CN114679203A

CN114679203A - Internet of things communication system and method

Info

Publication number: CN114679203A
Application number: CN202210268984.6A
Authority: CN
Inventors: 丁宝国; 杨子; 刘重军; 曹艳艳; 睢菲菲; 杨波; 区洋; 黄锦华
Original assignee: Comba Network Systems Co Ltd
Current assignee: Comba Network Systems Co Ltd
Priority date: 2022-03-18
Filing date: 2022-03-18
Publication date: 2022-06-28
Anticipated expiration: 2042-03-18
Also published as: CN114679203B

Abstract

The application relates to a communication system and a method of the Internet of things. The tag radio frequency transmitting module is used for continuously transmitting a carrier signal; the carrier signal is a carrier signal of a carrier channel. The label radio frequency receiving module is used for receiving the carrier signal and estimating the frequency offset between the received carrier signal and the carrier signal sent by the label radio frequency transmitting module. The label radio frequency transmitting module is used for sending a label checking instruction to the electronic label through the bearing channel. The tag radio frequency receiving module is used for receiving a tag reply signal sent by the electronic tag and carrying out carrier wave elimination processing on the tag reply signal based on the frequency offset so as to obtain tag information. The application can greatly improve the receiving sensitivity of the label information and realize remote checking.

Description

Internet of things communication system and method

Technical Field

The application relates to the technical field of Internet of things, in particular to a communication system and method of the Internet of things.

Background

The Ultra High Frequency (UHF) RFID (Radio Frequency Identification) technology has the advantages of being capable of reading a plurality of tags at one time, strong in penetrability, capable of reading and writing for multiple times, large in data memory capacity and the like, and the passive electronic tag has the characteristics of being low in cost, small in size, convenient to use, high in reliability, long in service life and the like. With the price reduction of electronic tags, the UHF RFID technology will be more widely applied in various industries. In the process of continuously expanding the application field of UHF RFID, the market has urgent need for a long-distance UHF RFID system with the working distance of more than 50 meters, so that higher requirements are put forward for the receiving sensitivity of a UHF RFID reader-writer. To meet the above requirement, it is highly desirable to provide a UHF RFID system with high receiving sensitivity, so that the working distance of the system can meet the requirement of long-distance transmission.

Disclosure of Invention

Therefore, in order to solve the technical problems, an internet of things communication system and method which have high receiving sensitivity and can meet the requirement of long-distance transmission are needed.

In a first aspect, an embodiment of the present application provides an internet of things communication system, where the system includes a first gateway and a second gateway, where the first gateway includes a tag radio frequency receiving module, and the second gateway includes a tag radio frequency transmitting module;

The label radio frequency transmitting module is used for continuously transmitting a carrier signal; wherein, the carrier signal is a carrier signal of a carrier channel;

the label radio frequency receiving module is used for receiving the carrier signal and estimating the frequency offset between the received carrier signal and the carrier signal sent by the label radio frequency transmitting module;

the label radio frequency transmitting module is used for sending a label checking instruction to the electronic label through the bearing channel;

the tag radio frequency receiving module is used for receiving a tag reply signal sent by the electronic tag and carrying out carrier wave elimination processing on the tag reply signal based on the frequency offset so as to obtain tag information.

In a second aspect, an embodiment of the application provides an internet of things communication method, which is applied to an internet of things communication system, wherein the system comprises a first gateway and a second gateway, the first gateway comprises a tag radio frequency receiving module, and the second gateway comprises a tag radio frequency transmitting module; the method comprises the following steps:

the tag radio frequency transmitting module is used for sending a tag checking instruction to the electronic tag through the bearing channel;

In the internet of things communication system and method, the first gateway comprises a tag radio frequency receiving module, and the second gateway comprises a tag radio frequency transmitting module. The tag radio frequency transmitting module and the tag radio frequency receiving module are arranged in different gateways, so that the receiving and transmitting separation can be realized, and the interference of the transmitting module on the receiving module is avoided.

The tag radio frequency transmitting module is used for continuously transmitting carrier signals (namely, carrier signals) of the bearing channel and transmitting a tag checking instruction to the electronic tag through the bearing channel. The label radio frequency receiving module is used for receiving the carrier signal and estimating the frequency offset between the received carrier signal and the carrier signal sent by the second gateway. The tag radio frequency receiving module is also used for receiving a tag reply signal sent by the electronic tag and carrying out carrier wave elimination processing on the tag reply signal based on the estimated frequency offset so as to obtain tag information. Therefore, the tag radio frequency receiving module can eliminate non-homologous carriers, tag information is obtained from the tag reply signal under the condition of transmitting and receiving separation, the communication of the Internet of things is completed, corresponding technical support is provided for the transmitting and receiving separation, the receiving sensitivity of the tag information can be greatly improved, and long-distance checking is realized.

Drawings

Fig. 1 is a schematic structural diagram of an internet of things communication system in one embodiment;

FIG. 2 is a block diagram of an exemplary tag RF receive chain in one embodiment;

FIG. 3 is a block diagram of an exemplary tag RF receiving module according to an embodiment;

FIG. 4 is a second schematic block diagram of an exemplary tag RF receiving module;

FIG. 5 shows one example of signal processing steps of the RF receiving module of the tag;

FIG. 6 illustrates a second exemplary signal processing step of the RF receiving module;

FIG. 7 is a third schematic block diagram of an exemplary tag RF receiving module;

FIG. 8 is a block diagram of a schematic configuration of a first gateway in one embodiment;

FIG. 9 is a block diagram of a schematic diagram of a second gateway in one embodiment;

FIG. 10 is a block diagram of an exemplary RF tag transmitter module;

FIG. 11 is a signal interaction diagram of an Internet of things communication system in one example;

fig. 12 is a flowchart illustrating a communication method of the internet of things in one embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be connected to the other element through intervening elements. In addition, "connection" in the following embodiments is understood to mean "electrical connection", "communication connection", and the like if there is a transfer of electrical signals or data between the connected objects. "plurality" refers to two or more, such as two, three, five, eight, and so on.

As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," or "having," and the like, specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Also, as used in this specification, the term "and/or" includes any and all combinations of the associated listed items.

In the application, "homologous" means that the tag radio frequency transmitting link and the tag radio frequency receiving link share a clock source, and "non-homologous" means that the tag radio frequency transmitting link and the tag radio frequency receiving link do not share a clock source, that is, the tag radio frequency transmitting link realizes radio frequency transmission through a first clock source, and the tag radio frequency receiving link realizes radio frequency reception through a second clock source. The label radio frequency transmitting link is used for transmitting a radio frequency signal meeting a UHF RFID protocol to the electronic label, and the label radio frequency receiving link is used for receiving a label reply signal transmitted by the electronic label.

