Passive internet of things communication method, apparatus and device, and storage medium

Abstract

This application provides a passive Internet of Things (IoT) communication method, apparatus, device, and storage medium, relating to the field of communication technology. The method includes, upon triggering a read request, determining a target resource block among multiple resource blocks of downlink time-frequency resources; generating a low peak-to-average power ratio (PAPR) and unmodulated target carrier based on the target resource block to power a passive tag; transmitting a downlink command signal to the passive tag based on the target resource block; transmitting the target carrier to the passive tag in response to the transmission of the downlink command signal for receiving a backscattered signal output by the passive tag; decoding the backscattered signal to obtain feedback data upon receiving it; and transmitting an acknowledgment signal to the passive tag if the feedback data passes verification. This method solves the problem of inefficient communication between base station equipment and passive tags, effectively improving the communication efficiency between base station equipment and passive tags in passive IoT.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a passive Internet of Things (IoT) communication method, apparatus, device, and storage medium. Background Technology

[0002] Due to the characteristics of passive IoT, ultra-low-power terminals such as UHF RFID (Ultra-High Frequency RFID) require a dedicated reader to interact with the network, relying on it to transmit continuous waves for power and communication. While passive IoT is a "non-electrical" IoT technology, passive tags convert radio frequency energy into DC energy by receiving electromagnetic waves in specific frequency bands, achieving low-power communication. However, deploying a large number of readers in cellular networks can easily lead to spectrum interference. Furthermore, the OFDM (Orthogonal Frequency Division Multiplexing) modulation waveform transmitted by base station equipment has a high peak-to-average power ratio (PAPR). This PAPR reduces the rectification efficiency of passive tags, hindering their power acquisition. Additionally, the cellular signals provided by base station equipment are bursty in timing, making it difficult to meet the stable, unmodulated pure carrier requirements of passive tags, resulting in inefficient communication. Summary of the Invention

[0003] This application provides a passive Internet of Things (IoT) communication method, apparatus, device, and storage medium, which solves the problem of inefficient communication between base station equipment and passive tags in related technologies. This solution can directly utilize the downlink carrier of the base station to wirelessly power, modulate commands, and read backscattered signals from passive tags without the need for additional RFID reader hardware. It can be achieved by controlling the base station equipment through software, effectively realizing communication between base station equipment and passive tags in passive IoT, improving communication efficiency and reducing communication costs.

[0004] In a first aspect, this application provides a passive Internet of Things (IoT) communication method applied to base station equipment, the passive IoT communication method comprising: When a read request is triggered, a target resource block is determined among multiple resource blocks of downlink time-frequency resources. Based on the target resource block, a low peak-to-average power ratio and unmodulated target carrier is generated to power the passive tag. Based on the target resource block, a downlink command signal is transmitted to the passive tag. The downlink command signal is obtained by modulating the target carrier. In response to the transmission operation of the downlink command signal, a target carrier is transmitted to the passive tag for receiving the backscattered signal output by the passive tag. The backscattered signal is generated by the passive tag based on the target carrier. Upon receiving a backscatter signal, the backscatter signal is decoded to obtain feedback data for the corresponding downlink command signal of the passive tag. If the feedback data passes the verification, an acknowledgment signal is transmitted to the passive tag.

[0005] Secondly, this application also provides a passive Internet of Things (IoT) communication device for use in base station equipment, the passive IoT communication device comprising: The resource configuration module is configured to determine the target resource block among multiple resource blocks of downlink time-frequency resources when a read request is triggered, and generate a low peak-to-average power ratio and unmodulated target carrier based on the target resource block to power the passive tag. The instruction output module is configured to transmit downlink instruction signals to passive tags based on target resource blocks. The downlink instruction signals are obtained by modulation based on the target carrier. The carrier illumination module is configured to transmit a target carrier toward the passive tag in response to the transmission operation of the downlink command signal, so as to receive the backscattered signal output by the passive tag, the backscattered signal being generated by the passive tag based on the target carrier; The signal receiving module is configured to decode the backscatter signal to obtain feedback data of the downlink command signal corresponding to the passive tag when it receives the backscatter signal, and to transmit an acknowledgment signal to the passive tag if the feedback data passes the verification.

[0006] Thirdly, this application also provides a base station device, which includes: One or more processors; A storage device for storing one or more programs, which, when executed by one or more processors, enable the one or more processors to implement the passive Internet of Things communication method of this application.

[0007] Fourthly, this application also provides a storage medium for storing computer-executable instructions, which, when executed by a processor, are used to execute the passive Internet of Things communication method of this application.

