Method for wireless communication and communication device

Abstract

Provided are a method for wireless communication and a communication device. The method comprises: a first device receives a first PPDU sent by a second device, wherein the first PPDU comprises a first signal domain used for carrying a carrier signal, and a second signal domain located before the first signal domain and associated with the carrier signal. In addition to the first signal domain used for carrying the carrier signal, the first PPDU used for carrying the carrier signal and sent by the second device to the first device further comprises the second signal domain located before the first signal domain and associated with the carrier signal, so that the first device can acquire timing information of the carrier signal on the basis of the second signal domain and thereby form a backscatter signal on the basis of the carrier signal, so as to implement communication with the second device.

Description

Wireless communication methods and communication devices Technical Field

[0001] This application relates to the field of communication technology, and more specifically, to a method and device for wireless communication. Background Technology

[0002] Ambient powered (AMP) devices can communicate using either active transmission or backscattering. For backscattering, the AMP device needs to receive a carrier signal and modulate it to generate a backscattered signal. Therefore, how the AMP device obtains the timing information of the carrier signal becomes a problem that needs to be solved.

[0003] Summary of the Invention

[0004] This application provides a method and apparatus for wireless communication. The various aspects covered by this application are described below.

[0005] In a first aspect, a wireless communication method is provided, comprising: a first device receiving a first physical layer protocol data unit (PPDU) sent by a second device, wherein the first PPDU includes a first signal field for carrying a carrier signal and a second signal field located before the first signal field and associated with the carrier signal.

[0006] In a second aspect, a wireless communication method is provided, comprising: a second device sending a first PPDU to a first device, wherein the first PPDU includes a first signal domain for carrying a carrier signal and a second signal domain located before the first signal domain and associated with the carrier signal.

[0007] Thirdly, a communication device is provided, the communication device being a first device, comprising: a transceiver unit for receiving a first PPDU sent by a second device, wherein the first PPDU includes a first signal field for carrying a carrier signal and a second signal field located before the first signal field and associated with the carrier signal.

[0008] Fourthly, a communication device is provided, the communication device being a second device, comprising: a transceiver unit for transmitting a first PPDU to a first device, wherein the first PPDU includes a first signal field for carrying a carrier signal and a second signal field located before the first signal field and associated with the carrier signal.

[0009] Fifthly, a communication device is provided, including a transceiver, a memory, and a processor, wherein the memory is used to store a program, and the processor is used to invoke the program in the memory and control the transceiver to receive or send signals, so that the communication device performs the method as described in the first aspect.

[0010] In a sixth aspect, a communication device is provided, including a transceiver, a memory, and a processor, wherein the memory is used to store a program, and the processor is used to invoke the program in the memory and control the transceiver to receive or send signals so that the communication device performs the method as described in the second aspect.

[0011] A seventh aspect provides an apparatus including a processor for calling a program from a memory to cause the apparatus to perform the method as described in any one of the first or second aspects.

[0012] Eighthly, a chip is provided, including a processor for calling a program from memory to cause a device having the chip mounted to perform the method as described in the first or second aspect.

[0013] Ninth aspect, a computer-readable storage medium is provided having a program stored thereon that causes a computer to perform the method as described in the first or second aspect.

[0014] A tenth aspect provides a computer program product, including a program that causes a computer to perform the method as described in the first or second aspect.

[0015] Eleventhly, a computer program is provided that causes a computer to perform the method as described in the first or second aspect.

[0016] In this embodiment of the application, the first PPDU for carrying a carrier signal sent by the second device to the first device includes not only a first information field for carrying the carrier signal, but also a second signal field located before the first signal field and associated with the carrier signal. Therefore, the first device can obtain the timing information of the carrier signal based on the second signal field, thereby forming a backscattered signal based on the carrier signal to achieve communication with the second device. Attached Figure Description

[0017] Figure 1 is a system architecture example diagram of a wireless communication system applicable to embodiments of this application.

[0018] Figure 2 is a schematic diagram of the principle of backscattering.

[0019] Figure 3 is a schematic diagram of the principle of carrier modulation.

[0020] Figure 4 is a schematic diagram of a Mono-static backscatter communication system.

[0021] Figure 5 is a schematic diagram of a Bi-static backscatter communication system.

[0022] Figure 6 is a schematic diagram of the PPDU carrying the carrier signal being sent from the AMP AP to the AMP STA.

[0023] Figure 7 is a schematic diagram of the PPDU carrying the carrier signal being sent from the carrier source to the AMP STA.

[0024] Figure 8 is a schematic diagram showing that the start time of the backscattered signal is later than the start time of the carrier signal.

[0025] Figure 9 is a schematic diagram showing that the start time of the backscattered signal is earlier than the start time of the carrier signal.

[0026] Figure 10 is a schematic diagram of the start time of the delayed backscattered signal.

[0027] Figure 11 is a schematic flowchart of a wireless communication method according to an embodiment of this application.

[0028] Figure 12 is a schematic diagram of the first PPDU sent by the AMP AP to the AMP STA.

[0029] Figure 13 is a schematic diagram of the first PPDU sent by the carrier source to the AMP STA.

[0030] Figure 14 is a schematic diagram of the first PPDU carrying the synchronization signal in the second signal domain.

[0031] Figure 15 is a schematic diagram of the first PPDU, where the second signal domain is the control domain.

[0032] Figure 16 is a schematic diagram of the first PPDU using the segmented PPDU format.

[0033] Figure 17 is a schematic diagram of the structure of the terminal device according to an embodiment of this application.

[0034] Figure 18 is a schematic diagram of the structure of a network device according to an embodiment of this application.

[0035] Figure 19 is a schematic diagram of a communication apparatus according to an embodiment of this application. Detailed Implementation

[0036] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0037] Communication system

[0038] The technical solutions of this application embodiment can be applied to various communication systems. For example, they can be applied to wireless local area networks (WLAN), wireless fidelity (WiFi), high-performance radio local area networks (HIPELAN), wide area networks (WAN), cellular networks, or other communication systems. As another example, they can be applied to communication systems using the 802.11 standard. Exemplarily, the 802.11 standard includes, but is not limited to, the 802.11a standard, the 802.11g standard, the 802.11ba standard, and next-generation 802.11 standards.