As background art shows, in order to meet the market demand for a long-distance UHF RFID system, it is urgently needed to provide a UHF RFID system with high receiving sensitivity, so that the working distance of the system can break through 50 meters, and the demand for long-distance transmission is met. Meanwhile, to promote large-scale application of the UHF RFID system, it is necessary to further reduce the reader cost, power consumption, and size. Along with the development of the passive internet of things, the inventory efficiency is improved, convenient networking between UHF RFID readers is realized, and the new requirement of the internet of things is met.

In the prior art, a common UHF RFID reader includes a fixed reader and a mobile reader, both of which are implemented by using a common device including a tag radio frequency transmitting link and a tag radio frequency receiving link, that is, the tag radio frequency transmitting link and the tag radio frequency receiving link are integrated into the same reader. The method has the advantage that the tag radio frequency transmitting link and the tag radio frequency receiving link share a clock source, so that carrier signals can be eliminated by a Self-interference elimination (SJC) method. However, due to the limitation of the size of the device, the isolation between the tag radio frequency transmitting link and the tag radio frequency receiving link is small, so that the reader-writer cannot meet the requirements of high-power carrier signals and high receiving sensitivity at the same time, that is, the reader-writer cannot realize high receiving sensitivity while transmitting the high-power carrier signals, and therefore, the working distance of the reader-writer is limited and the requirement of long-distance transmission cannot be met.

Some solutions of the prior art are also implemented with a reader-writer specific chip. However, according to the relevant provisions of the UHF RFID protocol, the reader should continuously transmit a carrier signal which is used for direct communication with the electronic tag. In this implementation manner, when the tag rf receiving link receives the tag reply signal, the tag rf transmitting link still continuously transmits the carrier signal, so that interference exists between the transmitting and receiving links, and thus the requirements of high power carrier signal and high receiving sensitivity cannot be considered. If the tag radio frequency receiving link and the tag radio frequency transmitting link are respectively arranged in two devices to communicate with the electronic tag in a receiving and transmitting separated mode, frequency offset exists between the receiving and transmitting devices, and the problem of non-homologous carrier elimination cannot be solved by a reader-writer special chip and a non-special chip, namely the existing reader-writer chip is difficult to realize carrier elimination under the condition that the receiving and transmitting devices have frequency offset so as to extract tag information from a tag reply signal, so that the receiving sensitivity of the reader-writer is low, and the requirement of long-distance transmission cannot be met.

In addition, with the transformation acceleration of industrial digitization in China, the 6G technology under study of 5G + and IMT-2030((International Mobile Telecommunications-2030, International Mobile Telecommunications-2030) enables the Mobile communication technology to further go deep into various industries in China, and the passive Internet of things technology based on the 5G and future Mobile communication technology becomes one of the most important grippers of industrial digitization.

Therefore, a communication system and a communication method of the internet of things are needed to realize the communication of the internet of things with high receiving sensitivity, so that the working distance of the communication of the internet of things is increased, and the requirement of long-distance transmission is met. In some embodiments, the internet of things communication of 'general disc integration' or 'general disc guidance integration' is also realized, that is, the functions of mobile communication, passive electronic tag checking and/or navigation positioning can be realized simultaneously.

In one embodiment, as shown in fig. 1, an internet of things communication system is provided. It can be understood that the working frequency of the communication system of the internet of things can be determined according to actual requirements, and the type of the electronic tag communicating with the communication system of the internet of things can also be determined according to actual requirements, which is not particularly limited in the present application. For convenience of description, the following embodiments take the internet of things communication system as a UHF RFID system, and the electronic tag as a passive electronic tag as an example.

Specifically, the internet of things communication system includes a first gateway 100 and a second gateway 200. It is understood that the specific number of the first gateway 100 and the second gateway 200 may be determined according to factors such as the distribution area of the electronic tags and/or the inventory efficiency, and the application is not particularly limited thereto. The number of the first gateways 100 may be one or more, and the number of the second gateways 200 may be one or more. In one embodiment, the number of the first gateways 100 may be one, and the number of the second gateways 200 may be plural.

The first gateway 100 includes a tag rf receiving module 110, and the second gateway 200 includes a tag rf transmitting module 210. The tag rf receiving module 110 is a device or circuit structure including one or more tag rf receiving links 112, and is configured to receive a tag reply signal sent by an electronic tag and obtain tag information from the tag reply signal. The tag rf transmitting module 210 is a device or circuit structure including one or multiple tag rf transmitting links, and is configured to transmit a carrier signal meeting the UHF RFID protocol specification, that is, a "carrier signal" according to the following embodiments.

The tag rf transmitting module 210 is configured to continuously transmit a carrier signal to satisfy the UHF RFID protocol. The carrier signal is a carrier signal of a carrier channel. The bearing channel can be used for bearing control messages sent by the communication system of the Internet of things to the electronic tag and carrier signals meeting UHF RFID protocol regulations. The bearer channel may also be used to carry tag information reflected by the electronic tag towards the first gateway 100, i.e. also to bear the tag reply signal.

Under the condition that a tag inventory instruction needs to be sent to the electronic tag, the tag radio frequency transmission module 210 can send the tag inventory instruction to the electronic tag through the bearing channel so as to trigger the electronic tag to respond to the tag inventory instruction and send a tag reply signal. The tag inventory instruction refers to an instruction capable of triggering the electronic tag to send a tag reply signal, and in one embodiment, the tag inventory instruction may be a tag read-write instruction.

Since the tag rf receiving module 110 and the tag rf transmitting module 210 are respectively disposed in two different gateways, and the two modules are non-homologous links, the tag rf receiving module 110 needs to determine a frequency of a carrier signal carried in the tag reply signal, so as to perform carrier cancellation processing on the tag reply signal and obtain tag information. Under the influence of signal transmission, algorithm precision, device processing precision, and other factors, the frequency of the carrier signal transmitted by the tag rf transmitting module 210 and the frequency of the carrier signal in the tag reply signal are different, but not completely identical. For example, the frequency of the carrier signal transmitted by the tag rf transmitter module 210 is f0, and the frequency of the carrier signal in the tag reply signal may be f0 +. DELTA.f, where Δ f is the frequency offset between the frequency of the carrier signal in the tag reply signal and the frequency of the carrier signal transmitted by the tag rf transmitter module 210. To achieve non-homologous carrier cancellation and obtain tag information from the tag reply signal, the tag rf receiving module 110 needs to estimate the frequency offset.

In this application, the tag rf receiving module 110 is configured to receive a carrier signal and estimate a frequency offset between the received carrier signal and the carrier signal sent by the tag rf transmitting module 210. That is, the tag rf receiving module 110 can receive the carrier signal continuously sent by the tag rf transmitting module 210, and estimate the frequency offset between the carrier signal received by the receiving module and the carrier signal transmitted by the transmitting module to obtain the frequency offset. It is to be understood that the frequency offset may be estimated by any frequency offset estimation method in the prior art, which is not limited in this application.

The tag reply signal sent by the electronic tag can be received by the tag rf receiving module 110. When receiving a tag reply signal sent by the electronic tag, the tag radio frequency receiving module 110 performs carrier cancellation processing on the tag reply signal based on the estimated frequency offset, so as to cancel a carrier signal in the tag reply signal and obtain tag information.