[0008] In this application, the base station equipment divides the target resource blocks in the downlink time-frequency resources into different time periods, and uses the target carriers of different time periods to directly use the downlink carrier of the base station to wirelessly power, modulate commands, and read backscatter signals from passive tags in the cellular network. No additional RFID reader hardware is required. It can be achieved by controlling the base station equipment through software, which effectively realizes the communication between the base station equipment and passive tags in the passive Internet of Things, improves communication efficiency, and reduces communication costs. Attached Figure Description

[0009] Figure 1 This is a schematic diagram illustrating the steps of a passive Internet of Things (IoT) communication method provided in an embodiment of this application.

[0010] Figure 2 This is a schematic diagram of the interaction architecture between a base station device and a passive tag, provided in an embodiment of this application.

[0011] Figure 3 This is a schematic diagram illustrating the steps for generating a target carrier according to an embodiment of this application.

[0012] Figure 4 This is a schematic diagram illustrating the steps for generating a target carrier according to another embodiment of this application.

[0013] Figure 5 This is a schematic diagram of the structure of a passive Internet of Things (IoT) communication device provided in an embodiment of this application.

[0014] Figure 6 This is a schematic diagram of the structure of a base station device provided in an embodiment of this application. Detailed Implementation

[0015] The embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the embodiments of this application and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, the accompanying drawings only show the parts related to the embodiments of this application, not all structures. Those skilled in the art, after reading this specification, should be able to conceive that any combination of technical features can constitute an optional implementation method, provided that the technical features do not contradict each other.

[0016] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects, not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, not limited in number; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship. In the description of this application, "multiple" means two or more, and "several" means one or more.

[0017] Due to the business characteristics of passive IoT, ultra-low power terminals in passive IoT, such as UHF RFID (ultra-high frequency RFID tags), require the assistance of a reader with read / write capabilities to interact with the network. This means they rely on a dedicated reader to transmit continuous waves for power and communication. In other words, a passive tag (also known as a passive RFID tag) is an electronic identification device powered by receiving radio frequency energy emitted by a reader. Its core module includes a power recovery circuit and a backscatter modulation circuit. The backscatter modulation circuit changes the antenna impedance to complete PSK (Phase Shift Keying) / ASK (Amplitude Shift Keying) data encoding, and then feeds the data back to the reader.

[0018] Although passive IoT is an "electricity-free" Internet of Things (IoT) technology, passive tags convert radio frequency energy into DC energy by receiving electromagnetic waves in specific frequency bands, thus achieving low-power communication. However, in cellular networks, deploying a large number of readers can easily lead to spectrum interference. Furthermore, the OFDM modulation waveforms transmitted by base station equipment have a high peak-to-average power ratio (PAPR), which can reduce the rectification efficiency of passive tags and prevent them from effectively acquiring power. In addition, the cellular signals provided by base station equipment are bursty in timing, making it difficult to meet the stable, unmodulated pure carrier requirements of passive tags, resulting in inefficient communication between base station equipment and passive tags.

[0019] In response, this application provides a passive IoT communication method, apparatus, device, and storage medium. This solution implements a passive IoT communication method in a base station device, and then uses the downlink carrier of the base station device in a cellular network to wirelessly power, modulate commands, and read backscatter signals from passive tags to transmit and receive data from the passive tags, thereby achieving communication with the passive tags.

[0020] Figure 1 The figure illustrates the steps of a passive IoT communication method according to an embodiment of this application. The passive IoT communication method provided in this embodiment is applied to a base station device. For ease of understanding, this embodiment uses data transmission and reception between the base station device and a passive tag as an example. Specifically, the base station device divides corresponding resource blocks in the downlink time-frequency resources to reconstruct the carrier waveform, and also configures read / write cycles in the frame structure to adapt to the communication protocol. The specific steps include steps S110-S140.

[0021] Step S110: When a read request is triggered, a target resource block is determined among multiple resource blocks of downlink time-frequency resources. Based on the target resource block, a target carrier with low peak-to-average power ratio and no modulation is generated to power the passive tag.

[0022] It is understandable that the read request is a request made during the operation of the base station equipment. For example, it could be a read / write request corresponding to a read instruction from a running process or other terminal device for reading tag information (such as tag number) of a passive tag, and the base station equipment would then trigger a response to the read request. Optionally, to avoid interfering with the terminal device in communication, the base station equipment's response to the read / write request can be made within the bandwidth edge range (such as the low-frequency band) of the base station equipment or in a dedicated target frequency band. It is conceivable that the frequency band communicating with the terminal device is located in the high-frequency band range of the base station equipment's bandwidth, and a guard band is separated from the aforementioned bandwidth edge range and high-frequency band range to achieve isolation.

