment of the present application.

In each time unit, the reader can send a query message in the form of broadcast (query or queryreq as shown in Figure 2b), thus, when the time unit selected by the tag is consistent with the time unit where the query message is located, the tag can send an uplink message including RN16 to the reader after receiving the query message. It can be understood that, in order to distinguish the query messages shown in Table 2a and Table 2b, the query messages shown in Table 2b can also be called query repeat messages, or query repeat messages, etc. The embodiment of the present application does not limit the specific names of the messages shown in Table 2b.

Exemplarily, the content of the query repeat (queryreq) message may be as shown in Table 2b.

Table 2b

Wherein, the instruction field is used to indicate the frame type of the query repetition message, for example, the frame type of the query message may be 00. The call field is used to indicate the call type. If the call type of the query repeat message is inconsistent with the call type in the previously received query message, the tag ignores the query repeat message. It can be understood that, for the description of the conversation field, reference may be made to the conversation field shown in Table 2a, which will not be described in detail here.

Exemplarily, the content of the uplink message including RN16 may be as shown in Table 3.

table 3

the	回应(reply)Reply

比特数(#of bits)Number of bits (#of bits)	1616
描述(description)description	RN16RN16

Exemplarily, the bit length of the uplink message is 16 (the number of bits shown in Table 3 is 16), and the frame type of the uplink message is RN16.

Further, after receiving the uplink message, the reader can send an acknowledgment (acknowledge, ACK) message to the tag, so that the tag can send its identification information to the reader after receiving the ACK message. The identification information may include an electronic product code (electronic product code, EPC), an extended product code (extended product code, XPC) or a tag identification (tag identification, TID) and the like. It can be understood that Fig. 2b shows an EPC as an example, which should not be construed as a limitation to this embodiment of the present application. Therefore, after receiving the identification information, the reader sends an inquiry message again, and so on, until the polling of ^2Q -1 time units is completed.

Exemplarily, the content of the ACK message may be as shown in Table 4.

Table 4

the	指令instruction	RNRN
比特数number of bits	22	1616
描述describe	0101	回应RN16Response to RN16

Exemplarily, the instruction field is used to indicate the frame type of the ACK message, for example, the frame type of the ACK message may be 01. The RN indicates that the ACK message confirms the RN16 indicated by the random number (random number, RN) field.

It can be understood that the bit length of the ACK message is 2, and the frame type of the ACK message is 01.

As shown in Figure 2b, the time unit randomly selected by the first tag is the first time unit, then in the first time unit, the first tag can send an uplink message including RN16 to the reader, receive the ACK message sent by the reader, and send an EPC to the reader, thus completing a poll. The time unit randomly selected by the second tag is the second time unit. In the second time unit, the second tag can send an uplink message including RN16 to the reader, receive the ACK message sent by the reader, and send an EPC to the reader.

In the polling method of the reader and the tag shown above, when multiple tags randomly determine the same time unit according to the Q value, according to the encoding method indicated by the inquiry message (M shown in Table 2a), the multiple tags will collide when they send uplink messages to the reader due to the same frequency and simultaneous reasons. That is to say, in one time unit, when multiple tags send uplink messages to the reader on the same frequency domain resource, the multiple messages will collide. Therefore, in the one time unit, the reader cannot parse the uplink message due to a collision, and all the information in the one time unit is discarded. At the same time, it can also be seen from the ACK message shown in Table 4 that the ACK message can only carry the RN16 of one tag, that is, the reader cannot notify multiple tags that their uplink messages have been received correctly, and cannot make multiple tags report their EPC information after receiving the ACK message.

In addition to the phenomenon of collision shown above, in the polling method shown above, the following phenomenon will also occur: the Q value does not match the total number of tags: if the Q value is small, more tags will choose the same time unit, resulting in aggravated collisions. Theoretical access efficiency of the polling method shown above S=number of effective time units/number of total time units=Ge ^−G =36.8%, G=1, e is a natural constant. It can be seen that the access efficiency of the polling method shown above is not high.

In view of this, the embodiments of the present application provide a communication method and device, which can effectively improve the situation where multiple tags select the same time unit and collide, causing all information in the time unit to be discarded, thereby not only effectively improving the access efficiency of the radio frequency identification system, but also effectively improving the utilization rate of time domain resources. Exemplarily, when multiple tags select the same time unit, the method provided in the embodiment of the present application avoids as much as possible that the multiple tags use the same encoding mode. By using different encoding methods for the plurality of tags, the situation of collision when the plurality of tags send uplink messages can be effectively improved, that is, the effect that the plurality of tags send uplink messages concurrently without collision can be achieved.

Fig. 3 is an interactive schematic diagram of an RFID-based communication method provided by an embodiment of the present application. Exemplarily, the communication method can be applied to a radio frequency identification system as shown in FIG. 1 . As another example, the communication method may be applied to a system including a first communication device and a second communication device, the first communication device may include a reader or a chip applied in the reader, and the second communication device may include a tag. For another example, the first communication device may include an active network device (such as an active base station), and the second communication device may include a passive terminal, a semi-active terminal, or an active terminal. It can be understood that for descriptions about passive terminals, semi-active terminals, and active terminals, reference may be made to the description about tags in FIG. 1 , and they will not be listed here. As long as the first communication device and the second communication device need to interact through back reflection communication, it falls within the scope of protection of the embodiments of the present application.

As shown in Figure 3, the method includes:

301. The first communication device sends a first message, where the first message is used to identify the second communication device. Correspondingly, the second communication device receives the first message.

The first message includes at least one item of indication information, starting position information, length information or the second sequence. The indication information may be used to instruct the second communication device to randomly determine the coding mode, or to determine the coding mode based on the sequence obtained by the second communication device, or to determine the coding mode based on the received signal energy strength obtained by the second communication device. The indication information shown above may also be collectively referred to as: the indication information is used to instruct the second communication apparatus to determine the first encoding manner according to a preset rule. The starting position information and the length information are used to determine a reference sequence, which can be used for comparison with the second sequence, and the comparison result between the reference sequence and the second sequence is used to identify the second communication device. The second telecommunications device may determine whether it interacts (or polls) with the first telecommunications device based on the starting location information, the length information and the second sequence. Exemplarily, the starting position information indicates the starting position of the data intercepted by the second communication device, and the length information indicates the length of the data intercepted by the second communication device. Based on the start position information and the length information, the second communication device can intercept a certain length of data (ie, a reference sequence) from the memory content based on the start position indicated by the start position information, and the certain length is indicated by the length information. In other words, the starting position information and the length information may be used to instruct the second communication device to start extracting the reference sequence from the memory content based on the starting position indicated by the starting position information, and the length of the reference sequence is determined by the length information. Optionally, the memory content may include any one of text type (file type), EPC, TID or a single text (such as file_0). Optionally, the memory content may be preset by the first communication device, and then the first communication device broadcasts the memory content in a broadcast manner. Optionally, memory content may be indicated by storage volume information. For example, the first message may also include storage volume information, where the storage volume information is used to indicate storage volume content.

Optionally, the first message includes starting location information. Then the length and/or the second sequence of the data intercepted by the second communication device may be preset, such as defined by a standard, or preset by the first communication device, and then broadcast the length information and/or the second sequence through a broadcast message. Optionally, the first message includes length information. The starting position information and/or the second sequence required by the second communication device may be preset, such as defined by a standard, or preset by the first communication device, and then broadcast the starting position information and/or the second sequence through a broadcast message. Optionally, the first message includes starting position information and length information. Thus, the second communication device can determine the reference sequence according to the start position information and the length information included in the first message. The second sequence can be preset. Optionally, the first message includes starting position information, length information and a second sequence. It can be understood that, in the case that the first message does not include the indication information, the second communication device may autonomously determine the first encoding method based on preset rules (eg, determine the first encoding method based on any one of the preset rules). Meanwhile, the second communication device does not determine the coding mode based on M indicated in the second message. For the determination method of the first encoding mode, reference may be made to the following, and details will not be described here.

Optionally, the first message includes at least one item of starting position information, length information, or the second sequence, and the first message includes indication information. In this case, by including the indication information in the first message, the second communication device can clearly know that it can determine the first encoding method based on preset rules (such as determining the first encoding method based on any rule in the preset rules). Meanwhile, the second communication device may not determine the encoding mode based on M indicated in the second message.

Optionally, the first message includes starting position information, length information, the second sequence and indication information.

Exemplarily, the value of the indication information included in the first message may be any one of 101, 110 or 111. For example, the indication information may be located in a target (target) field in the first message, and when the value of the target field is any one of 000, 001, 010, 011 or 100, the target field may be used to indicate a disk already marked. And when the value of the target field is any one of 101, 110 or 111, the target field can be used to instruct the second communication device to determine the first coding method based on preset rules (such as the second communication device randomly determines the first coding method, or determines the first coding method based on the sequence obtained by the second communication device, or determines the first coding method based on the received signal energy strength obtained by the second communication device). For the communication methods shown in Table 1 to Table 4, since each tag determines the encoding method based on the value of M in the inquiry message, the encoding method of each tag is the same. In contrast, the indication information shown in the embodiment of the present application is used to indicate that a multi-coding mode is enabled, or the indication information is used to indicate that the second communication device can independently determine a coding mode, or the indication information is used to indicate the interaction of multiple coding modes, or the indication information is used to indicate that at least two second communication devices are allowed to use different coding modes. The embodiment of the present application does not limit the description of the instruction information, as long as the second communication device can independently determine the encoding method based on the instruction information, or, based on the instruction information, the encoding methods used by at least two second communication devices are different, all belong to the protection scope of the embodiment of the application.

