Impedance modulation device, passive internet of things device and signal reception method and apparatus

Abstract

The application provides an impedance modulation device and a signal receiving method, and relates to the technical field of communication.The device comprises an antenna unit, a modulation load selection unit, and a modulation load selection circuit for selecting a load unit connected with the antenna unit from a first load unit and a second load unit; wherein the impedance of the antenna unit is Za, the impedance of the first load unit is Zc1, and the impedance of the second load unit Zc2 satisfies: 0<|(Г0 / |Г0|)+(Г1 / |Г1|)|<γ, wherein represents taking an absolute value, γ is a preset threshold value, Γ0=(Zc2‑Za * ) / (Zc2+Za * ), Γ1=(Zc1‑Za * ) / (Zc1+Za * ) and the symbol is a conjugate operator.The scheme of the application can realize modulation of a backscatter signal according to a digital signal when a carrier CW signal is received at a low cost, and can be applied in a passive Internet of Things device.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to an impedance modulation device, a signal receiving method, a device, and a storage medium. Background Technology

[0002] Currently, with the development and changes in mobile communications, many organizations have begun researching new wireless communication systems, namely 6G. The Internet of Things (IoT), based on the idea that everything can be connected to the network, aims to achieve ubiquitous connectivity and has already helped hundreds of millions of devices achieve interconnectivity. However, with the booming market growth, issues such as device cost, power supply, and battery life are becoming new challenges for IoT development. It can be said that how to achieve low-power, low-cost, and long-lifecycle terminal devices has become a key breakthrough urgently needed for the next stage of IoT development. Passive IoT utilizes environmental energy harvesting technology to convert available signals and energy from the surrounding environment into electrical energy capable of driving its own circuitry. Simultaneously, it uses a communication mode based on backscattering to transmit information to target nodes. Its most significant feature is that it does not rely on traditional power supplies, effectively solving the bottleneck problems in the development of low-power IoT and representing a key technology for the next generation of IoT development.

[0003] As the coverage of passive IoT gradually expands, the cost of terminal devices, i.e., passive IoT devices (tags), needs to be significantly reduced in application scenarios. Therefore, simple, low-cost, and effective modulation methods are particularly important in passive IoT communication systems. Here, low cost refers to reducing the production performance requirements of passive IoT devices (tags), and effective means still being able to transmit data correctly. Summary of the Invention

[0004] This application provides an impedance modulation device, a passive IoT device, a signal receiving method, a device, and a storage medium to meet the low-cost requirements of a large number of passive IoT devices.

[0005] In a first aspect, embodiments of this application provide an impedance modulation device, comprising:

[0006] Antenna unit;

[0007] A modulation load selection unit, wherein the modulation load selection circuit is used to select a load unit connected to the antenna unit from a first load unit and a second load unit;

[0008] Wherein, the impedance of the antenna element is Za, and the impedance of the first load element is Zc1, the impedance of the second load element Zc2 satisfies: 0 < |(Г0 / |Г0|) + (Г1 / |Г1|)| < γ, where This indicates taking the absolute value, where γ is a pre-set threshold, and Γ0 = (Zc2 - Za) / ( ...* ) / (Zc2+Za * ), Γ1=(Zc1-Za * ) / (Zc1+Za * ), * It is a conjugate operator.

[0009] In some embodiments, the modulation load selection unit is controlled by a binary logic output unit to switch between the first load unit and the second load unit. When the binary logic output unit outputs a first value, the first load unit is selected to be connected to the antenna unit. When the binary logic output unit outputs a second value, the second load unit is selected to be connected to the antenna unit.

[0010] In some embodiments, the modulation load selection unit includes an input terminal A, an input terminal B, a selection terminal Sel1, and an output terminal F, wherein the input terminal A is connected to the first load unit, the input terminal B is connected to the second load unit, the selection terminal Sel1 is connected to the output terminal of the binary logic output unit, and the output terminal F is connected to the antenna unit.

[0011] In some embodiments, the selection terminal Sel1 of the modulation load selection unit is connected to the two input terminals of the AND gate 1 via an inverter and the input terminal A, respectively. The selection terminal Sel1 and the input terminal B are connected to the two input terminals of the AND gate 2, respectively. The output terminals of the AND gate 1 and the AND gate 2 are connected to the two input terminals of the OR gate 1, respectively. The output terminal of the OR gate 1 serves as the output terminal F of the modulation load selection unit.

[0012] In some embodiments, the impedance modulation device further includes:

[0013] The third load unit, whose impedance Zc3 satisfies: Zc3=Za * ;

[0014] A blocking load selection unit is used to select whether to connect the output terminal F of the third load unit or the modulation load selection unit to the antenna unit.

[0015] In some embodiments, the selection terminal Sel2 of the blocking load selection unit is connected to the output terminal F of the modulation load selection unit via an inverter and is respectively connected to the two input terminals of the AND gate 3. The selection terminal Sel2 and the input terminal C are respectively connected to the two input terminals of the AND gate 4. The output terminals of the AND gate 3 and the AND gate 4 are respectively connected to the two input terminals of the OR gate 2. The output terminal F' of the OR gate 2 is connected to the antenna unit.