[0039] Figure 1 illustrates a schematic diagram of a communication system applicable to embodiments of this application. As shown in Figure 1, the communication system 100 includes a first device 110 and a second device 120. It is understood that Figure 1 only exemplarily shows two first devices 110 and one second device 120. In other implementations, the communication system 100 may include multiple second devices 120, or other numbers of first devices 110.

[0040] In some scenarios, such as in a WiFi system, the first device 110 can be a station (STA), and the second device 120 can be an access point (AP). The AP is used to create a wireless network and provide wireless network services to the STA. STAs can access the network through the AP.

[0041] In this context, an Access Point (AP) can be a device in a wireless network. An AP can be a communication server, router, switch, bridge, or other communication entity. Alternatively, an AP can include various forms of macro base stations, micro base stations, relay stations, etc. Of course, an AP can also be a chip, circuit, or processing system within these various types of devices to implement the methods and functions of the embodiments of this application. APs can be applied in various scenarios, such as sensor nodes in smart cities (e.g., smart water meters, smart electricity meters, smart air quality monitoring nodes); smart devices in smart homes (e.g., smart cameras, projectors, displays, televisions, speakers, refrigerators, washing machines, etc.); nodes in the Internet of Things (IoT); entertainment terminals (e.g., AR, VR wearable devices); smart devices in smart offices (e.g., printers, projectors, etc.); vehicle-to-everything (V2X) devices; and infrastructure in everyday life scenarios (e.g., vending machines, supermarket self-service navigation kiosks, self-checkout machines, self-service ordering machines, etc.).

[0042] A STA can be a device with wireless transceiver capabilities, such as a device that supports the 802.11 series of protocols and communicates with an AP or other STAs. As an example, an STA is any user communication device that allows a user to communicate with an AP and subsequently with a WLAN network. STAs include, for example, user equipment (UE), mobile station (MS), mobile terminal (MT), access terminal, user unit, user station, mobile station, mobile terminal, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent, or user device.

[0043] STA can also be a device that provides users with voice and / or data connectivity, such as a handheld device or in-vehicle device with wireless connectivity. As examples, STAs can include mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, wearable devices, terminal devices in 5G networks, or future evolution of public land mobile communication networks. Terminal devices in a network (PLMN), etc., are not limited to this in the embodiments of this application.

[0044] STA can also refer to wearable devices. Wearable devices, also known as wearable smart devices, are a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. For example, STA can include smartwatches or smart glasses, as well as devices focused on a specific application function that require interaction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0045] STA can also be a terminal device in the Internet of Things (IoT) system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network for human-machine interconnection and object-to-object interconnection.

[0046] STA can also refer to devices within a vehicle-to-everything (V2X) system. The communication methods within a V2X system are collectively referred to as V2X, where X can represent anything. For example, V2X communication includes vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian (V2P) communication, and vehicle-to-network (V2N) communication.

[0047] In addition, STA can also include sensors such as smart printers, train detectors, and gas stations. Its main functions include collecting data, receiving control information and downlink data from the AP, and sending electromagnetic waves to transmit data to the AP.

[0048] In this embodiment of the application, the AP can be a device used to communicate with the STA. The AP can be a network device or a terminal device in a wireless local area network. The AP can communicate with the STA through the wireless local area network.

[0049] From the perspective of the communication standards supported by the AP, in some implementations, the AP is a device that can support the 802.11 standard. Furthermore, the AP can also be a device that supports various current and future 802.11 family WLAN standards, such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, 802.11ba, and 802.11a.

[0050] From the perspective of the communication standards supported by the STA, in some implementations, the STA is a device that can support the 802.11 standard. The STA can also support various current and future 802.11 family WLAN standards such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, 802.11ba, and 802.11a.

[0051] It should be understood that the specific forms of STA and AP are not specifically limited in the embodiments of this application, and are merely illustrative examples.

[0052] Furthermore, the technical solution implemented in this application can also be extended to other scenarios beyond WiFi systems. For example, in some other scenarios, the first device 110 can be a terminal device, and the second device 120 can be a network device. The network device can be a device that communicates with the terminal device. The network device can provide communication coverage for a specific geographical area and can communicate with terminal devices located within that coverage area.

[0053] In this context, terminal equipment can 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, wireless communication equipment, user agent, or user device. In the embodiments of this application, the terminal equipment can 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 handheld devices with wireless connectivity, vehicle-mounted devices, etc. Terminal devices can also be mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, self-driving, remote medical surgery, smart grids, transportation safety, smart cities, and smart homes. Optionally, terminal devices can act as base stations. For example, a terminal device can act as a dispatching entity, providing sidelink signals between terminal devices in vehicle-to-everything (V2X) or device-to-device (D2D) systems. For instance, cellular phones and cars communicate with each other using sidelink signals. Cellular phones and smart home devices communicate without relaying communication signals through base stations.

[0054] Network equipment can be devices used to communicate with terminal devices. Network equipment can be access network equipment or wireless access network equipment. For example, network equipment can be a base station. The term "base station" can broadly encompass various names such as, or can be replaced by, the following: NodeB, evolved NodeB (eNB), next-generation NodeB (gNB), relay station, transmitting and receiving point (TRP), transmitting point (TP), master station (MeNB), secondary station (SeNB), multi-mode radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, micro base station, relay node, donor node, or similar entity, or a combination thereof. A base station can also refer to a communication module, modem, or chip installed within the aforementioned equipment or apparatus. A base station can also be a mobile switching center, or an entity that performs base station functions in device-to-device (D2D), vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, a network-side device in a 6G network, or an entity that performs base station functions in future communication systems. A base station can support networks using the same or different access technologies. The embodiments of this application do not limit the specific technologies or device forms used in the network equipment. A base station can support networks using the same or different radio access technologies (RATs). The embodiments of this application do not limit the specific technologies or device forms used in the network equipment.

[0055] Furthermore, base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move depending on the location of the mobile base station. In other examples, a helicopter or drone can be configured as a device to communicate with another base station.

[0056] In some deployments, a network device can refer to either a CU or a DU; or, a network device may include both a CU and a DU. A gNB may also include an AAU.

[0057] Network devices and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can also be deployed in the air on airplanes, balloons, and satellites. This application does not limit the scenario in which the network devices and terminal devices are located.