Exemplarily, for the description of the first message, refer to the above description of Table 1. For example, for the start position information, refer to the description of the pointer field shown in Table 1, for the length information, refer to the description of the length field shown in Table 1, for the second sequence, refer to the description of the mask field shown in Table 1, and for the storage bank information, refer to the description of the storage bank field shown in Table 1, etc., which will not be described in detail here.

It can be understood that the first message shown above includes at least one item of indication information, starting position information, length information or the second sequence, and can also be understood as: the first message includes a target field, and the value of the target field is any one of 101, 110 or 111; a pointer field; at least one of a length field or a mask field. For descriptions of other fields that may be included in the first message, refer to Table 1, which will not be detailed here.

302. The first communication device sends a second message, where the second message is used to instruct the second communication device to report a sequence.

Correspondingly, the second communication device receives the second message.

Exemplarily, the first communication device may send the second message in a broadcast form. For example, the first communication device may broadcast the second message to at least two second communication devices.

Exemplarily, the second message includes information used to indicate the Q value, and the Q value may be used to indicate the number of time units. For example, based on the Q value, the second communication device may know that it needs to randomly select a time unit in ^2Q -1 time units, so as to perform information interaction with the first communication device in the time unit. For the description of the Q value, you can refer to the related description in Table 2a, which will not be described in detail here. Exemplarily, the second message may also be called a query message or a query repeat message (such as including query or queryreq shown in FIG. 2b ). For the description of the second message, reference may be made to the description shown in Table 2a and/or Table 2b. It should be noted that the second communication device may not determine the encoding mode based on the value of M. Instead, the encoding method is determined based on preset rules. Exemplarily, the second communication device may know explicitly based on the indication information in the first message that it does not need to determine the encoding mode based on the value of M.

303. The second communication device sends a third message to the first communication device based on the first encoding manner, where the third message includes the first sequence. Correspondingly, the first communication device receives the third message.

Wherein, the first encoding manner may be determined based on preset rules. Alternatively, the first coding method is determined based on any one or more of the following: the first coding method is randomly determined by the second communication device; the first coding method is determined based on the sequence obtained by the second communication device; the first coding method is determined based on the received signal energy strength obtained by the second communication device.

Exemplarily, in the case that the time unit randomly selected by the second communication device based on the Q value (such as the first time unit) is consistent with the time unit where the second message sent by the first communication device is located, the second communication device may send the third message based on the first encoding method in the first time unit. The bit length of the first sequence may be 16 bits, or greater than 16 bits (such as 12 bits or 8 bits, etc.), or less than 16 bits (such as 20 bits or 24 bits), etc., which is not limited in the embodiment of the present application. It can be understood that, for the description about the third message, reference may also be made to the uplink messages shown in Table 3, which will not be described in detail here.

It should be noted that, in the method shown in Table 3, the encoding method adopted by the second communication device when sending the uplink message is determined based on the value of M in the inquiry message. However, in the method shown in the embodiment of the present application, the first encoding method adopted by the second communication device when sending the third message is determined based on preset rules. At the same time, in the method shown in Table 3, the encoding method adopted by each tag is the same. However, in the method shown in the embodiment of the present application, since the second communication device can determine the encoding method autonomously based on preset rules, there may be at least two second communication devices that use different encoding methods. That is to say, in the method shown in the embodiment of the present application, when at least two second communication devices respectively send the third message to the first communication device, the encoding methods adopted by the at least two second communication devices may be different, or the encoding methods adopted by the at least two second communication devices are different. It can be understood that, since the second communication device generates the third message through the baseband processor, the encoding manner shown in the embodiment of the present application may also be referred to as a baseband encoding manner.

Exemplarily, in the same time unit, at least two second communication devices that send the third message to the first communication device use different encoding methods. Thus, even in the same time unit, since each of the at least two second communication devices adopts a different encoding method, the first communication device can use different filtering methods to decode the third message, so that the first communication device can recover each third message. Through the method provided by the embodiment of the present application, the situation that the at least two second communication devices collide is effectively improved, and the situation that the at least two second communication devices collide is reduced as much as possible, thereby avoiding the situation that information in the same time unit is discarded as much as possible, and effectively improving the utilization rate of time domain resources.

Exemplarily, in the same time unit, there may be two second communication devices sending the third message, and the encoding methods adopted by the two second communication devices are different. For example, one of the second communication devices adopts the Miller coding mode of M=2, and the other second communication device adopts the Miller coding mode of M=4. For another example, in the same time unit, there may be three second communication devices sending the third message, and the encoding methods adopted by the three second communication devices are different. For example, the coding methods adopted by the three second communication devices may be any three of the FMO method, the Miller coding method with M=2 (which may be referred to as miller-2 for short), the Miller coding method with M=4 (which may be referred to as miller-4 for short), and the Miller coding method with M=8 (which may be referred to as miller-8 for short). For another example, in the same time unit, there may be four second communication devices sending the third message, and the four second communication devices use different encoding methods. For example, the coding schemes adopted by the four second communication devices are the FMO method, the Miller coding scheme with M=2, the Miller coding scheme with M=4, and the Miller coding scheme with M=8. In this embodiment of the present application, the encoding method includes four encoding methods as an example. When there are more types of encoding methods, the number of second communication devices that are allowed to send the third message within the same time unit is also greater.

Certainly, the following scheme may also exist in the method shown in the embodiment of the present application: in the same time unit, at least two second communication devices that send the third message to the first communication device use the same encoding method. Although, in the method provided in the embodiment of the present application, there may be at least two second communication devices using the same coding method in the same time unit, but since each second communication device determines the coding method based on preset rules, there is a high possibility that in the same time unit, at least two second communication devices use different coding methods. Therefore, using the method shown in the embodiment of the present application reduces the collisions caused by different second communication devices due to the same frequency at the same time as much as possible, thereby improving the access efficiency of the second communication device. For example, when each tag uses its obtained sequence to determine the encoding method, the sequences obtained by each tag are likely to be different. For another example, when each tag adopts its own received signal energy strength to determine the encoding method, since the signal quality between each tag and the reader is different, the received signal energy strength obtained by each tag is very likely to be different. Therefore, the method provided by the embodiment of the present application can improve as much as possible the situation that at least two second communication devices use the same encoding mode in the same time unit. It can be understood that in this embodiment of the present application, the preset rules adopted by different second communication devices may be the same. For example, different second communication devices can randomly determine the encoding method; or, different second communication devices can determine the encoding method based on the first sequence obtained respectively; or, different second communication devices can determine the encoding method based on the second sequence obtained respectively; or, different second communication devices can determine the encoding method based on the reference sequence obtained respectively; Of course, different second communication devices may also use different preset rules to determine the encoding manner.

The method provided by the embodiment of the present application can effectively improve the problem of collision when two or more second communication devices simultaneously access the system and send the third message in the same time unit. Based on the method shown in FIG. 2b, the messages in the same time unit cannot be parsed due to the collision of the second communication device, resulting in discarding all the information in this time unit, and at the same time, this time unit will also be invalidated. However, the method provided by the embodiment of the present application ensures that the second communication device uses different encoding methods when sending the third message as much as possible, so as to achieve the effect of concurrent uplink without collision and improve the utilization rate of time domain resources.

In a possible implementation manner, the method shown in FIG. 3 further includes step 304 and step 305 .

304. The first communications apparatus sends an ACK message to the second communications apparatus, where the ACK message is used to confirm one or more first sequences. Correspondingly, the second communication device receives the ACK message.

Optionally, the ACK message is used to confirm a first sequence. For example, if the time unit randomly selected by a second communication device is the same as the time unit of the second message sent by the first communication device, the first communication device may confirm the third message sent by the second communication device, or confirm the first sequence sent by the second communication device.

The ACK message is used to confirm at least two first sequences (also referred to as multiple first sequences). For example, the time unit randomly selected by at least two second communication devices is the same as the time unit of the second message sent by the first communication device, then the first communication device may confirm the first sequence sent by the at least two second communication devices.

Exemplarily, the content of the ACK message may be as shown in Table 5.

table 5

command

RN16(T1)

RN16(T2)

...