[0023] Furthermore, communication between the base station equipment and the passive tag is achieved through the target resource block in the downlink time-frequency resources. The downlink time-frequency resources consist of multiple resource blocks, with the target resource block being one of them. It can be understood that the downlink time-frequency resources are logical resource objects managed by the MAC (Media Access Control) layer scheduler of the base station equipment. Physically, they are represented as a two-dimensional resource grid formed by the intersection of OFDM symbols in the time domain and subcarriers in the frequency domain. One OFDM symbol and one subcarrier constitute a time-frequency resource element (RE), and all OFDM symbols within a time slot and 12 consecutive subcarriers in the frequency domain constitute a resource block (RB).

[0024] Based on this target resource block, the base station equipment generates a low peak-to-average power ratio (PAPR) and unmodulated target carrier during the scheduling process. PAPR, also known as peak factor, is a waveform measurement parameter equal to the waveform amplitude divided by its effective value. As the original carrier signal that has not been modulated with the baseband signal, the target carrier generated by the waveform generator on the base station equipment has a waveform amplitude divided by its effective value that is lower than a preset ratio. This ensures that after the base station equipment transmits the target carrier to the passive tag, the passive tag can receive effective power, thereby driving the passive tag to operate.

[0025] Step S120: Based on the target resource block, transmit downlink command signals to the passive tag.

[0026] The downlink command signal is obtained by modulation based on the target carrier. That is, after generating and transmitting the target carrier, the base station equipment modulates the target carrier to obtain the downlink command signal. It is conceivable that this downlink command signal is associated with the aforementioned read request; that is, the downlink command signal, as a modulated signal, uses a baseband signal during modulation that records data used to read information carried by the passive tag, which is then sent to the passive tag as control signaling. The base station equipment generates the downlink command signal through its waveform generator, so that the passive tag receiving the signal can upload corresponding data (i.e., as feedback data). It should be noted that the method of signal modulation can be implemented with reference to relevant technologies, and will not be elaborated further in this application. In one embodiment, the base station equipment can transmit the downlink command signal using the target resource block by modulating the characteristics of the baseband signal onto the target carrier using a preset modulation method after determining the target carrier, and then transmitting the modulated downlink command signal to the air interface environment through its antenna module.

[0027] Step S130: In response to the transmission operation of the downlink command signal, transmit the target carrier to the passive tag for receiving the backscattered signal output by the passive tag.

[0028] The transmission operation of the downlink command signal can be performed via the antenna module as described in the above embodiments. Specifically, the base station equipment can determine whether the transmission operation of the downlink command signal has been completed based on the baseband transmission completion flag, the time domain time slot and resource block transmission completion sequence, and the radio frequency transmission link status. The backscatter signal refers to the signal fed back by the passive tag to the received target carrier; it is used to feed back the passive tag's own data.

[0029] For example, Figure 2 This is a schematic diagram of the interaction architecture between a base station device and a passive tag according to an embodiment of this application. As shown in the figure, after the base station device completes the downlink command control signal through the waveform generator controlled by its MAC layer scheduler, it transmits the downlink command signal in the air interface environment through a full-duplex transmit / receive isolation mechanism and its antenna. After completing the signal transmission, the base station device also retransmits the target carrier, thereby providing a continuous carrier for the passive tag to send a backscattered signal to the base station device. That is, the backscattered signal is generated by the passive tag based on the target carrier. It can be understood that the passive tag does not have an active radio frequency transmission module. It relies on the target carrier transmitted by the base station device to complete energy acquisition (i.e., powered by the base station device) and signal modulation. By changing the electromagnetic reflection characteristics of its own antenna, it loads digital data onto the reflected carrier to form a backscattered signal that is transmitted back to the base station device. That is, in the whole process, the passive tag only performs reflection modulation rather than active transmission to send backscattered signals to realize the uploading of feedback data.

[0030] Optionally, to better receive backscattered signals transmitted by passive tags, the base station equipment also activates the self-interference cancellation function of the receive link. For example, the base station equipment uses passive radio frequency devices (such as circulators, directional couplers, etc.) as the first-level physical isolation to receive backscattered signals, and generates an inverted cancellation signal through digital capacitors or diode arrays to complete analog domain cancellation before the signal enters the LNA (Low Noise Amplifier). It also selects the radio frequency tap delay line and loads the tap coefficients, and then generates a digital cancellation waveform in the time / frequency domain through baseband digital processing hardware (such as FPGA adaptive filters, etc.) to complete the final interference reduction. In this regard, under the unified control of the MAC layer scheduler, the radio frequency front-end tuning, analog delay line tap update, and digital filter iteration are synchronized through a control bus (such as SPI or PCIe), forming a closed-loop self-interference cancellation channel from the antenna port to the baseband output.

[0031] Step S140: Upon receiving a backscatter signal, decode the backscatter signal to obtain feedback data of the downlink command signal corresponding to the passive tag. If the feedback data passes the verification, transmit an acknowledgment signal to the passive tag.