[0058] It should be understood that all or part of the functions of the communication device in this application can also be implemented by software functions running on hardware, or by virtualization functions instantiated on a platform such as a cloud platform.

[0059] The following description uses a Wi-Fi system as an example to illustrate the technical solutions of the embodiments of this application. It is understood that the technical solutions of the embodiments of this application can also be extended to other systems, such as cellular systems defined by 3GPP standards.

[0060] Cellular Passive Internet of Things

[0061] With the increasing application of 5G in various industries, the types of connected devices and application scenarios are also expanding, placing higher demands on the price and power consumption of terminal devices. The application of battery-free, low-cost passive IoT devices has become a key technology for cellular IoT, enriching the types and quantities of terminal devices in 5G networks and truly realizing the Internet of Everything. Passive IoT devices can employ zero-power technologies, such as radio frequency identification (RFID) technology, and can be extended to suit cellular IoT.

[0062] Devices based on ambient energy

[0063] In existing communication systems such as NR and WiFi, the battery-free and low-cost nature of devices enables the low-cost, mass deployment and maintenance-free operation of devices such as Internet of Things (IoT) devices. Current standards are investigating how to support ambient IoT (AMP IoT) devices in NR and WiFi systems, where the energy required for operation comes from environmental energy harvesting, such as wireless signals, solar energy, or thermal energy. These devices are similar to passive or semi-passive devices in zero-power communication.

[0064] A research project on ambient energy-based IoT devices was carried out in the 3GPP radio access network (RAN). The AMP IoT devices are roughly divided into three types, each with corresponding complexity and communication capabilities.

[0065] Device A: It does not have energy storage capacity and cannot transmit independent signals; that is, it uses a backscatter transmission method.

[0066] Device B: It has energy storage capabilities but cannot transmit independent signals. It uses a backscatter transmission method and can use the stored energy to amplify the backscattered signal.

[0067] Device C: It has energy storage capabilities and can send independent signals, that is, it has active transmission capabilities.

[0068] Device A has the lowest complexity and power consumption, as low as 1μW, but its communication distance is limited, typically only a few meters. Device A requires carrier signals provided by other devices for backscattering transmission. Device C generally has a large-capacity capacitor to store energy from the environment, supports power consumption of several hundred μW, supports active signal transmission, and has a longer communication distance. Because Device C can actively transmit, it does not require a carrier signal from the network. Device B's complexity and power consumption fall between those of Device A and Device C.

[0069] In addition, zero-power terminals can support various types of environmental energy harvesting, such as radio frequency (RF), solar, thermal, and mechanical energy. Among these, zero-power terminals based on RF energy harvesting may require a network to provide RF power signals.

[0070] Based on the discussion of Ambient IoT application scenarios in 3GPP SA1, Ambient IoT can be used in at least the following four scenarios:

[0071] 1) Object recognition, such as logistics, production line product management, and supply chain management;

[0072] 2) Environmental monitoring, such as monitoring of temperature, humidity, and harmful gases in the working environment and natural environment;

[0073] 3) Positioning, such as indoor positioning, smart item finding, and production line item positioning;

[0074] 4) Intelligent control, such as intelligent control of various electrical appliances in smart homes (e.g., turning on and off air conditioners, adjusting temperature, etc.) and intelligent control of various facilities in agricultural greenhouses (e.g., automatic irrigation, fertilization, etc.).

[0075] Ambient IoT research project in 3GPP R19

[0076] 3GPP Rel-19 initiated the Ambient IoT (A-IoT) research project. The A-IoT communication system introduces the following two types of A-IoT devices.

[0077] The first type of A-IoT device has a peak power consumption of about 1uW. This A-IoT device has energy storage, an initial sampling frequency offset of 10X ppm, no uplink or downlink power amplifiers, and performs uplink transmission by backscattering external carriers.

[0078] The second type of A-IoT device has a peak power consumption of less than several hundred uW. This A-IoT device has energy storage, an initial sampling deviation of 10X ppm, and may be equipped with uplink and / or downlink power amplifiers. It can transmit uplink data by generating it internally, i.e., actively transmitting, or by backscattering an external carrier.

[0079] IEEE Ambient IoT Research Project

[0080] IEEE has conducted research on AMP IoT devices and defines the types of AMP IoT devices as follows:

[0081] AMP-only IoT devices are characterized by extremely low complexity, ultra-low power consumption, very small size, and no battery power required, meaning they do not use traditional batteries. These devices may not require energy storage, or may only have limited energy storage (e.g., a capacitor). They can perform uplink transmission using either backscatter or active transmission.

[0082] AMP-assisted IoT devices: These possess enhanced capabilities similar to current Wi-Fi devices. A key design goal is to achieve a maintenance-free IoT network (e.g., no battery replacement required), providing relatively high performance comparable to current Wi-Fi devices. It should be optimized for power consumption and sustainability to adapt to environmental energy usage and achieve maintenance-free operation.

[0083] Backscatter communication

[0084] The principle of backscattering is shown in Figure 2. As an example, the AMP IoT device is a backscattering tag. It receives the carrier signal sent by the reader (or, writer, etc.), collects energy through the radio frequency (RF) energy harvesting module, and then supplies power to the low-power processing module (i.e., the logic processing module shown in Figure 3) to modulate the transmitted carrier signal and backscatter it based on the carrier signal.

[0085] Load modulation is a common method used by backscatter tags to transmit data to a reader. Load modulation involves adjusting the electrical parameters of the tag's oscillation circuit according to the data stream's pulse, thereby changing the tag's impedance and phase. Load modulation techniques include, for example, resistive load modulation and capacitive load modulation.

[0086] In resistive load modulation, as shown in Figure 3, a resistor is connected in parallel with the load. This resistor, called the load modulation resistor, is switched on and off according to the clock of the data stream. The switching of switch S is controlled by binary data encoding. In capacitive load modulation, a capacitor is connected in parallel with the load, replacing the load modulation resistor controlled by binary data encoding in Figure 3.

[0087] The main characteristics of the aforementioned backscattering tags may include:

[0088] 1) The tag does not actively transmit signals; it achieves backscatter communication by modulating a carrier signal.