RN16(Tn)

Optionally, the bit length of the ACK message may be fixed. For example, the bit length of the ACK message may be determined based on the length of the first sequence included in the third message and a reference value (such as may be expressed as Tn). For example, the reference value may be the type of encoding method. For example, if four encoding methods are included, the reference value may be 4. For another example, the reference value may be the number of second communication devices allowed to send an uplink message (eg, including a third message or an ACK message) in a time unit. The value of the reference value is not limited. Exemplarily, the bit length of the ACK message may be 64 bits. In this case, when there are four second communication devices respectively sending the third message in the first time unit, and the encoding methods used by every two second communication devices among the four second communication devices are different. Then the ACK message may confirm the third message sent by each of the four second communication devices. Of course, if at least one of the second communication devices (such as a second communication device) is not correctly decoded by the first communication device, the ACK message may confirm the correctly decoded third message. In this case, the 16 vacant bits in the ACK message can be filled with fixed values.

Optionally, the bit length of the ACK message may not be fixed, but changes with the number of third messages acknowledged by the first communication device. In this case, since the bit length of the ACK message is not fixed, in order to enable the second communication device to correctly decode the ACK message, the ACK message may further include information indicating the bit length of the ACK message.

It can be understood that RN16 ( T1 ), RN16 ( T2 ) to RN16 ( Tn ) shown in Table 5 represent different RN16 of the second communication device.

It can be understood that the ACK message shown in the embodiment of the present application may also be called an acknowledgment message.

305. The second communication device sends the identification information of the second communication device to the first communication device based on the first encoding manner. Correspondingly, the first communication device receives the identification information.

Exemplarily, the identification information of the second communication device may include EPC, XPC, or TID, etc., which is not limited in this embodiment of the present application. Taking the identification information including EPC or XPC as an example, for example, the second communication device may independently decide to send the EPC or XPC to the first communication device. Optionally, the second communication device may also send information indicating EPC or XPC to the first communication device, so that the first communication device may know whether the identification information sent by the second communication device is EPC or XPC based on the information indicating EPC or XPC.

In this embodiment of the present application, after the second communication device receives the ACK message, it may send identification information to the first communication device based on the first encoding manner. That is to say, the encoding manner of sending the third message by the second communication device is the same as the encoding manner of sending the identification information. Meanwhile, the time unit at which the second communication device sends the third message is the same as the time unit at which the identification information is sent.

In the embodiment of the present application, the encoding method is determined by indicating information, so that the second communication devices located in the same time unit adopt different encoding methods as much as possible, so that the first communication device can effectively recover messages from different second communication devices, effectively improve the situation of discarding information due to collisions, and improve the utilization rate of time domain resources.

Hereinafter, the encoding method involved in the embodiment of the present application will be described in detail by taking the first communication device including a reader and the second communication device including a tag as an example. For the encoding method involved in the communication method shown in FIG. 3 , refer to the following, and at the same time, refer to FIG. 3 for the communication method involved in the encoding method shown below, which will not be described in detail below.

It can be understood that the time unit shown in the embodiment of the present application means that the reader and the tag can complete the interaction process shown in FIG. 3 within one time unit; or, the reader and the tag can complete one polling within one time unit. That is to say, the embodiment of the present application does not limit the specific duration of one time unit. As long as the interaction between the reader and the tag enables the reader to obtain the identification information of the tag, it can be said that this interaction is within one time unit. For example, within a time unit, the reader may send a second message to the tag, the tag sends a third message to the reader, then the reader sends an ACK message to the tag, and the tag sends the tag's identification information to the reader. The above-mentioned second message, third message, ACK message and identification information may be called one polling, which is completed within one time unit. It can be understood that, in this embodiment of the present application, there is no limitation on whether the sending time or the receiving time of the first message needs to be within one time unit. For the description of time units reference can also be made to the above in relation to Figures 2a and 2b.

In a possible implementation manner, different encoding methods for different tags shown below may be for the same time unit. If the time units selected by the first label and the second label are the same, then in the time unit, the encoding methods determined by the first label and the second label based on preset rules may be different. In this case, by using different encoding methods for the first tag and the second tag, it can effectively ensure that the reader can correctly distinguish the third message of the first tag from the third message of the second tag, or the identification information of the first tag and the identification information of the second tag.

In another possible implementation, the different encoding methods shown below for different tags may also be for different time units. If the time units selected by the first tag and the second tag are different, then the first tag and the second tag may use different encoding methods in their selected time units.

In yet another possible implementation manner, when the time units selected by the first label and the second label are different, the first label and the second label may also use the same encoding manner.

As for the specific encoding methods used by the first label and the second label, they may be determined based on preset rules, and the description of the preset rules may refer to the following. It can be understood that the above is illustrated with the first tag and the second tag as examples, and the first tag and the second tag can be understood as the second communication device. At the same time, the number of tags that select the same time unit can include 2, 3, or 4, etc. The first tag and the second tag shown in the embodiment of the present application should not be interpreted as limiting the embodiment of the present application.

It should be noted that the following situation may also exist: at least three tags select the same time unit, two of the at least three tags determine the same encoding mode, and the remaining tags determine different encoding modes. In this case, since the encoding methods determined by the remaining tags are different, the reader can still determine the third message and/or identification information sent by the selected tags with different encoding methods.

In this embodiment of the present application, for different second communication devices, the use of different encoding methods by the second communication device can also be understood as follows: the frequency point used by the second communication device is different, or the frequency used by the second communication device is different, or the modulation frequency used by the second communication device is different, or the effect of the subcarrier used by the second communication device is different, or the frequency of the subcarrier used by the second communication device is different, or the baseband spectrum corresponding to the second communication device is different.

Exemplarily, taking the following four encoding methods specified in EPC-Gen2 UHF: FM0, Miller-2, Miller-4, and Miller-8 as examples, these four encoding methods can be shown in Figure 4a and Figure 4b. Based on Figure 4a and Figure 4b, when the tag modulates the carrier frequency of the reader with different codes and reflects to the reader, different subcarrier frequency components appear near the carrier frequency of the reader, and these subcarrier frequencies can be equal to its own baseband code rate. That is to say, different coding methods may correspond to different subcarrier effects and different subcarrier frequencies, such as the subcarrier frequencies shown in Fig. 4a and Fig. 4b.

Exemplarily, as shown in the FMO encoding manner shown in FIG. 4 a , the phase of the FMO encoding will be reversed at the boundary of each symbol. A phase flip in the middle of the symbol occurs at symbol 0. There will be two phase inversions for symbol 0, which are located at the start position of the symbol and the middle position of the symbol respectively. For symbol 1, there will only be one phase flip, at the beginning of the symbol. Exemplarily, as shown in the M=2, M=4 and M=8 coding modes shown in FIG. There will be no phase inversion within a symbol 0, but a phase inversion will occur between two consecutive symbol 0s. The Miller baseband code is multiplied by a square wave pulse sequence with a specific period to form a Miller subcarrier sequence (also called a subcarrier frequency) as shown in FIG. 4b. It can be understood that the value of M shown in the embodiment of the present application can be understood as the number of square waves included in one symbol, and the square wave includes a high level and a low level. For example, when M=2, one symbol includes two square waves, and the two square waves include two high levels and two low levels. For another example, when M=4, one symbol includes four square waves, and the four square waves include four high levels and four low levels. For another example, when M=8, one symbol includes eight square waves, and the eight square waves include eight high levels and eight low levels.

It can be understood that the embodiment of the present application does not limit specific encoding manners of FM0, the encoding manner of M=2, the encoding manner of M=4, and the encoding manner of M=8.

Fig. 4c is a schematic diagram between a coding method and a carrier frequency provided by an embodiment of the present application. As shown in Fig. 4c, the reader sends second messages to the first tag, the second tag and the third tag respectively through the carrier frequency f0. The carrier frequency f0 can also be understood as the carrier frequency sent by the reader for tag modulation or reflection. For example, the first tag modulates f0 based on miller-2 to obtain the subcarrier frequency f1, then the first tag can send the third message through the subcarrier frequency f1+carrier frequency f0. Another example is that the second tag modulates f0 based on miller-4 to obtain the subcarrier frequency f2, then the second tag can send the third message through the subcarrier frequency f2+carrier frequency f0. Another example is that the third tag obtains the subcarrier frequency f3 based on the miller-8 modulation f0, then the third tag can send the third message through the subcarrier frequency f3+carrier frequency f0. That is to say, when different tags reflect the carrier frequency and modulate their own information to the subcarrier frequency, from the frequency point of view, the modulated information can exist in the form of the subcarrier frequency near the carrier frequency of the reader, and the modulation frequency of the subcarrier is the coding rate of the tag. Wherein, the larger M is, the larger the coding rate is, and the larger the subcarrier frequency is. It can be understood that the description of the third message in this embodiment of the present application is also applicable to the identification information, and will not be described in detail here. It can be understood that, for descriptions about the respective time units of the first tag, the second tag, and the third tag, reference may be made to the above, and no further details are given here.

The center frequencies corresponding to different encoding methods are described below based on simulation results. Based on the pseudo-random sequence, it is FM0 coded or Miller subcarrier modulated, and its bit rate is 80kbps. According to the simulation results, it can be obtained that the bit rates of the four encoding methods are all 80 kbps. At the same time, it can be obtained from the spectrum simulation results:

When M=1, the center frequency of the subcarrier is 80kHz, and the occupied bandwidth is 160kHz;

When M=2, the center frequency of the subcarrier is 160kHz, and the occupied bandwidth is 320kHz;

When M=4, the center frequency of the subcarrier is 320kHz, and the occupied bandwidth is 320kHz;

When M=8, the center frequency of the subcarrier is 640kHz, and the occupied bandwidth is 320kHz.

