Communication method and device, storage medium and program product

Abstract

The embodiment of the invention provides a communication method and device, a storage medium and a program product, relates to the technical field of communication, and can process a downlink carrier measurement signal to generate a related back reflection measurement signal and ensure the correlation between the carrier measurement signal and the back reflection measurement signal so as to meet the requirements of distance measurement and positioning. The method is applied to a terminal node in an Internet of Things system, and comprises the following steps: receiving carrier measurement signals continuously sent by a center node in the Internet of Things system; and sending a back reflection measurement signal generated based on the carrier measurement signal to the central node, wherein the sending time of the back reflection measurement signal is within the time range of continuously sending the carrier measurement signal by the central node.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technology, and in particular to a communication method, device, storage medium and program product. Background Art

[0002] With the continuous advancement of radio technology, a variety of radio services have emerged in large numbers. A basic network or cell of traditional wireless communication generally includes a central node (such as a base station) and multiple terminal nodes (such as user equipment (UE)). For example, the central node and terminal nodes in the Internet of Things (IoT) scenario.

[0003] Currently, in IoT scenarios, terminal nodes usually back-reflect the carrier signal sent by the central node and carry information on the reflected signal to achieve communication with the central node. However, since the terminal node is an IoT device, it is limited by factors such as energy consumption and cost. The signal uploaded by the terminal node to the central node is difficult to meet the requirements of ranging and positioning between the central node and the terminal node.

[0004] Therefore, how to process the downlink carrier measurement signal to generate a related backscatter measurement signal and ensure the correlation between the carrier measurement signal and the backscatter measurement signal to meet the requirements of ranging and positioning has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The embodiments of the present disclosure provide a communication method, device, storage medium and program product, which can process a downlink carrier measurement signal to generate a related backscatter measurement signal, ensure the correlation between the carrier measurement signal and the backscatter measurement signal, and meet the requirements of ranging and positioning.

[0006] On the one hand, a communication method is provided, which is applied to a terminal node in an Internet of Things system, including: receiving a carrier measurement signal continuously sent by a central node in the Internet of Things system; sending a back-talk measurement signal generated based on the carrier measurement signal to the central node, wherein the sending time of the back-talk measurement signal is within the time range in which the central node continuously sends the carrier measurement signal.

[0007] On the other hand, a communication method is provided, which is applied to a central node in an Internet of Things system, comprising: continuously sending a carrier measurement signal to a terminal node in the Internet of Things system; receiving a back-reflection measurement signal generated based on the carrier measurement signal and sent by the terminal node, wherein the sending time of the back-reflection measurement signal is within the time range in which the central node continuously sends the carrier measurement signal.

[0008] On the other hand, a communication device is provided, which is applied to a terminal node in an Internet of Things system. The device includes: a receiving module and a sending module.

[0009] The receiving module is used to receive the carrier measurement signal continuously sent by the central node in the Internet of Things system; the sending module is used to send the back-reflection measurement signal generated based on the carrier measurement signal to the central node, and the sending time of the back-reflection measurement signal is within the time range of the central node continuously sending the carrier measurement signal.

[0010] On the other hand, a communication device is provided, which is applied to a central node in an Internet of Things system. The device includes: a sending module and a receiving module.

[0011] The sending module is used to continuously send a carrier measurement signal to a terminal node in the Internet of Things system; the receiving module receives a back-reflection measurement signal generated based on the carrier measurement signal and sent by the terminal node, and the sending time of the back-reflection measurement signal is within the time range of the central node continuously sending the carrier measurement signal.

[0012] In another aspect, a communication device is provided, comprising: a memory and a processor. The memory and the processor are coupled. The memory is used to store a computer program. When the processor executes the computer program, the communication method of any of the above embodiments is implemented.

[0013] On the other hand, a computer-readable storage medium is provided, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the communication method of any of the above embodiments is implemented.

[0014] On the other hand, a computer program product is provided, which includes computer program instructions, and when the computer program instructions are executed, the communication method of any of the above embodiments is implemented.

[0015] The disclosed embodiment discloses that the terminal node feeds back the back-reflection measurement signal during the continuous transmission of the carrier measurement signal by the central node, so that the central node can obtain the carrier measurement signal and the back-reflection measurement signal at the same time, and the carrier measurement signal at the historical moment responded by the back-reflection measurement signal is related to the carrier measurement signal sent at the current moment. In this way, the downlink carrier measurement signal can be processed to generate a related back-reflection measurement signal, ensuring the coexistence of the carrier measurement signal and the back-reflection measurement signal in the time domain, and improving the correlation between the carrier measurement signal and the back-reflection measurement signal to meet the needs of ranging and positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present disclosure, the drawings required for use in some embodiments of the present disclosure will be briefly introduced below. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure, and a person skilled in the art can also obtain other drawings based on these drawings.

[0017] Figure 1 A schematic diagram of a communication system provided for some embodiments of the present disclosure;

[0018] Figure 2 An example schematic diagram of a distance measurement provided in some embodiments of the present disclosure;

[0019] Figure 3 A flow chart of a communication method provided in some embodiments of the present disclosure;

[0020] Figure 4 A flowchart of another communication method provided for some embodiments of the present disclosure;

[0021] Figure 5 An example diagram of a time relationship between measurement signals provided in some embodiments of the present disclosure;

[0022] Figure 6 A flowchart of another communication method provided for some embodiments of the present disclosure;

[0023] Figure 7 A schematic diagram of a communication device provided in some embodiments of the present disclosure Figure 1 ;

[0024] Figure 8 A schematic diagram of a communication device provided in some embodiments of the present disclosure Figure 2 ;

[0025] Fig. 9 A schematic diagram of a communication device provided in some embodiments of the present disclosure Figure 3 . DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the present disclosure to clearly and completely describe the technical solutions in the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0027] It should be noted that, in the present disclosure, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present disclosure should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0028] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0029] In the description of the present disclosure, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, "at least one" means one or more, and "a plurality" means two or more.

[0030] With the continuous advancement of radio technology, various radio services have emerged in large numbers. A basic network or cell of traditional wireless communication generally includes a central node and multiple terminal nodes, such as the communication between a base station and multiple user terminals in a cellular network, including the fourth generation mobile communication technology (4G), the fifth generation mobile communication technology (5G), and the sixth generation mobile communication technology (6G); the communication between access points (AP) and stations (STA) in wireless local area networks; the communication between master nodes and subordinate nodes in wireless personal area networks (including Bluetooth); the communication between G nodes (management nodes) and T nodes (terminal nodes) in new short-range communications (such as Star Flash communications), etc. In the above wireless communications, the communication from the central node to the terminal node is generally called downlink (DL), while the communication from the terminal node to the central node is called uplink (UL), the direct communication between the terminal nodes can be called sidelink (SL), and the communication between the central nodes is called peer-to-peer communication (PL).

[0031] The IoT scenario includes a special scenario where the terminal node can obtain energy from the surrounding environment for communication, so it is also called ambient-IoT (A-IoT) or passive-IoT. The network structure of A-IoT wireless communication is similar to traditional wireless communication, that is, it includes central nodes and terminal nodes. The A-IoT central node is also called a reader, a reader-writer, an interrogator, etc., and the central node in IoT communication will be referred to as a reader in the future. The A-IoT terminal node is a low-cost IoT device that may not have a battery and can respond to the communication of the central node. It can also be called a tag and an A-IoT device. From the perspective of the A-IoT system, in addition to the above-mentioned central nodes and terminal nodes, it can also include network-side devices, including devices for configuring and managing communications, background databases, servers and other high-level network entities; it can also include special energy supply devices or carrier transmitters. For example, the energy supply of an A-IoT tag can come from the surrounding environment, such as light energy, radio frequency energy, etc., or special equipment can be used to provide energy or carrier to the tag. In addition, these special devices can also be integrated in the reader or deployed independently. Such devices can also be considered as a special reader.

[0032] For the convenience of description, the communication from reader to tag can be called forward communication (forward link, FL), also known as IoT DL communication, and the communication from tag to reader is called reverse communication (return / reverse link, RL), also known as IoT UL communication.

[0033] Tags can use backscattering technology to send signals to readers. Generally, readers or dedicated CW transmitters send unmodulated CW signals to tags, and tags use CW signals as carrier reflections to generate their own transmission signals. Generally, tags will modulate their own information onto the reflected signal while reflecting CW signals, thereby transmitting information from tags to readers. Tag modulation and reflection of CW is also called backscattering modulation. It can be seen that in this way, the carrier that carries the tag information is not generated by the tag itself, but comes from an external reader or CW transmitter.

[0034] At present, high-precision ranging and positioning systems based on traditional communications generally require that the measurement signal has a large bandwidth and that high-precision synchronization be achieved between communication devices, such as time and frequency. However, for IoT devices, especially environmental IoT devices, due to limitations in energy consumption, cost and other factors, these devices generally do not have strong synchronization capabilities, do not have high-precision clocks, and have very narrow operating bandwidths. How to achieve high-precision ranging and positioning based on these IoT devices is a problem that needs to be solved for future communications, including 6G communications.

[0035] That is to say, since the terminal nodes are IoT devices, they are limited by factors such as energy consumption and cost. The signals uploaded by the terminal nodes to the central nodes are difficult to meet the requirements of ranging and positioning between the central node and the terminal nodes.

[0036] In summary, how to process the downlink carrier measurement signal to generate a related backscatter measurement signal and ensure the correlation between the carrier measurement signal and the backscatter measurement signal to meet the requirements of ranging and positioning has become a technical problem that needs to be solved urgently.