[0032] Reference Figure 2 When a passive tag generates a backscattered signal, it adjusts the antenna impedance using an impedance modulation switch to achieve signal reflection. If the switch is closed, the passive tag's antenna impedance is mismatched, making it difficult for the tag to absorb signal energy and achieve strong reflection (this state corresponds to digital signal "1"). Conversely, if the switch is open, the passive tag's antenna impedance is matched, allowing it to fully absorb signal energy and achieve weak reflection (this state corresponds to digital signal "0"), thus transmitting the backscattered signal. Based on this, after receiving the backscattered signal, the base station decodes it, recovering the data carried by the signal. Optionally, the base station's baseband processing unit performs channel parameter estimation, frequency offset correction, and energy decision on the backscattered signal to restore the weak reflection phase and amplitude disturbances to the binary information carried by the backscattered signal, thus decoding the backscattered signal to obtain the feedback data provided by the passive tag. Furthermore, the base station verifies the obtained feedback data, for example, using CRC (Cyclic Redundancy Check) to verify the integrity of the feedback data. After the feedback data passes verification, the base station device also sends an acknowledgment signal to the passive tag to indicate that the data has been received, thus ending the communication. It should be noted that the base station device can also verify the feedback data using parity checking, checksum, or other methods.

[0033] As can be seen from the above scheme, this scheme can directly use the downlink carrier of the base station to wirelessly power, modulate commands, and read backscatter signals of passive tags in cellular networks. It does not require additional RFID reader hardware and can be achieved by controlling the base station equipment through software. This effectively realizes communication between the base station equipment and passive tags in passive Internet of Things, improves communication efficiency, and reduces communication costs.

[0034] In one embodiment, the downlink time-frequency resources of the base station device include a first resource block corresponding to the communication area and a second resource block corresponding to the read-write area. The first resource block is used for communication with the terminal device, and the second resource block is used for communication with the passive tag. That is, in the base station device, its communication with the terminal device and its communication with the passive tag are independent of each other. To this end, the signals transmitted by the base station device include communication subcarriers and read-write subcarriers. The communication subcarriers carry the PDSCH (Physical Downlink Shared Channel) / PDCCH (Physical Downlink Shared Channel) data of the terminal device to realize communication with the terminal device, and the read-write subcarriers are used to power, issue commands, and receive data from the passive tag to realize communication with the passive tag.

[0035] Then, a resource block corresponding to the target frequency band is selected from the second resource block as the first sub-resource block. This target frequency band is used for communication with the passive tag in the downlink time-frequency resources, and its corresponding target carrier frequency band. Furthermore, the first sub-resource block is divided into multiple time periods in the time domain as target resource blocks, so that different processing operations are performed on the target carrier in different time periods. It can be understood that the target carrier is divided into multiple segments in the time domain, each segment corresponding to a time period, and different processing operations are performed on the target carrier in each time period. Referring to the above example, the operation of the base station device powering the passive tag can be implemented through the target carrier in one of the aforementioned time periods, and the operation of the base station device sending downlink command signals to the passive tag can be implemented through the target carrier in another of the aforementioned time periods. The operation of the base station device continuously sending the target carrier to receive backscattered signals can be implemented through the target carrier in yet another of the aforementioned time periods.

[0036] Therefore, this solution divides the target resource block in the downlink time-frequency resources of the base station equipment in the time domain to achieve integrated power supply, communication and illumination in the interaction with the passive tag, which helps to stabilize signal transmission and enables the base station equipment and the passive tag to achieve efficient communication.

[0037] Optionally, the target resource block can be divided into multiple time periods in the time domain, including a first time period, a second time period, and a third time period. These three time periods are sequentially consecutive, allowing the target carrier to be divided in the time domain into a power storage segment corresponding to the first time period, a command segment corresponding to the second time period, and a pure carrier illumination segment corresponding to the third time period. Furthermore, the first, second, and third time periods are located between downlink time slots and flexible time slots in the time slot format. It is understood that in the 5G time slot format, a subframe includes several downlink time slots, one flexible time slot, and several uplink time slots. For example, during 5G communication between devices, data is transmitted through radio frames. Each radio frame includes 10 subframes, and each subframe includes several time slots. For instance, for a 60kHz subcarrier, each subframe includes 4 time slots; for a 120kHz subcarrier, each subframe includes 8 time slots. Based on this, the base station equipment processes the time periods allocated in the target resource block between downlink time slots and flexible time slots, utilizing the gaps between these time slots for processing operations corresponding to different time periods. To address this, this solution utilizes the communication resources within the base station equipment to rationally arrange communication data with the terminal equipment and read / write tasks with the passive tags in terms of time and frequency. This ensures communication with the passive tags while maintaining compatibility with communication protocols, effectively preventing interference between the base station equipment and the terminal equipment, as well as between the base station equipment and the passive tags. This improves communication efficiency and reduces communication costs.

[0038] Figure 3 This is a schematic diagram illustrating the steps of generating a target carrier according to an embodiment of this application. In one embodiment, the base station equipment generates a target carrier through a target resource block. Specifically, within the target resource block, the subcarriers are adjusted during a first time period to generate a target carrier with a low peak-to-average power ratio. The corresponding steps are as follows: Step S210: In the first time period divided in the time domain of the target resource block, activate only a single subcarrier in the frequency domain and set other subcarriers to zero, or activate a group of consecutive subcarriers and set other subcarriers to zero.

[0039] The target resource block is divided into three time periods in the time domain: a first time period, a second time period, and a third time period. These three time periods are sequentially continuous, with the first time period serving as a pre-divided continuous time range. This can be understood as the downlink time-frequency resource physically represented as a two-dimensional resource grid composed of time-domain OFDM symbols and frequency-domain subcarriers. Within a time slot, all OFDM symbols and 12 consecutive frequency-domain subcarriers form a resource block. Therefore, within the target resource block, only one subcarrier is activated within the first time period, while all other subcarriers are set to zero (i.e., all other subcarriers are inactive). Optionally, only a set of consecutive subcarriers can be activated, such as activating multiple consecutive frequency-domain subcarriers according to a preset number, while setting other subcarriers to zero.

[0040] Step S220: Configure the parameters of the activated subcarrier according to the preset waveform parameters to obtain the target carrier, and transmit the target carrier to the passive tag.

[0041] Then, according to preset waveform parameters, such as the amplitude and frequency of the activated subcarrier, the amplitude and frequency of the activated subcarrier are configured to obtain the target carrier, which is used to power the passive tag. Between downlink time slots and flexible time slots, the base station equipment generates a low peak-to-average power ratio target carrier by configuring subcarriers in the resource block, thereby improving the rectification efficiency of the passive tag to power it. This also helps the base station equipment communicate with the passive tag without affecting the communication of other terminal devices.

[0042] In related technologies, a high PAPR (peak-to-average power ratio) of a carrier originates from the time-domain superposition of N orthogonal subcarriers. That is, when the time-domain waveforms of multiple subcarriers are superimposed in phase, a high peak value is generated, resulting in a high PAPR. Optionally, Figure 4 This is a schematic diagram illustrating the steps for generating a target carrier according to another embodiment of this application. The base station equipment can also generate a target carrier with a low peak-to-average power ratio by applying a constant envelope precoding (CEP) matrix. The specific steps are as follows: Step S310: When the base station equipment transmits signals through the MIMO antenna, the OFDM symbol matrix is ​​obtained by linearly transforming the subcarriers in the OFDM symbol through the constant envelope precoding matrix.

[0043] MIMO (Multiple-Input Multiple-Output) antennas utilize multiple antennas at both the transmitting and receiving ends of the base station equipment to enhance signal transmission through spatial multiplexing and diversity techniques. OFDM symbols, as the basic unit of information transmission in OFDM technology, correspond to a continuous waveform in time and are associated with N mutually orthogonal subcarriers in the frequency domain. Constant envelope precoding, as a precoding technique to eliminate high PAPR (Peak-to-Average Power Ratio), is implemented through a pre-defined matrix (i.e., the constant envelope precoding matrix). It can be understood that the base station equipment, by employing a multi-transmit antenna system composed of MIMO antennas, provides antenna-dimensional freedom for peak cancellation, enabling the generation of carriers with low PAPR through the CEP (Constant Envelope Precoding) matrix. Specifically, in the multi-transmit antenna dimension, a linear transformation is performed using the frequency domain subcarrier-level CEP matrix to distribute the high peak energy of a single-antenna OFDM symbol across multiple transmit antennas, ensuring that the amplitude of the carrier waveform output by each transmit antenna is constant, thereby eliminating peak fluctuations in the OFDM symbol.

[0044] Step S320: Generate the target carrier according to the OFDM symbol matrix obtained after linear transformation.

[0045] The OFDM symbol matrix is ​​the matrix obtained by performing a linear transformation on the OFDM symbols using the CEP matrix.

[0046] For example, taking two transmit antennas, the base station equipment encodes and modulates the original bit stream to obtain frequency domain data symbols. These symbols are then mapped to activated subcarriers according to 5G frequency domain resource scheduling rules, resulting in single-data-stream frequency domain OFDM symbols. The base station equipment then uses a CEP matrix with constant envelope constraints to extract frequency domain data symbols from the single-data-stream OFDM symbols for each activated subcarrier and performs a linear transformation with the CEP matrix to obtain an OFDM symbol matrix for multiple transmit antennas. This achieves the dispersion and cancellation of peak values ​​from a single antenna to multiple antennas. The high peak energy of a single antenna is dispersed into the frequency domain symbols of the two transmit antennas by the CEP matrix, and the symbols between the antennas form an anti-phase superposition in the time domain, eliminating the peak value. An independent IFFT (Inverse Fast Fourier Transform) is performed row-by-row on the multi-antenna frequency domain OFDM symbol matrix. Each transmit antenna undergoes an IFFT separately to preserve the orthogonality of the OFDM subcarriers, resulting in a time-domain OFDM carrier with a constant envelope, i.e., the target carrier.

[0047] Therefore, by using a constant envelope precoding matrix to generate a target carrier with a low peak-to-average power ratio, the base station equipment can improve the rectification efficiency of passive tags, provide effective power to passive tags, and avoid wasting spectrum when generating the target carrier, thus effectively improving the utilization rate of frequency domain resources.

[0048] The target resource block is divided into a first time period, a second time period, and a third time period in the time domain. These three time periods are sequentially continuous, with the second time period serving as a pre-defined continuous time range. In one embodiment, during the generation of the downlink command signal, the base station modulates the signal within the second time period defined in the target resource block. Specifically, within the second time period defined in the time domain of the target resource block, the base station uses a preset modulation method to load control signaling onto the target carrier to generate the downlink command signal and transmits it to the passive tag. This control signaling is the data content to be transmitted. Optionally, the control signaling corresponds to data requested for reading, such as data used to read information carried by the passive tag. It can be understood that the bitstream signal corresponding to the control signaling is used as a baseband signal, and the base station loads it onto the target carrier using a preset modulation method. The preset modulation method includes amplitude modulation or direct sequence modulation, and the control signaling is the data content to be transmitted. It is understandable that amplitude modulation (AM) is a modulation method that changes the amplitude of a carrier wave according to the desired signal transmission pattern while keeping the carrier frequency constant. Based on this modulation method, the target carrier is modulated so that its amplitude changes according to the signal characteristics of the control signaling while maintaining the carrier frequency. Direct-sequence modulation (DSM), as a spread spectrum technique, distributes the signal energy evenly across the entire frequency band and spreads the signal by multiplying the data stream using a pseudo-random sequence. Specifically, the base station equipment generates a high-speed pseudo-random sequence. Both the base station equipment (transmitter) and the passive tag (receiver) are pre-configured with a high-speed pseudo-random code (such as a Barker code). The rate of this pseudo-random code is much higher than the bit rate of the original signaling. The control signaling is then XORed bit-by-bit with this high-speed pseudo-random code, thus expanding it into a long sequence of high-speed chips, i.e., the aforementioned high-speed pseudo-random sequence. Finally, the high-speed pseudo-random sequence after spread spectrum processing is loaded onto the carrier using traditional modulation methods (such as BPSK (Binary Phase Shift Keying) and QPSK (Quadrature Phase Shift Keying)) to obtain a downlink command signal for transmission to the passive tag.

[0049] In one embodiment, after transmitting the downlink command signal, the base station continues to transmit the target carrier to the passive tag for the tag to feed back the backscattered signal. To this end, the base station locks the phase and amplitude of the target carrier and transmits it to the passive tag to achieve stable and continuous carrier output. The base station also switches the current mode to full-duplex mode or FDD (Frequency Division Duplexing) reception mode to receive the backscattered signal output by the passive tag. In full-duplex mode, the base station divides the same frequency band into different sub-bands (i.e., further dividing a carrier into different smaller frequency bands) for uplink and downlink communication respectively, and the base station also activates the self-interference cancellation function of the receive link; the specific operation is as shown in the above embodiment. In FDD reception mode, the base station uses two separate, symmetrical frequencies. One frequency is dedicated to downlink transmission from the base station to other devices, and the other frequency is dedicated to uplink reception from other devices to the base station. A guard band exists between the two frequencies to ensure that the signals do not interfere with each other, thus enabling simultaneous and continuous transmission and reception.

[0050] Figure 5 This is a schematic diagram of a passive IoT communication device provided in an embodiment of this application. The device is applied to a base station device and is used to execute the passive IoT communication method provided in the above embodiment. It has functional modules for executing the method and desired effects. As shown in the figure, the passive IoT communication device includes a resource configuration module 401, an instruction output module 402, a carrier illumination module 403, and a signal receiving module 404.

[0051] Specifically, the resource configuration module 401 is configured to determine a target resource block among multiple resource blocks of downlink time-frequency resources when a read request is triggered, and generate a low peak-to-average power ratio and unmodulated target carrier based on the target resource block to power the passive tag. Command output module 402 is configured to transmit downlink command signals to passive tags based on target resource blocks, and the downlink command signals are obtained by modulation based on the target carrier. The carrier illumination module 403 is configured to transmit a target carrier to the passive tag in response to the transmission operation of the downlink command signal, so as to receive the backscattered signal output by the passive tag, the backscattered signal being generated by the passive tag based on the target carrier; The signal receiving module 404 is configured to decode the backscatter signal to obtain feedback data of the downlink command signal corresponding to the passive tag when it receives the backscatter signal, and to transmit an acknowledgment signal to the passive tag if the feedback data passes the verification.