[0016] When the output terminal F of the modulation load selection unit needs to be connected to the antenna unit, the input of the selection terminal Sel2 is logic level "0"; when the third load unit needs to be connected to the antenna unit, the input of the selection terminal Sel2 is logic level "1".

[0017] In some embodiments, the binary logic output unit controls the output to change between the first value and the second value according to a preset training sequence, wherein the training sequence is a binary bit sequence.

[0018] In some embodiments, the impedance modulation device further includes a binary logic output unit that controls the output to switch between the first value and the second value according to the data to be transmitted, wherein the data to be transmitted is a binary bit sequence.

[0019] In some embodiments, the training sequence is set in the impedance modulation device by an external device.

[0020] In some embodiments, the preset threshold is 0.1 or 0.01, wherein the threshold of 0.1 corresponds to a first type of passive IoT device, and the threshold of 0.01 corresponds to a second type of passive IoT device.

[0021] Secondly, embodiments of this application provide a passive Internet of Things (IoT) device, which includes the impedance modulation device described above.

[0022] In some embodiments, the passive IoT device further includes:

[0023] The setting unit is used to receive the training sequence sent by the network-side device or the Reader, and set the training sequence in the impedance modulation device.

[0024] Thirdly, embodiments of this application provide a method for receiving impedance-modulated signals, applied to a network-side device or a reader, including:

[0025] Receive the backscattered signal generated by the incident CW carrier signal from the impedance modulation device in the passive IoT device;

[0026] The received backscattered signal is demodulated using BPSK to obtain a demodulated sequence of the same length as the training sequence pre-set in the impedance modulation device.

[0027] The numerical average or geometric center value of the demodulated signals corresponding to bits 0 and 1 in the training sequence are calculated respectively to obtain the position A of bit 0 and the position B of bit 1 on the constellation diagram.

[0028] In some embodiments, the method for receiving an impedance modulation signal includes:

[0029] When a demodulation signal corresponding to a non-training sequence is received, the demodulation signal is determined based on the Euclidean distance L0 from the demodulation signal to position A and the Euclidean distance L1 from the demodulation signal to position B on the constellation diagram.

[0030] In some embodiments, the method for receiving an impedance modulation signal includes:

[0031] If L0 < L1, determine that the demodulation signal is bit 0;

[0032] If L0 > L1, determine that the demodulation signal is bit 1.

[0033] Fourthly, an impedance modulation signal receiving device provided by an embodiment of the present application includes: a memory, a transceiver, and a processor, where

[0034] The memory is used to store a computer program; the transceiver is used to transmit and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations:

[0035] Receive the backscattered signal generated by the impedance modulation device in the passive Internet of Things device when it is irradiated by an incident CW carrier signal;

[0036] Perform BPSK demodulation on the received backscattered signal to obtain a demodulation sequence with the same length as the training sequence preset in the impedance modulation device;

[0037] Respectively obtain the numerical average value or geometric center value of the demodulation signals corresponding to bit 0 and bit 1 in the training sequence in the demodulation sequence, so as to obtain position A corresponding to bit 0 on the constellation diagram and position B corresponding to bit 1 on the constellation diagram.

[0038] In some embodiments, the operations further include:

[0039] When a demodulation signal corresponding to a non-training sequence is received, the demodulation signal is determined based on the Euclidean distance L0 from the demodulation signal to position A and the Euclidean distance L1 from the demodulation signal to position B on the constellation diagram.

[0040] In some embodiments,

[0041] [[ID=​​​​​In a fifth aspect, an embodiment of the present application further provides an impedance modulation signal receiving device, including:

[0044] A receiving unit, configured to receive a backscattered signal generated by an impedance modulation device in a passive Internet of Things device when receiving an incident CW carrier signal, and perform BPSK demodulation;

[0045] A separation unit, configured to separate a demodulation sequence with the same length as a training sequence preset in the impedance modulation device from the BPSK demodulation result of the receiving unit;

[0046] A processing unit, configured to respectively obtain the numerical average value or geometric center value of the demodulation signals corresponding to bit 0 and bit 1 in the training sequence in the demodulation sequence, so as to obtain the position A corresponding to bit 0 on the constellation diagram and the position B corresponding to bit 1 on the constellation diagram.

[0047] In some embodiments, the separation unit is further configured to separate a demodulation signal corresponding to transmission data from the BPSK demodulation result of the receiving unit.

[0048] In some embodiments, the device further includes:

[0049] A transmission data determination unit, configured to perform a decision on the demodulation signal according to the Euclidean distance L0 between the demodulation signal corresponding to the transmission data and position A on the constellation diagram and the Euclidean distance L1 between the demodulation signal corresponding to the transmission data and position B on the constellation diagram.

[0050] In some embodiments,

[0051] If L0 < L1, determine that the demodulation signal is bit 0;

[0052] If L0 > L1, determine that the demodulation signal is bit 1.

[0053] In a sixth aspect, an embodiment of the present application further provides a processor-readable storage medium, where the processor-readable storage medium stores a computer program, and the computer program is used to enable the processor to execute the method for receiving an impedance modulation signal.