The application adopts a novel tag radio frequency transceiving module separation technology, and the tag radio frequency receiving module 110 can independently receive the tag reply signal sent by the electronic tag by adopting a non-homologous carrier wave elimination technology. Therefore, the receiving sensitivity of the UHF RFID label information can be greatly improved, the decoding distance is increased, and the long-distance checking is realized.

In the communication system of the internet of things, the first gateway 100 includes a tag rf receiving module 110, and the second gateway 200 includes a tag rf transmitting module 210. By separately arranging the tag rf transmitting module 210 and the tag rf receiving module 110 in different gateways, the receiving and transmitting can be separated, and the transmitting module is prevented from interfering with the receiving module.

The tag radio frequency transmission module 210 of the present application is configured to continuously transmit a carrier signal (i.e., a carrier signal) of a bearer channel, and transmit a tag inventory instruction to the electronic tag through the bearer channel. The tag rf receiving module 110 is configured to receive a carrier signal and estimate a frequency offset between the received carrier signal and the carrier signal sent by the second gateway 200. The tag radio frequency receiving module 110 is further configured to receive a tag reply signal sent by the electronic tag, and perform carrier cancellation processing on the tag reply signal based on the estimated frequency offset to obtain tag information. Therefore, the tag radio frequency receiving module 110 can eliminate non-homologous carriers to obtain tag information from the tag reply signal under the condition of transmitting and receiving separation, complete the communication of the internet of things, provide corresponding technical support for the transmitting and receiving separation, further greatly improve the receiving sensitivity of the tag information, and realize remote inventory.

In one embodiment, the first gateway 100 further includes a protocol processing module 120 and a data forwarding module 130. The protocol processing module 120 is configured to generate a label inventory instruction. The data forwarding module 130 is configured to send a tag inventory command to the tag radio frequency transmitting module 210 through a data channel, where a carrier frequency of the data channel is different from a carrier signal sent by the tag radio frequency transmitting module 210, that is, the carrier frequency of the data channel is different from the carrier frequency of the carrier channel, and the carrier frequency of the data channel and the carrier frequency of the carrier channel belong to different frequency bands. In one embodiment, the data forwarding module 130 may send the corresponding signal to the second gateway 200 through a forwarding protocol, which may use the same modulation and transmission mechanism as the UHF RFID protocol.

Specifically, the communication channel between the first gateway 100 and the second gateway 200 includes a data channel, and the data channel may be used to carry the UHF RFID control message and the response message that are sent by the first gateway 100 to the second gateway 200. In this application, the tag inventory command is generated by a protocol processing module of the first gateway 100, and the tag inventory command generated by the first gateway 100 is sent to the second gateway 200 through a data channel between the first gateway 100 and the second gateway 200. The tag radio frequency transmitting module 210 of the second gateway 200 may receive the tag inventory command sent by the first gateway 100, and forward the tag inventory command to the electronic tag through the bearer channel, so as to trigger the electronic tag to correspond to the tag inventory command. Thus, the pilot frequency relay forwarding can be realized. According to the method and the device, the working distance of the communication system of the Internet of things is increased from 5-10 meters to 150-200 meters through the combination of the transmitting-receiving separation and the pilot frequency relay technology, and the receiving distance of the label information is greatly increased.

In one embodiment, the tag rf transmitting module 210 may shift a frequency of the received tag inventory command and transmit the tag inventory command to the electronic tag through the bearer channel. In one embodiment, the protocol processing module 120 may generate a response message if the first gateway 100 successfully acquires the tag information, and send the response message to the data forwarding module 130. The data forwarding module 130 is configured to send the response message to the second gateway 200 through the data channel. The tag rf transmitting module 210 is further configured to forward the response message to the electronic tag through the bearer channel.

In this embodiment, the first gateway 100 generates a tag inventory instruction, and the tag inventory instruction is sequentially sent to the electronic tag via the data channel between the first gateway 100 and the second gateway 200 and the bearer channel between the second gateway 200 and the electronic tag, so that inter-frequency relay forwarding can be realized. Therefore, on one hand, the implementation complexity of the second gateway 200 can be reduced, the cost of the second gateway 200 is reduced, and the overall cost of the system is further reduced, on the other hand, the interference between the data forwarding module 130 and the tag radio frequency receiving module 110 at the first gateway 100 can also be reduced, and high receiving sensitivity and longer working distance are ensured. Thus, the system cost can be reduced while ensuring high reception sensitivity.

In one embodiment, the tag rf receiving module 110 includes one or more tag rf receiving chains 112. As shown in fig. 2, each tag-per-tag rf receive chain 112 includes a first antenna 410, an analog-to-digital conversion unit 420, and a digital carrier cancellation unit 430. The first antenna 410 is connected to the analog-to-digital conversion unit 420, the analog-to-digital conversion unit 420 is connected to the digital carrier cancellation unit 430, and the digital carrier cancellation unit 430 is connected to the protocol processing module 120.

The first antenna 410 is used for receiving a carrier signal and a tag reply signal. The analog-to-digital conversion unit 420 is configured to convert the received carrier signal into a first digital signal and convert the tag reply signal into a second digital signal. The digital carrier cancellation unit 430 is configured to estimate a frequency offset according to the first digital signal, and perform frequency shift on the second digital signal based on the frequency offset to obtain a frequency-shifted second digital signal. The digital carrier wave elimination unit 430 is further configured to correct the frequency-shifted second digital signal by using a preset measurement error correction strategy to obtain the tag information. The protocol processing module 120 is further configured to process the tag information using a UHF RFID protocol.

Specifically, the first antenna 410 may be configured to receive signals transmitted through the bearer channel and output the received signals to the analog-to-digital conversion unit 420. The analog-to-digital conversion unit 420 performs analog-to-digital conversion on the carrier signal to obtain a first digital signal when receiving the carrier signal. The digital carrier unit may receive the first digital signal, and estimate a frequency offset between the received carrier signal and the carrier signal sent by the second gateway 200 based on the first digital signal, so as to perform carrier cancellation processing on the tag reply signal based on the frequency offset when receiving the tag reply signal.

In the case that the tag reply signal is received by the analog-to-digital conversion unit 420 via the first antenna 410, the analog-to-digital conversion unit 420 performs analog-to-digital conversion on the tag reply signal to obtain a second digital signal. The digital carrier cancellation unit 430 may shift the frequency according to the estimated frequency offset to obtain a second digital signal after frequency shift. The second frequency-shifted digital signal may be a digital signal obtained by removing a carrier signal with a frequency (f0 +. DELTA.f '), where Δ f' is an estimated frequency offset.