[0089] 2) The tag does not rely on traditional active power amplifier transmitters and uses low-power computing units, which greatly reduces hardware complexity;

[0090] 3) Combined with energy harvesting, battery-free communication can be achieved.

[0091] Backscatter communication systems mainly include the following two typical topologies:

[0092] 1) Mono-static backscatter communication system:

[0093] It consists of two parts: a backscatter reader and a backscatter device (BD). As shown in Figure 4, the reader transmits the transmitted radio frequency signal to the backscatter device and receives the backscattered signal from the backscatter device. Because the power of the carrier signal transmitted by the reader reaching the BD has certain requirements, the distance between the reader and the backscatter device must be relatively short. Therefore, the communication distance of this backscatter communication system is often relatively short.

[0094] 2) Bi-static backscatter communication system

[0095] It consists of three parts: a backscatter reader, a carrier source device (or carrier generator, carrier transmitter, carrier source, etc.), and a backscatter device. As shown in Figure 5, a carrier source device is placed near the backscatter device to transmit the carrier signal. Because the distance between the carrier source device and the backscatter device can be set shorter, the path loss is reduced, and therefore the backscatter device can obtain more power from the carrier source device. Compared to mono-static backscattering, its communication distance is no longer limited by the power requirements of the radio frequency signal between the reader and the backscatter device, thus extending the communication distance between them.

[0096] During backscatter communication, AMP IoT devices determine the start time of backscatter based on their local clock. The local clock of the AMP IoT device needs to be synchronized with the carrier source device or reader to ensure that the transmission of backscatter and carrier signals is time-aligned. Current AMP IoT devices, with their extremely low complexity and power consumption, often lack high-precision local clocks, with accuracy typically ranging from 1000 to 10000 ppm. This can cause a significant discrepancy between the timing of the AMP IoT device and the timing of the carrier source device or reader, resulting in misalignment between the backscatter and carrier signal transmission, thus affecting the transmission and reception of the backscatter signal.

[0097] In this embodiment, the AMP IoT device can be used as a communication terminal in a WiFi system or a cellular network. For example, in a WiFi system, the AMP IoT device can be called an AMP STA; in a cellular system, the AMP IoT device can be called an AMP device. The reader can be an AP in a WiFi system or a network device such as a base station in a cellular system. The carrier source device can be an AP or a non-AP STA in a WiFi system, or a terminal device or network device such as a base station in a cellular system.

[0098] In backscatter communication, taking a WiFi system as an example, the AP (Access Point) acting as a network device can send a trigger signal. This trigger signal is used to instruct the STA (Stationary Target) to receive or send data frames. For example, this trigger signal can be used to instruct the STA to send a backscatter signal. In a mono-static backscatter communication system powered by ambient energy, the AP sends a trigger signal and provides a carrier signal for the STA's backscatter. For example, as shown in Figure 6, the AMP AP sends a trigger signal to instruct the AMP STA to send a backscatter signal at the end of the trigger signal (T). Tx Backscattering occurs after a certain duration. Simultaneously, the AMP AP will perform backscattering at the end of the trigger signal (T). Rx After a certain duration, a carrier signal is transmitted, and reception of the backscatter signal from the AMP STA begins. This carrier signal is part of the PPDU transmitted by the AMP AP. This PPDU also includes a legacy preamble, which can be a short training field (STF), a long training field (LTF), and a signaling (SIG) field. These fields are for coexistence with traditional WiFi devices. Existing WiFi devices supporting channel access protocols can detect the presence of this PPDU during clear channel assessment (CCA) using carrier detection, thus determining that the channel is not idle and taking avoidance measures. Furthermore, the PPDU may also include reference symbols. There is an inter-frame interval, such as a short inter-frame space (SIFS), between the PPDU carrying the carrier signal and the trigger signal.

[0099] For a bi-static backscatter communication system powered by ambient energy, the AMP AP sends a trigger signal to instruct the carrier source device to send a PPDU carrying the carrier signal, providing the carrier signal for the AMP STA's backscattering. As shown in Figure 7, the AMP AP sends a trigger signal, instructing the carrier source device to send the carrier signal T hours after the trigger signal ends, and simultaneously instructing the AMP STA to perform backscattering T hours after the trigger signal ends. At the same time, the AMP AP will send the carrier signal T hours after the trigger signal ends and begin receiving the backscattered signal sent by the AMP STA.

[0100] Based on the above description, if the clocks of the AMP STA and the AMP AP are always aligned, the start time of the carrier signal and the start time of the AMP STA's backscattered signal can be aligned. However, due to the poor accuracy of the AMP STA's local clock, drift occurs within the time period T = SIFS + T1 + T2. The time interval between the start time of the backscattered signal obtained by the AMP STA according to the local clock and the end time of the trigger signal may be greater than or less than T. The former will cause the start time of the AMP STA's backscattered signal to be later than the start time of the carrier signal, as shown in Figure 8; the latter will cause the start time of the AMP STA's backscattered signal to be earlier than the start time of the carrier signal, as shown in Figure 9.

[0101] As shown in Figure 10, one solution is to delay the start time of the AMP STA backscattering signal by a certain period of time, namely T. extra T Tx =T+T extra =SIFS+T1+T2+T extra Thus, in the case of an inaccurate clock, T Tx The value of T ensures that the start time of the backscattered signal of the AMP STA falls within the time period of the carrier signal transmission. extra The configuration takes into account the case where the clock offset of the AMP STA is the largest within a time period T, avoiding the failure of backscatter signal transmission and reception caused by the start time of the backscatter signal being earlier than the start time of the carrier signal. However, since the time interval between the trigger signal domain and the carrier signal is relatively large, the above method still makes it difficult to accurately align the carrier signal and the backscatter signal in time. Furthermore, the AMP AP needs to blindly detect the backscatter signal, which also results in the waste caused by the carrier signal not being fully utilized.

[0102] The PPDU format carrying the carrier signal shown in Figures 6 to 10 is only an example. The PPDU includes a preamble, a reference symbol, and a carrier signal, and the lengths of the signal fields corresponding to the preamble and the reference symbol are T1 and T2, respectively. The implementation in Figures 6 to 10 represents reception (Tx), and the dashed line represents reception (Rx).