[0054] The above technical solution of the present application has at least the following beneficial effects:

[0055] The impedance modulation device in the embodiment of the present application can effectively reduce the cost of terminal devices (tags) of passive Internet of Things. The method and device for receiving an impedance modulation signal in the embodiment of the present application, when the terminal device (tag) makes the index of the load matching circuit very low, that is, the error range is large, resulting in a large error in the constellation diagram of the received demodulation signal, eliminate the error of the demodulation signal constellation position through the detection of the training sequence, and ensure the detection reliability of the transmission data. Description of the Drawings

[0056] Figure 1 Schematic diagrams of two air interface architectures for passive Internet of Things (IoT);

[0057] Figure 2 Constellation diagram of π / 2-BPSK modulated signal;

[0058] Figure 3 Comparison of BPSK modulators and π / 2-BPSK modulators;

[0059] Figure 4 This is a schematic diagram of impedance modulation of the terminal device / tag in the prior art of this application;

[0060] Figure 5 A constellation diagram of impedance modulation signals for several terminals;

[0061] Figure 6 One of the schematic diagrams of the impedance modulation device provided in the embodiments of this application;

[0062] Figure 7 This is a schematic diagram of the internal logic circuit implementation of the modulation load selection unit provided in an embodiment of this application;

[0063] Figure 8 A second schematic diagram of the impedance modulation device provided in the embodiments of this application;

[0064] Figure 9 This is a flowchart of an impedance modulation signal receiving method provided in an embodiment of this application.

[0065] Figure 10 This is one of the structural schematic diagrams of the impedance modulation signal receiving device provided in the embodiments of this application;

[0066] Figure 11 This is a second schematic diagram of the impedance modulation signal receiving device provided in the embodiments of this application; Detailed Implementation

[0067] In this embodiment of the invention, the term "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0068] In the embodiments of this application, the term "multiple" refers to two or more, and other quantifiers are similar.

[0069] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0070] First, we will introduce the communication process of passive IoT, the π / 2 BPSK modulation method, and the implementation principle of BPSK modulation for terminal devices / tags.

[0071] (1) Communication process of passive Internet of Things

[0072] In passive IoT, there are two backscatter communication methods: (a) single-station backscatter and (b) dual-station backscatter, such as... Figure 1 As shown.

[0073] In the downlink of single-station backscatter mode, the Reader broadcasts a Carrier Wave (CW) signal and signaling information. Tags (terminal devices) can use the CW signal to transmit their information back to the Reader. The signaling information is used to activate a specific tag and transmit related signaling information. Once activated, the tag decodes the signaling information. Based on the Reader's signaling information, the tag transmits its output information by reflecting and modulating the CW signal. The Reader processes the received backscatter signal to detect the tag's output information.

[0074] In bistatic backscatter mode, there is an RF carrier wave source. The carrier wave transmitter (CWT) mainly provides the carrier signal. The reader is used to send signaling information to the tag (not shown in the figure) and receive information sent by the tag. This approach not only provides flexibility for actual deployment, but also improves the received signal strength at the reader. In addition, since the CWT and reader do not need to be in the same location, and the CWT can be closer to the tag, the tag can obtain higher incident signal power.

[0075] Currently, the modulation methods used for tags in passive IoT include OOK (On-Off Key), BPSK, and FSK. Among them, BPSK is considered a more valuable modulation method because of its better performance and simpler implementation.

[0076] (2)π / 2BPSK(pi / 2BPSK):

[0077] 5G NR supports QPSK, 16-QAM, 64-QAM, and 256-QAM modulation schemes for both uplink and downlink. Furthermore, 5G NR supports π / 2-BPSK in the uplink to further reduce the peak-to-average power ratio (PAPR) and improve the power efficiency of RF amplifiers at lower data rates.

[0078] π / 2-BPSK uses two sets of BPSK constellations offset by 90°, generated as shown in formula (1).

[0079]

[0080] The constellation point is selected based on the input data bit b[i] and bit position i, as shown in the constellation diagram. Figure 2 As shown.

[0081] Compared to traditional BPSK, when a long string of random input bits is input to both a BPSK modulator and a π / 2-BPSK modulator, the phase change of π / 2-BPSK is greater than that of BPSK. Therefore, π / 2-BPSK helps to achieve better synchronization, especially when 1s and 0s in the input sequence run for a long time.

[0082] like Figure 3 The image shows a comparison between a BPSK modulator and a π / 2-BPSK modulator.

[0083] (3) BPSK modulation implementation principle of terminal equipment (tag)

[0084] Implementation of impedance modulation in terminal devices / tags, such as Figure 4 As shown.

[0085] The terminal device / tag modulates the incident CW carrier signal by controlling and changing the impedance of the load, thereby causing changes in the amplitude / phase of the reflected signal. This process is called impedance modulation, or backscatter modulation caused by impedance switching. The antenna of the terminal device / tag reflects the CW signal alternately to achieve uplink information transmission. The reader obtains the transmitted information of the terminal device / tag by detecting changes in the backscatter signal.