Limited by the estimation accuracy, a certain error may exist during the frequency offset estimation, resulting in a certain deviation between the estimated frequency offset and the actual frequency offset. For example, when the estimation accuracy is ± 5Hz, the estimated frequency offset Δ f' may be Δ f ± 5Hz, and Δ f is the actual frequency offset. In order to eliminate the residual frequency offset introduced by the estimation accuracy, the digital carrier elimination unit 430 further corrects the frequency-shifted second digital signal by using a preset measurement error correction strategy, so as to obtain a zero-frequency second digital signal (i.e., tag information). It is understood that the preset measurement error correction strategy can be implemented by any correction strategy disclosed in the prior art, and the application is not limited thereto. In one embodiment, the predetermined measurement error correction strategy may be a notch filter, an amplitude normalization algorithm, and/or a phase tracking algorithm.

The protocol processing module 120 may be configured to complete parsing and controlling of the UHF RFID protocol, and may process tag information using the UHF RFID protocol. In one embodiment, the protocols supported by the protocol processing module 120 include, but are not limited to: EPC C1G 2 standard, ISO/IEC 18000-6C and GB/T29768-2013.

In this embodiment, through the analog-to-digital conversion unit 420 and the digital carrier cancellation unit 430, the tag rf receiving link 112 can support a mode of single digital carrier cancellation, so as to simplify the structure of the tag rf receiving link 112, and further reduce the volume of the first gateway 100. Meanwhile, in the embodiment, the measurement error of the frequency offset estimation is corrected by adopting the preset measurement error correction strategy, so that the tag information can be more accurately extracted from the tag reply signal, and the accuracy of the communication of the internet of things can be improved and the receiving sensitivity can be further improved.

In one embodiment, as shown in fig. 3, the tag rf receiving module 110 further includes a first clock phase-locked loop 114, and the tag rf receiving chain 112 further includes an analog carrier cancellation unit 440 and a first amplifier 450 sequentially connected between the first antenna 410 and the analog-to-digital conversion unit 420, that is, the first antenna 410, the analog carrier cancellation unit 440, the first amplifier 450, and the analog-to-digital conversion unit 420 are sequentially connected. The analog carrier cancellation unit 440 is also connected to the first clock phase locked loop 114.

The first clock phase locked loop 114 is used for outputting a local clock signal. The analog carrier cancellation unit 440 is configured to perform analog carrier cancellation on the tag reply signal according to the local clock signal under the condition that the local clock signal is synchronous with the frequency of the carrier signal sent by the tag radio frequency transmission module 210, so as to obtain a tag reply signal after cancellation. The first amplifier 450 is configured to amplify the cancelled tag reply signal and output the amplified tag reply signal to the analog-to-digital conversion unit 420. The analog-to-digital conversion unit 420 is configured to perform analog-to-digital conversion on the amplified tag reply signal to obtain a second digital signal.

Specifically, the first clock pll 114 may receive and perform clock recovery using the carrier signal transmitted by the tag rf transmitting module 210, so as to attempt to maintain frequency synchronization between the first gateway 100 and the second gateway 200, and output a local clock signal of the first gateway 100. The frequency of the local clock signal can be locked in a phase-locked loop mode, so that the local clock signal with stable frequency can be output. When the frequency of the local clock signal is the same as the frequency of the carrier signal sent by the tag rf transmitter module 210 or the difference between the two frequencies is within the allowable range, the local clock signal and the carrier signal sent by the tag rf transmitter module 210 can be considered to be synchronized. In the case of frequency synchronization, analog carrier cancellation may be performed on the tag reply signal according to the local clock signal to cancel the carrier signal with the frequency f1 in the tag reply signal. Wherein f1 is the frequency of the local clock signal, in one embodiment, f1 is equal to f0, and f0 is the frequency of the carrier signal sent by the tag rf transmitter module 210.

The tag reply signal after the analog carrier cancellation is amplified by the first amplifier 450 and then input to the analog-to-digital conversion unit 420, so that the amplified tag reply signal is subjected to analog-to-digital conversion by the analog-to-digital conversion unit 420, and a second digital signal is obtained.

In one embodiment, the first amplifier 450 may be a low noise amplifier.

In this embodiment, analog carrier cancellation is performed before digital carrier cancellation is performed, so as to reduce the signal amplitude of the tag reply signal input to the first amplifier 450 in an analog carrier cancellation manner, thereby reducing the occurrence of blocking of the first amplifier 450 and reducing the device requirement of the tag radio frequency receiving link 112 while ensuring high receiving sensitivity, and further improving the system reliability and reducing the system cost.

In one embodiment, as shown in fig. 4, the analog carrier cancellation unit 440 includes an amplitude and phase estimation circuit 442, an amplitude and phase adjustment circuit 444, and a coupler 446. The amplitude and phase estimation circuit 442 is connected to the analog-to-digital conversion unit 420 and the amplitude and phase adjustment circuit 444, respectively, the amplitude and phase adjustment circuit 444 is connected to the first clock phase locked loop 114 and the coupler 446, respectively, and the coupler 446 is connected to the first antenna 410 and the first amplifier 450, respectively.

The amplitude and phase estimation circuit 442 is configured to receive the first digital signal, and perform amplitude estimation and phase estimation on the first digital signal to obtain an amplitude estimator and a phase estimator, respectively. The amplitude and phase adjustment circuit 444 is configured to adjust the local clock signal based on the amplitude estimator and the phase estimator and output the adjusted local clock signal when the tag rf receive chain 112 receives the tag reply signal. The coupler 446 is configured to superimpose the adjusted local clock signal and the tag reply signal to obtain a cancelled tag reply signal.

In particular, where the carrier signal is received by the tag rf receive chain 112, the amplitude and phase estimation circuit 442 may perform an amplitude estimation on the first digital signal to obtain an amplitude estimate of the carrier signal. The amplitude and phase estimation circuit 442 may also perform phase estimation on the first digital signal to obtain a phase estimate of the carrier signal. Wherein the amplitude estimate reflects the amplitude of the carrier signal and the phase estimate reflects the phase of the carrier signal. The amplitude and phase estimation circuit 442 may output the amplitude estimate and the phase estimate to an amplitude and phase adjustment circuit 444. In the case of receiving the tag reply signal, the amplitude and phase adjustment circuit 444 may adjust the amplitude and phase of the local clock signal according to the amplitude estimator and the phase estimator, so that the adjusted local clock signal matches the amplitude and phase of the carrier-carrying signal sent by the tag radio frequency transmission module 210. In this way, the coupler 446 may superimpose the tag reply signal with the adjusted local clock signal to eliminate the carrier signal having the frequency f1 in the tag reply signal, and output the eliminated tag reply signal to the subsequent circuit.

In this embodiment, the analog carrier cancellation unit 440 is implemented by the amplitude and phase estimation circuit 442, the amplitude and phase adjustment circuit 444, and the coupler 446, so that the cost of the analog carrier cancellation unit 440 can be reduced, and the overall system cost can be further reduced.

In one example, for the tag rf receive chain structure shown in fig. 4, the receive chain may perform different signal processing steps depending on the frequency locking condition of the first clock phase locked loop 114.