That is to say, for different M values, the center frequencies of the subcarriers are different. Therefore, when the return signals of tags with different M values collide, according to their frequency characteristics, the reader can perform digital filtering respectively, so as to restore the signals of different tags, and then play the role of separating the collision signals. In this way, the purpose of multi-user access in the same time unit can be achieved. That is to say, if different tags adopt different codes in the uplink, multiple tags can be separated in frequency, so that the reader can receive and decode information of different frequencies at the same time. Exemplarily, when the second communication device sends the third message and/or identification information, it may modulate a square wave with a low information symbol rate by using high-speed Miller coding, where the order or type of Miller coding is M. According to the different frequency characteristics when the return signals of tags with different M values collide, the reader can filter different tags separately, thereby restoring the signals of different tags. In this way, the effect of collision signal separation can be achieved, thereby achieving the purpose of multi-user access in the radio frequency identification system. It should be noted that when the encoding methods are different, it means that the order M of the Miller encoding is different.

The indication information shown in FIG. 3 and the method for determining the first encoding mode will be described in detail below. The indication information shown in Figure 3 can be implemented in the following ways:

Implementation method one,

The indication information is used to instruct the second communication device to randomly determine the encoding mode. That is to say, the first encoding manner may be randomly determined by the second communication device; or, the first encoding manner may be determined autonomously by the second communication device. That is to say, in the method shown in FIG. 3 , the first coding manner used by the second communication device when sending the third message and/or identification information is randomly determined by it. For example, the tag may determine, according to the indication information in the first message, that it can randomly determine the encoding mode without referring to the value of M in the second message to determine the encoding mode.

In this implementation, the tag can determine the encoding method by itself without referring to the value of M in the second message to determine the encoding method. Therefore, tags (such as two tags, three tags, or four tags, etc.) in the same time unit may determine different encoding methods. Compared with the method shown in FIG. 2b , this implementation mode not only requires less changes, but is as compatible as possible with the method shown in FIG. 2b , and is also simple to implement.

Implementation method two,

The indication information is used to indicate that the encoding mode is determined based on the first sequence. That is to say, the first encoding manner is determined based on the first sequence; or, the second communication device determines the first encoding manner based on the first sequence.

With reference to the method shown in FIG. 3 , the first sequence is the sequence that the second communication device needs to report to the first communication device. For a specific description of the first sequence, reference may be made to the above method shown in FIG. 3 , which will not be described in detail here.

Exemplarily, the second communication device may determine the coding mode based on the mth bit and the nth bit in the first sequence. That is to say, the first coding manner may be determined based on the mth bit and the nth bit in the first sequence. Wherein, m is not equal to n, both m and n are less than or equal to the length of the first sequence, and both m and n are positive integers. That is to say, the second communication device may determine the coding mode based on certain two bits in the first sequence.

For example, the mth bit and the nth bit may be two consecutive bits (such as n=m+1). For another example, the mth bit and the nth bit may be the first bit and the last bit in the first sequence. For another example, the mth bit and the nth bit are two middle bits in the first sequence. Taking the bit length of the first sequence as 16 bits as an example, the two middle bits may be the 8th bit and the 9th bit. Taking the bit length of the first sequence as 15 bits as an example, the two bits in the middle position may be the 7th bit and the 8th bit, or may be the 8th bit and the 9th bit, which is not limited in this embodiment of the present application.

In this implementation manner, the values of the two bits of the mth bit and the nth bit correspond to the encoding manner. For example, the value of these two bits is 00, and the corresponding coding mode may be FM0. For another example, if the value of these two bits is 01, the corresponding encoding method may be miller-2. For another example, if the value of these two bits is 10, the corresponding encoding method may be miller-4. For another example, if the value of these two bits is 11, the corresponding encoding method may be miller-8. It can be understood that the correspondence between the values of the mth bit and the nth bit and the encoding mode shown here is only an example, and should not be construed as a limitation to this embodiment of the present application. Exemplarily, for different second communication apparatuses, values of the mth bit and the nth bit may be the same. In this implementation, the tag determines the encoding method based on its own RN16, which can reduce the collision probability of different tags in the same time unit as much as possible, and improve the utilization rate of time domain resources.

Implementation method three,

The indication information is used to indicate that the encoding mode is determined based on the energy strength of the received signal. That is to say, the first encoding method is determined based on the received signal energy strength of the second message received by the second communication device; or, the second communication device may determine the first encoding method based on the energy strength of the signal it receives. It can be understood that the received signal energy strength shown in the embodiment of the present application can also be understood as the carrier energy strength of the reader received by the tag.

Exemplarily, the second communication device may determine the coding mode based on a comparison result of the received signal energy strength of the second message with a preset threshold. For example, the first coding manner may be determined based on a comparison result between the received signal energy strength of the second message and a preset threshold.

Optionally, in a case where the received signal energy strength of the second message is greater than or equal to the first threshold, the first encoding manner includes M=8 Miller encoding manner. Optionally, in a case where the received signal energy strength of the second message is less than the first threshold and greater than or equal to the second threshold, the first encoding manner includes a Miller encoding manner of M=4. Optionally, in a case where the received signal energy strength of the second message is less than the second threshold and greater than or equal to the third threshold, the first encoding manner includes a Miller encoding manner of M=2. Optionally, when the received signal energy strength of the second message is less than the third threshold, the first encoding manner includes FMO. The first threshold is greater than the second threshold, and the second threshold is greater than the third threshold.

Exemplarily, the tag may select an encoding mode according to the energy intensity (such as represented by P _rx ) of the second message it receives. Meanwhile, the reader sets three energy intensity thresholds such as P ₁ , P ₂ and P ₃ , and P ₁ >P ₂ >P ₃ . When P _rx ≥ P ₁ , the corresponding encoding method may be miller-8. When P ₁ >P _rx ≥P ₂ , the corresponding encoding method may be miller-4. When P ₂ >P _rx ≥P ₃ , the corresponding encoding method may be miller-2. When P ₃ >P _rx , the corresponding coding mode may be FM0.

Among the four coding methods of Miller-8, miller-4, miller-2 and FM0, miller-8 has the highest subcarrier frequency and relatively high power consumption. The order of power consumption is miller-8>miller-4>miller-2>FM0. Therefore, the larger the value of M is, the more energy the tag needs to receive to send an uplink message. Therefore, through the relationship between the energy intensity and the threshold shown above, the second communication device can send the third message and the identification information in combination with the energy required by itself.

In this implementation manner, the reader does not need to explicitly indicate the encoding manner, and the tag determines the encoding manner based on the energy intensity of the signal it receives. Compared with the method shown in Fig. 2b, the modification is small, and the effect of multi-label frequency division multiplexing is achieved, and the utilization rate of time domain resources is improved.

Implementation method four,

The indication information is used to indicate to determine the encoding mode based on at least one of the second sequence or the reference sequence. For example, the indication information is used to indicate that the encoding mode is determined based on the second sequence. For another example, the indication information is used to indicate that the encoding manner is determined based on the reference sequence. For another example, the indication information is used to indicate that the encoding mode is determined based on the comparison result between the second sequence and the reference sequence. That is to say, the first coding method may be determined by the second communication device based on the second sequence; or, the first coding method may be determined based on a comparison result between the second sequence and the reference sequence; or, the first coding method may be determined based on the reference sequence. That is to say, the second communication device determines the first encoding manner based on the second sequence and/or the reference sequence.

In combination with the method shown in FIG. 3 , the second sequence may be included in the first message, and the reference sequence may be determined based on starting position information, length information, and memory content. For the description of the second sequence and the reference sequence, reference may be made to step 301 shown in FIG. 3 , which will not be described in detail here.

Optionally, the first encoding method is determined based on the i-th bit and the j-th bit in the second sequence, i is not equal to j, i and j are both less than or equal to the length of the second sequence, and both are positive integers. Optionally, the first encoding method is determined based on the p-th bit and the q-th bit in the reference sequence, p is not equal to q, both p and q are less than or equal to the length of the reference sequence, and both are positive integers. The first encoding method is determined based on the xth bit and the yth bit in the comparison result between the second sequence and the reference sequence, x is not equal to y, and both x and y are less than or equal to the length of the comparison result, and both are positive integers.

It can be understood that, for the description of the i-th bit and the j-th bit, the description of the p-th bit and the q-th bit, and the description of the x-th bit and the y-th bit, reference can be made to the description of the m-th bit and the n-th bit shown above, which will not be described in detail here.