[0086] The reflectance of the terminal device / tag can be expressed as:

[0087]

[0088] Where Zc is the complex load impedance of the terminal device / tag, and Za is the complex antenna impedance of the terminal device / tag. When the reflection coefficient Γ = 0, it is called the impedance absorption state, and the terminal device / tag does not generate any reflected signal. When the load impedance Zc takes two different values, Zc1 and Zc2, they can correspond to information bit 0 and information bit 1, respectively. The continuous switching of the load impedance realizes the transmission of the bit sequence. The terminal device / tag realizes the change of the reflection coefficient through the modulation of the load impedance. If the reflection coefficient corresponds to two constellation points of BPSK, then the BPSK modulation process of the CW signal is realized.

[0089] BPSK modulation can be implemented using complex switching circuits to adjust the phase of the backscattered RF carrier. BPSK has the theoretical advantage of lower reflection loss due to backscatter modulation, which is beneficial for optimizing the link budget for uplink transmissions in environmental IoT. In practice, ultra-low-power circuits may produce inaccurate phase, potentially resulting in a performance penalty for BPSK.

[0090] In the design and production process, the main consideration is the selection of Zc1 and Zc2, and the specific process is as follows:

[0091] First, obtain the impedance Za of the antenna element and the impedance Zc1 of the first load matching element; then, according to the formula Γ1=(Zc1-Za) * ) / (Zc1+Za * The reflection coefficient Γ1 is calculated; then Zc2 is designed, where Zc2 satisfies |(Г0 / |Г0|)+(Г1 / |Г1|)|<γ, where This indicates taking the absolute value, where γ is a given threshold, such as a very small number; then, according to the formula Γ0=(Zc2-Za * ) / (Zc2+Za * The reflection coefficient Γ0 is calculated. Note that it is not mandatory for the reflection coefficient Γ0 of bit 0 to be a given value and the reflection coefficient Γ1 of bit 1 to be another given value. Nor is it mandatory for there to be a relationship between the reflection coefficients Γ0 of bit 0 and the reflection coefficients of bit 1, Γ0 = -Γ1. Instead, it is only required that the backscattered signals generated by Γ0 and Γ1 are 180° out of phase, and this phase difference is allowed to have a certain error range, so as to reduce the cost of terminal equipment.

[0092] like Figure 5 As shown, a constellation diagram of the impedance modulation signal for the four terminals is presented. Figure 5-1 In the diagram, bit 0 corresponds to the constellation point where 0.12 + j * 0.52 is located, and bit 1 corresponds to the constellation point where -0.12 - j * 0.50 is located. Figure 5-2In the diagram, bit 0 corresponds to the constellation point where 0.60 + j * 0.22 is located, and bit 1 corresponds to the constellation point where -0.62 - j * 0.22 is located. Figure 5-3 In the diagram, bit 0 corresponds to the constellation point where -0.12 + j * 0.20 is located, and bit 1 corresponds to the constellation point where 0.10 - j * 0.22 is located. Figure 5-4 In the diagram, bit 0 corresponds to the constellation point where -0.12 + j * 0.20 is located, and bit 1 corresponds to the constellation point where 0.62 - j * 0.50 is located. These constellation diagrams show that the matching degree of Γ0 and Γ1 reflects the symmetry of the corresponding constellation points, while the difference between the values ​​of Γ0 and Γ1 indicates the randomness of impedance modulation. This randomness makes low-cost manufacturing of passive IoT devices possible; that is, reducing the impedance value requirements of impedance unit components can reduce costs during impedance unit production. Furthermore, by selecting and matching the Γ0 and Γ1 relationships during manufacturing, the constellation point differentiation of the impedance modulation signal can be improved, thereby enhancing signal detection performance. The randomness of the impedance data of impedance components needs to be overcome in circuit design by using training sequences.

[0093] This application provides an impedance modulation device, such as... Figure 6 As shown, it includes:

[0094] Antenna unit;

[0095] A modulation load selection unit, wherein the modulation load selection circuit is used to select a load unit connected to the antenna unit from a first load unit and a second load unit;

[0096] Wherein, the impedance of the antenna element is Za, and the impedance of the first load element is Zc1, the impedance of the second load element Zc2 satisfies: 0 < |(Г0 / |Г0|) + (Г1 / |Г1|)| < γ, where This indicates taking the absolute value, where γ is a pre-set threshold, and Γ0 = (Zc2 - Za) / ( ... * ) / (Zc2+Za * ), Γ1=(Zc1-Za * ) / (Zc1+Za * ), * It is a conjugate operator.

[0097] In some embodiments, the modulation load selection unit is controlled by a binary logic output unit to switch between the first load unit and the second load unit. When the binary logic output unit outputs a first value, the first load unit is selected to be connected to the antenna unit; when the binary logic output unit outputs a second value, the second load unit is selected to be connected to the antenna unit. It can be understood that the connection between the load unit and the antenna unit forms a loop, allowing a backscattered signal to be generated when a carrier signal of a certain frequency is received.

[0098] Since the impedance of the antenna element and the load element is related to the frequency of the carrier signal, given a fixed impedance of the antenna element, the constellation diagram of the backscattered signal is ideally positioned by satisfying the aforementioned relationship between the first and second load elements, thus facilitating signal decision and demodulation. Although the design of this embodiment is for a single frequency point, it can be easily extended to dual or multiple frequency points. The extension method involves designing matching circuits for each frequency point separately, then cascading the two circuits, and adjusting them to ensure that the matching circuits for the high-frequency point and the low-frequency point do not interfere with each other as much as possible.