Specifically, as shown in fig. 5, when the first clock phase-locked loop 114 can lock the frequency of the carrier signal transmitted by the tag rf transmitting module 210, the signal processing steps of the tag rf receiving link 112 are as follows:

s510, the tag rf receiving link 112 turns off the amplitude and phase adjusting circuit 444 according to the inventory control timing when the second gateway 200 sends the carrier signal, so that the amplitude and phase adjusting circuit 444 has no output.

S520, the amplitude and phase estimation circuit 442 receives the carrier signal without analog cancellation, and performs phase and amplitude estimation on the received complete carrier signal to obtain a phase estimator and an amplitude estimator, respectively.

S530, when the electronic tag sends a tag reply signal, the amplitude and phase adjustment circuit 444 is turned on, so that the amplitude and phase adjustment circuit 444 may adjust the phase and amplitude of the local clock according to the estimated phase estimator and amplitude estimator, and output an adjusted local clock signal.

S540, the coupler 446 superimposes the tag reply signal with the adjusted local clock signal to realize analog carrier cancellation, and outputs the cancelled tag reply signal.

S550, the tag reply signal after being eliminated is sequentially amplified and analog-to-digital converted and then input to the digital carrier eliminating unit 430, and the digital carrier eliminating unit 430 performs digital carrier eliminating processing on the second digital signal output by the analog-to-digital converting unit 420 to obtain the tag information. Specifically, the specific steps of the digital carrier elimination unit 430 performing the digital carrier elimination process can be as shown in fig. 6.

Specifically, as shown in fig. 6, when the first clock phase-locked loop 114 cannot lock the frequency of the carrier-carrying signal sent by the tag rf transmitting module 210, the tag rf receiving link 112 may eliminate the carrier only by means of digital carrier cancellation, and the signal processing steps of the tag rf transmitting link are as follows:

s610, the amplitude and phase adjusting circuit 444 is turned off, and the received carrier signal and the tag reply signal are directly amplified and analog-to-digital converted to obtain a first digital signal and a second digital signal, respectively.

S620, the digital carrier cancellation unit 430 performs frequency offset estimation on the first digital signal to obtain a frequency offset.

S630, the digital carrier cancellation unit 430 performs frequency shift on the second digital signal by using the frequency offset to obtain a frequency-shifted second digital signal.

S640, the digital carrier wave elimination unit 430 processes the frequency-shifted second digital signal by using a preset measurement error correction strategy to obtain the tag information.

Thus, the tag rf receiving link 112 can support a single digital carrier cancellation mode and a combination mode of analog carrier cancellation and digital carrier cancellation, thereby reducing the occurrence of blocking of the first amplifier 450 and reducing the device requirements of the tag rf receiving link 112 while ensuring high receiving sensitivity, and further improving the system reliability and reducing the system cost.

In one embodiment, the number of the tag rf receiving chains 112 is multiple, and the tag rf receiving module 110 further includes a diversity combining module 116 connected between the protocol processing module 120 and each of the tag rf receiving chains 112. That is, each road sign rf receiving link 112 is connected to the protocol processing module 120 through the diversity combining module 116. It is understood that the specific number of the tag rf receiving chains 112 can be set according to practical requirements, and the application is not limited thereto. In one example, the number of tag rf receive chains 112 may be 4.

The multi-path tag rf receiving link 112 is configured to receive a tag reply signal in a diversity manner, and output corresponding tag information to the diversity combining module 116. The diversity combining module 116 is configured to perform diversity combining on each piece of tag information, and output the combined tag information to the protocol processing module 120.

Specifically, the present application may arrange multiple tag rf receiving chains 112 to achieve diversity reception of the tag reply signals. Each tag rf receive link 112 may output its corresponding tag information to the diversity combining module 116. The diversity combining module 116 is configured to implement diversity combining of multiple radio frequency receiving links, and implement frame synchronization of UHF RFID signals and ASK demodulation and decoding, so that the overall performance of the first gateway 100 can be improved. In this embodiment, the multi-path tag radio frequency receiving link 112 uses a non-homologous carrier cancellation technique and a multi-path diversity receiving technique, so that high-sensitivity receiving of UHF RFID tag signals can be achieved.

In one example, in the case that the number of the tag rf receiving chains 112 is multiple, a schematic structural block diagram of the tag rf receiving module 110 may be as shown in fig. 7. The digital carrier cancellation unit 430 of each tag rf receiving link 112 is connected to the diversity combining module 116.

In one embodiment, the first gateway 100 further comprises a mobile communication rf transceiver module 140. The mobile communication rf transceiver module 140 is connected to the protocol processing module 120, and is configured to receive an uplink communication signal of the mobile terminal 300 and send a downlink communication signal to the mobile terminal 300. The protocol processing module 120 is further configured to process the uplink communication signal and the downlink communication signal by using a base station protocol.

Specifically, the first gateway 100 supports the functions of a mobile communication base station and a UHF RFID separation receiver, and can implement mobile device communication and passive internet of things inventory. The mobile communication rf transceiver module 140 of the first base station is used for completing the transceiving of the mobile communication rf signal. During the uplink communication, the mobile communication rf transceiver module 140 may receive an uplink communication signal sent by the mobile terminal 300 and send the uplink communication signal to the protocol processing module 120. The protocol processing module 120 may process the uplink communication signal using a base station protocol to implement uplink communication. During downlink communication, the protocol processing module 120 may send a downlink communication signal to the mobile terminal 300 through the mobile communication rf transceiver module 140.

In one embodiment, the protocol processing module 120 may support a 5G base station or a 6G base station protocol stack to complete the communication protocol processing between the base station and the mobile terminal 300. The mobile communication rf transceiver module 140 may include a 5G base station rf processing link or a 6G base station rf processing link, and implement networking management.

In one embodiment, the protocol processing module 120 may further send a management message to the second gateway 200 and receive the management message sent by the second gateway 200 through the mobile communication radio frequency transceiving module 140, so that the communication system of the internet of things may support networking control of multiple second gateways 200. Specifically, the first gateway 100 may implement transceiving of management messages through a management channel, where the management channel may be used to carry management messages such as networking control and upgrade management.

In the embodiment, a mobile communication base station technology, a receiving and transmitting separation mode and a non-homologous carrier wave elimination mode are combined, so that a novel integrated network of mobile communication and passive RFID (radio frequency identification) checking is realized, functions of an internet of things communication system can be enriched, and the applicability of the system is improved.

In one embodiment, the protocol processing module 120 is further configured to perform signal measurement on the electronic tag to determine the location information of the electronic tag. And/or the protocol processing module 120 is further configured to perform signal measurement on the mobile terminal 300 to determine location information of the mobile terminal 300.

Specifically, the protocol processing module 120 may be further configured to perform signal measurement on the electronic tag and/or the mobile terminal 300 to perform distance and location calculation, and determine location information of the electronic device and/or the mobile terminal 300 to implement a positioning function. In one embodiment, the protocol processing module 120 can be further configured to navigate according to the location information of the electronic device and/or the mobile terminal 300.