[0103] In this embodiment, a device capable of receiving a PPDU carrying a carrier signal is referred to as a first device, such as a STA or AP; a device capable of transmitting a PPDU carrying a carrier signal is referred to as a second device, such as an AP or carrier source. Furthermore, in this embodiment, a PPDU carrying a carrier signal is referred to as a first PPDU (or a first PPDU frame), and a PPDU carrying a trigger signal is referred to as a second PPDU (or a second PPDU frame), wherein the second PPDU can be a trigger frame in related technologies.

[0104] To address the aforementioned problem of timing misalignment between the carrier signal and the backscattered signal, this application provides a wireless communication method. In a first PPDU (Portable Component Distributed Unit) sent by a second device to a first device to carry a carrier signal, in addition to a first information field for carrying the carrier signal, a second signal field located before the first signal field and associated with the carrier signal is also included. Therefore, the first device can obtain the timing information of the carrier signal based on the second signal field, thereby forming a backscattered signal based on the carrier signal to achieve communication with the second device. For example, the second signal field can be used to determine the start time of the carrier signal to align the start time of the carrier signal with the start time of the backscattered signal, or to align the start time of the STA (Station) transmitting the backscattered signal with the start time of the AP (Access Point) receiving the backscattered signal.

[0105] In some scenarios, the signal field in the PPDU described in the embodiments of this application can also be referred to as the bit field. The PPDU may include a first signal field and a second signal field; or it may include a first signal field, a second signal field and a preamble (e.g., a conventional preamble); or it may include a first signal field, a second signal field, a preamble (e.g., a conventional preamble), and other signal fields (e.g., a signal field carrying a reference symbol, a signal field carrying a synchronization signal), etc.

[0106] The embodiments of this application will be described in detail below with reference to Figure 11.

[0107] Figure 11 is a schematic flowchart of a wireless communication method provided in an embodiment of this application. The method 1100 shown in Figure 11 can be executed by a first device and a second device. The first device is, for example, the first device 110 shown in Figure 1, and the second device is, for example, the second device 120 described in Figure 1.

[0108] In some implementations, the first device and the second device can be communication devices in a WiFi system. For example, the first device is a STA (Stationary Access Point), and the second device is an AP (Access Point) or a carrier source for providing a carrier signal; or, for example, the first device is a STA or AP, and the second device is a carrier source for providing a carrier signal. In other implementations, the first device and the second device can also be communication devices in a cellular network. For example, the first device is a UE (User Equipment), and the second device is a base station. The carrier source can be, for example, an AP or a non-AP STA in a WiFi system, or a base station in a cellular network.

[0109] Furthermore, the first and / or second devices can be AMP devices. For example, the first device can be an AMP device, such as an AMP STA or an AMP IoT device, and the second device can be a device that supports AMP communication, such as an AMP AP.

[0110] Referring to Figure 11, in step 1110, the second device sends the first PPDU to the first device.

[0111] Accordingly, in step 1120, the first device receives the first PPDU sent by the second device.

[0112] The first PPDU includes a first signal domain for carrying a carrier signal and a second signal domain associated with the carrier signal. The carrier signal is used for backscattering of the first device.

[0113] Since the second signal domain is associated with the carrier signal, the first device can accurately obtain the timing information of the carrier signal by detecting the second signal domain, such as the start time of the carrier signal or the start time of the first signal domain, and thus determine when to start backscattering, i.e., sending backscattered signals, or when to start receiving backscattered signals.

[0114] The start time of the carrier signal can be the end time of the second signal domain. The start time of the backscattered signal formed based on the carrier signal can be the end time of the second signal domain (i.e., backscattering occurs immediately after the second signal domain ends), or there can be a time interval between the start time of the backscattered signal and the end time of the second signal domain (i.e., backscattering occurs after the second signal domain ends, waiting for this time interval). Hereinafter, the length of the second signal domain is denoted as T3, and the time interval is denoted as T4. In some implementations, the time interval T4 can be determined in the following ways, for example: the time interval T4 is a predetermined inter-frame interval (e.g., T4 = SIFS or other types of inter-frame intervals); or, the time interval T4 is determined based on the indication information received by the first device; or, the time interval T4 is determined based on the type of the first device; or, the time interval is determined based on the capability of the first device. Here, the type or capability is related, for example, to the data processing speed and / or the transceiver conversion speed of the first device, and the time interval T4 may be different for first devices of different types and / or capabilities. As an example, the faster the data processing speed and / or the transmission and reception conversion speed of the first device, the shorter the time interval T4 can be set; the slower the data processing speed and / or the transmission and reception conversion speed of the first device, the longer the time interval T4 can be set.

[0115] The process of a first device accessing the basic service area (BSS) provided by a second device typically involves scanning, authentication, and association. The indication information for the time interval T4 can be sent from the second device (e.g., an AP or carrier source) to the first device (e.g., a STA). This indication information can be carried, for example, in a first PPDU, a trigger frame that triggers the first device to receive or transmit data frames, a beacon frame for discovering the BSS, a probe response frame during the first device's scanning process, an authentication response frame during the first device's authentication process, or an association response frame during the first device's association process.

[0116] In the embodiments of the present application, the second signal field in the first PPDU is located before the first signal field. For example, the second signal field is located before the first signal field and is adjacent to the first signal field. That is to say, the second signal field is the signal field that is located before the first signal field and is next to the first signal field. In this way, since the interval between the second signal field and the carrier signal is the smallest, after the first device detects the end of the second signal field, it can immediately start preparing for backscattering, making the clock offset as small as possible, which is beneficial to the temporal alignment of the carrier signal and the backscattered signal, and can reduce the waste caused by the insufficient utilization of the carrier signal.

[0117] In order to ensure that the second signal field can be detected, in some implementation manners, the starting position where the first device detects the second signal field needs to be located before the starting position of the second signal field. That is to say, the first device needs to start detecting the second signal field before the starting position of the second signal field to ensure that the second signal field can be detected.