[0099] In some embodiments, the modulation load selection unit includes an input terminal A, an input terminal B, a selection terminal Sel1, and an output terminal F, wherein the input terminal A is connected to the first load unit, the input terminal B is connected to the second load unit, the selection terminal Sel1 is connected to the output terminal of the binary logic output unit, and the output terminal F is connected to the antenna unit.

[0100] In some embodiments, the selection terminal Sel1 of the modulation load selection unit is connected to the two input terminals of an AND gate 1 via an inverter and input terminal A, respectively. The selection terminal Sel1 and input terminal B are connected to the two input terminals of an AND gate 2, respectively. The output terminals of AND gate 1 and AND gate 2 are connected to the two input terminals of an OR gate 1, and the output terminal of the OR gate 1 serves as the output terminal F of the modulation load selection unit. Figure 7 As shown.

[0101] In some embodiments, the impedance modulation device further includes:

[0102] The third load unit, whose impedance Zc3 satisfies: Zc3=Za * ;

[0103] A blocking load selection unit is used to select whether to connect the output terminal F of the third load unit or the modulation load selection unit to the antenna unit. When the third load unit and the antenna unit form a closed loop, the antenna unit will not generate backscatter signals, thereby avoiding interference to the outside. A schematic diagram of the impedance modulation device at this time is shown below. Figure 8 As shown.

[0104] In some embodiments, the selection terminal Sel2 of the blocking load selection unit, after passing through an inverter, is connected to the two input terminals of the AND gate 3, and the output terminal F of the modulation load selection unit is connected to the two input terminals of the AND gate 4, respectively. The output terminals of the AND gate 3 and the AND gate 4 are connected to the two input terminals of the OR gate 2, respectively. The output terminal F' of the OR gate 2 is connected to the antenna element. That is, the internal structure of the blocking load selection unit can be consistent with the internal structure of the modulation load selection unit, see [link to documentation]. Figure 7 By using this cascaded selection circuit method, it is possible to select one of the multiple input terminals to connect to the output terminal under the control of the selection terminal. N input terminals require N-1 selection terminals.

[0105] When the output terminal F of the modulation load selection unit needs to be connected to the antenna unit, the input of the selection terminal Sel2 is logic level "0"; when the third load unit needs to be connected to the antenna unit, the input of the selection terminal Sel2 is logic level "1".

[0106] In some embodiments, the binary logic output unit controls the output to switch between the first value and the second value according to a pre-set training sequence, wherein the training sequence is a binary bit sequence. In lower-cost passive IoT devices, the training sequence can be pre-set and fixed in the impedance modulation device of this embodiment. The training sequence can be generated from an M-sequence.

[0107] In some embodiments, the impedance modulation device further includes a binary logic output unit that controls the output to switch between a first value and a second value according to the data to be transmitted, wherein the data to be transmitted is a binary bit sequence. For example, the device identifier of a passive IoT device or other data that can be reported to the network can be sent to the network.

[0108] In some embodiments, the training sequence is obtained by an external device, such as a passive IoT device including the impedance modulation device, which receives the signal from a network-side device or a reader and sets it within the impedance modulation device. In some embodiments, the passive IoT device can receive signals from a network-side device or a reader and has a synchronization signal recognition function, thus it can distinguish the training sequence sent by the network-side device or the reader from the received signal and store it in a storage circuit or unit inside the impedance modulation device.

[0109] In the above scheme, both the modulation load selection unit and the blocking load selection unit are implemented using logic gate circuits. Other implementation methods, such as diodes and transistors, can also be used, allowing for low-cost implementation in passive IoT applications. In the above scheme, it is understood that the inverter connected to the selection terminals Sel1 and Sel2 can be replaced with the input of another AND gate, changing the selection logic from logic level "0" to logic level "1". In the above scheme, the logic levels "0" and "1" are not limited to specific voltage values, as long as they enable the modulation load selection unit and the blocking load selection unit to perform corresponding load switching when transitioning between logic levels "0" and "1", thus facilitating application in passive, low-energy environments.

[0110] In some embodiments, the preset threshold is 0.1 or 0.01, wherein a threshold of 0.1 corresponds to a first type of passive IoT device, and a threshold of 0.01 corresponds to a second type of passive IoT device. The first type of passive IoT device can be a common passive IoT device, and the second type of passive IoT device can be a more advanced passive IoT device. A smaller threshold indicates a higher accuracy in the impedance matching of Zc1 and Zc2, meaning the constellation positions of the generated backscattered signals are more symmetrical, which is beneficial for signal demodulation.

[0111] like Figure 9 As shown in the illustration, an impedance-modulated signal receiving method is also provided in this application embodiment, applied to a network-side device or a reader, including:

[0112] Receive the backscattered signal generated by the incident CW carrier signal from the impedance modulation device in the passive IoT device;

[0113] The received backscattered signal is demodulated using BPSK to obtain a demodulated sequence of the same length as the training sequence pre-set in the impedance modulation device.

[0114] Respectively obtain the numerical average value or geometric center value of the demodulation signals corresponding to bit 0 and bit 1 in the training sequence in the demodulation sequence, to obtain the position A corresponding to bit 0 on the constellation diagram and the position B corresponding to bit 1 on the constellation diagram.

[0115] The receiving end can sample using the BPSK symbol transmission period of the training sequence, or can sample using a higher period. The sampling process is essentially an integration process. When obtaining multiple received sampling values corresponding to the same training bit, a combining method with the same effect as integration can be used to combine the multiple sampling values into one.

[0116] In some embodiments, the method for receiving an impedance modulation signal includes:

[0117] When receiving a demodulation signal not corresponding to the training sequence, perform a decision on the demodulation signal according to the Euclidean distance L0 between the demodulation signal and position A on the constellation diagram and the Euclidean distance L1 between the demodulation signal and position B.

[0118] In some embodiments, the method for receiving an impedance modulation signal includes:

[0119] If L0 < L1, decide that the demodulation signal is bit 0;

[0120] If L0 > L1, decide that the demodulation signal is bit 1.

[0121] As Figure 10 shown, an embodiment of the present application further provides an impedance modulation signal receiving device, including: a memory, a transceiver, and a processor, where

[0122] The memory is used to store a computer program; the transceiver is used to transmit and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations:

[0123] Receive the backscattered signal generated by the impedance modulation device in the passive Internet of Things device when it is irradiated by an incident CW carrier signal;

[0124] Perform BPSK demodulation on the received backscattered signal to obtain a demodulation sequence with the same length as the training sequence preset in the impedance modulation device;

[0125] Respectively obtain the numerical average value or geometric center value of the demodulation signals corresponding to bit 0 and bit 1 in the training sequence in the demodulation sequence, to obtain the position A corresponding to bit 0 on the constellation diagram and the position B corresponding to bit 1 on the constellation diagram.

[0126] In some embodiments, the operation further includes:

[0127] When a demodulation signal corresponding to a non - said training sequence is received, the decision of the demodulation signal is made according to the Euclidean distance L0 from the demodulation signal to position A and the Euclidean distance L1 from the demodulation signal to position B on the constellation diagram.

[0128] In some embodiments,

[0129] If L0 < L1, the demodulation signal is determined to be bit 0;

[0130] If L0 > L1, the demodulation signal is determined to be bit 1.

[0131] It should be noted that the device embodiment corresponds to the above - mentioned method embodiment one by one. All implementation manners in the above - mentioned method embodiment are applicable to the device embodiment, and the same technical effects can be achieved.

[0132] Among them, in Figure 10 the bus architecture may include any number of interconnected buses and bridges. Specifically, various circuits of one or more processors represented by processor 1000 and memories represented by memory 1020 are linked together. The bus architecture can also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well - known in the art. Therefore, they will not be further described herein. The bus interface provides an interface. The transceiver 1010 can be multiple elements, that is, including a transmitter and a receiver, and provides a unit for communicating with various other devices on the transmission medium, and these transmission media include wireless channels, wired channels, optical fiber cables, and other transmission media. The processor 1000 is responsible for managing the bus architecture and general processing, and the memory 1020 can store the data used by the processor 1010 when executing operations.

[0133] The processor 1000 can be a central processing unit (CPU), an application - specific integrated circuit (ASIC), a field - programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor can also adopt a multi - core architecture.

[0134] The embodiment of the present application further provides an impedance modulation signal receiving device, as Figure 11 shown, including:

[0135] A receiving unit, configured to receive the backscattered signal generated by the impedance modulation device in the passive Internet of Things device when it is affected by the incident CW carrier signal, and perform BPSK demodulation;

[0136] A separating unit, configured to separate a demodulation sequence with the same length as a training sequence preset in the impedance modulation device from the BPSK demodulation result of a receiving unit;

[0137] A processing unit, configured to respectively calculate the numerical average value or geometric center value of the demodulation signals corresponding to bit 0 and bit 1 in the training sequence in the demodulation sequence, so as to obtain the position A corresponding to bit 0 on a constellation diagram and the position B corresponding to bit 1 on the constellation diagram.

[0138] In some embodiments, the separating unit is further configured to separate the demodulation signal corresponding to transmission data from the BPSK demodulation result of the receiving unit.

[0139] In some embodiments, the device further includes:

[0140] A transmission data determination unit, configured to perform a decision on the demodulation signal according to the Euclidean distance L0 between the demodulation signal corresponding to the transmission data and the position A on the constellation diagram and the Euclidean distance L1 between the demodulation signal and the position B.

[0141] In some embodiments,

[0142] If L0 < L1, the demodulation signal is determined to be bit 0;

[0143] If L0 > L1, the demodulation signal is determined to be bit 1.

[0144] It should be noted that the division of units in the embodiments of the present application is illustrative. It is only a logical function division, and there may be other division methods in actual implementation. In addition, in each embodiment of the present application, the functional units may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above integrated units may be implemented in the form of hardware or in the form of software functional units.

[0145] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a processor-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0146] It should be noted that the apparatus provided in this embodiment of the invention can implement all the method steps implemented in the above method embodiment and can achieve the same technical effect. Therefore, the parts and beneficial effects that are the same as those in the method embodiment will not be described in detail here.

[0147] It should be noted that the apparatus provided in this embodiment of the invention can implement all the method steps implemented in the above method embodiment and can achieve the same technical effect. Therefore, the parts and beneficial effects that are the same as those in the method embodiment will not be described in detail here.