[0037] Based on this, in order to solve the above technical problems, the embodiments of the present disclosure provide a communication method, which is applied to the ranging and positioning scenario between IoT devices. The terminal node feeds back the back-reflection measurement signal during the continuous transmission of the carrier measurement signal by the central node, so that the central node can obtain the carrier measurement signal and the back-reflection measurement signal at the same time, and the carrier measurement signal at the historical moment responded by the back-reflection measurement signal is related to the carrier measurement signal sent at the current moment. In this way, the downlink carrier measurement signal can be processed to generate a related back-reflection measurement signal, ensuring the coexistence of the carrier measurement signal and the back-reflection measurement signal in the time domain, and improving the correlation between the carrier measurement signal and the back-reflection measurement signal to meet the needs of ranging and positioning.

[0038] The network architecture of the mobile communication network (including but not limited to 2G, 3G, 4G, 5G and future mobile communication networks (such as the evolution of the fifth generation mobile communication technology (5th generation mobile communication technology Advanced, 5G-A), the sixth generation mobile communication technology (6th generation mobile communication technology, 6G)) in the disclosed embodiment may include at least a first communication node and a second communication node. It should be understood that in this example, in the uplink, the first communication node may be a terminal side device (for example, including but not limited to a terminal), and the second communication node may be a network (network, NW) side device (for example, including but not limited to a base station). Of course, in the downlink, the first communication node may also be a network side device, and the second communication node may also be a terminal side device. In the device-to-device communication between the two communication nodes, the first communication node and the second communication node may both be a base station or a terminal. The first communication node and the second communication node may be referred to as the first node and the second node, respectively.

[0039] Alternatively, in the communication of the Internet of Things system, the first node in the uplink may be a terminal node and the second node may be a central node, and the first node in the downlink may be a central node and the second node may be a terminal node.

[0040] For example, Figure 1 As shown, it is a schematic diagram of a communication system provided in an embodiment of the present disclosure, and the communication system may include: at least one terminal node (such as terminal node 101, terminal node 102 and terminal node 103) and a central node 104, and the terminal node 101, terminal node 102, terminal node 103 and central node 104 constitute an Internet of Things system.

[0041] Among them, the central node 104 can continuously send a carrier measurement signal to any terminal node (such as terminal node 101) in at least one terminal node for a period of time. Then, the terminal node 101 can generate a backscatter measurement signal from the carrier measurement signal using the backscattering technology, and feed back the backscatter measurement signal to the central node 104 during the duration of the central node 104 sending the carrier measurement signal, ensuring that the central node 104 receives the backscatter measurement signal fed back by the terminal node 101 during the continuous transmission of the carrier measurement signal, so that the carrier measurement signal and the backscatter measurement signal can be obtained at the same time, ensuring the coexistence of the carrier measurement signal and the backscatter measurement signal in the time domain, and improving the correlation between the carrier measurement signal and the backscatter measurement signal to meet the requirements of ranging and positioning.

[0042] Similarly, the central node 104 can also continuously send a carrier measurement signal to the terminal node 102 (or the terminal node 103), and receive a back-reflection measurement signal fed back by the terminal node 102 (or the terminal node 103) during the continuous sending process, to ensure the coexistence of the carrier measurement signal and the back-reflection measurement signal in the time domain, and to improve the correlation between the carrier measurement signal and the back-reflection measurement signal to meet the requirements of ranging and positioning.

[0043] For example, tag refers to the terminal node (which can be a traditional UE or an IoT device that obtains energy from the environment or a battery), and it is assumed here that the tag has the ability of backscattering transmission; reader refers to the central node (which can be a traditional base station, UE, CW transmitter and other devices), and it is assumed here that the reader can receive the back-reflected signal of the tag. In addition, the reader can also send a CW measurement signal. From the technical characteristics of backscattering, it can be seen that from a temporal point of view, the back-reflected signal of the tag is within the CW measurement signal sent by the reader. The embodiment of the present disclosure designs a high-precision positioning or ranging method based on the Internet of Things based on the characteristics of backscattering technology (since ranging and positioning are strongly related, positioning and ranging are not strictly distinguished in the future).

[0044] For example, Figure 2 As shown, it shows a schematic diagram of an example of ranging. The reader in the figure is responsible for the measurement process, and the tag only needs to process the CW measurement signal in a certain way to generate a back reflection measurement signal (i.e. CW incident and back reflected after processing). In addition, the reader here can be a device, that is, the transmission and reception are deployed in a single station in one device (mono-static), or it can be two separate devices, that is, the transmission and reception are deployed in two stations in different devices (bi-static). The deployment of the reader is not strictly distinguished here, and it is uniformly referred to as a reader.

[0045] In an embodiment of the present disclosure, the central node 104 may continuously send a carrier measurement signal to some of the terminal nodes in at least one terminal node (i.e., continuously send a carrier measurement signal in a targeted manner through time division), or the central node 104 may continuously send a carrier measurement signal to all terminal nodes in at least one terminal node at the same time (i.e., continuously send a carrier measurement signal through broadcasting).

[0046] It should be noted that all terminal nodes (such as terminal node 101, terminal node 102 and terminal node 103) and central node 104 may be terminals of the same type. Alternatively, all terminal nodes (such as terminal node 101, terminal node 102 and terminal node 103) and central node 104 may be terminals of different types. Alternatively, some of all terminal nodes and central node 104 are terminals of the same type, and the remaining terminal nodes and central node 104 are terminals of different types. Alternatively, all terminal nodes (such as terminal node 101, terminal node 102 and terminal node 103) are terminals, and central node 104 is a base station.

[0047] The terminal can be a device with wireless transceiver function. The terminal can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. The embodiments of the present disclosure do not limit the application scenarios. The terminal can sometimes also be called a user, user equipment (UE), A-IoT device, access terminal, UE unit, UE station, mobile station, mobile station, remote station, transmitter, remote terminal, mobile device, UE terminal, wireless communication equipment, UE agent or UE device, etc., and the embodiments of the present disclosure do not limit this.

[0048] A base station (BS) can be a base station or evolutionary node B (eNB or eNodeB) in LTE, long term evolution advanced (LTEA), a base station device (gNB) in a 5G network, or a base station in a future communication system. A base station can include various macro base stations, micro base stations, home base stations, wireless remote stations, reconfigurable intelligent surfaces (RISs), routers, relay stations, transmission and reception points (TRP), receivers, access points, wireless fidelity (WIFI) devices and other network-side devices. A base station can sometimes also be called a reader / writer for communicating with a terminal.

[0049] It should be noted that Figure 1 This is just an exemplary framework diagram. Figure 1 The number of devices included in the Figure 1 In addition to the devices shown, the communication system may also include other devices, such as core network devices.

[0050] The application scenarios of the embodiments of the present disclosure are not limited. The system architecture and business scenarios described in the embodiments of the present disclosure are intended to more clearly illustrate the technical solutions of the embodiments of the present disclosure, and do not constitute a limitation on the technical solutions provided by the embodiments of the present disclosure. It is known to those skilled in the art that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided by the embodiments of the present disclosure are also applicable to similar technical problems.

[0051] Figure 3 A flow chart of a communication method is shown, Figure 3 As shown, the communication method is applied to a terminal node in an Internet of Things system, including:

[0052] S301: Receive a carrier measurement signal continuously sent by a central node in an Internet of Things system.

[0053] Among them, the carrier measurement signal is a measurement signal pre-agreed by the terminal node and the central node in the Internet of Things system for ranging and positioning, and the carrier measurement signal can also be called a measurement signal or a ranging signal.

[0054] As a possible implementation method, the terminal node can detect whether there is a carrier measurement signal sent by the central node in the surrounding area within a preset time window (such as a periodic time window), and continuously receive the carrier measurement signal sent by the central node within the preset time window.

[0055] Optionally, the central node may also continuously send the carrier measurement signal to the surrounding terminal nodes within a time window, so that the surrounding terminal nodes can continuously receive the carrier measurement signal sent by the central node.

[0056] It should be noted that the time window in which the central node continuously sends the carrier measurement signal matches the time window in which the terminal node detects the carrier measurement signal. For example, the time window in which the central node continuously sends the carrier measurement signal includes the time window in which the terminal node detects the carrier measurement signal. For another example, the time window in which the terminal node detects the carrier measurement signal includes the time window in which the central node continuously sends the carrier measurement signal. For another example, the time window in which the central node continuously sends the carrier measurement signal is the same as the time window in which the terminal node detects the carrier measurement signal.

[0057] Alternatively, the time window for the terminal node to detect the carrier measurement signal may be configured by the central node through signaling.

[0058] In an embodiment of the present disclosure, a terminal node may receive first notification information sent by a central node, the first notification information including time domain location information for indicating at least one measurement time zone. Then, the terminal node may receive a carrier measurement signal continuously sent by the central node in each measurement time zone indicated by the time domain location information.

[0059] The central node may also continuously send a carrier measurement signal to the terminal node in each measurement time zone indicated by the time domain location information.

[0060] Exemplarily, if at least one measurement time zone indicated by the time domain location information includes: time zone A and time zone B, the central node may continuously send a carrier measurement signal to the terminal node in time zone A, and the terminal node may continuously detect and receive the carrier measurement signal sent by the central node in time zone A. Similarly, the central node may continuously send a carrier measurement signal to the terminal node in time zone B, and the terminal node may continuously detect and receive the carrier measurement signal sent by the central node in time zone B.

[0061] That is, the central node informs the terminal node in advance of the time range for ranging and positioning, so that the central node and the terminal node can perform ranging and positioning within the predetermined time range.

[0062] It should be noted that the above-mentioned time domain location information may include at least one of the following (1)-(6):

[0063] (1) the duration of each measurement time zone in at least one measurement time zone;

[0064] (2) a starting point of each measurement time zone in at least one measurement time zone;

[0065] (3) an end point of each measurement time zone in at least one measurement time zone;

[0066] (4) the number of each measurement time zone in at least one measurement time zone;

[0067] (5) the total duration of at least one measurement time zone;

[0068] (6) The interval between two adjacent measurement time zones in at least one measurement time zone.

