A method of communication for a base station with a passive tag

Abstract

A method for communication between a base station and passive tags, the process is: after the tags are woken up and paired by the base station, the base station selects to group sweep multiple tags or communicate with a single tag. The tags enter a working state after receiving the selection command. In the single tag response state, the base station sends a query command to the tag. The tag sends a tag ready signal to the base station after receiving the query command. The base station returns an acknowledgement signal after receiving the tag ready signal. The tag returns a data frame after receiving the acknowledgement signal. In the multiple tag response state, the base station sends a query command and a repeated query command to the tag. The query command contains a number of inventory cycles. The tag generates a random number according to the number of inventory cycles after receiving the query command. The tag performs increment or decrement operation on the random number after receiving the query command or the repeated query command. Until the random number is zero, the tag returns a ready signal. The base station returns an acknowledgement signal to the tag after receiving the tag ready signal. The tag returns a data frame after receiving the acknowledgement signal.

Description

Technical Field

[0001] The present invention belongs to the field of communication technology, and in particular relates to a communication method between a base station and a passive RFID tag. Background Art

[0002] The rapid development of the Internet of Things (IoT) industry relies heavily on the support of ID recognition technology. However, current mainstream active tag products rely on internal batteries or external power supplies, limiting their lifespan to the performance of the power supply. This technical solution not only requires frequent battery replacement and charging maintenance, but also hinders the widespread use of active tags in a wider range of applications.

[0003] Thanks to the low cost and convenience of passive tags, RFID technology has been fully developed and applied in the past decade. However, for passive tags to be more widely used, they need to break through the limitations of traditional RFID technology.

[0004] Because RFID technology relies on radio frequency energy emitted by the reader for tag communication, its communication range is limited. Furthermore, to power the tag chip, the reader must use PIE encoding for downlink signaling, which reduces tag communication efficiency. Specifically, the shortcomings of existing technologies include: 1. The communication range of passive tags using RFID technology is limited, making it difficult to increase. 2. To ensure tag power, the reader uses low encoding efficiency. Summary of the Invention

[0005] In order to solve the above problems, the present invention proposes a novel communication method between a base station and a passive tag, which includes the following steps:

[0006] First, the passive tag collects ambient energy through the energy harvesting circuit and stores it in the energy storage element. When the passive tag does not receive any signaling, it is in a sleep state.

[0007] Then, follow the steps below to communicate between the base station and the passive tag:

[0008] 1) The base station sends a wake-up signaling to wake up the passive tags, waking up the passive tags in the coverage area, and the corresponding tags enter the pairing state;

[0009] 2) The base station sends a selection signaling to the tag, and based on the signaling, performs group scanning information collection on multiple tags, or performs point-to-point communication with a single tag;

[0010] The tag in the paired state enters the working state after receiving the corresponding selection signaling; if the tag receives the selection signaling but fails to match successfully, it will re-enter the dormant state;

[0011] 3) For successfully paired tags:

[0012] 3.1) In the single-label response state,

[0013] 3.1.1) The base station sends a query signal to the tag;

[0014] 3.1.2) After receiving the query signaling, the tag sends a tag ready signal to the base station;

[0015] 3.1.3) After receiving the tag ready signal, the base station returns a confirmation signal to the tag;

[0016] 3.1.4) After receiving the confirmation signal, the tag packages its own identification information (such as EPC code or other identity-identifying information) into a data frame and sends it back to the base station, ending the process.

[0017] 3.2) In the multi-label response state,

[0018] 3.2.1) The base station sends a query signal to the tag, which contains the inventory cycle number. After receiving the query signal, the tag generates a random number in its internal counter based on the inventory cycle number.

[0019] 3.2.2) The base station then sends repeated query signaling to the tag;

[0020] 3.2.3) After receiving the query signaling or repeated query signaling, the tag increases or decreases the random number;

[0021] If the random number does not return to zero, go to step 3.2.4);

[0022] If the random number is zero, go to step 3.2.5);

[0023] 3.2.4) If the random number does not return to zero, the tag continues to wait for the next repeated query signaling and returns to step 3.2.3);

[0024] 3.2.5) When the random number is zero, the tag returns a set of tag ready signals;

[0025] 3.2.6) After receiving the tag ready signal, the base station returns a confirmation signal to the tag;

[0026] 3.2.7) After receiving the confirmation signal, the tag packages its own identification information into a data frame and sends it back to the base station, ending the process.