[0148] In some embodiments of the present invention, a processor-readable storage medium is also provided, the processor-readable storage medium storing program instructions for causing the processor to perform the following steps:

[0149] Receive the backscattered signal generated by the incident CW carrier signal from the impedance modulation device in the passive IoT device;

[0150] The received backscattered signal is demodulated using BPSK to obtain a demodulated sequence of the same length as the training sequence pre-set in the impedance modulation device.

[0151] The numerical average or geometric center value of the demodulated signals corresponding to bits 0 and 1 in the training sequence are calculated respectively to obtain the position A of bit 0 and the position B of bit 1 on the constellation diagram.

[0152] When this program instruction is executed by the processor, it can achieve the above-mentioned applications, such as... Figure 9 The implementation methods shown in the network side or Reader method embodiments will not be repeated here to avoid repetition.

[0153] The technical solutions provided in this application can be applied to various systems, especially future 6G systems. For example, applicable systems include Global System for Mobile communication (GSM), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA) General Packet Radio Service (GPRS), Long Term Evolution (LTE), LTE Frequency Division Duplex (FDD), LTE Time Division Duplex (TDD), Long Term Evolution Advanced (LTE-A), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX), and 5G New Radio (NR). All of these systems include terminal equipment and network equipment. The system may also include a core network component, such as the Evolved Packet System (EPS) or the 5G system (5GS).

[0154] The network-side equipment involved in this application embodiment can be a base station, which may include multiple cells providing services to terminals. Depending on the specific application, a base station may also be called an access point, or a device in the access network that communicates with wireless terminal devices through one or more sectors on the air interface, or other names. The network device can be used to exchange received air frames with Internet Protocol (IP) packets, acting as a router between the wireless terminal device and the rest of the access network, where the rest of the access network may include an Internet Protocol (IP) communication network. The network device can also coordinate the attribute management of the air interface. For example, the network equipment involved in the embodiments of this application can be a base transceiver station (BTS) in a Global System for Mobile communications (GSM) or Code Division Multiple Access (CDMA) system, a 5G base station (gNB) in a next-generation 5G network architecture, an evolved Node B (eNB or e-NodeB) in a Long Term Evolution (LTE) system, a Home evolved Node B (HeNB), a relay node, a femto, a pico, etc., and is not limited in the embodiments of this application. In some network structures, the network equipment may include centralized unit (CU) nodes and distributed unit (DU) nodes, and the centralized unit and distributed unit may be geographically separated.

[0155] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0156] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-executable instructions. These computer-executable instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0157] These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the processor-readable memory produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0158] These processors can execute instructions that can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable device for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0159] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. An impedance modulation device, characterized in that, include: Antenna unit; A modulation load selection unit is used to select a load unit connected to the antenna unit from a first load unit and a second load unit. Wherein, the impedance of the antenna element is Za, and the impedance of the first load element is Zc1, the impedance of the second load element Zc2 satisfies: 0 < |(Г0 / |Г0|) + (Г1 / |Г1|)| < γ, where This indicates taking the absolute value, where γ is a pre-set threshold, and Γ0 = (Zc2 - Za) / ( ... * ) / (Zc2+Za * ), Γ1=(Zc1-Za * ) / (Zc1+Za * ), * It is a conjugate operator.

2. The impedance modulation device according to claim 1, characterized in that, The modulation load selection unit is controlled by a binary logic output unit to switch between the first load unit and the second load unit. When the binary logic output unit outputs a first value, the first load unit is selected to be connected to the antenna unit. When the binary logic output unit outputs a second value, the second load unit is selected to be connected to the antenna unit.

3. The impedance modulation device according to claim 2, characterized in that, The modulation load selection unit includes an input terminal A, an input terminal B, a selection terminal Sel1, and an output terminal F. The input terminal A is connected to the first load unit and the second load unit. The selection terminal Sel1 is connected to the output terminal of the binary logic output unit, and the output terminal F is connected to the antenna unit.

4. The impedance modulation device according to claim 3, characterized in that, The selection terminal Sel1 of the modulation load selection unit is connected to the two input terminals of the AND gate 1 via an inverter and the input terminal A. The selection terminal Sel1 and the input terminal B are connected to the two input terminals of the AND gate 2. The output terminals of the AND gate 1 and the AND gate 2 are connected to the two input terminals of the OR gate 1. The output terminal of the OR gate 1 serves as the output terminal F of the modulation load selection unit.

5. The impedance modulation device according to claim 2, characterized in that, Also includes: The third load unit, whose impedance Zc3 satisfies: Zc3=Za * ; A blocking load selection unit is used to select whether to connect the output terminal F of the third load unit or the modulation load selection unit to the antenna unit.

6. The impedance modulation device according to claim 5, characterized in that, The selection terminal Sel2 of the blocking load selection unit is connected to the output terminal F of the modulation load selection unit via an inverter and is connected to the two input terminals of the AND gate 3. The selection terminal Sel2 and the input terminal C are connected to the two input terminals of the AND gate 4. The output terminals of the AND gate 3 and the AND gate 4 are connected to the two input terminals of the OR gate 2. The output terminal F' of the OR gate 2 is connected to the antenna unit. When the output terminal F of the modulation load selection unit needs to be connected to the antenna unit, the input of the selection terminal Sel2 is logic level "0"; when the third load unit needs to be connected to the antenna unit, the input of the selection terminal Sel2 is logic level "1".