It should be noted that the embodiments of the present application do not limit whether the values of the combinations m and n, i and j, p and q, and x and y shown above are the same. For example, m can be equal to i, n can be equal to j, or m can be equal to j, etc., which will not be listed here. It can be understood that the above mentioned m and n, i and j, p and q, x and y are examples including four coding modes, for example, two bits can determine four states, and the four states can correspond to the four coding modes. However, when the tag can use more coding methods, the tag can also determine the coding method based on more bits. Exemplarily, when the types of encoding modes that the tag can use are greater than 4 and less than or equal to 8, the tag can determine the encoding mode based on the three bits in the acquired sequence. For example, the tag can determine the encoding method based on the three bits in the first sequence; or, determine the encoding method based on the three bits in the second sequence; or determine the encoding method based on the three bits in the reference sequence; or determine the encoding method based on the three bits in the comparison result between the second sequence and the reference sequence, etc., which will not be listed here. The coding method is determined by the number of bits corresponding to the coding method, which is simple to implement, and the tag can quickly determine the coding method in a manner closer to the type of the coding method.

In the embodiment of the present application, when the reader sends the first message, the first message will include the second sequence. At the same time, the tag also needs to determine the reference sequence according to the first message. Therefore, by determining the encoding method based on the second sequence or the reference sequence or the comparison result between the second sequence and the reference sequence, not only the improvement of the first message is small, but also enables the tag to determine the encoding method.

Exemplarily, the specific content indicated by the indication information shown above may be set by the first communication device, or may also be defined by a standard. For example, the first communication device may indicate to the second communication device the specific content of the indication information in the first message through the value of M in the second message. For the method shown in FIG. 2b, M indicated by the first communication device is the same for all second communication devices. However, in the embodiment of the present application, the value of M corresponds to the content indicated by the indication information. That is, the four values of M, such as 00, 01, 10, and 11, may correspond to the above four implementation manners. For example, when the value of M is 00, the indication information is used to indicate that the second communication device can randomly determine the encoding mode. For another example, when the value of M is 01, the indication information is used to indicate that the second communication device can determine the encoding manner based on the first sequence. For another example, when the value of M is 10, the indication information is used to instruct the second communication device to determine the encoding mode based on the received signal energy strength of the second message it receives. For another example, when the value of M is 11, the indication information is used to instruct the second communication device to determine the encoding manner based on the second sequence. For another example, when the value of M is 11, the indication information is used to instruct the second communication device to determine the encoding mode based on the comparison result between the second sequence and the reference sequence. For another example, when the value of M is 11, the indication information is used to instruct the second communication apparatus to determine a coding scheme based on the reference sequence. It can be understood that the above-mentioned correspondence between the value of M and the specific content indicated by the indication information is only an example, and should not be construed as a limitation to the embodiment of the present application.

Fig. 5 is an interactive schematic diagram of another communication method provided by the embodiment of the present application. In the method shown in FIG. 5 , for the description about select, refer to the first message shown in FIG. 3 , or refer to the description about Table 1 in FIG. 2 b adaptively. For the description about the query, refer to the second message shown in FIG. 3 , or, adaptively refer to the description about Table 2a and/or Table 2b in FIG. 2b. For descriptions of RN16(f1), RN16(f2), and RN16(f3), reference may be made to the third message shown in FIG. 3 , or, reference may be made to the description of Table 3 in FIG. 2b. It can be understood that the f1, f2, and f3 shown here are used to represent the differences in the encoding methods used when sending the RN16. For example, RN16(f1) may indicate that the first tag modulates the sending subcarrier frequency to f1, and the first tag sends a message including RN16 through the subcarrier frequency f1 and the carrier frequency f0. Others are similar and will not be explained here. For the description of New ACK, refer to the ACK message shown in Figure 3, or refer to the description of Table 4 in Figure 2b for adaptation. For the description of Queryreq, refer to the description in FIG. 2b . For the descriptions of EPC(f1) to EPC(f4), refer to the identification information shown in FIG. 3 , or refer to the description about Table 5 in FIG. 2b.

As shown in FIG. 5 , the reader can send a select message through broadcast, and the select message can be used to select a tag with fixed characteristics to poll with the reader. For example, the select message may be used to select tags with fixed characteristics to enter the inventory process (for example, the reader needs to inventory the tags). Exemplarily, through the select message, the first label, the second label and the third label all belong to labels with fixed characteristics. It can be understood that for the description of how to select a tag with a fixed feature through the select message, reference may be made to the above, and details will not be detailed here.

The first tag, the second tag, and the third tag are determined by the value in the target field in the select message to determine the encoding method based on preset rules; or determine that they can use different encodings for concurrent access; or determine that they can perform frequency division multiplexing concurrent access procedures.

The reader sends a query message through broadcast, and each tag randomly selects a time unit according to the query message. For example, the time units selected by the first label and the second label are the same, and both are in the time unit where the query message is located. Thus, the first label and the second label can determine the encoding method based on a preset rule, and at the same time, the encoding methods determined by the first label and the second label are different. The first tag sends RN16 to the reader based on subcarrier frequency f1 and carrier frequency f0, and the second tag sends RN16 to the reader based on subcarrier frequency f2 and carrier frequency f0.

The reader sends a new ACK to the first tag and the second tag, and the new ACK is used to simultaneously confirm the RN16 of the first tag and the RN16 of the second tag. Thus, the first tag can send the EPC to the reader based on the subcarrier frequency f1 and the carrier frequency f0, and the second tag can send the EPC to the reader based on the subcarrier frequency f2 and the carrier frequency f0.

The reader continues polling with other tags. For example, the reader sends a queryreq message by broadcast, the third tag sends RN16 to the reader based on the subcarrier frequency f3 and carrier frequency f0, and the reader sends new ACK to the third tag. Since there is only one label in the time unit of the queryreq message, the new ACK is used to confirm the RN16 sent by the third label.

It can be understood that the embodiment of the present application does not limit whether the select message is in the same time unit as the query. For example, select may be located before the time unit of the query message, or may be located at the same time unit as the query message.

It can be understood that, for other descriptions about the method shown in FIG. 5 , reference may be made to the foregoing embodiments, and detailed descriptions are omitted here. The ellipsis in Figure 5 is the polling between the reader and the tag in other time units.

The method provided by the embodiment of this application can make different tags choose different coding methods to upload RN16 and EPC as far as possible, so that multiple tags use different frequency resources (such as subcarrier frequencies). The reader can correctly decode concurrent RN16 (or EPC) through filtering and other methods, achieving the effect of concurrent access of multiple tags in the same time slot, improving the number of tag access per unit time and the overall tag access efficiency.

It should be noted that, in the various embodiments shown above, for an implementation manner not described in detail in one embodiment, reference may be made to other embodiments. For example, the description about the encoding method involved in FIG. 3 may refer to FIG. 4a to FIG. 4c. For another example, reference may be made to FIG. 3 for the description of the RFID-based communication method shown in FIG. 4a to FIG. 4c. For another example, reference may be made to FIG. 5 for the description of the RFID-based communication method shown in FIG. 3 . The description of each message shown in FIG. 5 may refer to FIG. 3 . For another example, reference may be made to FIG. 4a to FIG. 4c for the description of the encoding manner shown in FIG. 5 , which will not be listed here.

The communication device provided by the embodiment of the present application will be introduced below.

The present application divides the communication device into functional modules according to the above method embodiments. For example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules. It should be noted that the division of modules in this application is schematic, and is only a logical function division, and there may be other division methods in actual implementation. The communication device according to the embodiment of the present application will be described in detail below with reference to FIG. 6 to FIG. 8 .

FIG. 6 is a schematic structural diagram of a communication device provided by an embodiment of the present application. As shown in FIG. 6 , the communication device includes a processing unit 601 , a receiving unit 602 and a sending unit 603 .

The communication device may be the tag shown above or a second communication device or the like. That is, the communication device can be used to execute the steps or functions executed by the tag in the method embodiments above.

a receiving unit 602, configured to receive a first message;

a receiving unit 602, further configured to receive a second message;

A sending unit 603, configured to send the third message based on the first encoding manner.

It can be understood that, for descriptions about the first message, the second message, the third message, and the first encoding manner, reference may be made to the above, and details will not be detailed here.

It can be understood that the processing unit 601 is configured to determine the third message according to the acquired first message and the second message, and send the third message based on the first encoding manner through the sending unit 603 . Regarding the relationship between the processing unit 601, the receiving unit 602, and the sending unit 603, this embodiment of the present application makes no limitation.

In a possible implementation manner, the receiving unit 602 is further configured to receive the ACK message; the sending unit 603 is further configured to send the identification information based on the first coding manner.

It can be understood that the specific descriptions of the sending unit, receiving unit, and processing unit shown in the embodiments of the present application are only examples. For the specific functions or steps performed by the sending unit, receiving unit, and processing unit, reference can be made to the above method embodiments, which will not be described in detail here. For example, the receiving unit 602 may also be configured to perform the receiving steps shown in step 301 and step 302 shown in FIG. 3 . The sending unit 603 may also be configured to execute the sending step in step 303 shown in FIG. 3 . For another example, the receiving unit 602 may also be used to perform the receiving step in step 304 shown in FIG. 3 , and the sending unit 603 may also be used to perform the sending step in step 305 shown in FIG. 3 . For another example, the processing unit 601 may also be configured to execute the encoding manners shown in FIG. 4a to FIG. 4c. It can be understood that descriptions of the processing unit 601, the receiving unit 602, and the sending unit 603 are not listed here one by one.

Reusing FIG. 6 , the above-mentioned communication device may be the reader or the first communication device shown above, or the like. That is, the communication device can be used to execute the steps or functions executed by the reader in the above method embodiments.

a sending unit 603, configured to send the first message;

a sending unit 603, further configured to send a second message;

The receiving unit 602 is configured to receive the third message.

Exemplarily, the processing unit 601 may be configured to acquire the first message and acquire the second message. Optionally, the processing unit 601 may also be configured to process the acquired third message, such as obtaining an ACK message.

In a possible implementation manner, the sending unit 603 is further configured to send an ACK message; the receiving unit 602 is further configured to receive identification information.

In each embodiment of the present application, for descriptions of the first message, the second message, the third message, the first encoding method, indication information, the first sequence, the second sequence, and the reference sequence, etc., reference may also be made to the introduction in the method embodiments above, and details will not be detailed here.

It can be understood that the specific descriptions of the sending unit, receiving unit, and processing unit shown in the embodiments of the present application are only examples. For the specific functions or steps performed by the sending unit, receiving unit, and processing unit, reference can be made to the above method embodiments, which will not be described in detail here. For example, the sending unit 603 may also be configured to execute the sending steps shown in step 301 and step 302 shown in FIG. 3 . The receiving unit 602 may also be configured to perform the receiving step in step 303 shown in FIG. 3 . For another example, the sending unit 603 may also be configured to execute the sending step in step 304 shown in FIG. 3 , and the receiving unit 602 may also be configured to execute the receiving step in step 305 shown in FIG. 3 . It can be understood that descriptions of the processing unit 601, the receiving unit 602, and the sending unit 603 are not listed here one by one.

The tags and readers of the embodiments of the present application are described above, and possible product forms of the tags and readers are introduced below. It should be understood that any form of product having the function of the tag described above in FIG. 6 , or any form of product having the function of the reader described above in FIG. 6 falls within the scope of protection of the embodiments of the present application. It should also be understood that the following introduction is only an example, and the product form of the tag and the reader in the embodiment of the present application is not limited thereto.

Exemplarily, the processing unit 601 may be one or more processors, the sending unit 603 may be a transmitter, and the receiving unit 602 may be a receiver, or the sending unit 603 and the receiving unit 602 may be integrated into one device, such as a transceiver. Alternatively, the processing unit 601 may be one or more processors (or the processing unit 601 may be one or more logic circuits), the sending unit 603 may be an output interface, and the receiving unit 602 may be an input interface, or the sending unit 603 and the receiving unit 602 may be integrated into one unit, such as an input and output interface. Details will be given below.

In a possible implementation manner, in the communication device shown in FIG. 6 , the processing unit 601 may be one or more processors, and the sending unit 603 and the receiving unit 602 may be integrated into a transceiver. In the embodiment of the present application, the processor and the transceiver may be coupled, and the connection manner of the processor and the transceiver is not limited in the embodiment of the present application.

As shown in FIG. 7 , the communication device 70 includes one or more processors 720 and a transceiver 710 .

Exemplarily, when the communication device is used to execute the steps or methods or functions performed by the above tag, the transceiver 710 is used to receive the first message and the second message; the transceiver 710 is also used to send the third message. Exemplarily, the transceiver 710 may use the processor 720 to send the third message based on the first coding manner.

When the communication device 70 is used to execute the above steps or methods or functions performed by the tag, optionally, when the tag is a passive device or a semi-active device, the processor 720 may be a baseband processor; optionally, when the tag is an active device, the processor 720 may include a baseband processor and a radio frequency processor. The processor 720 shown here is only an example, and should not be construed as limiting the embodiment of the present application.

Exemplarily, when the communication device is used to execute the steps or methods or functions performed by the above reader, the transceiver 710 is used to send the first message and the second message; the transceiver 710 is also used to receive the third message.

Exemplarily, the processor 720 may be configured to acquire the first message, the second message, and so on.

It can be understood that for the specific description of the processor and the transceiver, reference may also be made to the introduction of the processing unit, the sending unit, and the receiving unit shown in FIG. 6 , which will not be repeated here.

In various implementations of the communication device shown in FIG. 7 , the transceiver may include a receiver and a transmitter, the receiver is used to perform a function (or operation) of reception, and the transmitter is used to perform a function (or operation) of transmission. And the transceiver is used to communicate with other devices/devices through the transmission medium.

Optionally, the communication device 70 may further include one or more memories 730 for storing program instructions and/or data. The memory 730 is coupled to the processor 720 . The coupling in the embodiments of the present application is an indirect coupling or a communication connection between devices, units or modules, which may be in electrical, mechanical or other forms, and is used for information exchange between devices, units or modules. Processor 720 may cooperate with memory 730 . Processor 720 may execute program instructions stored in memory 730 .

In this embodiment of the present application, a specific connection medium among the transceiver 710, the processor 720, and the memory 730 is not limited. In the embodiment of the present application, in FIG. 7, the memory 730, the processor 720, and the transceiver 710 are connected through a bus 740. The bus is represented by a thick line in FIG. The bus can be divided into address bus, data bus, control bus and so on. For ease of representation, only one thick line is used in FIG. 7 , but it does not mean that there is only one bus or one type of bus.

In the embodiment of the present application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc., and may realize or execute the methods, steps and logic block diagrams disclosed in the embodiments of the present application. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of the methods disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor.

In the embodiment of the present application, the memory may include but not limited to hard disk drive (hard disk drive, HDD) or non-volatile memory such as solid-state drive (solid-state drive, SSD), random access memory (Random Access Memory, RAM), erasable programmable read-only memory (Erasable Programmable ROM, EPROM), read-only memory (Read-Only Memory, ROM) or portable read-only memory (Compact Disc Read-Only Memory, CD-ROM) and so on. The memory is any storage medium that can be used to carry or store program codes in the form of instructions or data structures, and can be read and/or written by a computer (such as the communication device shown in this application, etc.), but is not limited thereto. The memory in the embodiment of the present application may also be a circuit or any other device capable of implementing a storage function, and is used for storing program instructions and/or data.

The processor 720 is mainly used to process communication protocols and communication data, control the entire communication device, execute software programs, and process data of the software programs. The memory 730 is mainly used to store software programs and data. The transceiver 710 may include a control circuit and an antenna, and the control circuit is mainly used for converting a baseband signal to a radio frequency signal and processing the radio frequency signal. Antennas are mainly used to send and receive radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, and keyboards, are mainly used to receive data input by users and output data to users.

Exemplarily, when the communication device is turned on, the processor 720 can read the software program in the memory 730, interpret and execute the instructions of the software program, and process the data of the software program. Exemplarily, for an active device, when data needs to be transmitted wirelessly, the processor 720 performs baseband processing on the data to be transmitted, and then outputs the baseband signal to a radio frequency circuit, and the radio frequency circuit performs radio frequency processing on the baseband signal, and then transmits the radio frequency signal through the antenna in the form of electromagnetic waves. When data is sent to the communication device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor 720, and the processor 720 converts the baseband signal into data and processes the data. Exemplarily, for a passive device or a semi-active device, since the radio frequency processor may not be included, the input radio frequency signal may be processed by the baseband processor, or the signal processed by the baseband processor may be output by radio frequency.

In another implementation, the radio frequency circuit and antenna may be arranged independently of the processor performing baseband processing. For example, in a distributed scenario, the radio frequency circuit and antenna may be arranged remotely from the communication device.

It can be understood that the working mode of the tag or the reader in the embodiment of the present application is only an example, which should not be interpreted as a limitation to the embodiment of the present application. It can be understood that the communication device shown in the embodiment of the present application may have more components than those shown in FIG. 7 , which is not limited in the embodiment of the present application. The method performed by the processor and the transceiver shown above is only an example, and for the specific steps performed by the processor and the transceiver, reference may be made to the method introduced above.

In another possible implementation manner, in the communication device shown in FIG. 6 , the processing unit 601 may be one or more logic circuits, the sending unit 603 may be an output interface, and the receiving unit 602 may be an input interface. Alternatively, the sending unit 603 and the receiving unit 602 may be integrated into one unit, such as an input and output interface. The input-output interface is also called a communication interface, or an interface circuit, or an interface, or the like. As shown in FIG. 8 , the communication device shown in FIG. 8 includes a logic circuit 801 and an interface 802 . That is, the above-mentioned processing unit 601 can be realized by a logic circuit 801 , and the receiving unit 602 and the sending unit 603 can be realized by an interface 802 . Wherein, the logic circuit 801 may be a chip, a processing circuit, an integrated circuit or a system on chip (SoC) chip, etc., and the interface 802 may be a communication interface, an input/output interface, or a pin. Exemplarily, FIG. 8 takes the communication device as an example as a chip, and the chip includes a logic circuit 801 and an interface 802 .

In the embodiment of the present application, the logic circuit and the interface may also be coupled to each other. The embodiment of the present application does not limit the specific connection manner of the logic circuit and the interface.

Exemplarily, when the communication device is used to execute the method or function or steps performed by the above tag, the interface 802 is used to input the first message and the second message; the interface 802 is also used to output the third message.

In a possible implementation manner, the interface 802 is also used to input an ACK message and output identification information.

It can be understood that the logic circuit 801 is configured to obtain the third message according to the input first message and the second message. Optionally, the logic circuit 801 is further configured to acquire identification information according to the input ACK message.

Exemplarily, when the communication device is used to execute the method or function or steps performed by the above reader, the logic circuit 801 is used to obtain configuration information, the interface 802 is used to output the first message and the second message, and the interface 802 is also used to input the third message.

It can be understood that the logic circuit 801 may be used to obtain the first message and the second message.

In a possible implementation manner, the interface 802 is also configured to output an ACK message and input tag identification information.

It can be understood that the logic circuit 801 may be used to obtain the ACK message.

It can be understood that the communication device shown in the embodiment of the present application may implement the method provided in the embodiment of the present application in the form of hardware, or may implement the method provided in the embodiment of the present application in the form of software, which is not limited in the embodiment of the present application.

For the specific implementation manners of the various embodiments shown in FIG. 8 , reference may also be made to the above-mentioned various embodiments, which will not be described in detail here.

An embodiment of the present application also provides a wireless communication system, the wireless communication system includes a tag and a reader, and the tag and the reader can be used to execute the method in any of the foregoing embodiments.

In addition, the present application also provides a computer program, which is used to implement the operations and/or processing performed by the tag in the method provided in the present application.

The present application also provides a computer program, which is used to implement the operations and/or processing performed by the reader in the method provided in the present application.

The present application also provides a computer-readable storage medium, the computer-readable storage medium stores computer codes, and when the computer codes run on the computer, the computer executes the operations and/or processing performed by the tag in the method provided by the present application.

The present application also provides a computer-readable storage medium, in which computer code is stored, and when the computer code is run on the computer, the computer is made to perform the operations and/or processing performed by the reader in the method provided by the present application.

The present application also provides a computer program product, the computer program product includes computer code or computer program, and when the computer code or computer program is run on the computer, the operation and/or processing performed by the tag in the method provided in the present application is executed.

The present application also provides a computer program product, the computer program product includes computer code or computer program, and when the computer code or computer program is run on the computer, the operations and/or processing performed by the reader in the method provided in the present application are executed.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not implemented. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices or units, and may also be electrical, mechanical or other forms of connection.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to realize the technical effects of the solutions provided by the embodiments of the present application.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application is essentially or part of the contribution to the prior art, or all or part of the technical solution can be embodied in the form of a software product, the computer software product is stored in a readable storage medium, and includes several instructions to make a computer device (which can be a personal computer, server, or network device, etc.) execute all or part of the steps of the method described in each embodiment of the application. The above-mentioned readable storage medium includes: U disk, mobile hard disk, read-only memory (read-only memory, ROM), random access memory (random access memory, RAM), magnetic disk or optical disk and other various media that can store program codes.

The above is only a specific embodiment of the application, but the scope of protection of the application is not limited thereto. Anyone skilled in the art within the scope of the technology disclosed in this application can easily think of changes or replacements, which should be covered within the scope of protection of the application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims

A communication method based on radio frequency identification RFID, is characterized in that, described method comprises:

The tag receives a first message, where the first message is used to identify the tag, and the first message includes indication information, where the indication information is used to instruct the tag to randomly determine an encoding mode, or determine an encoding mode based on a sequence acquired by the tag, or determine an encoding mode based on received signal energy strength acquired by the tag;

The tag receives a second message, and the second message is used to indicate the tag reporting sequence;

The tag sends a third message to the reader based on the first encoding method, and the third message includes the first sequence.
The method according to claim 1, further comprising:

The tag receives a confirmation ACK message from the reader, the ACK message is used to confirm one or more of the first sequences;

The tag sends the identification information of the tag to the reader based on the first encoding manner.
The method according to claim 1 or 2, wherein the sequence obtained by the tag includes at least one of the following:

Said first sequence, second sequence or reference sequence.
The method according to any one of claims 1-3, wherein the first encoding method is determined based on any of the following:

The first encoding method is determined based on the m-th bit and the n-th bit in the first sequence, the m is not equal to the n, the m and the n are both less than or equal to the length of the first sequence, and the m and the n are positive integers;

The first encoding method is determined based on the i-th bit and the j-th bit in the second sequence, the i is not equal to the j, the i and the j are both less than or equal to the length of the second sequence, and the i and the j are positive integers;

The first encoding method is determined based on the pth bit and the qth bit in the reference sequence, the p is not equal to the q, the p and the q are both less than or equal to the length of the reference sequence, and the p and the q are positive integers;

The first encoding method is determined based on the xth bit and the yth bit in the comparison result between the second sequence and the reference sequence, the x is not equal to the y, the x and the y are both less than or equal to the length of the comparison result, and the x and the y are positive integers;

The first encoding method is determined based on a comparison result between the received signal energy strength of the second message and a preset threshold;

The first encoding manner is randomly determined by the label.
The method according to claim 4, wherein the first encoding method is determined based on a comparison result between the received signal energy strength of the second message and a preset threshold, comprising:

In the case where the received signal energy strength of the second message is greater than or equal to a first threshold, the first coding method includes a Miller coding method with M=8; or,

In the case where the received signal energy strength of the second message is less than the first threshold and greater than or equal to the second threshold, the first coding method includes a Miller coding method with M=4, and the first threshold is greater than the second threshold; or,

In the case where the received signal energy strength of the second message is less than a second threshold and greater than or equal to a third threshold, the first encoding mode includes a Miller encoding mode with M=2, and the second threshold is greater than the third threshold; or,

In a case where the received signal energy strength of the second message is less than a third threshold, the first encoding manner includes a Miller encoding manner with M=1.
The method according to any one of claims 1-5, wherein the first message further includes at least one of starting position information, length information or a second sequence, the starting position information and the length information are used to determine a reference sequence, the reference sequence is used for comparison with the second sequence, and the comparison result of the reference sequence and the second sequence is used to identify the tag.
The method according to any one of claims 1-6, wherein the first encoding method includes any of the following:

M=1 Miller coding scheme, M=2 Miller coding scheme, M=4 Miller coding scheme, M=8 Miller coding scheme.
A communication method based on radio frequency identification RFID, is characterized in that, described method comprises:

The reader sends a first message, the first message is used to identify the tag, and the first message includes indication information, the indication information is used to instruct the tag to randomly determine the encoding mode, or determine the encoding mode based on the sequence obtained by the tag, or determine the encoding mode based on the received signal energy strength obtained by the tag;

The reader sends a second message, and the second message is used to indicate the tag reporting sequence;

The reader receives a third message from the tag, the third message includes the first sequence, and the encoding method of the third message includes the first encoding method.
The method according to claim 8, wherein the reader receiving the third message from the tag comprises:

The reader receives the third messages sent by at least two of the tags, and at least two of the tags use different encoding methods when sending the third messages.
The method according to claim 8 or 9, wherein the method further comprises:

The reader sends an acknowledgment ACK message, where the ACK message is used to confirm one or more of the first sequences;

The reader receives identification information of the tag.
The method according to any one of claims 8-10, wherein the sequence obtained by the tag includes at least one of the following:

Said first sequence, second sequence or reference sequence.
The method according to any one of claims 8-11, wherein the indication information is used to indicate that determining the encoding method based on the sequence obtained from the tag includes:

The indication information is used to indicate that the encoding method is determined based on the m-th bit and the n-th bit in the first sequence, the m is not equal to the n, the m and the n are both less than or equal to the length of the first sequence, and the m and the n are positive integers; or,

The indication information is used to indicate that the encoding method is determined based on the i-th bit and the j-th bit in the second sequence, the i is not equal to the j, the i and the j are both less than or equal to the length of the second sequence, and the i and the j are positive integers; or,

The indication information is used to indicate that the encoding method is determined based on the pth bit and the qth bit in the reference sequence, the p is not equal to the q, the p and the q are both less than or equal to the length of the reference sequence, and the p and the q are positive integers; or,

The indication information is used to indicate that the encoding method is determined based on the xth bit and the yth bit in the comparison result of the second sequence and the reference sequence, the x is not equal to the y, the x and the y are both less than or equal to the length of the comparison result, and the x and the y are positive integers.
The method according to any one of claims 8-11, wherein the indication information is used to indicate that determining the encoding method based on the received signal energy strength obtained by the tag includes:

The indication information is used to indicate to determine an encoding mode based on a comparison result between the received signal energy strength of the second message and a preset threshold.
The method according to claim 13, wherein determining the encoding method based on a comparison result between the received signal energy strength of the second message and a preset threshold comprises:

In the case where the received signal energy strength of the second message is greater than or equal to the first threshold, the coding scheme determined by the tag includes a Miller coding scheme with M=8; or,

In the case where the received signal energy strength of the second message is less than the first threshold and greater than or equal to the second threshold, the coding method determined by the label includes a Miller coding method with M=4, and the first threshold is greater than the second threshold; or,