[0118] As an example, as shown in FIGS. 12 and 13, in the process of backscatter communication, after the first device obtains an indication related to backscattering through a trigger signal, it can detect the signal carried in the second signal field, so as to determine the starting moment of the carrier signal and the corresponding starting moment of the backscattered signal. For this purpose, the first device starts detecting the target signal at a certain time after receiving the trigger signal. The first device needs to start detecting before the starting moment of the second signal field. The duration T between the start time when the first device starts detecting the signal carried in the second signal field and the end time of the trigger signal Rx satisfies T Rx <SIFS + T1 + T2. If the first device is an AMP STA, considering the low accuracy of its local clock, the selection of T Rx needs to consider the maximum drift that may occur in the local clock of the first device, and reserve sufficient advance to avoid the starting moment when the first device starts detecting the signal carried in the second signal field being later than the starting moment of the second signal field.

[0119] The formats of the first PPDU carrying the carrier signal shown in the embodiments of the present application are all examples. For example, the reference symbol in the first PPDU is just a possible signal field, and this signal field can also be omitted or replaced with a signal field carrying other information. The embodiments of the present application do not limit this.

[0120] Hereinafter, the signal carried in the second signal field will be described in detail.

[0121] In this embodiment, the second signal domain can be used to carry, for example, a trigger signal, a synchronization signal, a reference signal, or a first signal. That is, the signal carried in the second signal domain can be a trigger signal, a synchronization signal, a reference signal, or a first signal. The first signal is used to determine the start time of the carrier signal and / or the start time of the backscattered signal. The signals that may be carried in the second signal domain are described below.

[0122] The second signal domain carries the trigger signal.

[0123] The second signal field in the first PPDU can be associated with a trigger signal used to trigger the first device to receive or transmit a data frame. Here, the association of the second signal field with the trigger signal may, for example, include the trigger signal being carried in the second signal field, or the trigger signal being carried in a second PPDU preceding the first PPDU and used to indicate that the first PPDU includes the second signal field.

[0124] First, the case where the trigger signal is carried in the second signal domain is described. In related technologies, the trigger signal is usually carried in a trigger frame preceding the first PPDU. That is, the trigger signal and the carrier signal are transmitted through different PPDUs, and an inter-frame interval is set between the trigger frame and the first PPDU. Because the interval between the trigger frame and the carrier signal carried in the first PPDU is relatively large, determining the start time of the carrier signal based on the trigger signal will cause time misalignment between the carrier signal and the backscattered signal due to clock offset. In this embodiment, the signal carried in the second signal domain can be the trigger signal. That is, the trigger signal, which was originally carried in the trigger frame, can now be carried in the same PPDU, i.e., the first PPDU, along with the carrier signal. In the first PPDU, the first signal domain is used to carry the carrier signal, and the second signal domain is used to carry the trigger signal. Since the time interval between the trigger signal and the carrier signal is reduced, the clock offset is minimized, which is beneficial for time alignment between the carrier signal and the backscattered signal.

[0125] Secondly, the case where the trigger signal is carried on different PPDUs is described. The trigger signal can be carried on a second PPDU preceding the first PPDU, and the trigger signal is used to indicate that the first PPDU includes a second signal field. This second PPDU can be a trigger frame in the related art. This situation is equivalent to the trigger signal and the carrier signal being transmitted through different PPDUs, with the trigger signal carried on the trigger frame and the carrier signal carried on the first PPDU, and an inter-frame interval set between the trigger frame and the first PPDU. In this case, the trigger signal can be used to indicate whether the first PPDU contains a second signal field. If the trigger signal indicates that the first PPDU contains a second signal field, then after receiving the trigger frame, the first device will detect the second signal field when receiving the first PPDU, and determine the starting position of the carrier signal and / or backscattering based on the second signal field. Of course, whether the trigger signal and the carrier signal are located in the same PPDU can also implicitly indicate whether the first PPDU includes a second signal field. For example, if the trigger signal and the carrier signal are located in different PPDUs, it implicitly indicates that the first PPDU includes a second signal field.

[0126] The second signal domain carries the synchronization signal.

[0127] The second signal domain can also carry a synchronization signal, which can reuse the design of the synchronization signal (AMP-Sync) used in other types of downlink PPDUs. For example, as shown in the format of the first PPDU in Figure 14, the first PPDU includes a preamble, a synchronization signal, and a carrier signal (or excitation signal). The synchronization signal can reuse the AMP-Sync design used for downlink data synchronization in other types of downlink PPDUs. Alternatively, the synchronization signal in the second signal domain may not reuse the AMP-Sync design. For example, as shown in the format of the first PPDU in Figure 15, an independent signal domain can be added to the first PPDU. For example, the control section shown in Figure 15 can be used to carry a different synchronization signal than the AMP-Sync design to determine the start time of the carrier signal and / or backscatter signal.

[0128] The second signal domain carries the first signal.

[0129] The second signal domain can also carry the first signal, which is a newly added signal in this embodiment of the application. Its function is to determine the start time of the carrier signal and / or the backscattered signal. For example, the first device detects the first signal carried in the second signal domain. When the first signal is detected, the first device determines that backscattering will begin after a time interval T4 from the end time of the first signal, or backscattering will begin at the end time of the first signal (i.e., T4 = 0). Referring again to Figure 12, which illustrates the case of T4 = 0, the first device is an AMP STA. In the Mono-static backscattering system and the Bi-static backscattering system, the AMP STA determines that backscattering will begin when the detection of the first signal ends, based on the detection of the first signal carried in the second signal domain.

[0130] When the first device is a STA, it can send a backscattered signal to the AP based on the second signal domain. For example, the STA can receive a first PPDU sent by the AP or a carrier source, and determine the start time of backscattering based on the detection of the second signal domain in the first PPDU, thereby sending the backscattered signal to the AP. Alternatively, when the first device is an AP, it can receive a first PPDU sent by a carrier source, and determine the start time of the backscattered signal based on the detection of the second signal domain in the first PPDU, thereby receiving the backscattered signal sent by the STA. For example, if the first device is an AMP AP, due to the high accuracy of the AMP AP's local clock, it can start detecting the backscattered signal after the second signal domain ends according to the timing. Or, continuing to refer to Figure 13, in a bi-static backscattering system, the AMP AP can also detect the second signal domain of the first PPDU sent by the carrier source to determine when to start receiving the backscattered signal sent by the AMP STA.