In the embodiment, a three-dimensional integrated network of mobile communication, passive RFID (radio frequency identification) checking and wireless equipment positioning is realized, so that the functions of the communication system of the Internet of things can be enriched, and the applicability of the system is improved.

In one example, the first gateway 100 may include a tag rf receiving module 110, a protocol processing module 120, a mobile communication rf transceiving module 140, and a data forwarding module 130, as shown in fig. 8. The tag rf receiving module 110 may include a plurality of tag rf receiving links 112, and the protocol processing module 120 may include a UHF RFID protocol processing module, a base station protocol processing module, and a management/positioning navigation module. It should be noted that the protocol processing module 120 may be implemented based on one or more controllers, that is, the UHF RFID protocol processing module, the base station protocol processing module, and the management control/positioning navigation module may be implemented wholly or partially by software, hardware, or a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.

In one embodiment, as shown in fig. 9, the second gateway 200 further includes a management control module 220. The tag rf transmitting module 210 includes a second antenna 231, a modulating unit, a channel selector 232 and a multi-path third antenna 233, which are connected in sequence, and the channel selector 232 is further connected to the management control module 220.

The management control module 220 is configured to receive target configuration information sent by the protocol processing module 120, and determine a third antenna 233 determined corresponding to the target configuration information; the second antenna 231 is configured to receive the tag inventory instruction through the data channel; the modulation unit is used for modulating the label checking instruction to the carrier signal to obtain a modulated label checking instruction; the channel selector 232 is configured to turn on a transmission path between the modulation unit and the corresponding third antenna 233, so as to send the modulated tag inventory instruction through the corresponding third antenna 233.

Specifically, the tag rf transmitter module 210 receives the signal of the data channel, and recovers, shifts, and forwards the received signal of the data channel. Specifically, the second antenna 231 is configured to receive a tag inventory instruction through a data channel, and the modulation unit is configured to shift a frequency of the received tag inventory instruction, so that the second gateway 200 sends the tag inventory instruction to the electronic tag through a bearer channel. The second gateway 200 may transmit a tag inventory instruction to the electronic tag through the third antenna 233. The second gateway 200 of the present application includes a plurality of third antennas 233, and the management control module 220 gates the corresponding third antennas 233 under the configuration of the first gateway 100, so as to send a tag inventory instruction to the electronic tag through the corresponding third antennas 233. In one embodiment, the second antenna 231 may further receive the response message sent by the first gateway 100 through a data channel, process the response message according to the aforementioned processing procedure for the tag inventory instruction, and send the response message to the electronic tag through a bearer channel.

In one example, as shown in fig. 10, the tag rf transmitting module 210 may include a second clock phase locked loop 234, a modulation unit including an ASK signal recovery module 235, a second amplifier 236, a first multiplier 237, and a second multiplier 238, a channel selector 232, and a plurality of third antennas 233. The second clock phase-locked loop 234 is configured to output a carrier signal with a frequency f0 and a carrier signal with a frequency f2, where f0 is a carrier frequency of a bearer channel, f2 is a carrier frequency of a data channel, and f0 is not equal to f2, so as to implement inter-frequency forwarding. The first multiplier 237 is configured to shift the frequency of the tag inventory command received via the data channel according to the carrier signal of f2, so as to obtain the ASK-modulated tag inventory command from the received signal. The ASK signal recovery module 235 is configured to perform ASK decoding to obtain a tag inventory instruction. The second multiplier 238 is used for ASK-modulating the tag inventory command according to the carrier signal of f 0. The second amplifier 236 amplifies the signal output from the second multiplier 238, and the amplified signal is output to the corresponding third antenna 233 via the channel selector 232 and transmitted to the electronic tag.

In this embodiment, by setting a plurality of third antennas 233 and gating the corresponding third antennas 233 by using the channel selector 232, a plurality of RFID bearers can be sent in a time-sharing manner, the coverage area of a single second gateway 200 is enlarged, and the cost of the communication system of the internet of things is reduced.

In one embodiment, as shown in fig. 9, the second gateway 200 further includes a CPE (Customer Premise Equipment) module 230 connected to the management control module 220 for communicating with the base station. In one embodiment, the mobile communication CPE module 230 may be a 5G CPE or a 6G CPE, which is responsible for communication with the base station. In this embodiment, the second gateway 200 may adopt a combination of the mobile communication CPE and the RFID repeater technology to implement a "universal" integrated internet of things communication system and a passive internet of things networking with low cost and high efficiency.

In one embodiment, the management control module 220 in the second gateway 200 is further responsible for receiving the management control message sent by the first gateway 100, and accordingly, the functions of software upgrade, monitoring management, and the like of the second gateway 200 are implemented.

In one embodiment, the protocol processing module 120 is further configured to send initial configuration information to the management control module 220 before sending the tag inventory instruction. The initial configuration information includes a carrier frequency of the data channel, a carrier frequency of the bearer channel, and/or an antenna number. The management control module 220 is further configured to perform configuration according to the initial configuration information. In this way, networking between the first gateway 100 and the second network manager can be realized, so as to facilitate subsequent communication between the first gateway 100 and the second gateway 200.

In an example, a signal interaction process of the internet of things communication system of the present application may be as shown in fig. 11, which specifically includes:

s702, the second gateway sends a networking registration request to the first gateway through the management channel so as to execute a mobile communication CPE module access base station process and a management control/positioning navigation module registration process (namely, the second gateway registers to the management control/positioning navigation module). The networking registration request comprises equipment information such as equipment identification and support capability of the second gateway.

S704, the management and control/positioning navigation module records the equipment information of the registered equipment. If a data security isolation scene is needed, the control message of the mobile communication CPE can be separated locally, so that the processing in the first gateway equipment is realized, and the data can not be sent out of a local network. If a remote data acquisition and control scene is needed, the data can be uploaded to a corresponding server through a core network, and the remote networking control requirement is met.

S706, the first gateway sends networking permission information through the management channel to complete networking registration of the second gateway.

S708, the first gateway may send the initial configuration information to the second gateway through the management channel before the label is checked. The initial configuration information includes: the carrier frequency (f2) of the RFID data channel, the carrier frequency (f0) of the RFID carrying channel, the strength of the power amplifier sending signal, the number of the sending antenna of the second gateway and the like.

And S710, the second gateway carries out configuration according to the initial configuration parameters.

And S712, the first gateway sends a label checking instruction to the second gateway through the RFID data channel. The label checking instruction conforms to standards such as EPC C1G 2, ISO/IEC 18000-6C, GB/T29768-2013 and the like.

And S714, the second gateway forwards the tag inventory command sent by the first gateway to the electronic tag through the RFID bearing channel so as to activate the electronic tag to enter an inventory state.

And S716, the electronic tag reflects the tag reply signal according to the received tag inventory command.

And S718, the first gateway performs multi-path diversity reception through the RFID bearing channel, analyzes the tag reply signal sent by the electronic tag, and completes protocol message processing through the UHF RFID protocol processing module.

S720, the first gateway sends a response message to the second gateway through the RFID data channel.