[0069] That is to say, for the time domain position of a measurement time zone, it can generally be uniquely determined using the start point and the end point, or it can be uniquely determined using the start point or the end point plus a duration, and there is no restriction here. If there are multiple time zones, it may be necessary to indicate the number of time zones. If multiple time zones are continuous, the time domain positions of other time zones can be inferred by the position of one time zone (for example, the first time zone), thereby saving indication overhead. For example, if the position of the nth time zone is known, then it can be known that the starting position of the n+1th time zone is equal to the end position of the nth time zone, and the indication information of the starting point can be saved. If multiple time zones are non-continuous, it is generally necessary to determine the interval between the time zones. The interval can be directly indicated or calculated through other indication information, such as indicating the total duration of multiple time zones, and then based on the time domain position information of each time zone, it is equivalent to knowing the interval.

[0070] Similarly, part of this information can be explicitly indicated or configured to the tag (i.e., terminal node) through signaling, part of this information can be predefined, part of this information can be determined implicitly, or a combination of these notification methods, and the notification method is not limited here.

[0071] In this way, the central node describes the specific information of each measurement time zone to the terminal node so that the terminal node can accurately locate each measurement time zone to ensure the coexistence of subsequent carrier measurement signals and back-reflection measurement signals in the time domain, thereby improving the correlation between the carrier measurement signals and the back-reflection measurement signals.

[0072] It should be noted that a measurement time zone can also be dynamically activated by a specific signal. For example, the reader (i.e., the central node) can send a signaling or trigger signal to trigger the activation of at least one measurement time zone. At this time, the signaling or trigger signal can also be considered as a type of communication information. For example, a special preamble signal (preamble) or synchronization signal (sync signal) can be used to activate one or more measurement processes.

[0073] As a possible implementation, the first notification information may also include trigger information for starting at least one measurement time zone. In the process in which the terminal node receives the carrier measurement signal continuously sent by the central node in each measurement time zone indicated by the time domain location information, the terminal node may receive the carrier measurement signal continuously sent by the central node in each measurement time zone indicated by the time domain location information in response to the trigger information.

[0074] That is to say, when the central node informs the terminal node in advance of the time range for ranging and positioning, the central node can also promptly inform the terminal node to use (i.e., turn on) the trigger stimulus for the time range, so that the terminal node can prepare in time to perform ranging and positioning with the central node within the predetermined time range.

[0075] Optionally, after the terminal node receives the first notification information sent by the central node, the terminal node may also receive trigger information from the central node for any measurement time zone in at least one measurement time zone indicated by the first notification information, and then receive the carrier measurement signal continuously sent by the central node in the measurement time zone indicated by the trigger information.

[0076] That is to say, after the central node informs the terminal node in advance of the time range for ranging and positioning (i.e., the time range for scheduled ranging and positioning), the central node can also promptly inform the terminal node to use (i.e., turn on) the trigger stimulus for the time range, so that the terminal node can prepare in time to perform ranging and positioning with the central node within the scheduled time range.

[0077] In some embodiments, after the terminal node receives the carrier measurement signal continuously sent by the central node in each measurement time zone, the terminal node may respectively determine the mode of the corresponding carrier measurement signal in each measurement time zone.

[0078] The mode of the carrier measurement signal may be any one of the following (1)-(4):

[0079] Single carrier mode using a single frequency component;

[0080] A multi-carrier mode using at least two frequency components;

[0081] A carrier modulation mode modulated by a modulation signal having a preset frequency component;

[0082] The carrier frequency switching mode of the frequency component used for periodic / non-periodic switching.

[0083] That is to say, the CW measurement signal used by the reader for measurement can be a known signal that does not carry information. The CW measurement signal can be a single-carrier mode, for example, a sine wave or cosine wave with a single frequency component, where the frequency is denoted as fc. Or the CW measurement signal can be a multi-carrier mode, that is, it contains at least two frequency components, for example, two carriers with frequencies f1 and f2. According to the modulation principle, general modulation will also contain multiple frequency components. For example, when a signal amplitude of a frequency fm is used to modulate a carrier with a frequency fc to generate CW, the CW measurement signal will at least contain frequency components with frequencies fc+fm and fc-fm, and may also contain a frequency component of fc. It can be seen that there is no essential difference between the multi-carrier mode and the carrier modulation mode, and both will have multiple frequency components at the same time at any time.

[0084] As for the carrier frequency switching mode, the frequency components contained in the CW measurement signal at different times may be different, for example, the frequency components contained in the CW measurement signal are switched according to a certain rule. In one example, it can be a single carrier switching mode, that is, in time, the CW measurement signal switches between at least two frequency components, at a specific time 1, the CW measurement signal contains a single frequency component f1, at a specific time 2, the CW measurement signal contains a single frequency component f2, and so on.

[0085] Alternatively, it can be a multi-carrier switching mode, that is, in terms of time, the multi-carrier frequency components contained in the CW measurement signal at different times may be different. For example, at a specific time 1, the CW measurement signal contains frequency components f1 and f2, at a specific time 2, the CW measurement signal contains frequency components f3 and f4, and so on.

[0086] Alternatively, it may be any combination of the single-carrier switching mode and the multi-carrier switching mode. For example, at a specific time, the CW measurement signal includes a single frequency component, and at another specific time, the CW measurement signal includes multiple frequency components.

[0087] For the format of the CW measurement signal, the embodiment of the present disclosure may be predefined as a mode, that is, only one mode is supported or defaulted to, and as long as the measurement process is executed, CW adopts this mode by default, for example, defaults to single carrier mode, or other modes.

[0088] Alternatively, the measurement process may also support multiple CW measurement signal formats. In this case, it is necessary to determine which CW measurement signal format is used in a measurement process or a measurement time zone. Specifically, the reader may determine the format to be used autonomously, or determine it through configuration or indication information.

[0089] In this way, by distinguishing the models of the carrier measurement signals, the carrier measurement signals used for ranging and positioning in different time ranges (ie, measurement time zones) can be identified, making it easier to distinguish and count the results of multiple ranging and positioning.

[0090] It should be noted that a measurement time zone here can also be understood as a group of measurement resources. Generally, it is difficult to achieve high-precision ranging through a measurement process in a measurement time zone, so the reader (i.e., the central node) needs to allocate multiple groups of measurement resources for measurement. The CW measurement signals sent in different measurement processes can be different, for example, the format of CW, the carrier frequency of CW, etc. can be different, and the processing of the back-reflected CW generated by the tag (i.e., the terminal node) in different measurement processes can also be different. In addition, if multiple tags are involved in the above process, the above process can be performed independently for each tag, for example, different tags can be arranged at different times, or different frequency domain resources at the same time for measurement, and a tag will be described later. The usual measurement process requires the reader and tag to cooperate with each other to complete, so the reader needs to notify the tag of relevant measurement information here, and these measurement information at least includes the information of the measurement time zone (measurement resource). In addition, the tag can also be notified how to process the CW measurement signal in a measurement time zone to generate the corresponding back-reflected measurement signal, such as the following embodiment. The notification information here can be sent to the tag at one time or in multiple times, and the specific sending method is not limited here.

[0091] In some embodiments, the terminal node can perform targeted processing on the continuously received carrier measurement signal (such as S302 below) so that the back-reflection measurement signal fed back to the central node and the carrier measurement signal sent by the central node coexist in the time domain, thereby improving the correlation between the carrier measurement signal and the back-reflection measurement signal.

[0092] S302: Send a backscatter measurement signal generated based on the carrier measurement signal to the central node.

[0093] As a possible implementation, after receiving the carrier measurement signal from the central node, the terminal node can generate a backscatter measurement signal from the carrier measurement signal through a backscattering technique. The backscatter measurement signal may also be called a backscatter measurement signal or a backscatter ranging signal.

[0094] That is, the terminal node may back-reflect the carrier measurement signal from the central node, and send the back-reflected measurement signal generated by the carrier measurement signal to the central node.

[0095] The method of generating the backscatter measurement signal based on the carrier measurement signal may be any one of the following (1)-(4):

[0096] (1) Generated by the carrier measurement signal after back reflection (i.e. backscattering);

[0097] (2) Generated by the carrier measurement signal after back reflection and energy amplification;

[0098] (3) Generated by the carrier measurement signal after back reflection and signal modulation;

[0099] (4) Generated by the carrier measurement signal after back reflection, signal modulation and energy amplification.

[0100] In other words, the back reflection here can also be called reflection or total reflection. Simply reflecting the CW measurement signal will not change the frequency domain characteristics of the CW measurement signal. Amplification refers to increasing the energy of the back reflection measurement signal generated by the reflection. Similarly, amplification will not change the frequency domain characteristics of the CW measurement signal. For example, the reader sends a carrier with a frequency of f1 as a CW measurement signal, and the frequency of the back reflection measurement signal generated by the tag's simple back reflection is also f1.

[0101] In one instance, the terminal node can send a notification message to the central node to inform it of its ability to process the carrier measurement signal to generate a back-echo measurement signal or its ability to measure and locate the distance, which may include at least one of the following: whether it supports the generation of a back-echo measurement signal; supported methods for processing the carrier measurement signal to generate a back-echo measurement signal; supported measurement modes and other information.

[0102] For modulation, the back-reflection measurement signal generally has a frequency characteristic different from that of the CW measurement signal. For example, assuming that the CW measurement signal is a single carrier with a frequency of fc, the tag uses a signal amplitude modulation with a period of T and reflects the CW measurement signal. Then the generated back-reflection measurement signal has at least frequency components of fc+fd and fc-fd, where fd is equal to the inverse of T, and the amplitude or envelope of the back-reflection measurement signal changes according to the period T of the modulation signal. In addition to the above-mentioned amplitude modulation, this method of changing the frequency components contained in the CW measurement signal to generate the back-reflection measurement signal is collectively referred to as modulation, which may include frequency shifting, frequency doubling, frequency division, frequency expansion, amplitude modulation, phase modulation, frequency modulation, harmonic generation, etc., which are not listed here one by one.

[0103] It can be seen that although the back-reflection measurement signal can generate new frequency components through modulation, the new frequency components are still related to the frequency fc of the CW measurement signal. It can also be understood that the back-reflection measurement signal actually retains some characteristics associated with the carrier frequency fc, such as phase characteristics. This feature can be used here. The reader can extract the corresponding carrier signal receiving phase from the received back-reflection measurement signal, and derive the equivalent carrier phase difference based on the carrier transmission phase of the CW measurement signal currently sent, so as to facilitate subsequent ranging and positioning.

[0104] In this way, the terminal node can perform targeted processing on the carrier measurement signal from the central node in a variety of ways to match the correlation between the backscatter measurement signal and the carrier measurement signal in different scenarios.

[0105] It should be noted that, with respect to the specific method of generating a back-measurement signal based on a carrier measurement signal, the terminal node may select any one of the methods (1)-(4) above to execute, or the terminal node may select an indication method from the methods (1)-(4) above based on pre-configured signaling, or the terminal node may select an indication method from the methods (1)-(4) above based on signaling sent by a central node.

[0106] In the embodiment of the present disclosure, when the terminal node sends the back-talk measurement signal generated based on the carrier measurement signal to the central node, the terminal node may receive second notification information sent by the central node, where the second notification information is used to indicate a method for generating the back-talk measurement signal based on the carrier measurement signal. Then, the terminal node may select a method indicated by the second notification information from (1) to (4) above to generate the back-talk measurement signal.

[0107] That is to say, if the reader and the tag only support one measurement mode, that is, the tag has only one way of processing the backscattered measurement signal, then once the measurement process starts, the tag's processing mode for the CW measurement signal is determined by default.

[0108] If the reader and the tag support multiple measurement modes, that is, the tag supports multiple CW measurement signal processing modes, the reader can inform the tag how to process the CW measurement signal to generate a back-reflection measurement signal through notification information. The processing mode can be directly and explicitly notified as only reflection, or reflection and amplification, or reflection and modulation, or reflection, modulation and amplification. For example, these processing modes are numbered, and indicating the number of a certain processing mode is equivalent to indicating the processing mode. The processing mode can also be notified using a bitmap or other information indication mode. The specific indication method is not limited here.

[0109] Alternatively, one or more measurement modes may be predefined or configured, each measurement mode corresponding to its CW measurement signal processing method, and indicating the use of a certain measurement mode will determine the processing method of the CW measurement signal accordingly.

[0110] Alternatively, the reader may also implicitly instruct the tag how to process the CW measurement signal. For example, the format of the CW measurement signal sent by the reader may correspond to a certain processing method. The tag may implicitly determine how to process the CW measurement signal based on the format of the CW measurement signal notified by the reader or detected by itself. For example, if the CW measurement signal is in multi-carrier mode or carrier modulation mode, the tag processes the CW signal by default to back reflection only, or back reflection and amplification; if the CW measurement signal is in single carrier or single carrier frequency switching mode, the tag processes the CW measurement signal by default to back reflection and adjustment, or back reflection plus modulation and amplification. The correspondence between the CW measurement signal sending method of other readers and the tag's processing method of the CW measurement signal can also be used, which are not listed here one by one.

[0111] Alternatively, implicit and explicit indication methods may be used in combination. For example, a certain CW measurement signal transmission method may correspond to multiple CW processing methods. In order to determine the final processing method, explicit signaling may be used to further indicate one of the multiple corresponding CW processing methods.

[0112] In this way, the central node can directly instruct the terminal node on the response mode of the carrier measurement signal from the central node, so that the central node can distinguish and identify the back-talk measurement signal sent by the terminal node from multiple back-talk measurement signals.

[0113] It should be noted that, in the embodiment of the present disclosure, the time at which the terminal node sends the backscatter measurement signal is within the time range at which the central node continuously sends the carrier measurement signal.

[0114] That is to say, the terminal node feeds back the back-reflection measurement signal during the continuous transmission of the carrier measurement signal by the central node, so that the central node can obtain the carrier measurement signal and the back-reflection measurement signal at the same time, and the carrier measurement signal at the historical moment responded by the back-reflection measurement signal is related to the carrier measurement signal sent at the current moment. In this way, the downlink carrier measurement signal can be processed to generate a related back-reflection measurement signal, ensuring the coexistence of the carrier measurement signal and the back-reflection measurement signal in the time domain, and improving the correlation between the carrier measurement signal and the back-reflection measurement signal to meet the needs of ranging and positioning.

[0115] As a possible implementation manner, in combination with the above embodiment, the terminal node may send a back-scattered measurement signal to the central node within each measurement time zone indicated by the time domain location information.

[0116] Among them, the measurement time zone is located within the time range in which the central node continuously sends the carrier measurement signal, and the difference between the end time point of the measurement time zone and the end time point of the time range in which the carrier measurement signal is continuously sent is greater than or equal to the transmission delay of the back-propagation measurement signal from the terminal node to the central node.

[0117] In some embodiments, during the process of a terminal node sending a back-measurement signal to a central node, the terminal node may receive a third notification message sent by the central node, and then send a back-measurement signal to the central node based on the time domain / frequency domain / power parameter information indicated by the third notification message.

[0118] The third notification information may include at least one of the following (1)-(3):

[0119] (1) Time domain parameter information of the reflected measurement signal;

[0120] (2) Frequency domain parameter information of the reflected measurement signal;

[0121] (3) Power parameter information of the reflected measurement signal.

[0122] That is, the back-scattering measurement signal sent by the terminal node to the central node meets the time domain / frequency domain / power transmission requirements indicated by the third notification information.

[0123] It should be noted that the time domain parameter information may include at least one of the following (1.1)-(1.4):

[0124] (1.1) The transmission duration of the backscatter measurement signal;

[0125] (1.2) The symbol length of the back-reflection measurement signal;

[0126] (1.3) The symbol period of the back-reflection measurement signal;

[0127] (4) The sending time and position information of the back-reflection measurement signal.

[0128] Furthermore, the frequency domain parameter information may include at least one of the following (2.1)-(2.3):

[0129] (2.1) Frequency domain position of the reflected measurement signal;

[0130] (2.2) The relative position of the backscattered measurement signal and the carrier measurement signal in the frequency domain;

[0131] (2.3) The modulated carrier measures the frequency domain information of the modulated signal.

[0132] In addition, the power parameter information may include at least one of the following (3.1) and (3.2):

[0133] (3.1) Power level of the reflected measurement signal;

[0134] (3.2) Amplification factor of the back reflection measurement signal.

[0135] That is to say, in order to better receive the backscatter measurement signal of the tag and obtain measurement information together with the CW measurement signal, the reader can not only qualitatively control the way the tag processes the CW measurement signal to generate the backscatter measurement signal, but also quantitatively control how the tag generates the backscatter measurement signal. As mentioned above, the time domain parameters, frequency domain parameters, power parameters, etc. of the backscatter measurement signal can be controlled.

[0136] In some embodiments, before the terminal node sends the backlash measurement signal to the central node, the terminal node may first send a start signal or a preamble signal to the central node, where the start signal or the preamble signal is used to indicate the start of sending the backlash measurement signal.

[0137] That is, before feeding back the backscatter measurement signal to the central node, the terminal node may inform the central node in advance of the timing of sending the backscatter measurement signal, so that the central node can prepare for receiving the backscatter measurement signal from the terminal node to avoid omission.

[0138] In some embodiments, the terminal node may also send geographic location information of the terminal node to the central node. The information may be sent before, during or after the distance measurement process.

[0139] In this way, the central node can simultaneously use the ranging results of the carrier measurement signal and the backscatter measurement signal and the geographical location information of the terminal node for positioning, that is, in the case of the relative distance between the central node and the terminal node, the coordinate position of the central node is combined with the coordinate position of the terminal node. For example, according to the three-point positioning method, the central node can determine the geographical location of the central node based on the relative distance to at least three terminal nodes and the geographical location information of these terminal nodes.

[0140] The present disclosure also provides a communication method, which is applied to a central node in an Internet of Things system. Figure 4 As shown, the communication method may include:

[0141] S401. Continuously send a carrier measurement signal to a terminal node in an Internet of Things system.

[0142] As a possible implementation method, in the process of the central node continuously sending a carrier measurement signal to the terminal node, the central node can first send a first notification message to the terminal node, and then continuously send a carrier measurement signal to the terminal node within each measurement time zone indicated by the time domain location information in the first notification message.

[0143] It should be noted that, for the introduction of the time domain location information and the measurement time zone, reference may be made to the description in the above embodiment, which will not be repeated here.

[0144] Optionally, the first notification information may further include trigger information for starting at least one measurement time zone.

[0145] It should be noted that, for the application process of the trigger information, reference may be made to the description in the above embodiment, which will not be described in detail here.

[0146] In the embodiment of the present disclosure, before the central node sends the carrier measurement signal to the terminal node, the central node may determine a signal mode, and then send the carrier measurement signal to the terminal node based on the determined signal mode.

[0147] The carrier measurement signal satisfies any one of the following (1)-(4):

[0148] (1) Single carrier mode using a single frequency component;

[0149] (2) a multi-carrier mode using at least two frequency components;

[0150] (3) a carrier modulation mode modulated by a modulation signal having a preset frequency component;

[0151] (4) Carrier frequency switching pattern of frequency components used for periodic / non-periodic switching.

[0152] It should be noted that for the introduction of the signal modes in (1)-(4) above, reference can be made to the description in the above embodiments and will not be repeated here.

[0153] S402: Receive a backscatter measurement signal generated based on a carrier measurement signal and sent by a terminal node.

[0154] It should be noted that, for the introduction of the back reflection measurement signal, reference may be made to the description in the above embodiment, which will not be repeated here.

[0155] As a possible implementation manner, before the central node receives the backscatter measurement signal sent by the terminal node, the central node may also send second notification information to the terminal node, where the second notification information is used to indicate a manner of generating the backscatter measurement signal based on the carrier measurement signal.

[0156] It should be noted that, for the introduction of the method of generating the back-reflection measurement signal based on the carrier measurement signal, reference may be made to the description in the above embodiment, which will not be described in detail here.

[0157] Optionally, before the central node receives the back-measurement signal sent by the terminal node, the central node may also send third notification information to the terminal node.

[0158] It should be noted that, for the introduction of the third notification information, reference may be made to the description in the above embodiment, which will not be repeated here.

[0159] In the embodiment of the present disclosure, in the process of receiving the back-talk measurement signal sent by the terminal node, the central node may first receive the start signal or the pilot signal sent by the terminal node, and the start signal or the pilot signal is used to indicate the start of sending the back-talk measurement signal. Then, the central node may detect and receive the back-talk measurement signal sent by the terminal node in response to the start signal or the pilot signal.

[0160] In some embodiments, after receiving the backscatter measurement signal sent by the terminal node, the central node may determine the distance between the central node and the terminal node according to the phase difference between the carrier measurement signal and the backscatter measurement signal.

[0161] That is to say, the central node can accurately measure the distance between the central node and the terminal node based on the phase difference between the downlink measurement signal and the backscatter measurement signal transmitted at the same time.

[0162] It should be noted that, in the embodiment of the present disclosure, when the frequency of the back reflection measurement signal is the same as the frequency of the carrier measurement signal, or when the method of generating the back reflection measurement signal based on the carrier measurement signal does not include modulation, the phase difference includes at least one of the following:

[0163] The carrier phase difference between the back reflection measurement signal and the carrier measurement signal;

[0164] The envelope phase difference between the reflection measurement signal and the carrier measurement signal.

[0165] That is, if the reader has explicitly requested the tag in the second notification information to process the CW measurement signal in a manner that does not include modulation, the reader may consider that the carrier phase difference and / or envelope phase difference is used.

[0166] In addition, when the frequency of the back reflection measurement signal is different from the frequency of the carrier measurement signal, or when the method of generating the back reflection measurement signal based on the carrier measurement signal includes modulation, the phase difference includes at least one of the following:

[0167] The equivalent carrier phase difference between the back reflection measurement signal and the carrier measurement signal at the same frequency;

[0168] The equivalent envelope phase difference between the reflection measurement signal and the carrier measurement signal at the same frequency.

[0169] That is, if the reader has explicitly requested the tag in the second notification information to process the CW measurement signal in a manner including modulation, the reader may consider that an equivalent carrier phase difference and / or an equivalent envelope phase difference is used.

[0170] It should be noted that the embodiment of the present disclosure obtains high-precision distance measurement based on phase difference, that is, a distance measurement process includes sending a CW measurement signal, receiving a back-reflection measurement signal from a tag, obtaining the phase difference between the sent CW measurement signal and the back-reflection measurement signal received from the tag, and finally obtaining the distance between the reader and the corresponding tag based on at least one phase difference according to the principles of communication and electromagnetic wave propagation. Among them, only when the CW measurement signal and the back-reflection measurement signal exist at the same time at a certain moment can the phase difference be measured based on the two at that moment.

[0171] For example, in the time domain, assuming that the measurement time zone includes a measurement process, the time relationship between the two measurement signals in a measurement process is as follows: Figure 5 The time of the back-reflection measurement signal is included in the CW measurement signal time, and its duration is generally less than or equal to the sending duration of the CW measurement signal, and also less than the duration of the measurement time zone. In order to ensure the completion of the measurement process, the sending duration of the CW measurement signal may be greater than or equal to the length of the measurement time zone.

[0172] Moreover, the phase difference may be measured in different ways according to the difference between the CW measurement signal and the back reflection measurement signal, and the measurement result of the phase difference may also have different meanings. For example, the phase difference may be a carrier phase difference, an equivalent carrier phase difference, a signal envelope phase difference, an equivalent signal envelope phase difference, etc. If there are multiple measurement processes in multiple measurement time zones, or a measurement time zone may perform multiple measurement processes, and multiple phase differences corresponding to the multiple measurement processes may be obtained, then the distance information may be obtained based on the multiple phase differences, for example, the distance information may be obtained based on the difference between the phase differences of two measurement processes.

[0173] The distance measurement method provided by the embodiment of the present disclosure is introduced below with reference to specific examples.

[0174] Example 1: Ranging principle based on carrier phase difference in back-to-back communication.

[0175] 1.1. A single-frequency CW measurement signal (i.e., carrier) is transmitted from the reader (R) to the tag device (D). Assuming the frequency is f, the wavelength is Where c is the speed of light. According to the electromagnetic wave transmission theory, at any time t, there is a phase difference between the phase of the CW measurement signal emitted by R and the phase of the CW measurement signal received at D at that time. This phase difference is only related to the distance d between the two. According to this principle, if the emission phase of R can be obtained at the same time, and the receiving phase of D Then the distance d can be calculated in reverse based on the phase difference to complete the ranging process.

[0176] However, due to the cost limitation of tags, it is impossible to measure the phase of R and D at the same time. In particular, tags cannot measure their own receiving phase. Readers, as devices with stronger capabilities, can measure it. Considering this, the tag can reflect the CW measurement signal back to the reader, and the reader can detect the receiving phase of the back-reflected measurement signal. Simultaneously measure the transmit phase on the reader side and receiving phase Phase difference can also be obtained And then get the distance information.

[0177] For example, without considering the phase change introduced by tag back reflection, the distance d can be determined by the following formulas 1 and 2:

[0178]

[0179] Among them, n is used to indicate Business.

[0180] 1.2. Considering that the above measurement method is only valid when the distance d is comparable to the wavelength, for example, comparable means that the distance is less than or equal to the wavelength or half the wavelength, but the frequency used by the communication system is generally higher, such as the microwave band, the corresponding wavelength is shorter, and the measurement distance of this method is also shorter. Therefore, for IoT communication, the above measurement method cannot be used directly and needs to be improved. This problem can be solved by using multiple carrier frequencies to perform multiple measurement processes. The following takes two carrier frequencies as an example for explanation. Multiple measurement processes are similar and will not be repeated here.

[0181] In the first measurement process, a signal with a frequency of f is emitted from the reader (R). 1 Carrier, according to the above process, the tag back-reflects the back-reflected measurement signal corresponding to the frequency, and R obtains the phase difference corresponding to the carrier frequency Similarly, in the second measurement process, a frequency of f is emitted. 2 Carrier, according to the above process to obtain the phase difference corresponding to the carrier frequency According to the relevant principles and The difference It is also related to the distance, and the distance range that the difference can measure is the same as λ d Comparable, where λ d Equal to the speed of light divided by f 1 and f 2 It can be seen that although f 1 and f 2 The frequency of is higher and the wavelength is shorter, but the difference fd between the two is generally small and controllable, which increases the range of the measurement distance, that is, and λ d Comparable, i.e. less than or equal to λ d or d half.

[0182] In this way, the distance d can be determined by the following formulas 3 and 4:

[0183]

[0184] Among them, n is used to indicate Business.

[0185] In some embodiments, the reader may be combined with and and their difference To obtain a higher precision distance measurement, for example, first Get low-precision measurements over long distances, and then and / or Get higher-precision measurement results.

[0186] Considering that surrounding objects will also reflect the CW measurement signal sent by the reader, in order to allow the reader to obtain the desired phase difference information more accurately, it is possible to consider letting the tag amplify the back reflection measurement signal. However, it should be noted that in the embodiment of the present disclosure, the back reflection measurement signal and the CW measurement signal emitted by the reader, as well as the signal reflected by the surrounding objects are still at the same frequency. Even if the back reflection signal is amplified, the impact of interference is only reduced, but the same-frequency interference still exists.

[0187] Example 2: Ranging principle based on envelope phase difference in back-to-back communication.

[0188] In the above example 1, although distance measurement can be performed through multiple frequencies of multiple measurement processes, in one measurement process, the CW measurement signal and the back reflection measurement signal are signals of a single frequency. Since the back reflection measurement signal is a signal generated by simply reflecting or amplifying the CW measurement signal, its frequency characteristics are the same as those of the CW measurement signal.

[0189] In Example 2, the CW measurement signal is in a multi-carrier format or a carrier modulation format, that is, the CW measurement signal in a measurement process includes multiple frequency components, and two frequency components are taken as an example for description below.

[0190] The reader simultaneously transmits two CW measurement signals of frequency, denoted as f 1 and f 2 In fact, according to the trigonometric formula, the CW measurement signal can be equivalent to an amplitude modulation signal. The envelope of the CW measurement signal, also known as the amplitude, is calculated according to the frequency f m Here, one envelope corresponds to one envelope phase, f m =(f 1 -f 2 ) / 2, the tag back-reflects the CW measurement signal to generate a back-reflection measurement signal, and the reader can receive the back-reflection measurement signal and measure the envelope of the back-reflection measurement signal and the received envelope phase. Similar to the above example 1, at a moment, the reader can obtain the envelope phase of the currently transmitted CW measurement signal, and also the envelope phase of the back-reflection measurement signal received at that moment. The envelope phase difference is obtained by the difference between the two. The distance information can be obtained, that is, the distance d can be determined by the following formulas 5 and 6:

[0191]

[0192] Among them, n is used to indicate The quotient of m is the envelope frequency f m The corresponding wavelength can be seen m The wavelength is longer, so this method measures distance and λ m The wavelengths are comparable and also longer.

[0193] In Example 2, the distance measurement can be completed in one measurement process in theory, and the high frequency f can be omitted in Example 2. 1 and f 2 The carrier phase of the signal is measured at a lower frequency (i.e., the lower frequency f m In addition, the reader can also measure the carrier phase and combine Example 1 and Example 2 to obtain a higher distance measurement accuracy, for example, using the envelope phase to obtain a coarse-precision measurement result, and then obtaining a high-precision measurement result based on the carrier phase.

[0194] Similarly, surrounding objects will also reflect the CW measurement signal sent by the reader. In order to allow the reader to obtain the desired phase difference information more accurately, you can consider letting the tag amplify the back reflection measurement signal. However, it should be noted that in this example, the back reflection measurement signal and the CW measurement signal emitted by the reader and the signal reflected by the surrounding objects are still at the same frequency. Even if the back reflection signal is amplified, the impact of interference is only reduced, but the same frequency interference still exists.

[0195] Example 3: Ranging principle based on equivalent carrier phase difference in back-to-back communication.

[0196] Taking into account the co-channel interference problem in Example 1 above, the tag's processing of the CW measurement signal in Example 3 includes modulation. The modulation here is a broad concept, that is, all processing that changes the original frequency component of the CW measurement signal is collectively referred to as modulation, which is also called back-reflection modulation. However, the modulation here allows the back-reflection signal to carry the data to be transmitted, or it may not carry any data. Through modulation, the back-reflection measurement signal has a frequency component different from that of the CW measurement signal. Therefore, this frequency component of the back-reflection measurement signal is different from the CW measurement signal, and is also different from the reflection of the CW measurement signal by surrounding objects, which reduces the impact of co-channel interference and makes it easier for the reader to detect the back-reflection measurement signal and obtain high-precision distance information. This Example 3 uses the amplitude modulation of the tag as an example for explanation.

[0197] The reader transmits the carrier frequency at the same time 1 The tag back-reflects and amplitude-modulates the single-carrier CW measurement signal to generate a back-reflection measurement signal. The frequency of the tag modulation signal is set to f t According to the trigonometric formula and amplitude modulation principle, the back-reflection measurement signal includes at least the frequency component f 1 -f t (also called the lower sideband) and the frequency component f 1 +f t (also called upper sideband), the envelope of the reflected measured signal, also called amplitude, at frequency f t Here, one envelope corresponds to one envelope phase. The reader can receive the reflected measurement signal and measure the envelope of the reflected measurement signal and the received envelope phase. Different from the above example 2, the CW measurement signal transmitted by the reader is a single-frequency signal with constant amplitude (i.e., single-carrier mode). There is no envelope phase, only carrier phase. At the same time, the envelope phase of the backscattered measurement signal received at that moment can also be obtained The reader can also obtain the carrier phase corresponding to the upper sideband of the backscattered measurement signal The carrier phase corresponding to the lower sideband of the back-reflected measurement signal can also be obtained Taking the upper sideband as an example, according to relevant mathematical principles, the reader can obtain the carrier f according to the above parameters. 1 The corresponding equivalent carrier phase difference As shown in the following formula 7:

[0198]

[0199] Since the upper and lower sidebands are generally completely correlated, such as mirror images of each other, the situation of the lower sideband is not described here. It can be seen that Example 3 finally obtains the equivalent carrier f by the phase difference between the received signal and the transmitted signal with different frequencies. 1 The corresponding phase difference is different from the above example 1, in which the frequencies of the CW measurement signal and the back-reflection measurement signal are both f 1 Here, additional processing is introduced on both the reader side and the tag side, but modulation is used to avoid the co-frequency interference of the CW measurement signal, the surrounding reflected signal and the back-reflected measurement signal, thereby improving the measurement accuracy.

[0200] In some embodiments, if the equivalent carrier phase difference is obtained directly according to the above formula seven, three phases need to be measured, namely, the CW measurement signal transmission phase, the back-reflection measurement signal upper sideband phase, and the back-reflection measurement signal envelope phase. The first two are high-frequency signals, and the phase measurement error is large. In fact, mixing (remodulation) can be used to avoid measuring the high-frequency phase, that is, a copy of the current transmitted CW is used to directly modulate the received upper sideband signal to obtain a frequency of f t According to the amplitude modulation principle, the phase of the modulated low-frequency signal is The final equivalent carrier phase difference can be converted into the measurement of the phase of two low-frequency signals, which improves the measurement accuracy and reduces the difficulty, as shown in the following formula 8:

[0201]

[0202] It should be noted that the method for the reader to process the transmitted CW measurement signal and the received backscatter measurement signal to obtain the equivalent carrier phase difference is not limited here.

[0203] Similar to Example 1 above, the reader can first obtain the carrier frequency f according to the above process 1 The corresponding equivalent carrier phase difference Then use the same method to obtain the carrier frequency f 2 The corresponding equivalent carrier phase difference And according to the relevant principles, the difference between the two is obtained And obtain the distance information, and the difference can measure the distance range and λ d Comparable, where λ d Equal to the speed of light divided by f 1 and f2 The difference.

[0204] Similarly, the reader can be combined with and and their difference To obtain a higher precision distance measurement, for example, first Get low-precision measurements over long distances, and then and / or Get higher-precision measurement results.

[0205] Example 4: Ranging principle based on equivalent envelope phase difference in back-reflection communication.

[0206] In this example 4, the CW measurement signal is in a multi-carrier format or a carrier modulation format, that is, the CW measurement signal in a measurement process contains multiple frequency components, which are collectively referred to as a multi-carrier format. At the same time, in order to avoid the co-channel interference problem in the above example 2, the tag can modulate the CW measurement signal sent by the reader, that is, change its frequency component to generate a back-reflection measurement signal. This can be considered as a combination of the above example 2 and the above example 3.

[0207] In some embodiments, the tag can shift the frequency of the CW measurement signal, but keep its envelope characteristics unchanged, so that the reader simultaneously transmits two CW measurement signals at different frequencies, denoted as f 1 and f 2 , for example, the CW measurement signal can be equivalent to an amplitude modulation signal. The envelope of the CW measurement signal, also known as the amplitude, is calculated according to the frequency f m Here, one envelope corresponds to one envelope phase, f m =(f 1 -f 2 ) / 2, the tag back-reflects and modulates the CW measurement signal to generate a back-reflection measurement signal. Assuming that the original frequency component is shifted by Δf (i.e., modulated), the back-reflection measurement signal contains at least two frequency components, f 1 +Δf and f 2 +Δf, it can be seen that the two frequency components of the back-reflected measurement signal have changed, but the difference between the two remains unchanged, and it can still be equivalent to an amplitude modulation signal, and its envelope still follows the frequency f m The reader can receive the back reflection measurement signal, and measure the envelope of the back reflection measurement signal and the received envelope phase.

[0208] At a certain moment, the reader can obtain the envelope phase of the CW measurement signal currently being sent, and can also obtain the envelope phase of the reflected measurement signal received at that moment. The equivalent envelope phase difference is obtained by the difference between the two. Distance information can be obtained.

[0209] Alternatively, the tag can not only shift the frequency of the CW measurement signal, but also change its envelope, but this change can be measured by the reader, that is, the reader can correct the envelope phase change introduced by the tag's back reflection signal, and finally it is similar to the case where the envelope characteristic remains unchanged, that is, the reader can receive the back reflection measurement signal and measure the back reflection measurement signal.

[0210] At a certain moment, the reader can obtain the envelope phase of the currently transmitted CW measurement signal and calculate the equivalent envelope phase difference based on the two. Then the distance information can be obtained.

[0211] Similarly, all the methods of the above examples can be used in combination with each other. The reader can use the equivalent envelope phase difference to obtain a wider range of distance measurement. At the same time, the reader can obtain higher-precision distance measurement information based on the carrier phase difference or the equivalent carrier phase difference.

[0212] It should be noted that the above is an embodiment of the communication ranging method, and the central node can also perform spatial positioning through interaction with the terminal node.

[0213] In some embodiments, after the central node receives the backscatter measurement signal sent by the terminal node, the central node may also receive geographic location information of the terminal node sent by the terminal node.

[0214] In this way, the central node can further use the geographical location information of the terminal node for positioning based on the distance measurement using the carrier measurement signal and the backscatter measurement signal, that is, the coordinate position of the central node can be determined based on the relative distance between the central node and the terminal node and the coordinate position of the terminal node.

[0215] The following takes the interaction between the terminal node and the central node as an example to introduce the communication method provided in the above embodiment. Figure 6 As shown, including:

[0216] S601: The central node continuously sends a carrier measurement signal to a terminal node in the Internet of Things system.

[0217] S602: The terminal node receives a carrier measurement signal continuously sent by the central node in the Internet of Things system.

[0218] S603: The terminal node sends a backscatter measurement signal generated based on the carrier measurement signal to the central node.

[0219] S604: The central node receives a backscatter measurement signal generated based on the carrier measurement signal and sent by the terminal node.

[0220] It is understandable that, in order to implement the above functions, the communication device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the algorithm steps of each example described in the embodiments of the present disclosure, the present disclosure can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present disclosure.

[0221] The embodiments of the present disclosure may divide the functional modules of the communication device according to the above method embodiments. For example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one functional module. The above integrated modules may be implemented in the form of hardware or software. It should be noted that the division of modules in the embodiments of the present disclosure is schematic and is only a logical function division. There may be other division methods in actual implementation. The following is an example of dividing each functional module corresponding to each function.

[0222] Figure 7 A communication device according to an embodiment of the present disclosure is shown in FIG. Figure 1 The communication device can be applied to the terminal node in the IoT system and perform the above Figure 3 The communication method shown, and Figure 6 An embodiment of the terminal node side in FIG. Figure 7 As shown, the communication device 700 includes: a receiving module 701 and a sending module 702.

[0223] The receiving module 701 is used to receive the carrier measurement signal continuously sent by the central node in the Internet of Things system; the sending module 702 is used to send a back-reflection measurement signal generated based on the carrier measurement signal to the central node, and the sending time of the back-reflection measurement signal is within the time range when the central node continuously sends the carrier measurement signal.

[0224] In some embodiments, the receiving module 701 is also used to receive a first notification message sent by the central node, the first notification message includes time domain location information for indicating at least one measurement time zone; the receiving module 701 is specifically used to receive a carrier measurement signal continuously sent by the central node in each measurement time zone indicated by the time domain location information.

[0225] In some embodiments, the temporal location information includes at least one of the following:

[0226] a duration of each measurement time zone in at least one measurement time zone;

[0227] a starting point of each of the at least one measurement time zone;

[0228] an end point of each of the at least one measurement time zone;

[0229] the number of measurement time zones in at least one measurement time zone;

[0230] the total duration of at least one measurement time zone;

[0231] The intervals between two adjacent measurement time zones in at least one measurement time zone.

[0232] In some embodiments, the first notification information also includes trigger information for starting at least one measurement time zone, and the receiving module 701 is specifically used to receive the carrier measurement signal continuously sent by the central node in each measurement time zone indicated by the time domain location information in response to the trigger information.

[0233] In some embodiments, the communication device 700 further includes: a processing module 703. The processing module 703 is configured to respectively determine the mode of the carrier measurement signal corresponding to each measurement time zone; wherein the mode of the carrier measurement signal is any one of the following:

[0234] Single carrier mode using a single frequency component;

[0235] A multi-carrier mode using at least two frequency components;

[0236] A carrier modulation mode modulated by a modulation signal having a preset frequency component;

[0237] The carrier frequency switching mode of the frequency component used for periodic / non-periodic switching.

[0238] In some embodiments, the method of generating the backscatter measurement signal based on the carrier measurement signal is any one of the following:

[0239] Generated by the carrier measurement signal after back reflection;

[0240] Generated by the carrier measurement signal after back reflection and energy amplification;

[0241] Generated by carrier measurement signal after back reflection and signal modulation;

[0242] It is generated by the carrier measurement signal after back reflection, signal modulation and energy amplification.

[0243] In some embodiments, the receiving module 701 is further used to receive second notification information sent by the central node, where the second notification information is used to indicate a method for generating a backscatter measurement signal based on the carrier measurement signal.

[0244] In some embodiments, the receiving module 701 is further configured to receive third notification information sent by the central node; wherein the third notification information includes at least one of the following:

[0245] Time domain parameter information of the back-reflection measurement signal;

[0246] Frequency domain parameter information of the reflected measurement signal;

[0247] The power parameter information of the reflected measurement signal.

[0248] In some embodiments, the time domain parameter information includes at least one of the following:

[0249] Backscatter measurement signal transmission duration;

[0250] The symbol length of the back-measurement signal;

[0251] The symbol period of the backscattered measurement signal;

[0252] The transmission time and position information of the back-measurement signal.

[0253] In some embodiments, the frequency domain parameter information includes at least one of the following:

[0254] The frequency domain position of the reflected measurement signal;

[0255] The relative position of the backscattered measurement signal and the carrier measurement signal in the frequency domain;

[0256] The modulated carrier measures the frequency domain information of the modulated signal.

[0257] In some embodiments, the power parameter information includes at least one of the following:

[0258] Backscatter measurement signal power level;

[0259] Amplification factor of the backscattered measurement signal.

[0260] In some embodiments, the sending module 702 is further used to send a start signal or a leading signal to the central node, where the start signal or the leading signal is used to indicate the start of sending the backscatter measurement signal.

[0261] In some embodiments, the sending module 702 is further configured to send the geographic location information of the terminal node to the central node.

[0262] Figure 8 A communication device according to an embodiment of the present disclosure is shown in FIG. Figure 2 The communication device can be applied to the central node of the Internet of Things system and perform the above Figure 4 The communication method shown, and Figure 6 An embodiment of the central node side. Figure 8 As shown, the communication device 800 includes: a sending module 801 and a receiving module 802 .

[0263] The sending module 801 is used to continuously send a carrier measurement signal to a terminal node in the Internet of Things system; the receiving module 802 is used to receive a back-reflection measurement signal generated based on the carrier measurement signal and sent by the terminal node, and the sending time of the back-reflection measurement signal is within the time range of the central node continuously sending the carrier measurement signal.

[0264] In some embodiments, the sending module 801 is also used to send a first notification message to the terminal node, and the first notification message includes time domain location information for indicating at least one measurement time zone; the sending module 801 is specifically used to continuously send a carrier measurement signal to the terminal node in each measurement time zone indicated by the time domain location information.

[0265] In some embodiments, the temporal location information includes at least one of the following:

[0266] a duration of each measurement time zone in at least one measurement time zone;

[0267] a starting point of each of the at least one measurement time zone;

[0268] an end point of each measurement time zone in at least one measurement time zone;

[0269] the number of measurement time zones in at least one measurement time zone;

[0270] the total duration of at least one measurement time zone;

[0271] The intervals between two adjacent measurement time zones in at least one measurement time zone.

[0272] In some embodiments, the first notification information further includes trigger information for starting at least one measurement time zone.

[0273] In some embodiments, the sending module 801 is further used to send second notification information to the terminal node, where the second notification information is used to indicate a method for generating a backscatter measurement signal based on the carrier measurement signal.

[0274] In some embodiments, the method of generating the backscatter measurement signal based on the carrier measurement signal is any one of the following:

[0275] Generated by the carrier measurement signal after back reflection;

[0276] Generated by the carrier measurement signal after back reflection and energy amplification;

[0277] Generated by carrier measurement signal after back reflection and signal modulation;

[0278] It is generated by the carrier measurement signal after back reflection, signal modulation and energy amplification.

[0279] In some embodiments, the sending module 801 is further configured to send third notification information to the terminal node; wherein the third notification information includes at least one of the following:

[0280] Time domain parameter information of the back-reflection measurement signal;

[0281] Frequency domain parameter information of the reflected measurement signal;

[0282] The power parameter information of the reflected measurement signal.

[0283] In some embodiments, the time domain parameter information includes at least one of the following:

[0284] Backscatter measurement signal transmission duration;

[0285] The symbol length of the back-measurement signal;

[0286] The symbol period of the backscattered measurement signal;

[0287] The transmission time and position information of the back-measurement signal.

[0288] In some embodiments, the frequency domain parameter information includes at least one of the following:

[0289] The frequency domain position of the reflected measurement signal;

[0290] The relative position of the backscattered measurement signal and the carrier measurement signal in the frequency domain;

[0291] The modulated carrier measures the frequency domain information of the modulated signal.

[0292] In some embodiments, the power parameter information includes at least one of the following:

[0293] Backscatter measurement signal power level;

[0294] Amplification factor of the backscattered measurement signal.

[0295] In some embodiments, the carrier measurement signal satisfies any of the following:

[0296] Single carrier mode using a single frequency component;

[0297] A multi-carrier mode using at least two frequency components;

[0298] A carrier modulation mode modulated by a modulation signal having a preset frequency component;

[0299] The carrier frequency switching mode of the frequency component used for periodic / non-periodic switching.

[0300] In some embodiments, the communication device 800 further includes: a processing module 803. The processing module 803 is configured to determine the distance between the central node and the terminal node according to the phase difference between the carrier measurement signal and the backscatter measurement signal.

[0301] In some embodiments, when the frequency of the backscatter measurement signal is the same as the frequency of the carrier measurement signal, or when the manner in which the backscatter measurement signal is generated based on the carrier measurement signal does not include modulation, the phase difference includes at least one of the following:

[0302] The carrier phase difference between the back reflection measurement signal and the carrier measurement signal;

[0303] The envelope phase difference between the reflection measurement signal and the carrier measurement signal.

[0304] In some embodiments, when the frequency of the backscatter measurement signal is different from the frequency of the carrier measurement signal, or when the manner of generating the backscatter measurement signal based on the carrier measurement signal includes modulation, the phase difference includes at least one of the following:

[0305] The equivalent carrier phase difference between the back reflection measurement signal and the carrier measurement signal at the same frequency;

[0306] The equivalent envelope phase difference between the reflection measurement signal and the carrier measurement signal at the same frequency.

[0307] In some embodiments, the receiving module 802 is further used to receive a start signal or a preamble signal sent by a terminal node, where the start signal or the preamble signal is used to indicate the start of sending the backscatter measurement signal.

[0308] In some embodiments, the receiving module 802 is further configured to receive geographic location information of the terminal node sent by the terminal node.

[0309] In the case of implementing the functions of the above integrated modules in the form of hardware, the embodiment of the present disclosure provides another possible structural schematic diagram of the communication device involved in the above embodiment. Figure 3 .like Fig. 9As shown, the communication device 900 includes: a processor 902 and a bus 904. Optionally, the communication device may further include a memory 901; optionally, the communication device may further include a communication interface 903.

[0310] The processor 902 may be a processor that implements or executes various exemplary logic blocks, modules, and circuits described in conjunction with the embodiments of the present disclosure. The processor 902 may be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array, or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute various exemplary logic blocks, modules, and circuits described in conjunction with the embodiments of the present disclosure. The processor 902 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like.

[0311] The communication interface 903 is used to connect with other devices via a communication network, such as Ethernet, wireless access network, wireless local area network (WLAN), etc.

[0312] The memory 901 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto.

[0313] As a possible implementation, the memory 901 may exist independently of the processor 902, and the memory 901 may be connected to the processor 902 via a bus 904 to store instructions or program codes. When the processor 902 calls and executes the instructions or program codes stored in the memory 901, the communication method provided in the embodiment of the present disclosure can be implemented.

[0314] In another possible implementation, the memory 901 may also be integrated with the processor 902 .

[0315] The bus 904 may be an extended industry standard architecture (EISA) bus, etc. The bus 904 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig. 9 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0316] Some embodiments of the present disclosure provide a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium), in which computer program instructions are stored. When the computer program instructions are executed on a computer, the computer executes the communication method described in any of the above embodiments.

[0317] Exemplarily, the above-mentioned computer-readable storage media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks or magnetic tapes, etc.), optical disks (e.g., compact disks (CDs), digital versatile disks (DVDs), etc.), smart cards and flash memory devices (e.g., erasable programmable read-only memory (EPROM), cards, sticks or key drives, etc.). The various computer-readable storage media described in the present disclosure may represent one or more devices and / or other machine-readable storage media for storing information. The term "machine-readable storage medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing and / or carrying instructions and / or data.

[0318] An embodiment of the present disclosure provides a computer program product including instructions. When the computer program product is run on a computer, the computer is enabled to execute the communication method described in any one of the above embodiments.

[0319] The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A communication method, characterized in that: Terminal nodes used in IoT systems include: Receiving a carrier measurement signal continuously sent by a central node in the Internet of Things system; A back-talk measurement signal generated based on the carrier measurement signal is sent to the central node, and a sending time of the back-talk measurement signal is within a time range in which the central node continuously sends the carrier measurement signal.

2. The method according to claim 1, characterized in that The receiving a carrier measurement signal continuously sent by a central node in the Internet of Things system includes: receiving first notification information sent by the central node, wherein the first notification information includes time domain location information for indicating at least one measurement time zone; The carrier measurement signal continuously sent by the central node is received in each of the measurement time zones indicated by the time domain location information.

3. The method according to claim 2, characterized in that The time domain location information includes at least one of the following: The duration of each of the at least one measurement time zone; a starting point of each of the at least one measurement time zone; an end point of each of said at least one measurement time zone; the number of the measurement time zones in the at least one measurement time zone; the total duration of the at least one measurement time zone; The intervals between two adjacent measurement time zones in the at least one measurement time zone.

4. The method according to claim 2, characterized in that: The first notification information further includes trigger information for starting the at least one measurement time zone, and the receiving the carrier measurement signal continuously sent by the central node in each of the measurement time zones indicated by the time domain location information includes: In response to the trigger information, the carrier measurement signal continuously sent by the central node is received in each of the measurement time zones indicated by the time domain location information.

5. The method according to claim 2, characterized in that: The method further comprises: respectively determining the mode of the carrier measurement signal corresponding to each of the measurement time zones; The mode of the carrier measurement signal is any one of the following: Single carrier mode using a single frequency component; A multi-carrier mode using at least two frequency components; A carrier modulation mode modulated by a modulation signal having a preset frequency component; The carrier frequency switching mode of the frequency component used for periodic / non-periodic switching.

6. The method according to claim 1, characterized in that The method of generating the backscatter measurement signal based on the carrier measurement signal is any one of the following: Generated by the carrier measurement signal after back reflection; Generated by the carrier measurement signal after back reflection and energy amplification; Generated by the carrier measurement signal after back reflection and signal modulation; The carrier measurement signal is generated after back reflection, signal modulation and energy amplification.

7. The method according to claim 6, characterized in that The method further comprises: Second notification information sent by the central node is received, where the second notification information is used to indicate a method for generating the backscatter measurement signal based on the carrier measurement signal.

8. The method according to claim 1, characterized in that The method further comprises: Receiving third notification information sent by the central node; The third notification information includes at least one of the following: Time domain parameter information of the backscattered measurement signal; Frequency domain parameter information of the backscattered measurement signal; The backscattered measurement signal has power parameter information.

9. The method according to claim 8, characterized in that The time domain parameter information includes at least one of the following: The transmission duration of the back-reflection measurement signal; The symbol length of the back-scattered measurement signal; The symbol period of the backscattered measurement signal; The back-scattered measurement signal sends time and position information.

10. The method according to claim 8, characterized in that The frequency domain parameter information includes at least one of the following: The frequency domain position of the backscattered measurement signal; The relative position of the backscatter measurement signal and the carrier measurement signal in the frequency domain; The carrier measurement signal is modulated to obtain frequency domain information of a modulation signal.

11. The method according to claim 8, characterized in that The power parameter information includes at least one of the following: The power level of the backscattered measurement signal; The amplification factor of the reflected measurement signal.

12. The method according to claim 1, characterized in that The method further comprises: A start signal or a preamble signal is sent to the central node, where the start signal or the preamble signal is used to indicate the start of sending the backscatter measurement signal.

13. The method according to claim 1, characterized in that The method further comprises: The geographical location information of the terminal node is sent to the central node.

14. A communication method, characterized in that: The central nodes used in the IoT system include: Continuously sending a carrier measurement signal to a terminal node in the Internet of Things system; A back-talk measurement signal generated based on the carrier measurement signal and sent by the terminal node is received, wherein the sending time of the back-talk measurement signal is within a time range in which the central node continuously sends the carrier measurement signal.

15. The method according to claim 14, characterized in that The continuously sending a carrier measurement signal to a terminal node in the Internet of Things system includes: Sending first notification information to the terminal node, where the first notification information includes time domain location information for indicating at least one measurement time zone; The carrier measurement signal is continuously sent to the terminal node in each of the measurement time zones indicated by the time domain location information.

16. The method according to claim 15, characterized in that The time domain location information includes at least one of the following: The duration of each of the at least one measurement time zone; a starting point of each of the at least one measurement time zone; an end point of each of said at least one measurement time zone; the number of the measurement time zones in the at least one measurement time zone; the total duration of the at least one measurement time zone; The intervals between two adjacent measurement time zones in the at least one measurement time zone.

17. The method according to claim 15, characterized in that The first notification information further includes trigger information for starting the at least one measurement time zone.

18. The method according to claim 14, characterized in that The method further comprises: Sending second notification information to the terminal node, where the second notification information is used to indicate a manner of generating the backscatter measurement signal based on the carrier measurement signal.

19. The method according to claim 18, characterized in that The method of generating the backscatter measurement signal based on the carrier measurement signal is any one of the following: Generated by the carrier measurement signal after back reflection; Generated by the carrier measurement signal after back reflection and energy amplification; Generated by the carrier measurement signal after back reflection and signal modulation; The carrier measurement signal is generated after back reflection, signal modulation and energy amplification.

20. The method according to claim 14, characterized in that The method further comprises: Sending third notification information to the terminal node; The third notification information includes at least one of the following: Time domain parameter information of the backscattered measurement signal; Frequency domain parameter information of the backscattered measurement signal; The backscattered measurement signal has power parameter information.

21. The method according to claim 20, characterized in that The time domain parameter information includes at least one of the following: The transmission duration of the back-reflection measurement signal; The symbol length of the back-scattered measurement signal; The symbol period of the backscattered measurement signal; The back-scattered measurement signal sends time and position information.

22. The method according to claim 20, characterized in that The frequency domain parameter information includes at least one of the following: The frequency domain position of the backscattered measurement signal; The relative position of the backscatter measurement signal and the carrier measurement signal in the frequency domain; The carrier measurement signal is modulated to obtain frequency domain information of a modulation signal.

23. The method according to claim 20, characterized in that The power parameter information includes at least one of the following: The power level of the backscattered measurement signal; The amplification factor of the reflected measurement signal.

24. The method according to claim 14, characterized in that The carrier measurement signal satisfies any of the following conditions: Single carrier mode using a single frequency component; A multi-carrier mode using at least two frequency components; A carrier modulation mode modulated by a modulation signal having a preset frequency component; The carrier frequency switching mode of the frequency component used for periodic / non-periodic switching.

25. The method according to claim 14, characterized in that The method further comprises: The distance between the central node and the terminal node is determined according to the phase difference between the carrier measurement signal and the backscatter measurement signal.

26. The method according to claim 25, characterized in that In the case where the frequency of the back-reflection measurement signal is the same as the frequency of the carrier measurement signal, or in the case where the manner in which the back-reflection measurement signal is generated based on the carrier measurement signal does not include modulation, the phase difference includes at least one of the following: A carrier phase difference between the backscatter measurement signal and the carrier measurement signal; The envelope phase difference between the reflection measurement signal and the carrier measurement signal.

27. The method according to claim 25, characterized in that In the case where the frequency of the back-reflection measurement signal is different from the frequency of the carrier measurement signal, or in the case where the manner of generating the back-reflection measurement signal based on the carrier measurement signal includes modulation, the phase difference includes at least one of the following: An equivalent carrier phase difference between the backscatter measurement signal and the carrier measurement signal at the same frequency; The equivalent envelope phase difference between the backscatter measurement signal and the carrier measurement signal at the same frequency.

28. The method according to claim 14, characterized in that The method further comprises: A start signal or a preamble signal sent by the terminal node is received, where the start signal or the preamble signal is used to indicate the start of sending the backscatter measurement signal.

29. The method according to claim 14, characterized in that The method further comprises: Receive geographic location information of the terminal node sent by the terminal node.

30. A communication device, characterized in that: include: Memory and processor; Memory and processor coupling; The memory is used to store instructions executable by the processor; When the processor executes the instructions, the method according to any one of claims 1 to 29 is performed.

31. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the computer instructions are executed on a computer, the computer is enabled to execute the method according to any one of claims 1 to 29.

32. A computer program product, characterized in that The computer program product comprises computer program instructions which, when executed, implement the method according to any one of claims 1 to 29.

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