[0131] In this embodiment, the first PPDU can also be in the format of a segmented PPDU. For example, the first PPDU may include multiple sets of signal fields, each set of signal fields including a second signal field and a first signal field. That is, the second device can alternately send the second signal field and the first signal field. Taking the second signal field carrying the synchronization signal as an example, as shown in Figure 16, after the second device sends the preamble, it sequentially sends the second signal field #1, the first signal field #1 associated with the second signal field #1, the second signal field #2, the first signal field #2 associated with the second signal field #2, ..., the second signal field #N, and the first signal field #N associated with the second signal field #N. Wherein, the second signal domain #1 is used for timing the first signal domain #1 (e.g., for determining the starting position of the carrier signal and / or backscattered signal of the first signal domain #1), the second signal domain #2 is used for timing the first signal domain #2 (e.g., for determining the starting position of the carrier signal and / or backscattered signal of the first signal domain #2), ..., the second signal domain #N is used for timing the first signal domain #N (e.g., for determining the starting position of the carrier signal and / or backscattered signal of the first signal domain #N). The lengths of the first signal domains in different sets of signal domains can be the same or different, or it can be understood that the timing duration maintained by the second signal domain in each signal group can be the same or different.

[0132] Optionally, the carrier signal of the first signal domain can be used for backscattering by one or more devices. These devices can determine the starting position of the first signal domain (i.e., the carrier signal) and / or the position where they each begin backscattering based on the second signal domain preceding the first signal domain. In the case of multiple devices, these devices can, for example, transmit backscattered signals sequentially in different time periods based on a time-division multiplexing approach.

[0133] In some implementations, the first signal mentioned above can be a first sequence, a first sequence group, or a delimiter. The following describes each of these possible first signals.

[0134] The first signal includes a first sequence or a group of first sequences.

[0135] The first signal may include a single sequence, i.e., the first sequence, or the first signal may include a group of sequences formed by multiple sequences, i.e., the first sequence group. Where the first signal includes the first sequence group, the first sequence group may also carry information, such as the time interval T4, indicating the time interval between the start time of the backscattered signal and the end time of the second signal domain. For example, if the first sequence group includes four sequences, it can represent 2 bits of information. These 2 bits can be used to represent four different time intervals T4, where T4 can be equal to 0 or greater than 0.

[0136] The first device detects sequences in the first sequence or the first sequence group through sequence correlation detection. Sequence correlation detection is typically used to measure the similarity or correlation between two or more sequences. In correlation detection, there is usually a reference sequence (or template sequence) and one or more target sequences (or test sequences). By calculating the correlation between the target sequence and the reference sequence, a numerical value is obtained, representing the degree of similarity between the two sequences. When the target sequence and the reference sequence are very similar, the calculated correlation value will be high, which can be considered a "peak". Using sequence correlation, a high correlation peak value is considered to indicate that the target sequence has been detected, while the correlation detection output for non-target sequences is a lower value, much smaller than the correlation peak value. Here, the target sequence is the first sequence or the sequence in the first sequence group. In this embodiment, the type of the first sequence or the sequence in the first sequence group is not limited; for example, the first sequence and / or the sequence in the first sequence group can be an m-sequence or a Gold sequence. The m-sequence and Gold sequence are described below respectively.

[0137] m sequence

[0138] The length of the m-sequence is related to the series *n* of the linear feedback shift register. The characteristic polynomial and the initial state of the shift register determine the m-sequence of length 2^n-1. Different characteristic polynomials produce different m-sequences; at a given series, N different characteristic polynomials correspond to N basic m-sequences. Since the characteristic polynomial must be a primitive polynomial, the number of primitive polynomials at different series is finite. Table 1 shows the number of primitive polynomials corresponding to different series, which is also the number of basic m-sequences corresponding to different series. Therefore, given a series, the number of basic m-sequences corresponding to that series can be obtained.

[0139] Table 1

[0140] For a basic m-sequence, more m-sequences can be generated through cyclic shifting. Cyclic shifting of an m-sequence refers to moving each bit of the sequence to the left or right according to a certain pattern, that is, shifting the most significant bit or the least significant bit to the other side. A cyclic left shift moves the most significant bit to the least significant bit in sequence. A cyclic right shift moves the least significant bit to the most significant bit in sequence. By cyclically shifting a basic m-sequence, multiple different m-sequences can be generated. An n-order m-sequence has a length of 2^n-1. If each cyclic shift is one bit, a maximum of S = 2^n-1 cyclic shifted sequences (including the basic m-sequence) can be generated; if each cyclic shift is k bits (i.e., the offset of the cyclic shift is k), a maximum of... There are cyclic shift sequences (including the basic m-sequence), where, This indicates rounding down to the nearest integer.

[0141] Small cyclic shift offsets can cause the detection correlation peaks of adjacent sequences to be close together, leading to aliasing in the sequence detection results and a decrease in sequence detection performance. Therefore, sequences with a certain offset can be selected to better carry information. The length and offset of the m-sequence can be determined according to actual needs, such as coverage area, the amount of information carried, and the detection performance (e.g., detection capability) of the first device. As an example, a larger coverage area requires a larger offset. For networks supporting AMP, the coverage area is usually smaller, and the offset can be smaller to obtain more usable m-sequences. In addition, the length and offset of the sequence are also limited by the detection performance of the first device, which determines the resolution between the length of the detection sequence and the cyclic shift of the sequence.

[0142] As an example, assuming an m-sequence of order 4 is chosen, the sequence length is 2^4 - 1 = 15. Based on Table 1, there are two basic m-sequences. Each basic m-sequence can generate 2^4 - 1 = 15 m-sequences through cyclic shifting. Therefore, the number of m-sequences of order 4 is 15 + 15 = 30. If 30 different m-sequences are used to carry information, then 4 bits of information can be carried. In this case, different m-sequences in the first sequence group can represent 4 bits of information, which can be used, for example, to represent different time intervals T4. Of course, the second information domain can also include only one m-sequence. In this case, the second information domain may not carry any information, but is only used by the first device to determine the start time of the carrier signal and / or backscattered signal.

[0143] Gold sequence

[0144] The Gold code sequence is constructed by adding m-sequence pairs modulo 2. Each change in the cyclic shift of one m-sequence yields a new Gold sequence, thus each pair of m-sequence pairs can generate 2^n+1 Gold sequences. If the cyclic shifts of two m-sequences in a pair are changed simultaneously, followed by modulo 2 addition, a maximum of (2^n-1)*(2^n-1) Gold sequences can be formed.