And S722, the second gateway forwards the response message to the electronic tag through the RFID bearing channel, and the complete tag inventory process is completed. The tag inventory timing meets the timing requirements of T1 (time from the end of the command sent by the reader-writer to the transmission of the next command by the tag), T2 (time from the end of the response packet sent by the tag to the transmission of the next command by the reader-writer), T3 (after T1, the reader-writer continues to detect the time of the tag response packet)/T4 (interval time between two commands of the reader-writer) of EPC C1G 2 standard, ISO/IEC 18000-6C, GB/T29768-2013 and other standards.

In one embodiment, as shown in fig. 12, a communication method of the internet of things is provided, and the method is applied to the communication system of the internet of things. The method comprises the following steps:

s810, the label radio frequency transmitting module is used for continuously transmitting a carrier signal; wherein, the carrier signal is the carrier signal of the carrier channel;

s820, the label radio frequency receiving module is used for receiving the carrier signal and estimating the frequency offset between the received carrier signal and the carrier signal sent by the label radio frequency transmitting module;

s830, the label radio frequency transmitting module is used for sending a label checking instruction to the electronic label through the bearing channel;

and S840, the tag radio frequency receiving module is used for receiving the tag reply signal sent by the electronic tag and carrying out carrier wave elimination processing on the tag reply signal based on the frequency offset so as to obtain tag information.

In one embodiment, the first gateway further comprises a protocol processing module and a data forwarding module. The method further comprises the following steps:

the protocol processing module generates a label checking instruction;

the data forwarding module sends a tag checking instruction to the tag radio frequency transmitting module through the data channel; the carrier frequency of the data channel is different from the frequency of the carrier-bearing signal sent by the tag radio frequency transmitting module.

In one embodiment, the tag radio frequency receiving module comprises a tag radio frequency receiving link, wherein the tag radio frequency receiving link comprises a first antenna, an analog-to-digital conversion unit and a digital carrier wave elimination unit which are connected in sequence; the digital carrier wave elimination unit is also connected with the protocol processing module.

The label radio frequency receiving module is used for receiving the carrier signal and estimating the frequency offset between the received carrier signal and the carrier signal sent by the label radio frequency transmitting module, and the steps comprise:

a first antenna receives a carrier signal; the analog-to-digital conversion unit converts the received carrier signal into a first digital signal; the digital carrier cancellation unit estimates a frequency offset from the first digital signal.

The label radio frequency receiving module is used for receiving a label reply signal sent by the electronic label and carrying out carrier wave elimination processing on the label reply signal based on the frequency offset so as to obtain the label information, and the method comprises the following steps:

the first antenna receives a tag reply signal; the analog-to-digital conversion unit converts the tag reply signal into a second digital signal; the digital carrier wave eliminating unit shifts the frequency of the second digital signal based on the frequency offset to obtain a second digital signal after frequency shifting; the digital carrier wave eliminating unit also adopts a preset measurement error correction strategy to correct the second digital signal after frequency shift so as to obtain label information; the protocol processing module also adopts UHF RFID protocol to process the label information.

In one embodiment, the tag rf receiving module further includes a first clock phase-locked loop, the tag rf receiving link further includes an analog carrier cancellation unit and a first amplifier sequentially connected between the first antenna and the analog-to-digital conversion unit, and the analog carrier cancellation unit is connected to the first clock phase-locked loop.

The label radio frequency receiving module is used for receiving a label reply signal sent by the electronic label, and carrying out carrier wave elimination processing on the label reply signal based on the frequency offset, so as to obtain the label information, and the label radio frequency receiving module further comprises the following steps:

the first clock phase-locked loop outputs a local clock signal; the analog carrier wave elimination unit carries out analog carrier wave elimination on the label reply signal according to the local clock signal under the condition that the local clock signal is synchronous with the frequency of the carrier wave signal sent by the label radio frequency emission module so as to obtain an eliminated label reply signal; the first amplifier amplifies the eliminated tag reply signal and outputs the amplified tag reply signal to the analog-to-digital conversion unit; and the analog-to-digital conversion unit performs analog-to-digital conversion on the amplified tag reply signal to obtain a second digital signal.

In one embodiment, the analog carrier cancellation unit comprises an amplitude and phase estimation circuit, an amplitude and phase adjustment circuit and a coupler, wherein the amplitude and phase estimation circuit is respectively connected with the analog-to-digital conversion unit and the amplitude and phase adjustment circuit, the amplitude and phase adjustment circuit is respectively connected with the first clock phase-locked loop and the coupler, and the coupler is respectively connected with the first antenna and the first amplifier.

The step of carrying out analog carrier wave elimination on the tag reply signal according to the local clock signal to obtain the eliminated tag reply signal comprises the following steps:

the amplitude and phase estimation circuit receives the first digital signal, and carries out amplitude estimation and phase estimation on the first digital signal so as to respectively obtain an amplitude estimator and a phase estimator; the amplitude and phase adjusting circuit adjusts a local clock signal based on the amplitude estimator and the phase estimator under the condition that a tag radio frequency receiving link receives a tag reply signal, and outputs the adjusted local clock signal; and the coupler superposes the adjusted local clock signal and the tag reply signal to obtain a tag reply signal after elimination.

In one embodiment, the number of the tag rf receiving links is multiple, and the tag rf receiving module further includes a diversity combining module connected between the protocol processing module and each of the tag rf receiving links.

The label radio frequency emission module is used for sending a label checking instruction to the electronic label through the bearing channel, and comprises the following steps:

the multi-path label radio frequency receiving link diversity receives the label reply signal and outputs corresponding label information to the diversity combining module; the diversity combining module performs diversity combining on each label information and outputs the combined label information to the protocol processing module.

In one embodiment, the first gateway further comprises a mobile communication radio frequency transceiving module connected with the protocol processing module. The method further comprises the following steps:

the mobile communication radio frequency transceiving module receives an uplink communication signal of the mobile terminal and sends a downlink communication signal to the mobile terminal; the protocol processing module adopts a base station protocol to process the uplink communication signal and the downlink communication signal.

In one embodiment, the method further comprises:

the protocol processing module is also used for measuring signals of the electronic tag so as to determine the position information of the electronic tag;

and/or

The protocol processing module is also used for measuring signals of the mobile terminal so as to determine the position information of the mobile terminal.

In one embodiment, the second gateway further includes a management control module, the tag radio frequency transmission module includes a second antenna, a modulation unit, a channel selector and a multi-path third antenna, which are connected in sequence, and the channel selector is connected with the management control module. The method further comprises the following steps:

the management control module receives target configuration information sent by the protocol processing module and determines a third antenna determined corresponding to the target configuration information; the second antenna receives a label checking instruction through a data channel; the modulation unit modulates the label checking instruction to a carrier signal to obtain a modulated label checking instruction; the channel selector conducts a transmission channel between the modulation unit and the corresponding third antenna so as to send the modulated label checking instruction through the corresponding third antenna.