[0052] Therefore, the passive IoT communication device of this solution, when applied in base station equipment, enables the base station equipment to directly use downlink carriers in cellular networks to wirelessly power, modulate commands, and read backscattered signals from passive tags without the need for additional RFID reader hardware. This can be achieved by controlling the base station equipment through software, effectively realizing communication between the base station equipment and passive tags in passive IoT, improving communication efficiency and reducing communication costs.

[0053] Based on the above embodiments, the downlink time-frequency resources of the base station equipment include a first resource block corresponding to the communication area and a second resource block corresponding to the read-write area. The first resource block is used for communication with the terminal equipment, and the second resource block is used for communication with the passive tag. The resource configuration module 401 is specifically configured as follows: Select the resource block corresponding to the target frequency band in the second resource block as the first sub-resource block; The first sub-resource block is divided into multiple time periods in the time domain as target resource blocks, so that different processing operations can be performed on the target carrier in different time periods.

[0054] Based on the above embodiments, the multiple time periods divided in the time domain of the target resource block include a first time period, a second time period, and a third time period. The first time period, the second time period, and the third time period are sequentially continuous, and the first time period, the second time period, and the third time period are located between the downlink time slot and the flexible time slot in the time slot format.

[0055] Based on the above embodiments, the resource configuration module 401 is further configured as follows: In the first time period divided in the time domain of the target resource block, only a single subcarrier is activated in the frequency domain while other subcarriers are set to zero, or a group of consecutive subcarriers is activated while other subcarriers are set to zero. Configure the parameters of the activated subcarrier according to the preset waveform parameters to obtain the target carrier, and transmit the target carrier to the passive tag.

[0056] Based on the above embodiments, the resource configuration module 401 is further configured as follows: When the base station equipment transmits signals through the MIMO antenna, the OFDM symbol matrix is ​​obtained by linearly transforming the subcarriers in the OFDM symbol through the constant envelope precoding matrix. The target carrier is generated according to the OFDM symbol matrix after linear transformation.

[0057] Based on the above embodiments, the instruction output module 402 is specifically configured as follows: During the second time period divided in the time domain of the target resource block, control signaling is loaded onto the target carrier using a preset modulation method to generate a downlink command signal, and the downlink command signal is transmitted to the passive tag. The preset modulation method includes amplitude modulation or direct sequence modulation, and the control signaling is the data content to be transmitted.

[0058] Based on the above embodiments, the signal receiving module 404 is specifically configured as follows: Lock onto the phase and amplitude of the target carrier and transmit the target carrier to the passive tag; Switch the current mode to full-duplex mode or FDD receive mode to receive the backscattered signal output by the passive tag.

[0059] It is worth noting that in the above embodiments, the functional modules are divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional module are only for easy differentiation and are not used to limit the scope of protection of this application.

[0060] Figure 6 This is a schematic diagram of a base station device provided in an embodiment of this application. It is used to execute the passive IoT communication method provided in the above embodiment, and has corresponding functional modules and beneficial effects for executing the method. As shown in the figure, the base station device includes a processor 501, a memory 502, an input device 503, and an output device 504. The number of processors 501 can be one or more; the figure shows one processor 501 as an example. The processor 501, memory 502, input device 503, and output device 504 can be connected via a bus or other means; the figure shows a connection via a bus as an example. The memory 502, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the passive IoT communication method in the embodiments of this application. The processor 501 executes various corresponding functional applications and data processing by running the software programs, instructions, and modules stored in the memory 502, thereby realizing the above-mentioned passive IoT communication method.

[0061] The memory 502 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function; the data storage area may store data recorded or created during use. Furthermore, the memory 502 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 502 may further include a memory remotely located relative to the processor 501, which can be connected to a server via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0062] The input device 503 can be used to input corresponding digital or character information to the processor 501, and to generate key signal inputs related to the user settings and function control of the device; the output device 504 can be used to send or display key signal outputs related to the user settings and function control of the device.

[0063] This application also provides a storage medium storing computer-executable instructions, which, when executed by a processor, are used to perform related operations in the passive IoT communication method provided in any embodiment of this application.

[0064] Computer-readable storage media include both permanent and non-permanent, removable and non-removable media, and information storage can be achieved by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0065] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0066] Note that the above are merely preferred embodiments and the technical principles employed in this application. Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application, the scope of which is determined by the scope of the appended claims.