7. The impedance modulation device according to claims 2 to 6, characterized in that, The binary logic output unit controls the output to switch between the first value and the second value according to a pre-set training sequence, wherein the training sequence is a binary bit sequence.

8. The impedance modulation device according to claim 7, characterized in that, It also includes the binary logic output unit controlling the output to switch between the first value and the second value according to the data to be sent, wherein the data to be sent is a binary bit sequence.

9. The impedance modulation device according to claim 7, characterized in that, The training sequence is set in the impedance modulation device by an external device.

10. The impedance modulation device according to claim 1, characterized in that, The preset threshold is 0.1 or 0.01, wherein the threshold of 0.1 corresponds to the first type of passive IoT device, and the threshold of 0.01 corresponds to the second type of passive IoT device.

11. A passive Internet of Things (IoT) device, characterized in that, The passive Internet of Things device includes an impedance modulation device as described in any one of claims 1 to 10.

12. The passive Internet of Things device according to claim 11, characterized in that, It further includes: A setting unit configured to receive a training sequence sent by a network-side device or a Reader and set the training sequence in the impedance modulation device.

13. A method for receiving impedance-modulated signals, applied to network-side devices or readers, characterized in that, It includes: Receiving a backscattered signal generated by an incident CW carrier signal on the impedance modulation device in the passive Internet of Things device; Performing BPSK demodulation on the received backscattered signal to obtain a demodulation sequence having the same length as the training sequence pre-set in the impedance modulation device; Respectively obtaining the numerical average value or geometric center value of the demodulation signals corresponding to bit 0 and bit 1 in the training sequence in the demodulation sequence, to obtain the position A corresponding to bit 0 on the constellation diagram and the position B corresponding to bit 1 on the constellation diagram.

14. The method for receiving impedance-modulated signals according to claim 13, characterized in that, It includes: When receiving a demodulation signal not corresponding to the training sequence, making a decision on the demodulation signal according to the Euclidean distance L0 of the demodulation signal from position A on the constellation diagram and the Euclidean distance L1 from position B.

15. The method for receiving impedance-modulated signals according to claim 14, characterized in that, It includes: If L0 < L1, deciding that the demodulation signal is bit 0; If L0 > L1, deciding that the demodulation signal is bit 1.

16. An impedance modulation signal receiving device, characterized in that, It includes a memory, a transceiver, and a processor: The memory is used to store a computer program; the transceiver is used to transmit and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations: Receiving a backscattered signal generated by an incident CW carrier signal on the impedance modulation device in the passive Internet of Things device; Performing BPSK demodulation on the received backscattered signal to obtain a demodulation sequence having the same length as the training sequence pre-set in the impedance modulation device; Respectively obtaining the numerical average value or geometric center value of the demodulation signals corresponding to bit 0 and bit 1 in the training sequence in the demodulation sequence, to obtain the position A corresponding to bit 0 on the constellation diagram and the position B corresponding to bit 1 on the constellation diagram.

17. The apparatus according to claim 16, characterized in that, The operations further include: When receiving a demodulation signal not corresponding to the training sequence, making a decision on the demodulation signal according to the Euclidean distance L0 of the demodulation signal from position A on the constellation diagram and the Euclidean distance L1 from position B.

18. The apparatus according to claim 17, characterized in that, It includes: If L0 < L1, deciding that the demodulation signal is bit 0; If L0 > L1, deciding that the demodulation signal is bit 1.

19. An impedance modulation signal receiving device, characterized in that, It includes: A receiving unit configured to receive a backscattered signal generated by an incident CW carrier signal on the impedance modulation device in the passive Internet of Things device and perform BPSK demodulation; A separating unit configured to separate a demodulation sequence having the same length as the training sequence pre-set in the impedance modulation device from the BPSK demodulation result of the receiving unit; A processing unit configured to respectively obtain the numerical average value or geometric center value of the demodulation signals corresponding to bit 0 and bit 1 in the training sequence in the demodulation sequence, to obtain the position A corresponding to bit 0 on the constellation diagram and the position B corresponding to bit 1 on the constellation diagram.

20. The apparatus according to claim 19, characterized in that, The separating unit is further configured to separate a demodulation signal corresponding to transmission data from the BPSK demodulation result of the receiving unit.

21. The apparatus according to claim 20, characterized in that, It further includes: A transmission data determination unit for making a decision on the demodulation signal based on the Euclidean distance L0 from the demodulation signal corresponding to the transmission data to position A and the Euclidean distance L1 from the demodulation signal to position B on the constellation diagram.

22. The apparatus according to claim 19, characterized in that, Comprising: If L0 < L1, determine that the demodulation signal is bit 0; If L0 > L1, determine that the demodulation signal is bit 1.

23. A processor-readable storage medium, characterized in that, The processor-readable storage medium stores a computer program, and the computer program is used to cause the processor to execute the method according to any one of claims 13 to 15.

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