[0027] Furthermore, in step 3.1), the base station communicates with a single tag, then:

[0028] In 3.1.1), the base station sends query signaling;

[0029] The query signaling contains the coded communication rate information required by the passive tag and is also used to initialize the tag and specify the inventory cycle as 1;

[0030] In 3.1.2), after receiving the query signaling, the tag returns the ready signaling; the ready signaling consists of a 16-bit random number;

[0031] In 3.1.3), after receiving the ready signaling, the base station sends a confirmation signaling to the tag; the confirmation signaling consists of the signaling code and the 16 random numbers sent in 3.1.2);

[0032] In 3.1.4), after the tag successfully verifies the confirmation signaling, it sends the data frame back to the base station, completing one communication, and then enters the sleep state.

[0033] Furthermore, in step 3.2), the base station communicates with multiple passive tags, then:

[0034] In 3.2.1), the base station sends a query signaling, and initializes the number of time slots of an inventory cycle for the tag according to the number of tags to be inventoried. M ;

[0035] After the tag receives the query signaling, M Generate a random number within the range and place it into the internal time slot counter;

[0036] In 3.2.2), the base station sends a repeated query signaling to the tag that has not successfully received the ready signaling, so that the tag adjusts the random value of the counter;

[0037] In 3.2.3), each time the tag receives a query signal or a repeated query signal, the random value in the counter is reduced by one;

[0038] In 3.2.5), when the randomizer value is zero, the tag sends a ready signaling to the base station;

[0039] In 3.2.6), after multiple tags return ready signals, the base station detects conflicts when receiving the ready signals.

[0040] If there is no conflict, the base station returns a confirmation signaling to the tag that successfully received the ready signaling;

[0041] If there is a conflict, the corresponding confirmation signaling is returned for the ready signaling that can be successfully parsed, or no confirmation signaling is returned, and then return to step 3.2.2);

[0042] A collision occurs when the base station receives ready signaling from multiple tags simultaneously;

[0043] In 3.2.7), the corresponding tag packages its own information into a data frame and sends it back to the base station, and then enters the sleep state.

[0044] In the present invention, the signaling modulation except the wake-up signaling adopts ASK modulation or PSK modulation.

[0045] During the communication process, the base station performs modulation in ASK mode, and the modulated signal adopts Manchester coding or Miller coding.

[0046] Manchester encoding uses the high-low transitions of two level signals to represent logic 0 and logic 1. A low-to-high transition represents 1, and a high-to-low transition represents 0. For example, if a two-bit binary sequence 01 is sent, the encoded level signal is high → low (0) + low → high (1).

[0047] Miller encoding is a method where a level transition at the midpoint of a bit represents a logic 1, and a level transition at this potential represents a logic 0. If logic 0s appear continuously, the level transition begins at the second start bit representing a logic 0. Each logic signal's level transition begins at the start bit. For example, if a four-bit binary sequence 1001 is sent, the level signal changes after encoding: low / high (1) → low (0) → high (0) → low / high (1).

[0048] Furthermore, when not communicating with the base station, the tag is in a dormant state, and only the tag's listening circuit is working.

[0049] Furthermore, in step 1) and step 2):

[0050] In step 1), the wake-up signaling is modulated in ASK mode;

[0051] After receiving and identifying the wake-up signaling, the passive tag enters the pairing state from the sleep mode and waits for the base station to send the selection signaling;

[0052] In step 2), the base station sends a selection signaling; the selection signaling includes the state switching of the passive tag and the electronic product coding information;

[0053] After receiving the selection signaling, the tag calls its own ID information for verification, and enters the working state after successful verification.

[0054] Furthermore, in step 3.2.2), the base station sends at most the repeated query signaling of step 3.2.2) in one inventory cycle. M times until every tag has been successfully counted.

[0055] In the present invention, the number of time slots in an inventory cycle is determined by the number of inventory cycles.

[0056] Compared with the traditional passive tag communication mode, the present invention adds a wake-up mode. The passive tag collects energy from the outside world through the energy harvesting circuit during communication to meet the communication needs. Therefore, the present invention has the following beneficial effects:

[0057] 1. The communication method of the present invention adds a wake-up mode, which reduces the power consumption of the tag and greatly increases the communication distance compared to the traditional RFID technology passive tag.

[0058] 2. In the present invention, the base station adopts a more efficient encoding method such as Manchester or Miller, which improves the communication efficiency of the passive tag. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a schematic diagram of the communication process between a base station and a single passive tag.

[0060] Figure 2 This is a workflow diagram of communication between a base station and multiple passive tags. DETAILED DESCRIPTION

[0061] In order to solve the problems existing in the prior art, expand the application scenarios of passive tags, and realize communication from base stations to passive tags, the present invention proposes a communication method between a base station and a passive tag. The communication process between the base station and the tag is as follows:

[0062] First, a wake-up signaling is sent to wake up the passive tag, and the tag enters the pairing state.