Claims

1. A passive Internet of Things (IoT) communication method, characterized in that, The passive IoT communication method, applied to base station equipment, includes: When a read request is triggered, a target resource block is determined among multiple resource blocks of downlink time-frequency resources. Based on the target resource block, a low peak-to-average power ratio and unmodulated target carrier is generated to power the passive tag. Based on the target resource block, a downlink command signal is transmitted to the passive tag, the downlink command signal being modulated based on the target carrier; In response to the transmission operation of the downlink command signal, the target carrier is transmitted to the passive tag for receiving the backscattered signal output by the passive tag, the backscattered signal being generated by the passive tag based on the target carrier; Upon receiving the backscatter signal, the backscatter signal is decoded to obtain feedback data corresponding to the downlink command signal of the passive tag. If the feedback data passes the verification, an acknowledgment signal is transmitted to the passive tag.

2. The passive IoT communication method according to claim 1, characterized in that, The downlink time-frequency resources of the base station equipment include a first resource block corresponding to the communication area and a second resource block corresponding to the read-write area. The first resource block is used to communicate with the terminal equipment, and the second resource block is used to communicate with the passive tag. The step of determining the target resource block among multiple resource blocks of downlink time-frequency resources includes: In the second resource block, a resource block corresponding to the target frequency band is selected as the first sub-resource block; The first sub-resource block is divided into multiple time periods in the time domain as the target resource block, so that different processing operations are performed on the target carrier in different time periods.

3. The passive IoT communication method according to claim 2, characterized in that, The target resource block is divided into multiple time periods in the time domain, including a first time period, a second time period, and a third time period. The first time period, the second time period, and the third time period are sequentially continuous, and the first time period, the second time period, and the third time period are located between the downlink time slot and the flexible time slot in the time slot format.

4. The passive Internet of Things communication method according to any one of claims 1-3, characterized in that, The step of generating a low peak-to-average power ratio and unmodulated target carrier to power passive tags based on the target resource block includes: In the first time period divided in the time domain of the target resource block, only a single subcarrier is activated in the frequency domain while other subcarriers are set to zero, or a group of consecutive subcarriers is activated while other subcarriers are set to zero. Configure the parameters of the activated subcarrier according to the preset waveform parameters to obtain the target carrier, and transmit the target carrier to the passive tag.

5. The passive Internet of Things communication method according to any one of claims 1-3, characterized in that, The step of generating a low peak-to-average power ratio target carrier based on the target resource block to power passive tags includes: When the base station equipment transmits signals through a MIMO antenna, the OFDM symbol matrix is ​​obtained by linearly transforming the subcarriers in the OFDM symbol using a constant envelope precoding matrix. The target carrier is generated according to the OFDM symbol matrix obtained after linear transformation.

6. The passive IoT communication method according to claim 1, characterized in that, The step of transmitting a downlink command signal to the passive tag based on the target resource block includes: During the second time period divided in the time domain of the target resource block, control signaling is loaded onto the target carrier using a preset modulation scheme to generate the downlink command signal, and the downlink command signal is transmitted to the passive tag; The preset modulation method includes amplitude modulation or direct sequence modulation, and the control signaling is the data content to be transmitted.

7. The passive IoT communication method according to claim 1 or 6, characterized in that, The step of transmitting the target carrier to the passive tag in response to the transmission of the downlink command signal, for receiving the backscattered signal output by the passive tag, includes: Lock the phase and amplitude of the target carrier, and transmit the target carrier to the passive tag; Switch the current mode to full-duplex mode or FDD receive mode to receive the backscattered signal output by the passive tag.

8. A passive Internet of Things (IoT) communication device, characterized in that, The passive IoT communication device, applied to base station equipment, includes: The resource configuration module is configured to determine a target resource block among multiple resource blocks of downlink time-frequency resources when a read request is triggered, and generate a low peak-to-average power ratio and unmodulated target carrier based on the target resource block to power the passive tag. The instruction output module is configured to transmit a downlink instruction signal to the passive tag based on the target resource block, wherein the downlink instruction signal is modulated based on the target carrier. The carrier illumination module is configured to transmit the target carrier to the passive tag in response to the transmission operation of the downlink command signal, for receiving the backscattered signal output by the passive tag, the backscattered signal being generated by the passive tag based on the target carrier; The signal receiving module is configured to, upon receiving the backscatter signal, decode the backscatter signal to obtain feedback data corresponding to the downlink command signal of the passive tag, and, if the feedback data passes verification, transmit an acknowledgment signal to the passive tag.

9. A base station device, characterized in that, include: One or more processors; A storage device for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the passive Internet of Things communication method as described in any one of claims 1-7.

10. A storage medium for storing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a processor, are used to perform the passive Internet of Things communication method as described in any one of claims 1-7.

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