In one embodiment, the second gateway further comprises a mobile communications CPE module connected to the management control module. The method further comprises the following steps: the mobile communication CPE module is communicated with the base station.

In one embodiment, the method further comprises:

the protocol processing module also sends initial configuration information to the management control module before sending the label checking instruction; the initial configuration information comprises carrier frequency of a data channel, carrier frequency and/or antenna number of a bearing channel;

the management control module also configures according to the initial configuration information.

It should be understood that, although the steps in the flowcharts related to the embodiments as described above are sequentially displayed as indicated by arrows, the steps are not necessarily performed sequentially as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a part of the steps in the flowcharts related to the embodiments described above may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, and the execution order of the steps or stages is not necessarily sequential, but may be rotated or alternated with other steps or at least a part of the steps or stages in other steps.

All possible combinations of the technical features in the above embodiments may not be described for the sake of brevity, but should be considered as being within the scope of the present disclosure as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, and these are all within the scope of protection of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. The communication system of the Internet of things is characterized by comprising a first gateway and a second gateway, wherein the first gateway comprises a tag radio frequency receiving module, and the second gateway comprises a tag radio frequency transmitting module;

2. The internet-of-things communication system of claim 1, wherein the first gateway further comprises a protocol processing module and a data forwarding module;

the protocol processing module is used for generating the label checking instruction;

the data forwarding module is used for sending the tag checking instruction to the tag radio frequency transmitting module through a data channel; and the carrier frequency of the data channel is different from the frequency of the carrier-bearing signal sent by the label radio frequency transmitting module.

3. The internet of things communication system of claim 2, wherein the tag radio frequency receiving module comprises a tag radio frequency receiving link, and the tag radio frequency receiving link comprises a first antenna, an analog-to-digital conversion unit and a digital carrier cancellation unit which are connected in sequence; the digital carrier wave elimination unit is also connected with the protocol processing module;

Wherein the first antenna is configured to receive the carrier signal and the tag reply signal; the analog-to-digital conversion unit is used for converting the received carrier signal into a first digital signal and converting the tag reply signal into a second digital signal; the digital carrier wave eliminating unit is used for estimating the frequency offset according to the first digital signal and carrying out frequency shift on the second digital signal based on the frequency offset to obtain a second digital signal after frequency shift; the digital carrier wave eliminating unit is also used for adopting a preset measurement error correction strategy to correct the second digital signal after frequency shift so as to obtain the label information; the protocol processing module is also used for processing the label information by adopting a UHF RFID protocol.

4. The internet of things communication system according to claim 3, wherein the tag radio frequency receiving module further comprises a first clock phase-locked loop, the tag radio frequency receiving link further comprises an analog carrier cancellation unit and a first amplifier which are sequentially connected between the first antenna and the analog-to-digital conversion unit, and the analog carrier cancellation unit is connected with the first clock phase-locked loop;

The first clock phase-locked loop is used for outputting a local clock signal; the analog carrier wave elimination unit is used for eliminating analog carrier waves of the label reply signals according to the local clock signals under the condition that the local clock signals are synchronous with the frequency of the carrier wave-bearing signals sent by the label radio frequency emission module so as to obtain eliminated label reply signals; the first amplifier is used for amplifying the eliminated tag reply signal and outputting the amplified tag reply signal to the analog-to-digital conversion unit; the analog-to-digital conversion unit is used for performing analog-to-digital conversion on the amplified tag reply signal to obtain the second digital signal.

5. The communication system of the internet of things according to claim 4, wherein the analog carrier cancellation unit comprises an amplitude and phase estimation circuit, an amplitude and phase adjustment circuit and a coupler;

the amplitude and phase estimation circuit is respectively connected with the analog-to-digital conversion unit and the amplitude and phase adjustment circuit, the amplitude and phase adjustment circuit is respectively connected with the first clock phase-locked loop and the coupler, and the coupler is respectively connected with the first antenna and the first amplifier;

The amplitude and phase estimation circuit is used for receiving the first digital signal, and performing amplitude estimation and phase estimation on the first digital signal to obtain an amplitude estimator and a phase estimator respectively; the amplitude and phase adjusting circuit is used for adjusting the local clock signal based on the amplitude estimator and the phase estimator and outputting the adjusted local clock signal under the condition that the tag radio frequency receiving link receives the tag reply signal; the coupler is used for superposing the adjusted local clock signal and the tag reply signal to obtain the tag reply signal after elimination.

6. The internet of things communication system of any one of claims 2 to 5, wherein the number of the tag radio frequency receiving links is multiple, and the tag radio frequency receiving module further comprises a diversity combining module connected between the protocol processing module and each of the tag radio frequency receiving links;

the multiple paths of label radio frequency receiving links are used for receiving the label reply signals in a diversity mode and outputting corresponding label information to the diversity combining module; the diversity combining module is used for performing diversity combining on each label information and outputting the combined label information to the protocol processing module.

7. The internet-of-things communication system according to any one of claims 2 to 5, wherein the first gateway further comprises a mobile communication radio frequency transceiver module connected to the protocol processing module;

the mobile communication radio frequency transceiver module is used for receiving an uplink communication signal of a mobile terminal and sending a downlink communication signal to the mobile terminal; the protocol processing module is used for processing the uplink communication signal and the downlink communication signal by adopting a base station protocol.

8. The internet of things communication system of claim 7, wherein the protocol processing module is further configured to perform signal measurement on the electronic tag to determine location information of the electronic tag;

and/or

The protocol processing module is also used for measuring the signal of the mobile terminal so as to determine the position information of the mobile terminal.

9. The internet of things communication system according to any one of claims 2 to 5, wherein the second gateway further comprises a management control module, the tag radio frequency transmission module comprises a second antenna, a modulation unit, a channel selector and a multi-path third antenna which are connected in sequence, and the channel selector is connected with the management control module;

The management control module is configured to receive target configuration information sent by the protocol processing module, and determine a third antenna determined corresponding to the target configuration information; the second antenna is used for receiving the tag inventory instruction through the data channel; the modulation unit is used for modulating the label checking instruction to the carrier signal to obtain a modulated label checking instruction; the channel selector is configured to conduct a transmission channel between the modulation unit and the corresponding third antenna, so as to send the modulated tag inventory instruction through the corresponding third antenna.

10. The internet of things communication system of claim 9, wherein the second gateway further comprises a mobile communication CPE module connected to the management control module;

the mobile communication CPE module is used for communicating with a base station.

11. The IOT communication system of claim 9,

the protocol processing module is further configured to send initial configuration information to the management control module before sending the tag inventory instruction; the initial configuration information comprises a carrier frequency of the data channel, a carrier frequency and/or an antenna number of the bearer channel;

The management control module is further configured to perform configuration according to the initial configuration information.

12. The communication method of the Internet of things is characterized by being applied to a communication system of the Internet of things, wherein the system comprises a first gateway and a second gateway, the first gateway comprises a tag radio frequency receiving module, and the second gateway comprises a tag radio frequency transmitting module; the method comprises the following steps: