Communication method, terminal and WIFI device

Abstract

The invention provides a communication method, a terminal and WIFI equipment. The communication method comprises: a terminal backscattering a first signal on a first channel (S720); wherein the first signal comprises a first preamble and / or a first carrier, and the first signal is transmitted by the WIFI device (S710). When the terminal occupies the first channel to perform backscatter communication, other WIFI devices can determine that the first channel is occupied by detecting the first preamble based on a carrier detection mode, and / or other WIFI devices can determine that the first channel is occupied by detecting the first carrier based on an energy detection mode. Therefore, the situation that other WIFI devices also occupy the first channel is avoided.

Description

Communication method, terminal and WIFI device Technical Field

[0001] The present application relates to the field of communication technology, and more specifically, to a communication method, a terminal, and a WIFI device. Background Art

[0002] The low complexity of backscatter terminals prevents them from generating the preambles used in Wi-Fi systems to sense channels. This results in the inability to transmit preambles when performing backscatter communications on unlicensed frequency channels. Other Wi-Fi devices in the system cannot detect the channel's occupancy by detecting the preambles, potentially allowing other Wi-Fi devices to use the channel for data transmission, potentially causing interference or conflicts.

[0003] Summary of the Invention

[0004] The present application provides a communication method, a terminal, and a WIFI device.

[0005] In a first aspect, a communication method is provided, comprising: a terminal backscattering a first signal on a first channel; wherein the first signal comprises a first preamble and / or a first carrier, and the first signal is sent by a WIFI device.

[0006] In a second aspect, a communication method is provided, which includes: a WIFI device sending a first signal on a first channel; wherein the first signal includes a first preamble and / or a first carrier, and the first signal is used for backscattering by a terminal.

[0007] According to a third aspect, a terminal is provided, comprising: a backscattering unit configured to backscatter a first signal on a first channel; wherein the first signal comprises a first preamble and / or a first carrier, and the first signal is sent by a WIFI device.

[0008] In a fourth aspect, a WIFI device is provided, comprising: a sending unit configured to send a first signal on a first channel; wherein the first signal comprises a first preamble and / or a first carrier, and the first signal is used for backscattering by a terminal.

[0009] In a fifth aspect, a terminal is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the terminal device executes the method described in the first aspect.

[0010] In a sixth aspect, a WIFI device is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the network device executes the method of the second aspect.

[0011] In a seventh aspect, an embodiment of the present application provides a communication system, which includes the above-mentioned terminal and / or WIFI device. In another possible design, the system may also include other devices that interact with the terminal or network device in the solution provided in the embodiment of the present application.

[0012] In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program enables a terminal to execute part or all of the steps in the method of the first aspect above.

[0013] In a ninth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program enables a WIFI device to execute some or all of the steps in the method of the second aspect above.

[0014] In a tenth aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a terminal to perform some or all of the steps of the method of the first aspect. In some implementations, the computer program product may be a software installation package.

[0015] In an eleventh aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a Wi-Fi device to perform some or all of the steps of the method of the second aspect. In some implementations, the computer program product may be a software installation package.

[0016] In the twelfth aspect, an embodiment of the present application provides a chip, which includes a memory and a processor. The processor can call and run a computer program from the memory to implement some or all of the steps described in the method of the first or second aspect above.

[0017] In a thirteenth aspect, a computer program product is provided, comprising a program, wherein the program enables a computer to execute the method described in the first aspect.

[0018] In a fourteenth aspect, a computer program product is provided, comprising a program, wherein the program enables a computer to execute the method described in the second aspect.

[0019] In a fifteenth aspect, a computer program is provided, which enables a computer to execute the method described in the first aspect.

[0020] In a sixteenth aspect, a computer program is provided, which enables a computer to execute the method described in the second aspect.

[0021] When the terminal occupies the first channel for backscatter communication, other WIFI devices can determine that the first channel is occupied by detecting the first preamble based on a carrier detection method, and / or, other WIFI devices can determine that the first channel is occupied by detecting the first carrier based on an energy detection method, thereby avoiding the situation where other WIFI devices also occupy the first channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a wireless communication system used in an embodiment of the present application.

[0023] FIG2 shows a possible structure of an energy harvesting module.

[0024] FIG3 illustrates the backscatter communication principle of an embodiment of the present application.

[0025] FIG4 shows a circuit diagram of a terminal based on a resistive load modulation technique.

[0026] FIG5 is an example diagram of a data frame including a preamble.

[0027] FIG6 is another example diagram of a data frame including a preamble.

[0028] FIG7 is a schematic flowchart of a communication method provided in an embodiment of the present application.

[0029] FIG8 is a schematic diagram of resources provided in an embodiment of the present application.

[0030] FIG9 is another resource schematic diagram provided in an embodiment of the present application.

[0031] FIG10 is another resource schematic diagram provided in an embodiment of the present application.

[0032] FIG11 is another resource schematic diagram provided in an embodiment of the present application.

[0033] FIG12 is another resource schematic diagram provided in an embodiment of the present application.

[0034] FIG13 is a schematic structural diagram of a terminal provided in an embodiment of the present application.

[0035] FIG14 is a schematic structural diagram of a WIFI device provided in an embodiment of the present application.

[0036] FIG15 is a schematic structural diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] The technical solution in this application will be described below with reference to the accompanying drawings.

[0038] Zero-power communication technology

[0039] With the development of wireless communication technology, there is a desire to integrate wireless communication systems with various vertical industries, such as logistics, manufacturing, transportation, and energy. For example, wireless communication systems can be integrated with industrial wireless sensor networks (IWSNs). Another example is the integration of wireless communication systems with smart logistics and smart warehousing. Another example is the integration of wireless communication systems with smart home networks.

[0040] However, in these industries, terminals are typically required to have low cost, small size (e.g., ultra-thin), maintenance-free, and long lifespans. Therefore, to meet these requirements, network devices and terminals can utilize zero-power communication technology. In this case, the terminal can be referred to as a "zero-power communication terminal." For example, radio frequency identification (RFID) is a typical zero-power communication technology. RFID utilizes spatial coupling of wireless radio frequency signals to achieve contactless, automatic transmission and identification of tag information.

[0041] The following describes zero-power communication technology and zero-power terminals in conjunction with Figures 1 to 4. Figure 1 shows the architecture of a zero-power communication system 100 applicable to an embodiment of the present application. The architecture shown in Figure 1 includes communication devices such as a network device 110 and a terminal 120. The network device 110 can be a device that communicates with the terminal device 120. The network device 110 can provide communication coverage for a specific geographic area and can communicate with the terminal device 120 located within the coverage area.

[0042] Network device 110 is configured to transmit a wireless power supply signal to terminal 120 to power the terminal. Accordingly, terminal 120 may transmit data to network device 110 or other communication devices via backscattered signals. In some implementations, the wireless power supply signal may also carry data or control information transmitted by network device 110 to terminal 120. Of course, the wireless power supply signal may also be used solely for power supply, which is not limited in this embodiment of the present application.

[0043] It should be noted that Figure 1 exemplarily shows a network device and a terminal. Optionally, the communication system 100 may include multiple network devices and the coverage range of each network device may include other numbers of terminal devices. This embodiment of the present application does not limit this.

[0044] It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: fifth generation (5G) system or new radio (NR), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), cellular Internet of Things, WIFI communication system, etc. The technical solutions provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system, etc.

[0045] The terminal in the embodiment of the present application may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal device, wireless communication device, user agent or user device. The terminal device in the embodiment of the present application may be a device that provides voice and / or data connectivity to a user, and can be used to connect people, objects and machines, such as household appliances, sensors, electronic tags (tags) with wireless connection functions, etc. Among them, electronic tags may also be called "radio frequency tags". In radio frequency identification (RFID) technology, electronic tags may also be called "RFID tags". The terminal in the embodiment of the present application may be a wireless terminal in a smart home, a wireless terminal in an IWSN, a wireless terminal in smart logistics and smart warehousing, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, etc.

[0046] The network device in the embodiment of the present application can be a device for communicating with a terminal device. If the terminal is an electronic tag, the network device can be a reader / writer for reading and writing the electronic tag. The reader / writer can be, for example, a reader / writer based on RFID technology.

[0047] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on the water; they can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the scenarios in which the network equipment and terminal devices are located.

[0048] It should be understood that all or part of the functions of the communication device in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (such as a cloud platform).

[0049] Taking RFID technology as an example, the terminal can be an electronic tag, and the network device can be a reader / writer. An electronic tag can consist of a coupling component and a chip. Each electronic tag can have a unique electronic code. The electronic tag can be placed on a target to mark the object. The reader / writer can not only read the information on the electronic tag but also write it. The reader / writer also provides the electronic tag with the energy needed for communication. When the electronic tag enters an electromagnetic field, it can receive the radio frequency signal emitted by the reader / writer. The electronic tag uses the energy generated by the electromagnetic field in space to transmit the information stored on the electronic tag. The reader / writer reads the information and decodes it, thereby identifying the electronic tag.

[0050] As shown in Figure 1, the terminal 120 may include an energy collection module 121 and a backscatter communication module 122. The energy collection module 121 and the backscatter communication module 122 will be introduced below in conjunction with Figures 2 to 4. For the sake of brevity, they will not be repeated here. In some cases, the terminal 120 may also include a low-power computing module 123. The low-power computing module 123 is used to provide computing functions for the terminal, such as data processing. In other cases, the terminal 120 may also include a sensor 124 for collecting external information (for example, ambient temperature, ambient humidity, etc.). In other cases, the terminal 120 may also include a memory 125 for storing some information (for example, external information collected by the above-mentioned sensors, or such as item identification, etc.).

[0051] The energy harvesting module 121 can be used for power harvesting. The harvested energy can include, for example, various forms of energy such as radio waves, solar energy, light energy, thermal energy, and mechanical energy. The energy harvested by the energy harvesting module 121 can be used to drive the device to work, thereby achieving battery-free operation. In some implementations, energy can be harvested through a wireless power supply signal sent by a network device. The wireless power supply signal can be a radio frequency (RF) signal sent by a network device. Therefore, the energy harvesting module can also be referred to as a "radio frequency energy harvesting module" (abbreviated as "RF module").

[0052] FIG2 shows a possible structure of an energy harvesting module. As shown in FIG2 , the energy harvesting module can harvest electromagnetic wave energy in space through electromagnetic induction, thereby driving the load circuit (including low-power computing, sensors, etc.). The energy harvesting module shown in FIG2 can be an RF module. For example, the energy harvesting module 121 can store the harvested energy in a capacitor C, which is the process of charging the capacitor C. When the charging process of the capacitor C is completed, the capacitor C can start to discharge to provide energy for the terminal operation.

[0053] The backscatter communication module 122 can be used for backscattering communication between the terminal and the network device. The following describes the backscatter communication principle of an embodiment of the present application in conjunction with FIG3 . Referring to FIG3 , the terminal 120 receives a wireless signal (e.g., a carrier) transmitted by the network device 110 and modulates the wireless signal to carry the data to be transmitted. Finally, the modulated signal is radiated from the antenna. This information transmission process is called backscatter communication.

[0054] In some implementations, the transmit (transmit, TX) path of the network device 110 may be further provided with other devices for processing the transmitted signal, such as an amplifier (AMP). The receive (receive, RX) path of the network device 110 may also be provided with other devices for processing the received signal, such as a low noise amplifier (LNA).

[0055] In some implementations, the terminal 120 may be provided with an energy collection unit for collecting energy from the wireless power supply signal sent by the network device. The terminal 120 may also be provided with a low-power processing module (such as the logic processing unit shown in Figure 3) to perform corresponding calculation functions.

[0056] It is understood that in backscatter communication, terminal 120 does not need to actively transmit signals; rather, it can achieve backscatter communication through modulated waves. Furthermore, terminal 120 does not rely on active power amplifier transmitters as used in related technologies and can use low-power computing units, significantly reducing hardware complexity. Furthermore, in backscatter communication, terminal 120 can incorporate energy harvesting to achieve battery-free communication.

[0057] It should be noted that, whether it is the network device 110 or the terminal 120, Figure 3 only exemplarily shows the connection structure of the signal processing circuit. The processing circuit of the network device 110 and / or the terminal 120 may include other components, and the embodiments of the present application do not specifically limit this.

[0058] Backscatter communication and load modulation are closely related. Load modulation is a method commonly used by terminals to transmit data to network devices. Load modulation can be understood as the modulation process that adjusts and controls the circuit parameters of the terminal's oscillator circuit according to the rhythm of the data stream, thereby changing parameters such as the terminal's impedance and phase.

[0059] The load modulation function can be realized by two methods: resistance load modulation and capacitance load modulation. FIG4 shows a circuit diagram of a terminal based on resistance load modulation technology. It should be noted that the circuit shown in FIG4 implements the load modulation technology in a manner similar to that of the existing circuits for implementing load modulation technology. For the sake of simplicity, the resistor R2 and the load R L The functions of capacitors C1, C2 and inductors L1, L2 are not described in detail.

[0060] In resistive load modulation, a resistor R3 can be connected in parallel with the load. Switch S can be controlled by a binary data stream to turn resistor R3 on and off. This switching of resistor R3 causes a change in the circuit voltage, which in turn controls the amplitude of the backscattered signal at the terminal, thereby modulating the backscattered signal using amplitude-shift keying (ASK).

[0061] Similarly, in capacitive load modulation, a capacitor can be connected in parallel with the load, and the capacitor can be turned on and off based on a binary data stream to change the circuit resonant frequency, thereby changing the operating frequency of the backscattered signal to achieve frequency-shift keying (FSK) modulation.

[0062] Data transmitted by a terminal (such as an electronic tag) can use various encoding schemes to represent binary "1" and "0." Common encoding methods used in zero-power communication technologies include non-return-to-zero (NRZ), Manchester, unipolar return-to-zero (RZ), differential binary phase (DBP), Miller, and differential encoding. In other words, different pulse signals can be used to represent "1" and "0."

[0063] As mentioned above, terminals can use load modulation to modulate incoming signals (i.e., signals sent by network devices) to achieve backscatter communication. Therefore, terminals in backscatter communication generally have the following advantages.

[0064] Advantage 1: Since the terminal does not need to actively transmit signals, there is no need to construct a complex RF path. For example, components such as power amplifiers (PAs) and RF filters can be omitted in the RF path, reducing the cost and size of the terminal.

[0065] The second advantage is that since the terminal does not need to actively generate high-frequency signals, a high-frequency crystal oscillator is not required, thereby reducing the cost and size of the terminal.

[0066] Advantage three: Since the terminal can use backscatter technology to communicate with network equipment, the terminal consumes less energy during communication and does not even need to consume its own energy.

[0067] Based on the above introduction to zero-power communication technology, we can see that zero-power terminals consume very little, or even no, energy for communication. Therefore, in zero-power communication technology, terminals can be divided into three categories based on their energy source and how they use energy: passive zero-power terminals, semi-passive zero-power terminals, and active zero-power terminals.

[0068] 1. Passive zero-power terminal.

[0069] Passive zero-power terminals typically do not require internal batteries. When a terminal is close to a network device, it is within the near field formed by the network device's antenna radiation. At this time, the terminal's antenna can generate an induced current through electromagnetic induction. This induced current can provide energy to the terminal to demodulate received signals and / or modulate and encode transmitted signals.

[0070] As an implementation, the passive zero-power terminal can be an electronic tag (i.e., a passive electronic tag or a passive electronic tag). Accordingly, the network device can be a reader / writer for the electronic tag, used to read and / or modify the content of the electronic tag. When the passive electronic tag is close to the reader / writer, the electronic tag can be within the near field formed by the reader / writer's antenna radiation. The electronic tag's antenna can generate an induced current through electromagnetic induction, which can drive the electronic tag's chip circuit. The chip circuit transmits the identification information stored in the tag to the reader / writer via the electronic tag antenna.

[0071] It is understandable that the passive zero-power terminal does not require a built-in battery to drive either the forward link or the reverse link, and is a true zero-power terminal.

[0072] 2. Semi-passive zero-power terminal

[0073] The semi-passive zero-power terminal itself does not have a conventional battery installed, but can use the energy collection module 121 to collect radio wave energy and store the collected energy in an energy storage unit (such as a capacitor). After the energy storage unit obtains energy, it can power the terminal to achieve demodulation of the received signal and / or modulation and encoding of the transmitted signal. The semi-passive zero-power terminal inherits the advantages of passive zero-power devices in terms of small size, light weight, low price and long service life.

[0074] In one implementation, the semi-passive, zero-power device can be an electronic tag (i.e., a semi-active electronic tag). Accordingly, the network device can be a reader / writer for the electronic tag. When the semi-active electronic tag is not being accessed by a reader / writer, the built-in battery can only power a small number of circuits within the chip. When the reader / writer is accessing the tag, the built-in battery can power the chip (e.g., an RFID chip), thereby increasing the read / write distance of the electronic tag and improving communication reliability.

[0075] It is understandable that the semi-passive zero-power terminal does not require a built-in battery to drive either the forward link or the reverse link. Although energy stored in capacitors is used during operation, the energy comes from the radio energy collected by the energy harvesting module. Therefore, it is also a true zero-power terminal.

[0076] 3. Active Zero Power Consumption Terminal

[0077] Active zero-power terminals can have built-in batteries. These batteries power the low-power chip circuitry in these terminals, enabling forward link signal demodulation and reverse link signal modulation. For backscatter links, these zero-power terminals use backscattering to transmit signals. Therefore, the zero-power nature of these terminals stems from the fact that reverse link signal transmission does not require the terminal's own power, but rather utilizes backscattering.

[0078] Powering a device with a built-in battery can extend the communication distance and improve communication reliability. Therefore, in scenarios with relatively high requirements for communication distance and read latency, zero-power devices with built-in batteries (including active zero-power terminals and semi-passive zero-power terminals) are used.

[0079] In some implementations, the active zero-power terminal can be an electronic tag (i.e., an active electronic tag or an active electronic tag), and the network device can be a reader / writer. In this case, the electronic tag's operating energy can be provided by a battery. The battery, memory, and antenna together constitute an active electronic tag. Unlike passive RF activation, an active electronic tag can continue to transmit information using a set frequency band until the battery is replaced.

[0080] Unlicensed spectrum

[0081] Unlicensed spectrum is spectrum that can be used for radio communications. It can be considered shared spectrum, meaning that communications equipment in different systems can use it as long as they meet national or regional regulations for that spectrum, without having to apply for exclusive spectrum authorization from the government. Unlicensed spectrum can also be referred to as unlicensed spectrum.

[0082] In order to allow various communication systems that use unlicensed spectrum for wireless communication to coexist in a friendly manner on the spectrum, some countries or regions have stipulated regulatory requirements that must be met when using unlicensed spectrum. For example, in Europe, communication equipment follows the "listen-before-talk" (LBT) principle, that is, before a communication device sends a signal on a channel in the unlicensed spectrum, it needs to first perform channel sensing. Only when the channel sensing result is that the channel is idle can the communication device send a signal. If the channel sensing result of the communication device on the channel in the unlicensed spectrum is that the channel is busy, the communication device cannot send a signal. In order to ensure fairness, in one transmission, the duration that a communication device uses a channel in the unlicensed spectrum for signal transmission cannot exceed the maximum channel occupation time (MCOT).

[0083] Currently, systems that use unlicensed spectrum for communication include Wi-Fi communication systems, 3GPP's NR-U communication systems, etc.

[0084] Channel sensing (or channel monitoring) is a key technology in the LBT principle. Based on this principle, a communication device performs LBT on a carrier in the unlicensed spectrum upon service arrival and begins transmitting signals on that carrier after successful LBT. Different communication systems using unlicensed spectrum employ different channel sensing technologies, each of which must meet regulatory requirements to ensure fairness among communication systems when using the unlicensed spectrum. The following detailed explanation of channel sensing uses a Wi-Fi communication system as an example.

[0085] For the WIFI communication system, channel sensing adopts the carrier sensing mechanism. The carrier sensing mechanism can be divided into physical carrier sensing and virtual carrier sensing. Physical carrier sensing and virtual carrier sensing can each correspond to an indicator. If any indicator indicates that the channel is busy, the channel is busy and the channel cannot be used to send signals. Among them, physical carrier sensing can adopt the following three channel idle detection methods: energy detection (ED), carrier sense (CS) and energy carrier hybrid detection (ED&CS). These detection methods can be collectively referred to as clear channel assessment (CCA). The above three detection methods will be explained below.

[0086] Energy detection can be used to determine the energy level of the received signal on a channel. If the power of the received signal is greater than a first threshold (e.g., the ED_threshold threshold specified by the physical layer), the channel is considered occupied. If the power of the received signal is less than the first threshold, the channel is considered idle. The setting of the first threshold is related to the signal's transmit power.

[0087] Carrier detection, also known as carrier sensing, determines whether a channel is idle by identifying a portion of a data frame. Taking the 802.11 standard as an example, the preamble portion of the physical layer convergence protocol (PLCP) header of an 802.11 data frame can be identified. The preamble will be described in detail below with reference to Figures 5 and 6, so it will not be detailed here. The 802.11 preamble is constructed using a specific sequence. This sequence is known to both the sender and receiver and can be used for frame and symbol synchronization. During actual monitoring, nodes can continuously sample channel signals and perform correlation operations using the preamble. Correlation operations can include autocorrelation and cross-correlation. Autocorrelation is commonly performed in technologies based on orthogonal frequency division multiplexing (OFDM), such as the 802.11a standard. Cross-correlation is commonly performed in technologies based on direct sequence spread spectrum (DSSS), such as the 802.11b standard. Similar to the energy detection method, the result of the correlation calculation can be compared with a second threshold. If the result is greater than the second threshold, it is considered that a signal on the channel has been detected, that is, the channel is occupied. If the result is less than the second threshold, it is considered that no signal on the channel has been detected, that is, the channel is idle.

[0088] In hybrid energy and carrier detection, the detection technique used can be determined based on the specific physical layer technology. For example, DSSS technology can combine energy detection and carrier detection. Frequency-hopping spread spectrum (FHSS) technology can use only carrier detection. In hybrid detection, if any detection result exceeds the limit, the channel is considered occupied.

[0089] Figures 5 and 6 are exemplary diagrams of a data frame including a preamble. When a WIFI device sends a PLCP Protocol Data Unit (PPDU) frame, the PPDU frame may include a physical layer header.

[0090] As shown in FIG. 5 , in some protocols (eg, 802.11a / g), the physical layer header may include a short training field (STF), a long training field (LTF), and a signal.

[0091] STF can be composed of 10 short symbols (for example, symbols t1-t10). Each short symbol can be 0.8us. Through STF, multiple functions can be achieved. For example, through STF, frame synchronization and coarse frequency synchronization can be achieved. Among them, based on symbols t1-t7, the main functions that can be achieved are signal detection, automatic gain control (AGC), and diversity selection. Based on symbols t8-t10, the main functions that can be achieved are coarse frequency synchronization, offset estimation, and timing synchronization.

[0092] Based on the LTF, fine frequency synchronization and channel estimation can be achieved. For the carrier detection method, the STF can be used as a preamble, that is, the STF can be autocorrelated or cross-correlated to complete the carrier detection.

[0093] As shown in Figure 6, in some communication protocols (such as 802.11b), the first part of the physical layer header can be a preamble. The preamble can include two parts: a synchronization part (sync) and a start of frame delimiter (SFD). Sync can be used to achieve frame synchronization. The SFD can serve as a frame start identifier. The PPDU can also include a physical service data unit (PHY service data unit, PSDU) or a message protocol data unit (MPDU).

[0094] As applications in the communications industry (e.g., 5G communication systems) increase, the types of connected objects and application scenarios are expanding, placing higher demands on terminal prices and power consumption. Therefore, the application of battery-free, low-cost passive IoT devices has become a key technology for cellular IoT. It is understandable that zero-power devices can enrich the types and number of terminals connected to communication networks in related technologies, truly realizing the interconnection of everything. For example, passive IoT devices can be implemented based on zero-power communication systems (e.g., RFID technology) and extended to suit cellular IoT.

[0095] Deploying zero-power communication systems in unlicensed frequency bands offers numerous advantages. For example, unlicensed spectrum is free to use, eliminating the expense of spectrum purchases and reducing operating costs. Furthermore, the large user base of unlicensed devices, such as the widespread deployment of Wi-Fi devices in homes, businesses, and shopping malls, facilitates the promotion and deployment of zero-power communication systems.

[0096] As mentioned above, the terminals in the zero-power communication system have the characteristics of low complexity and need to support low power consumption. Therefore, most terminals only support simple modulation methods, such as amplitude shift keying (ASK) modulation. For complex modulation methods, such as OFDM modulation supported by WIFI devices, most zero-power terminals cannot support it. The preamble mentioned above for channel sensing in the WIFI system is based on OFDM waveform modulation. It can be seen that zero-power terminals cannot generate preambles. If the terminal does not send a preamble when performing backscatter communication in the unlicensed frequency band, other WIFI devices in the WIFI system will not be able to detect that the channel is in use by detecting the preamble, and may also use the channel for data transmission, thereby causing interference on the channel.

[0097] This application proposes a communication method to solve the above problems. Figure 7 is a schematic flow chart of a communication method provided in an embodiment of this application.

[0098] The method shown in FIG. 7 can be executed by a terminal and a WIFI device.

[0099] The terminal can be a device capable of backscatter communication. For example, the terminal can be a zero-power terminal. It should be noted that the name of the zero-power terminal does not restrict the source and use of its energy. For example, the energy required for the operation of the zero-power terminal can be derived from the external environment. In this case, the zero-power terminal can be zero-power or low-power. Alternatively, the energy required for the operation of the zero-power terminal can be derived from the power supply of the terminal itself. In this case, the zero-power terminal can be a low-power terminal. The definition of a zero-power terminal mainly includes features such as low complexity, support for environmental power supply, backscatter, and new waveforms. The name of the zero-power terminal is not unique and can also be other names, such as an environmentally powered terminal, a terminal based on energy harvesting, etc.

[0100] A Wi-Fi device can also be called a Wi-Fi node. A Wi-Fi device can be a Wi-Fi wireless access point (AP). A Wi-Fi AP can enable Wi-Fi terminals to access the network. For example, a Wi-Fi AP can be a Wi-Fi wireless switch, router, or other device.

[0101] The communication method shown in FIG7 includes step S710 and step S720.

[0102] Step S710: The WIFI device sends a first signal on a first channel.

[0103] The first channel may be any channel in the frequency domain resources that meets the conditions. For example, the first channel may be a channel in an unlicensed frequency band. After occupying the first channel, the WiFi device may send the first signal on the first channel.

[0104] The first signal may include a first preamble and / or a first carrier.

[0105] The first preamble may be a preamble included in the data frame of the Wi-Fi system described above. For example, the first preamble may be a preamble portion of a PLCP header that meets the requirements of the 802.11 standard. As an implementation, the first preamble may include one or more of an STF, an LTF, and other signals.

[0106] It is understood that the first preamble may be generated by the Wi-Fi device with the assistance of the terminal. The information carried in the first preamble may be set based on the needs of the terminal. For example, information such as the duration of channel occupation included in the first preamble may be set based on the needs of the terminal, rather than based on the needs of the Wi-Fi device.

[0107] The first preamble can be consistent with the preamble portion used by the Wi-Fi system to implement carrier detection. In other words, channel sensing can be achieved based on the first preamble. When other Wi-Fi devices detect the first preamble, they know that the first channel used to transmit the first preamble is occupied and therefore do not send data on the first channel.

[0108] The first signal may be used for backscattering by the terminal. That is, the method shown in FIG7 may include step S720, where the terminal may backscatter the first signal on the first channel.

[0109] When the first signal includes a first preamble, the terminal may backscatter the first signal including the first preamble on the first channel. It is understood that even if the terminal cannot generate a preamble on its own, it can still transmit the first preamble by backscattering the first signal including the first preamble. For example, before sending data, the terminal may backscatter the first preamble on the first channel. When other Wi-Fi devices detect the first preamble, they know that the first channel is occupied and will not transmit data on the first channel, thereby avoiding conflicts.

[0110] The first carrier may occupy a portion of the frequency domain resources in the first channel. For example, the first carrier may occupy a frequency point or a range of frequency domain resources in the first channel. In addition, the present application does not limit the waveform of the first carrier. For example, the first carrier may be a sine wave.

[0111] When the first signal includes the first carrier, the terminal can modulate the first carrier and transmit data by backscattering based on the first carrier. It is understood that based on the first carrier, other devices supporting unlicensed band communication (such as WiFi devices) can detect that the first channel is occupied through energy detection, and thus will not transmit data on the first channel, thereby avoiding conflicts.

[0112] It can be seen from this that when the terminal occupies the first channel for backscatter communication, other WIFI devices can determine that the first channel is occupied by detecting the first preamble based on the carrier detection method, and / or, other WIFI devices can determine that the first channel is occupied by detecting the first carrier based on the energy detection method, thereby avoiding the situation where other WIFI devices also occupy the first channel.

[0113] When the first signal includes the first preamble, the Wi-Fi device may transmit the first signal on all or part of the frequency domain resources of the first channel. Accordingly, the terminal may backscatter the first signal including the first preamble on all or part of the frequency domain resources of the first channel. The frequency domain resources used by the Wi-Fi device to transmit the first signal and the frequency domain resources used by the terminal to backscatter the first channel may be the same or different.

[0114] In one embodiment, the first signal may be transmitted on the first frequency domain resource. That is, the WIFI device may send the first signal on the first frequency domain resource.

[0115] The first frequency domain resources may be all frequency domain resources of the first channel. Alternatively, the first frequency domain resources may be all available frequency domain resources of the first channel. The available frequency domain resources may be frequency domain resources in the first channel that are available for communication by the communication device. For example, the first channel may include available frequency domain resources and protection frequency domain resources. The protection frequency domain resources may be used to avoid interference from other channels. The protection frequency domain resources may be reserved. The protection frequency domain resources may be located at the edge of the first channel. The protection frequency domain resources are generally not available for use by the communication device. The available resources may be frequency domain resources in the first channel excluding the protection frequency domain resources.

[0116] If the first signal is transmitted on the first frequency domain resource, the terminal can backscatter the first signal on the first frequency domain resource. It can be understood that the first signal includes the first preamble, so the frequency domain resources occupied by the WiFi device and the terminal for sending the first preamble are the same.

[0117] Figure 8 is a schematic diagram of resources for transmitting a first signal and backscattering the first signal, provided in an embodiment of the present application. Figure 8 takes the first frequency domain resources as the entire frequency domain resources of the first channel as an example. As shown in Figure 8, after the Wi-Fi device occupies the first channel, before the terminal transmits data, the Wi-Fi device generates a first preamble for the terminal. The Wi-Fi device sends the first preamble to the terminal on the first channel. The terminal sends the first preamble on the first channel in a backscattering manner. That is, in Figure 8, both the Wi-Fi device and the terminal occupy the first channel.

[0118] It should be noted that, for ease of understanding, FIG8 shows the first channels occupied by the WIFI device and the terminal separately. In fact, the first channels occupied by the WIFI device and the terminal may overlap.

[0119] Optionally, when the first signal includes a first carrier, the WIFI device may transmit the first carrier on a first frequency domain resource. The terminal device may transmit data (i.e., a data signal) by backscattering on the first frequency domain resource based on the first carrier. It is understood that the data signal transmitted by the terminal backscattering may be located on the same channel as the carrier signal sent by the WIFI device.

[0120] It should be noted that the first carrier may occupy part or all of the first frequency domain resources, and this application does not impose any restrictions on this. For example, the first carrier may occupy a frequency point in the first frequency domain resources.

[0121] 8 , after sending the first preamble, the WIFI device further sends a first carrier to the terminal on the first channel. The terminal sends data based on the first carrier on the first channel in a backscattering manner.

[0122] In another embodiment, the first signal includes a first preamble, and the first signal may be transmitted on a portion of the frequency domain resources of the first channel. For example, the first signal may be transmitted on the second subband. In other words, the WiFi device may send the first signal to the terminal on the second subband. The second subband may be a portion of the frequency domain resources of the first channel. In some implementations, a subband may also be referred to as a subchannel.

[0123] When the first signal is transmitted on the second subband, the terminal can backscatter the first preamble on the first subband. The first subband can be a frequency domain resource in the first channel that is different from the second subband. In other words, the Wi-Fi device and the terminal use different frequencies to transmit the first preamble.

[0124] It is understood that the first subband may be part of the frequency domain resources in the first channel. For example, the first subband may be part of the frequency domain resources in the first channel. The second subband may be part or all of the frequency domain resources in the first channel excluding the first subband. For example, the first preamble may be transmitted on part of the frequency domain resources in the first channel, and the terminal may backscatter the first preamble on another part of the frequency domain resources in the first channel.

[0125] In one implementation, the Wi-Fi device and the terminal may each occupy half of the frequency domain resources of the first channel. For example, the width of the first channel may be 2 MHz. The first preamble sent by the Wi-Fi device and the first preamble backscattered by the terminal may each occupy a 1 MHz sub-channel in the upper and lower sub-channels of the first channel.

[0126] Figure 9 is a schematic diagram of another embodiment of the present application, providing resources for transmitting a first signal and backscattering the first signal. As shown in Figure 9, after the Wi-Fi device occupies the first channel and before the terminal transmits data, the Wi-Fi device generates a first preamble for the terminal. The Wi-Fi device sends the first preamble to the terminal on the second subband. The terminal sends the first preamble on the first subband via backscatter. That is, in Figure 9, the Wi-Fi device and the terminal occupy different frequency domain resources on the first channel to send the first preamble.

[0127] The Wi-Fi device can transmit a first carrier. Based on the first carrier, the terminal can transmit data via backscatter on the first subband. The first carrier can be located in a frequency domain resource other than the first subband in the first channel. For example, the first carrier can be located in the second subband. It is understood that the data signal backscattered by the terminal can be located on a different frequency domain resource than the first carrier transmitted by the Wi-Fi device in the same channel.

[0128] It should be noted that, when the first carrier is located in the second sub-band, the first carrier may not occupy all frequency domain resources of the second sub-band. For example, the first carrier may occupy one frequency point in the second carrier.

[0129] It is understandable that the frequency domain resources used by the WIFI device to send the first preamble and the frequency domain resources used by the terminal to backscatter the first preamble are different, which can reduce interference between the signal sent by the WIFI device and the signal sent by the terminal device.

[0130] Optionally, the Wi-Fi device may also transmit a second signal on the first subband. The second signal may include the first preamble. That is, the Wi-Fi device may repeatedly transmit the first preamble in two different subbands of the first channel. Accordingly, the terminal may backscatter the first preamble in either the first subband or the second subband. For example, the terminal may backscatter the first preamble on the first subband based on the first preamble transmitted in the first subband. Alternatively, the terminal may backscatter the first preamble on the first subband based on the first preamble transmitted in the second subband.

[0131] As can be seen, the WiFi device can repeatedly transmit the first preamble in different parts of the first channel (e.g., the first subband and the second subband). This allows the WiFi device to transmit the first preamble at a higher transmit power, allowing other WiFi devices within a larger range to detect that the first channel is occupied by the WiFi device, thereby preventing other WiFi devices from occupying the channel during the terminal's backscatter communication. For example, this can prevent other WiFi devices at a distance from being unable to detect that the first channel is occupied due to the terminal's low transmit power during backscatter communication.

[0132] In the case where the Wi-Fi device occupies a portion of the first channel to send the first preamble, the Wi-Fi device can send the second preamble on all frequency domain resources or all available frequency domain resources of the first channel. Because the frequency domain resources occupied by the second preamble are wider than those occupied by the first preamble, the second preamble can also be called a wideband preamble.

[0133] It is understood that a subband can be narrower than the first channel. If the terminal backscatters the first preamble on a subband, the first preamble is suitable for other WiFi devices operating on channels narrower than the first channel, allowing these WiFi devices to detect that the narrower channel (e.g., the first subband or the second subband) is occupied. The second preamble can occupy the entire bandwidth of the first channel. Therefore, the second preamble is suitable for other WiFi devices that expect to operate on the entire first channel, allowing these WiFi devices to detect that the entire first channel is occupied.

[0134] The implementation of the second preamble is illustrated below using Figure 10 as an example. As shown in Figure 10, the terminal occupies the first subband in the first channel, and the WIFI device occupies the second subband in the first channel. The width of the first channel can be 2MHz, and the first subband and the second subband are 1MHz sub-channels above and below the first channel, respectively. The second preamble sent by the WIFI device occupies the entire first channel. Therefore, the second preamble can be used for carrier sensing of the first channel by other WIFI devices that expect to operate on the 2MHz first channel. The first preamble sent by the WIFI device and the first preamble backscattered by the terminal occupy the upper and lower 1MHz sub-channels of the first channel, respectively, and can be used for carrier sensing of these sub-bands by other WIFI devices that expect to operate on the first subband and / or the second subband.

[0135] In another embodiment, the WIFI device may send first indication information to the terminal. The first indication information may be used to instruct the terminal to backscatter the first signal.

[0136] The first channel may be a channel obtained by the WIFI device in an unlicensed frequency band. The WIFI device may obtain the first channel, for example, by LBT. The WIFI device may send a third preamble to notify other WIFI devices that the first channel is occupied.

[0137] The WIFI device may share the first channel with the terminal through the first indication information to instruct the terminal to perform backscatter communication on the first channel. For example, after the WIFI device obtains the first channel, it may send an indication of channel occupancy of the first channel and share the occupied first channel resources with the terminal for backscatter communication.

[0138] This application does not limit the manner in which the first channel resources are shared by the WIFI devices. For example, the WIFI device may share the duration of occupying the first channel with the terminal.

[0139] As an implementation, the first indication information may include a first transmission duration and / or a first start time. The first transmission duration may be the transmission duration during which the terminal can occupy the first channel. The terminal may occupy the first channel for part or all of the first transmission duration. The first start time may be the start time at which the terminal can occupy the first channel. The terminal may begin occupying the first channel after the first start time.

[0140] The first transmission duration may be a portion of the total duration indicated by the transmission opportunity (TXOP) occupied by the WIFI device. It is understood that after the WIFI device obtains the first channel, the total duration for which the WIFI device expects to occupy the first channel may be sent through the TXOP, and a portion of the total duration may be shared with the terminal. Optionally, the first transmission duration may be all or part of the total duration indicated by the TXOP, excluding the duration occupied by the WIFI device for communication. The duration occupied by the WIFI device for communication may include the duration for sending the third preamble and / or the duration for sending the data signal.

[0141] The start time of the terminal device performing backscatter communication can be determined based on the end time of the WIFI device occupying the first channel for communication. For example, the start time of the terminal device performing backscatter communication can be equal to or later than the end time of the WIFI device occupying the first channel for communication. It is understood that the first start time in the first indication information can also be determined based on the end time of the WIFI device occupying the first channel for communication.

[0142] As an implementation, there may be an interval between the start time of the backscatter communication of the terminal device and the end time of the communication of the WIFI device. The interval may be less than or equal to a first threshold value. The first threshold value may be 16 microseconds.

[0143] It can be understood that the interval between the start time of the terminal device performing backscatter communication and the end time of the WIFI device performing communication is less than the first threshold, which can avoid the first channel being occupied by other WIFI devices after the WIFI device ends communication and within the total duration indicated by the TXOP.

[0144] The WIFI device may transmit a first carrier wave for the terminal to perform backscatter communication. The first carrier wave may be transmitted at any time between the end of communication by the WIFI device and the start of backscatter communication by the terminal, and this application does not impose any limitation on this.

[0145] It is understandable that, compared to the terminal performing backscattering, the WIFI device may be a node with higher capabilities. That is, the WIFI device can send a PPDU or preamble (hereinafter referred to as the third preamble) that is compatible with other WIFI devices in the WIFI communication system. Therefore, when other WIFI devices detect the third preamble sent by the WIFI device, they can determine that the channel is busy. Other WIFI devices can also delay their access time according to the TXOP indication sent by the WIFI device. Therefore, when the terminal sends a signal via backscattering, the terminal does not need to send a preamble compatible with other WIFI devices, so that other WIFI devices know that the first channel is occupied.

[0146] FIG11 is a schematic diagram of a WIFI device and a terminal sharing a first channel provided by an embodiment of the present application. As shown in FIG11 , within the total duration indicated by the TXOP, the WIFI device occupies T duration, and the remaining TXOP duration can be shared with the terminal. The remaining TXOP duration can be a first transmission duration. The WIFI device can indicate to the terminal through the first indication information that it can transmit within the remaining TXOP duration. After receiving the first indication information, the terminal can perform backscatter communication within the remaining TXOP duration. After the T duration ends, the terminal starts backscatter communication at an interval of t1. t1 can be less than 16 microseconds. After T ends, the WIFI device can send a first carrier for the terminal to perform backscatter communication.

[0147] It should be noted that the WIFI device may also share the acquired first channel with multiple terminals. Multiple terminals may all occupy the first channel for backscatter communication. The WIFI device may send corresponding first indication information to each of the multiple terminals to indicate the allocation of the first channel.

[0148] This application does not limit the specific manner in which multiple terminals and WIFI devices share the first channel. For example, each terminal may sequentially occupy the first channel for backscatter communication.

[0149] There may be an interval between the times when different terminals occupy the first channel for backscatter communication. The interval may be less than or equal to a second threshold. The second threshold may be, for example, 16 microseconds.

[0150] Figure 12 is a schematic diagram of a Wi-Fi device sharing a first channel with two terminals, provided by an embodiment of the present application. The two terminals may be a first terminal and a second terminal. As shown in Figure 12, within the total TXOP duration indicated by the Wi-Fi device, the Wi-Fi device occupies T, while the remaining TXOP duration is shared between the two terminals. The Wi-Fi device may, through first indication information from the first terminal, indicate to the first terminal that it may transmit within T1. After receiving this first indication information, the first terminal may conduct backscatter communication within T1. After T expires, the first terminal may begin backscatter communication after a delay of t1. t1 may be less than 16 microseconds. The Wi-Fi device may, through first indication information from the second terminal, indicate to the second terminal that it may transmit within T2. ​​After receiving this first indication information, the second terminal may send data via backscatter within T2. ​​After T1 expires, the second terminal may begin backscatter communication after a delay of t2. t2 may be less than 16 microseconds. After T expires, the Wi-Fi device may transmit the first carrier for backscatter communication between the first and second terminals.

[0151] The method embodiment of the present application is described in detail above in conjunction with Figures 1 to 12. The device embodiment of the present application is described in detail below in conjunction with Figures 13 to 15. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment. Therefore, for parts not described in detail, reference can be made to the above method embodiment.

[0152] FIG13 is a schematic structural diagram of a terminal 1300 according to an embodiment of the present application. The terminal 1300 may include a backscatter unit 1310 .

[0153] The backscatter unit 1310 is configured to backscatter a first signal on a first channel; wherein the first signal includes a first preamble and / or a first carrier, and the first signal is sent by a WIFI device.

[0154] Optionally, when the first signal includes the first preamble, the backscattering unit 1310 is used to: backscatter the first signal on a first frequency domain resource; wherein the first frequency domain resource is all frequency domain resources or all available frequency domain resources of the first channel.

[0155] Optionally, the first signal is transmitted on the first frequency domain resources.

[0156] Optionally, when the first signal includes the first carrier, the terminal 1300 is further configured to: transmit data on the first frequency domain resources by backscattering based on the first carrier.

[0157] Optionally, when the first signal includes the first preamble, the backscattering unit 1310 is used to: backscatter the first signal on a first subband; wherein the first subband is part of the frequency domain resources in the first channel.

[0158] Optionally, the first signal is transmitted on a second sub-band, and the second sub-band is part or all of the frequency domain resources in the first channel except the first sub-band.

[0159] Optionally, when the first signal includes the first carrier, the terminal 1300 is further configured to: transmit data on the first subband by backscattering based on the first carrier.

[0160] Optionally, the first carrier is located in frequency domain resources other than the first subband in the first channel.

[0161] Optionally, the first preamble includes a short training field STF and / or a long training field LTF.

[0162] Optionally, the terminal 1300 is further configured to: receive first indication information sent by the WIFI device;

[0163] Optionally, the first indication information is used to instruct the terminal to backscatter the first signal.

[0164] Optionally, the first channel is a channel obtained by the WIFI device in an unlicensed frequency band.

[0165] Optionally, the first indication information includes a first transmission duration and / or a first start time; wherein, the first transmission duration is the transmission duration during which the terminal can occupy the first channel, and the first start time is the start time when the terminal can occupy the first channel.

[0166] Optionally, when the first indication information includes the first transmission duration, the first transmission duration is a portion of the total duration indicated by the contention transmission opportunity TXOP occupied by the WIFI device.

[0167] Optionally, the first transmission duration is all or part of the total duration excluding the duration occupied by the WIFI device for communication.

[0168] Optionally, a time interval between a start time of backscatter communication performed by the terminal and an end time of communication performed by the WIFI device is less than or equal to a first threshold.

[0169] Optionally, the first threshold is 16 microseconds.

[0170] FIG14 is a schematic structural diagram of a WIFI device 1400 provided in an embodiment of the present application. The WIFI device 1400 may include a sending unit 1410 .

[0171] The sending unit 1410 is configured to send a first signal on a first channel; wherein the first signal includes a first preamble and / or a first carrier, and the first signal is used for backscattering by the terminal.

[0172] Optionally, when the first signal includes the first preamble, the first signal is used for the terminal to perform backscattering on first frequency domain resources, and the first frequency domain resources are all frequency domain resources or all available frequency domain resources of the first channel.

[0173] Optionally, the first signal occupies the first frequency domain resources for transmission.

[0174] Optionally, when the first signal includes the first carrier, the first carrier is used for the terminal to transmit data on the first frequency domain resources by backscattering.

[0175] Optionally, when the first signal includes the first preamble, the first signal is used for the terminal to perform backscattering on a first sub-band, where the first sub-band is part of the frequency domain resources in the first channel.

[0176] Optionally, the first signal is transmitted on a second sub-band, and the second sub-band is part or all of the frequency domain resources in the first channel except the first sub-band.

[0177] Optionally, the WIFI device 1400 is further configured to: send a second signal on the first subband, where the second signal includes the first preamble.

[0178] Optionally, when the first signal includes the first carrier, the first carrier is used for the terminal to transmit data on the first subband by backscattering.

[0179] Optionally, the first carrier is located in frequency domain resources other than the first subband in the first channel.

[0180] Optionally, the WIFI device 1400 is further configured to: send a second preamble on all frequency domain resources or all available frequency domain resources of the first channel.

[0181] Optionally, the first preamble includes a short training field STF and / or a long training field LTF.

[0182] Optionally, the WIFI device 1400 is further used to: send first indication information to the terminal; wherein the first indication information is used to instruct the terminal to backscatter the first signal.

[0183] Optionally, the first channel is a channel obtained by the WIFI device in an unlicensed frequency band.

[0184] Optionally, the first indication information includes a first transmission duration and / or a first start time; wherein, the first transmission duration is the transmission duration during which the terminal can occupy the first channel, and the first start time is the start time when the terminal can occupy the first channel.

[0185] Optionally, when the first indication information includes the first transmission duration, the first transmission duration is a portion of the total duration indicated by the contention transmission opportunity TXOP occupied by the WIFI device.

[0186] Optionally, the first transmission duration is all or part of the total duration excluding the duration occupied by the WIFI device for communication.

[0187] Optionally, a time interval between a start time of backscatter communication performed by the terminal and an end time of communication performed by the WIFI device is less than or equal to a first threshold.

[0188] Optionally, the first threshold is 16 microseconds.

[0189] Figure 15 is a schematic block diagram of a communication device according to an embodiment of the present application. The dashed lines in Figure 15 indicate that the unit or module is optional. Apparatus 1500 may be used to implement the method described in the above method embodiment. Apparatus 1500 may be a chip, a terminal device, or a Wi-Fi device.

[0190] The device 1500 may include one or more processors 1510. The processor 1510 may support the device 1500 to implement the method described in the method embodiment above. The processor 1510 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0191] The apparatus 1500 may further include one or more memories 1520. The memories 1520 store programs that can be executed by the processor 1510, causing the processor 1510 to perform the methods described in the above method embodiments. The memories 1520 may be independent of the processor 1510 or integrated into the processor 1510.

[0192] The apparatus 1500 may further include a transceiver 1530. The processor 1510 may communicate with other devices or chips via the transceiver 1530. For example, the processor 1510 may transmit and receive data with other devices or chips via the transceiver 1530.

[0193] The present application also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to a terminal or network device provided in the present application, and the program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0194] The present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to a terminal or network device provided in the present application, and the program causes a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0195] The embodiments of the present application also provide a computer program. The computer program can be applied to the terminal or network device provided in the embodiments of the present application, and the computer program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0196] It should be understood that the terms "system" and "network" in this application can be used interchangeably. In addition, the terms used in this application are only used to explain the specific embodiments of this application and are not intended to limit this application. The terms "first", "second", "third", and "fourth" in the specification and claims of this application and the accompanying drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0197] In the embodiments of this application, the term "indication" may refer to a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" may refer to a direct indication of B, e.g., B can obtain information through A; it may refer to an indirect indication of B, e.g., A indicates C, e.g., B can obtain information through C; or it may refer to an association between A and B.

[0198] In the embodiment of the present application, "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should be understood that determining B based on A does not mean determining B based solely on A, but B can also be determined based on A and / or other information.

[0199] In the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and indication, configuration and configuration, etc.

[0200] In the embodiments of the present application, "pre-definition" or "pre-configuration" may be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (e.g., a terminal device and a network device). The present application does not limit the specific implementation method. For example, pre-definition may refer to information defined in a protocol.

[0201] In the embodiments of the present application, the “protocol” may refer to a standard protocol in the communications field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

[0202] In the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0203] In various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0204] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0205] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of the solution of this embodiment according to actual needs.

[0206] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0207] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be read by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0208] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: The communication method comprises: The terminal backscatters the first signal on the first channel; The first signal includes a first preamble and / or a first carrier, and the first signal is sent by a WIFI device.

2. The communication method according to claim 1, wherein: In case the first signal includes the first preamble, The terminal backscattering the first signal on the first channel includes: the terminal backscattering the first signal on a first frequency domain resource; The first frequency domain resources are all frequency domain resources or all available frequency domain resources of the first channel.

3. The communication method according to claim 2, wherein: The first signal is transmitted on the first frequency domain resource.

4. The communication method according to claim 2 or 3, characterized in that: In a case where the first signal includes the first carrier, the communication method further includes: The terminal transmits data on the first frequency domain resources by backscattering based on the first carrier.

5. The communication method according to claim 1, wherein: In case the first signal includes the first preamble, The terminal backscattering the first signal on the first channel includes: the terminal backscattering the first signal on the first subband; The first sub-band is part of the frequency domain resources in the first channel. The communication method according to claim 5 , wherein: The first signal is transmitted on a second sub-band, and the second sub-band is part or all of the frequency domain resources in the first channel except the first sub-band.

7. The communication method according to claim 5 or 6, characterized in that: In a case where the first signal includes the first carrier, the communication method further includes: The terminal transmits data on the first subband by backscattering based on the first carrier.

8. The communication method according to claim 7, wherein: The first carrier is located in frequency domain resources other than the first subband in the first channel.

9. The communication method according to any one of claims 1 to 8, characterized in that: The first preamble includes a short training field STF and / or a long training field LTF.

10. The communication method according to any one of claims 1 to 9, characterized in that: The communication method further includes: The terminal receives first indication information sent by the WIFI device; The first indication information is used to instruct the terminal to backscatter the first signal.

11. The communication method according to claim 10, wherein: The first channel is a channel obtained by the WIFI device in an unlicensed frequency band.

12. The communication method according to claim 10 or 11, characterized in that: The first indication information includes a first transmission duration and / or a first start time; The first transmission duration is the transmission duration during which the terminal can occupy the first channel, and the first start time is the start time when the terminal can occupy the first channel.

13. The communication method according to claim 12, wherein: In a case where the first indication information includes the first transmission duration, the first transmission duration is a portion of the total duration indicated by the contention transmission opportunity TXOP occupied by the WIFI device.

14. The communication method according to claim 13, wherein: The first transmission duration is all or part of the total duration excluding the duration occupied by the WIFI device for communication.

15. The communication method according to any one of claims 10 to 14, characterized in that: A time interval between a start time of backscatter communication performed by the terminal and an end time of communication performed by the WIFI device is less than or equal to a first threshold.

16. The communication method according to claim 15, characterized in that: The first threshold is 16 microseconds.

17. A communication method, characterized in that: The communication method comprises: The WIFI device sends a first signal on a first channel; The first signal includes a first preamble and / or a first carrier, and the first signal is used for backscattering by the terminal.

18. The communication method according to claim 17, wherein: In the case where the first signal includes the first preamble, the first signal is used for the terminal to perform backscattering on first frequency domain resources, where the first frequency domain resources are all frequency domain resources or all available frequency domain resources of the first channel.

19. The communication method according to claim 18, wherein: The first signal occupies the first frequency domain resources for transmission.

20. The communication method according to claim 18 or 19, characterized in that: In a case where the first signal includes the first carrier, the first carrier is used for the terminal to transmit data on the first frequency domain resources by way of backscattering.

21. The communication method according to claim 17, wherein: In the case where the first signal includes the first preamble, the first signal is used for backscattering by the terminal on a first subband. The first sub-band is part of the frequency domain resources in the first channel.

22. The communication method according to claim 21, wherein: The first signal is transmitted on a second sub-band, and the second sub-band is part or all of the frequency domain resources in the first channel except the first sub-band.

23. The communication method according to claim 22, wherein: The communication method further includes: The WIFI device sends a second signal on the first sub-band, where the second signal includes the first preamble.

24. The communication method according to any one of claims 21 to 23, characterized in that: In a case where the first signal includes the first carrier, the first carrier is used for the terminal to transmit data on the first subband by way of backscattering.

25. The communication method according to claim 24, characterized in that The first carrier is located in frequency domain resources other than the first subband in the first channel.

26. The communication method according to any one of claims 21 to 25, characterized in that: The communication method further includes: The WIFI device sends a second preamble on all frequency domain resources or all available frequency domain resources of the first channel.

27. The communication method according to any one of claims 17 to 26, characterized in that: The first preamble includes a short training field STF and / or a long training field LTF.

28. The communication method according to any one of claims 17 to 27, characterized in that: The communication method further includes: First indication information sent by the WIFI device to the terminal; The first indication information is used to instruct the terminal to backscatter the first signal.

29. The communication method according to claim 28, characterized in that The first channel is a channel obtained by the WIFI device in an unlicensed frequency band.

30. The communication method according to claim 28 or 29, characterized in that: The first indication information includes a first transmission duration and / or a first start time; The first transmission duration is the transmission duration during which the terminal can occupy the first channel, and the first start time is the start time when the terminal can occupy the first channel.

31. The communication method according to claim 30, wherein: In a case where the first indication information includes the first transmission duration, the first transmission duration is a portion of the total duration indicated by the contention transmission opportunity TXOP occupied by the WIFI device.

32. The communication method according to claim 31, wherein: The first transmission duration is all or part of the total duration excluding the duration occupied by the WIFI device for communication.

33. The communication method according to any one of claims 28 to 32, characterized in that: A time interval between a start time of backscatter communication performed by the terminal and an end time of communication performed by the WIFI device is less than or equal to a first threshold.

34. The communication method according to claim 33, wherein: The first threshold is 16 microseconds.

35. A terminal, characterized in that: The terminal includes: a backscattering unit, configured to backscatter the first signal on the first channel; The first signal includes a first preamble and / or a first carrier, and the first signal is sent by a WIFI device.

36. The terminal according to claim 35, characterized in that In case the first signal includes the first preamble, The backscattering unit is configured to: backscatter the first signal on a first frequency domain resource; The first frequency domain resources are all frequency domain resources or all available frequency domain resources of the first channel.

37. The terminal according to claim 36, characterized in that The first signal is transmitted on the first frequency domain resource.

38. The terminal according to claim 36 or 37, characterized in that In a case where the first signal includes the first carrier, the terminal is further configured to: Based on the first carrier, data is transmitted on the first frequency domain resources by backscattering.

39. The terminal according to claim 35, characterized in that In case the first signal includes the first preamble, The backscattering unit is configured to: backscatter the first signal on the first sub-band; The first sub-band is part of the frequency domain resources in the first channel.

40. The terminal according to claim 39, wherein: The first signal is transmitted on a second sub-band, and the second sub-band is part or all of the frequency domain resources in the first channel except the first sub-band.

41. The terminal according to claim 39 or 40, characterized in that In a case where the first signal includes the first carrier, the terminal is further configured to: Based on the first carrier, data is transmitted on the first subband by backscattering.

42. The terminal according to claim 41, characterized in that The first carrier is located in frequency domain resources other than the first subband in the first channel.

43. The terminal according to any one of claims 35 to 42, characterized in that: The first preamble includes a short training field STF and / or a long training field LTF.

44. The terminal according to any one of claims 35 to 43, characterized in that: The terminal is also used for: Receiving first indication information sent by the WIFI device; The first indication information is used to instruct the terminal to backscatter the first signal.

45. The terminal according to claim 44, characterized in that The first channel is a channel obtained by the WIFI device in an unlicensed frequency band.

46. ​​The terminal according to claim 44 or 45, characterized in that The first indication information includes a first transmission duration and / or a first start time; The first transmission duration is the transmission duration during which the terminal can occupy the first channel, and the first start time is the start time when the terminal can occupy the first channel.

47. The terminal according to claim 46, characterized in that In a case where the first indication information includes the first transmission duration, the first transmission duration is a portion of the total duration indicated by the contention transmission opportunity TXOP occupied by the WIFI device.

48. The terminal according to claim 47, characterized in that The first transmission duration is all or part of the total duration excluding the duration occupied by the WIFI device for communication.

49. The terminal according to any one of claims 44 to 48, characterized in that A time interval between a start time of backscatter communication performed by the terminal and an end time of communication performed by the WIFI device is less than or equal to a first threshold.

50. The terminal according to claim 49, characterized in that The first threshold is 16 microseconds.

51. A WIFI device, characterized in that: The WIFI device includes: a sending unit, configured to send a first signal on a first channel; The first signal includes a first preamble and / or a first carrier, and the first signal is used for backscattering by the terminal.

52. The WIFI device according to claim 51, wherein: In the case where the first signal includes the first preamble, the first signal is used for the terminal to perform backscattering on first frequency domain resources, where the first frequency domain resources are all frequency domain resources or all available frequency domain resources of the first channel.

53. The WIFI device according to claim 52, wherein: The first signal occupies the first frequency domain resources for transmission.

54. The WIFI device according to claim 52 or 53, wherein: In a case where the first signal includes the first carrier, the first carrier is used for the terminal to transmit data on the first frequency domain resources by way of backscattering.

55. The WIFI device according to claim 51, wherein: In the case where the first signal includes the first preamble, the first signal is used for backscattering by the terminal on a first subband. The first sub-band is part of the frequency domain resources in the first channel.

56. The WIFI device according to claim 55, characterized in that The first signal is transmitted on a second sub-band, and the second sub-band is part or all of the frequency domain resources in the first channel except the first sub-band.

57. The WIFI device according to claim 56, characterized in that The WIFI device is also used for: A second signal is transmitted on the first subband, the second signal including the first preamble.

58. The WIFI device according to any one of claims 55-57, characterized in that In a case where the first signal includes the first carrier, the first carrier is used for the terminal to transmit data on the first subband by way of backscattering.

59. The WIFI device according to claim 58, characterized in that The first carrier is located in frequency domain resources other than the first subband in the first channel.

60. The WIFI device according to any one of claims 55-59, characterized in that: The WIFI device is also used for: The second preamble is sent on all frequency domain resources or all available frequency domain resources of the first channel.

61. The WIFI device according to any one of claims 51 to 60, characterized in that: The first preamble includes a short training field STF and / or a long training field LTF.

62. The WIFI device according to any one of claims 51 to 61, characterized in that: The WIFI device is also used for: first indication information sent to the terminal; The first indication information is used to instruct the terminal to backscatter the first signal.

63. The WIFI device according to claim 62, wherein: The first channel is a channel obtained by the WIFI device in an unlicensed frequency band.

64. The WIFI device according to claim 62 or 63, wherein: The first indication information includes a first transmission duration and / or a first start time; The first transmission duration is the transmission duration during which the terminal can occupy the first channel, and the first start time is the start time when the terminal can occupy the first channel.

65. The WIFI device according to claim 64, characterized in that In a case where the first indication information includes the first transmission duration, the first transmission duration is a portion of the total duration indicated by the contention transmission opportunity TXOP occupied by the WIFI device.

66. The WIFI device according to claim 65, characterized in that The first transmission duration is all or part of the total duration excluding the duration occupied by the WIFI device for communication.

67. The WIFI device according to any one of claims 62-66, characterized in that A time interval between a start time of backscatter communication performed by the terminal and an end time of communication performed by the WIFI device is less than or equal to a first threshold.

68. The WIFI device according to claim 67, wherein: The first threshold is 16 microseconds.

69. A terminal, characterized in that: The system comprises a memory and a processor, wherein the memory is used to store a program, and the processor is used to call the program in the memory to execute the method according to any one of claims 1 to 16.

70. A network device, characterized in that The system comprises a memory and a processor, wherein the memory is used to store a program, and the processor is used to call the program in the memory to execute the method according to any one of claims 17 to 34.

71. A device, characterized in that The device comprises a processor, configured to call a program from a memory to execute the method according to any one of claims 1 to 16.

72. A device, characterized in that The device comprises a processor configured to call a program from a memory to execute the method according to any one of claims 17 to 34.

73. A chip, characterized in that The device comprises a processor configured to call a program from a memory so that a device equipped with the chip executes the method according to any one of claims 1 to 16.

74. A chip, characterized in that The device comprises a processor configured to call a program from a memory so that a device equipped with the chip executes the method according to any one of claims 17 to 34.

75. A computer-readable storage medium, characterized in that A program is stored thereon, and the program causes a computer to execute the method according to any one of claims 1 to 16.

76. A computer-readable storage medium, characterized in that A program is stored thereon, the program causing a computer to execute the method according to any one of claims 17 to 34.

77. A computer program product, characterized in that The method comprises a program for causing a computer to execute the method according to any one of claims 1 to 16.

78. A computer program product, characterized in that The method comprises a program for causing a computer to execute the method according to any one of claims 17 to 34.

79. A computer program, characterized in that The computer program enables a computer to execute the method according to any one of claims 1 to 16.

80. A computer program, characterized in that The computer program causes a computer to execute the method according to any one of claims 17 to 34.

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