[0063] The base station then sends a selection signaling to the tag, which determines whether to perform group scanning for multiple tags or point-to-point communication with a single tag. Paired tags enter the active state after receiving the corresponding selection signaling. If the tag receives the selection signaling but fails to match, it reenters the dormant state.

[0064] In the single-tag response state, the base station sends a query signal to the tag. After receiving the query signal, the tag sends a tag-ready signal to the base station. After receiving the tag-ready signal, the base station returns a confirmation signal to the tag. After receiving the confirmation signal, the tag packages its EPC code or other information into a data frame and sends it back to the base station.

[0065] In the multi-tag response state, the base station sends a query signaling to the tag. The query signaling includes the number of time slots in the inventory cycle. After receiving the query signaling, the tag generates a random number within a certain range in its internal time slot counter based on its time slot number. The base station then sends a repeated query signaling to the tag. Upon receiving it, the tag increments or decrements the random number. When the random number reaches zero, the tag returns a set of tag ready signals. After receiving the tag ready signaling, the base station returns a confirmation signal to the tag. After receiving the confirmation signal, the tag packages its EPC code or other information into a data frame and sends it back to the base station. If the random number has not returned to zero, it continues to wait for the next query repeat signaling to adjust it. Repeated query signaling continues until no tags are missed.

[0066] The passive tag in the present invention has the function of collecting environmental energy through the energy collection circuit. When the environmental energy collection conditions (such as light energy, radio frequency energy / electromagnetic energy, thermal energy, etc.) are met, it will automatically collect energy and store it in energy storage elements such as capacitors to supply energy consumption when communicating with the base station in the sleep state.

[0067] When the passive tag does not receive relevant signaling and does not communicate with the base station, the passive tag is in sleep mode to reduce energy consumption.

[0068] There are two communication modes between the base station and the passive tag. One is the base station pairing with a single tag, and the other is the base station performing inventory scanning on multiple tags.

[0069] Figure 1 It is a schematic diagram of the communication process of pairing a base station with a single tag in the present invention.

[0070] When not communicating with the base station, the tag is in sleep mode, with only the listening circuitry operating. The base station sends a wake-up signal to the tag, modulated using ASK (Ask-key) modulation. This signal can be a low-rate, 8-bit, pre-set 01 signal, such as 11101010. After receiving and recognizing the wake-up signal, the passive tag exits sleep mode and enters pairing mode, waking up its high-precision demodulation circuitry. It then waits for the base station to send a selection signal. After the base station completes the wake-up signal, it sends a selection signal. To improve coding efficiency and interference immunity, the selection, query, and confirmation signaling (excluding the wake-up signal) can be modulated using ASK or PSK modulation, and encoded using Manchester or Miller coding. The selection signaling includes information such as the passive tag's state transition and electronic product code. Upon receiving the selection signaling, the tag retrieves its own ID information for verification. Upon successful verification, it enters active mode, activating high-energy circuitry such as sensors and the RF front-end. The base station continues to send query signals, which contain the passive tag's coded communication rate requirements. These signals are also used to initialize the tag and specify an inventory cycle. For single-tag communication, the inventory cycle is 1. After receiving the query signal, the tag returns a ready signal consisting of a 16-bit random number. After receiving the ready signal, the base station sends a confirmation signal to the tag, which can consist of a signaling code and the previously sent 16-bit random number. After successfully verifying the confirmation signal, the tag packages its electronic product code and other information, such as sensor or battery level, into a data frame and sends it back to the base station. After completing a communication session, the tag enters a sleep state.

[0071] Figure 2 It is a workflow diagram of the communication between the base station and multiple passive tags.

[0072] When a base station inventories multiple tags, it first sends a wake-up signaling signal to wake up passive tags within its coverage area and enter pairing mode. The base station then sends a selection signaling ... The base station repeats the query signaling up to M times in one round of inventorying until every tag is successfully inventoried. The value of the inventorying period M is determined by the number of tags to be inventoried.