In the case where the received signal energy strength of the second message is less than a second threshold and greater than or equal to a third threshold, the encoding method determined by the label includes a Miller encoding method of M=2, and the second threshold is greater than the third threshold; or,

In a case where the received signal energy strength of the second message is less than the third threshold, the encoding manner determined by the tag includes a Miller encoding manner with M=1.
The method according to any one of claims 8-14, wherein the first message further includes at least one of starting position information, length information or a second sequence, the starting position information and the length information are used to determine a reference sequence, the reference sequence is used for comparison with the second sequence, and a comparison result between the reference sequence and the second sequence is used to identify the tag.
The method according to any one of claims 8-15, wherein the encoding method determined by the label includes any of the following:

M=1 Miller coding scheme, M=2 Miller coding scheme, M=4 Miller coding scheme, M=8 Miller coding scheme.
A label, characterized in that the label comprises:

The receiving unit is configured to receive a first message, the first message is used to identify the tag, the first message includes indication information, and the indication information is used to instruct the tag to randomly determine the encoding mode, or determine the encoding mode based on the sequence obtained by the tag, or determine the encoding mode based on the received signal energy strength obtained by the tag;

a sending unit, configured to receive a second message, where the second message is used to indicate the label reporting sequence;

The sending unit is further configured to send a third message to the reader based on the first encoding method, where the third message includes the first sequence.
The label according to claim 17, characterized in that,

The receiving unit is further configured to receive an acknowledgment ACK message from the reader, where the ACK message is used to confirm one or more of the first sequences;

The sending unit is further configured to send the identification information of the tag to the reader based on the first encoding method.
The tag according to claim 17 or 18, wherein the sequence acquired by the tag includes at least one of the following:

Said first sequence, second sequence or reference sequence.
The label according to any one of claims 17-19, wherein the first encoding method is determined based on any of the following:

The first encoding method is determined based on the m-th bit and the n-th bit in the first sequence, the m is not equal to the n, the m and the n are both less than or equal to the length of the first sequence, and the m and the n are positive integers;

The first encoding method is determined based on the i-th bit and the j-th bit in the second sequence, the i is not equal to the j, the i and the j are both less than or equal to the length of the second sequence, and the i and the j are positive integers;

The first encoding method is determined based on the pth bit and the qth bit in the reference sequence, the p is not equal to the q, the p and the q are both less than or equal to the length of the reference sequence, and the p and the q are positive integers;

The first encoding method is determined based on the xth bit and the yth bit in the comparison result between the second sequence and the reference sequence, the x is not equal to the y, the x and the y are both less than or equal to the length of the comparison result, and the x and the y are positive integers;

The first encoding method is determined based on a comparison result between the received signal energy strength of the second message and a preset threshold;

The first encoding manner is randomly determined by the label.
The tag according to claim 20, wherein the first encoding method is determined based on a comparison result between the received signal energy strength of the second message and a preset threshold value comprising:

In the case where the received signal energy strength of the second message is greater than or equal to a first threshold, the first coding method includes a Miller coding method with M=8; or,

In the case where the received signal energy strength of the second message is less than the first threshold and greater than or equal to the second threshold, the first coding method includes a Miller coding method with M=4, and the first threshold is greater than the second threshold; or,

In the case where the received signal energy strength of the second message is less than a second threshold and greater than or equal to a third threshold, the first encoding mode includes a Miller encoding mode with M=2, and the second threshold is greater than the third threshold; or,

In a case where the received signal energy strength of the second message is less than a third threshold, the first encoding manner includes a Miller encoding manner with M=1.
The tag according to any one of claims 17-21, wherein the first message further includes at least one of starting position information, length information or a second sequence, the starting position information and the length information are used to determine a reference sequence, the reference sequence is used for comparison with the second sequence, and a comparison result between the reference sequence and the second sequence is used to identify the tag.
The label according to any one of claims 17-22, wherein the first encoding method includes any of the following:

M=1 Miller coding scheme, M=2 Miller coding scheme, M=4 Miller coding scheme, M=8 Miller coding scheme.
A reader, characterized in that the reader includes:

A sending unit, configured to send a first message, where the first message is used to identify a tag, and the first message includes indication information, where the indication information is used to instruct the tag to randomly determine an encoding mode, or determine an encoding mode based on a sequence acquired by the tag, or determine an encoding mode based on received signal energy strength acquired by the tag;

The sending unit is further configured to send a second message, where the second message is used to indicate the label reporting sequence;

A receiving unit, configured to receive a third message from the tag, the third message includes the first sequence, and the coding method of the third message includes the first coding method.
The reader according to claim 24, wherein the receiving unit is specifically configured to receive the third messages sent by at least two of the tags, and at least two of the tags use different encoding methods when sending the third messages.
A reader according to claim 24 or 25, characterized in that,

The sending unit is further configured to send an acknowledgment ACK message, where the ACK message is used to confirm one or more of the first sequences;

The receiving unit is further configured to receive the identification information of the tag.
The reader according to any one of claims 24-26, wherein the sequence acquired by the tag includes at least one of the following:

Said first sequence, second sequence or reference sequence.
The reader according to any one of claims 24-27, wherein the indication information is used to indicate that the encoding method determined based on the sequence obtained by the tag includes:

The indication information is used to indicate that the encoding method is determined based on the mth bit and the nth bit in the first sequence, the m is not equal to the n, the m and the n are both less than or equal to the length of the first sequence, and the m and the n are positive integers; or,

The indication information is used to indicate that the encoding method is determined based on the i-th bit and the j-th bit in the second sequence, the i is not equal to the j, the i and the j are both less than or equal to the length of the second sequence, and the i and the j are positive integers; or,

The indication information is used to indicate that the encoding method is determined based on the pth bit and the qth bit in the reference sequence, the p is not equal to the q, the p and the q are both less than or equal to the length of the reference sequence, and the p and the q are positive integers; or,

The indication information is used to indicate that the encoding method is determined based on the xth bit and the yth bit in the comparison result between the second sequence and the reference sequence, the x is not equal to the y, the x and the y are both less than or equal to the length of the comparison result, and the x and the y are positive integers.
The reader according to any one of claims 24-28, wherein the indication information is used to indicate that determining the encoding method based on the received signal energy strength obtained by the tag includes:

The indication information is used to indicate to determine an encoding mode based on a comparison result between the received signal energy strength of the second message and a preset threshold.
The reader according to claim 29, wherein determining the encoding method based on the comparison result of the received signal energy strength of the second message with a preset threshold comprises:

In the case where the received signal energy strength of the second message is greater than or equal to the first threshold, the coding scheme determined by the label includes a Miller coding scheme with M=8; or,

In the case where the received signal energy strength of the second message is less than the first threshold and greater than or equal to the second threshold, the coding method determined by the label includes a Miller coding method with M=4, and the first threshold is greater than the second threshold; or,

In the case where the received signal energy strength of the second message is less than a second threshold and greater than or equal to a third threshold, the encoding method determined by the label includes a Miller encoding method of M=2, and the second threshold is greater than the third threshold; or,

In a case where the received signal energy strength of the second message is less than the third threshold, the encoding manner determined by the tag includes a Miller encoding manner with M=1.
The reader according to any one of claims 25-30, wherein the first message further includes at least one of starting position information, length information or a second sequence, the starting position information and the length information are used to determine a reference sequence, the reference sequence is used for comparison with the second sequence, and the comparison result between the reference sequence and the second sequence is used to identify the tag.
The reader according to any one of claims 25-31, wherein the encoding method determined by the label includes any of the following:

M=1 Miller coding scheme, M=2 Miller coding scheme, M=4 Miller coding scheme, M=8 Miller coding scheme.
A second communication device, characterized by comprising a processor and a memory;

The memory is used to store instructions;

The processor is configured to execute the instructions, so that the method described in any one of claims 1-7 is executed.
A first communication device, characterized by comprising a processor and a memory;

The memory is used to store instructions;

The processor is configured to execute the instructions, so that the method described in any one of claims 8-16 is performed.
A second communication device, characterized in that it includes a logic circuit and an interface, and the logic circuit is coupled to the interface;

The interface is used to input and/or output code instructions, and the logic circuit is used to execute the code instructions, so that the method described in any one of claims 1-7 is executed.
A first communication device, characterized in that it includes a logic circuit and an interface, and the logic circuit and the interface are coupled;

The interface is used to input and/or output code instructions, and the logic circuit is used to execute the code instructions, so that the method described in any one of claims 8-16 is executed.
A computer-readable storage medium, characterized in that the computer-readable storage medium is used to store a computer program, and when the computer program is executed, the method according to any one of claims 1-7 is executed.
A computer-readable storage medium, characterized in that the computer-readable storage medium is used to store a computer program, and when the computer program is executed, the method according to any one of claims 8-16 is executed.
A computer program, wherein when the computer program is executed, the method according to any one of claims 1-7 is executed.
A computer program, wherein when the computer program is executed, the method according to any one of claims 8-16 is executed.
A communication system, characterized by comprising a first communication device and a second communication device, the second communication device is used to execute the method according to any one of claims 1-7, and the first communication device is used to execute the method according to any one of claims 8-16.