Claims

1. A communication method between a base station and a passive tag, characterized by the following steps include: First, the passive tag collects ambient energy through the energy harvesting circuit and stores it in the energy storage element; When a passive tag does not receive any signaling, it is in sleep mode; Then, follow the steps below to communicate between the base station and the passive tag: 1) The base station sends a wake-up signaling to wake up the passive tags, waking up the passive tags in the coverage area, and the corresponding tags enter the pairing state; 2) The base station sends a selection signaling to the tag, and based on the signaling, performs group scanning information collection on multiple tags, or performs point-to-point communication with a single tag; The tag in the paired state enters the working state after receiving the corresponding selection signaling; if the tag receives the selection signaling but fails to match successfully, it will re-enter the dormant state; 3) For successfully paired tags: 3.1) In the single-label response state, 3.1.1) The base station sends a query signaling to the tag; 3.1.2) After receiving the query signaling, the tag sends a tag ready signal to the base station; 3.1.3) After receiving the tag ready signal, the base station returns a confirmation signal to the tag; 3.1.4) After receiving the confirmation signal, the tag packages its own identification information into a data frame and sends it back to the base station, ending the process. 3.2) In the multi-label response state, 3.2.1) The base station sends a query signal to the tag, which contains the inventory cycle number. After receiving the query signal, the tag generates a random number in its internal counter based on the inventory cycle number. 3.2.2) The base station then sends repeated query signaling to the tag; 3.2.3) After receiving the query signaling or repeated query signaling, the tag increases or decreases the random number; If the random number does not return to zero, go to step 3.2.4); If the random number is zero, go to step 3.2.5); 3.2.4) If the random number does not return to zero, the tag continues to wait for the next repeated query signaling and returns to step 3.2.3); 3.2.5) When the random number is zero, the tag returns a set of tag ready signals; 3.2.6) After receiving the tag ready signal, the base station returns a confirmation signal to the tag; 3.2.7) After receiving the confirmation signal, the tag packages its own identification information into a data frame and sends it back to the base station, ending the process.

2. The communication method between a base station and a passive tag according to claim 1, wherein Signaling modulation other than the wake-up signaling adopts ASK modulation or PSK modulation.

3. The communication method between a base station and a passive tag according to claim 1, wherein During the communication process, the base station performs modulation in ASK mode, and the modulated signal adopts Manchester coding or Miller coding.

4. The communication method between a base station and a passive tag according to claim 1, wherein When not communicating with the base station, the tag is in a dormant state, and only the tag's listening circuit is working.

5. The communication method between a base station and a passive tag according to claim 1, Its characteristics are that in step 1) and step 2): In step 1), the wake-up signaling is modulated in ASK mode; After receiving and identifying the wake-up signaling, the passive tag enters the pairing state from the sleep mode and waits for the base station to send the selection signaling; In step 2), the base station sends a selection signaling; the selection signaling includes the state switching of the passive tag and the electronic product coding information; After receiving the selection signaling, the tag calls its own ID information for verification, and enters the working state after successful verification.

6. The method for communication between a base station and a passive tag according to claim 1, wherein in step 3.1), the base station communicates with a single tag, then: In 3.1.1), the base station sends query signaling; The query signaling contains the coded communication rate information required by the passive tag and is also used to initialize the tag and specify the inventory cycle as 1; In 3.1.2), after receiving the query signaling, the tag returns the ready signaling; the ready signaling consists of a 16-bit random number; In 3.1.3), after receiving the ready signaling, the base station sends a confirmation signaling to the tag; the confirmation signaling consists of the signaling code and the 16 random numbers sent in 3.1.2); In 3.1.4), after the tag successfully verifies the confirmation signaling, it sends the data frame back to the base station, completing one communication, and then enters the sleep state.

7. The communication method between a base station and a passive tag according to claim 1, wherein In step 3.2), the base station communicates with multiple passive tags, then: In 3.2.1), the base station sends a query signaling, and initializes the number of time slots of an inventory cycle for the tag according to the number of tags to be inventoried. M ; After the tag receives the query signaling, M Generate a random number within the range and place it into the internal time slot counter; In 3.2.2), the base station sends a repeated query signaling to the tag that has not successfully received the ready signaling, so that the tag adjusts the random value of the counter; In 3.2.3), each time the tag receives a query signal or a repeated query signal, the random value in the counter is reduced by one; In 3.2.5), when the randomizer value is zero, the tag sends a ready signaling to the base station; In 3.2.6), after multiple tags return ready signals, the base station detects conflicts when receiving the ready signals. If there is no conflict, the base station returns a confirmation signaling to the tag that successfully received the ready signaling; If there is a conflict, the corresponding confirmation signaling is returned for the ready signaling that can be successfully parsed; or no confirmation signaling is returned, and then return to step 3.2.2); A collision occurs when the base station receives ready signaling from multiple tags simultaneously; In 3.2.7), the corresponding tag packages its own information into a data frame and sends it back to the base station, and then enters the sleep state.

8. The communication method between a base station and a passive tag according to claim 1, wherein In step 3.2.2), the base station sends at most the repeated query signaling of step 3.2.2) in one inventory cycle. M times until every tag has been successfully inventoried.

Images