[0145] As an example, assuming an m-sequence of level 4 is chosen, the sequence length is 2^4 - 1 = 15. For a single preferred pair of m-sequences, 2^4 + 1 = 17 Gold sequences can be generated, or (2^4 - 1) * (2^4 - 1) = 225 Gold sequences can be generated. The Gold sequences generated by a single preferred pair of m-sequences can be defined as a Gold sequence group; multiple preferred pairs of m-sequences correspond to multiple Gold sequence groups.

[0146] Similar to the m-sequence, when the first sequence group carried in the second information field includes multiple different Gold sequences, it can also be used to carry information, such as to indicate the value of different time intervals T4. For details, please refer to the relevant description of the m-sequence above, which will not be repeated here.

[0147] In some implementations, the first sequence and / or the first sequence group are associated with the BSS. That is, when the first signal includes the first sequence, the first sequence corresponding to different BSSs may be different; when the first signal includes the first sequence group, the first sequence group corresponding to different BSSs may be different. Furthermore, the sequences included in different first sequence groups may be partially or completely different, and the number of sequences included in different first sequence groups may be the same or different.

[0148] For example, the first sequence or first sequence group carried in the second signal field of the first PPDU sent by different AMP APs can be different. This can prevent the AMP STA from receiving the sequence sent by other unrelated AMP APs, so that the information it obtains is not sent by the AMP AP currently providing the service, thus causing errors in the synchronization information.

[0149] Because the aforementioned sequences have good cross-correlation properties, when the first signals carried in the second signal domain of the first PPDU transmitted by different AMP APs are different sequences or different sequence groups, the first device can correctly detect the sequence transmitted by the AMP AP currently providing services to it. Simultaneously, because the aforementioned sequences have good autocorrelation properties, the AMP STA can obtain the corresponding amount of information from the sequence and achieve better synchronization based on it, while also overcoming interference between signals from different mobile BSSs.

[0150] The first sequence used by different BSSs can be determined in a variety of ways. For example, the first device can obtain information about the first sequence and / or the first sequence group in the following ways.

[0151] Method 1: The first sequence and / or the first sequence group are carried in a beacon frame for BSS discovery.

[0152] Taking AMP STA and AP as examples, in passive scanning mode, the AMP STA discovers the wireless network by searching for beacon frames periodically sent by the AP in the channel. The beacon frames carry basic information and capabilities of the BSS to which the AP belongs, such as BSS ID, SSID, supported rates, authentication method, encryption algorithm, beacon frame transmission interval, and the channel used. During this process, the AMP STA can obtain information about the first sequence and / or the first sequence group through the beacon frames sent by the AMP AP.

[0153] Method 2: The first sequence and / or the first sequence group are carried in the probe response frame during the scanning process of the first device.

[0154] Taking AMP STA and AP as examples, in active scanning mode, AMP STA sends probe request frames on its supported channels to detect surrounding wireless networks. After receiving the probe request frame, AP sends a probe response frame. AMP STA can obtain information about the first sequence and / or first sequence group used by BSS through the probe response frame.

[0155] Method 3: The first sequence and / or the first sequence group are carried in the authentication response frame during the authentication process of the first device.

[0156] Taking an AMP STA and an AP as an example, the AMP STA discovers the BSS through a scanning process and obtains its information. Next, the STA initiates an authentication process to verify its identity; only STAs that pass authentication can access the wireless network. The authentication process includes two steps: an authentication request frame sent by the AMP STA and an authentication response frame sent by the AP. The AMP STA can obtain information about the first sequence and / or first sequence group used by the BSS through the authentication response frame sent by the AMP AP.

[0157] Method 4: The first sequence and / or the first sequence group are carried in the association response frame during the association process of the first device.

[0158] Taking an AMP STA and an AP as an example, the STA initiates an authentication process to determine its identity. Once authenticated, the STA initiates an association process. The association process is a negotiation of radio link services between the AMP STA and the AP. It includes two steps: an association request frame and an association response frame. The AMP STA can obtain information about the first sequence and / or first sequence group used by the BSS through the association response frame sent by the AMP AP.

[0159] Method 5: The first sequence and / or the first sequence group are determined based on predetermined rules.

[0160] For example, the first sequence and / or the first sequence group are determined based on BSSID. As an example, the number of the first sequence is determined based on the result of modulo the number of candidate sequences using the BSSID; and / or, the number of the first sequence group is determined based on the result of modulo the number of candidate sequence groups using the BSSID. The first sequence can be a sequence from the candidate sequences, and the first sequence group can be a sequence group from the candidate sequence groups.

[0161] Taking AMP STA and AP as examples, during the scanning process, AMP STA can obtain basic information and capabilities of the BSS. Based on this information, AMP STA can deduce the first sequence or first sequence group to be used according to certain rules. For example, there is a predetermined association between the first sequence or first sequence group corresponding to the BSS and the BSSID of that BSS; the number of the first sequence or first sequence group to be used can be deduced from the BSSID. Different first sequences have different numbers, and different first sequence groups also have different numbers. For example, the number of the first sequence can be determined based on the BSSID and the number of candidate sequences. As an example, the modulo of the number of candidate sequences with the BSSID yields the number of the first sequence used by the BSS. Similarly, the number of the first sequence group can be determined based on the BSSID and the number of candidate sequence groups. As an example, the modulo of the number of candidate sequence groups with the BSSID yields the number of the first sequence group used by the BSS. Alternatively, the number of the first sequence group can also be determined based on the BSSID and the number of sequences included in the first sequence group. As an example, the number of sequences included in the first sequence group can be moduloed by the BSSID of the BSS, and the result is the number of the first sequence group used by that BSS. In this way, the first sequence or first sequence group can be used as evenly as possible among different BSSs, thereby reducing the conflict between the first sequences or first sequence groups used by different BSSs.

[0162] Method 6: The first sequence and / or the first sequence group are predefined. For example, the information in the first sequence is predefined by the protocol.

[0163] The information of the first sequence obtained in methods 1 to 6 above may include one or more of the following: information about the m-basic sequence; the number of m-sequences; the offset of the cyclic shift; information about the Gold sequence group; the Gold sequence generation method; and the number of Gold sequences. The information about the m-basic sequence may include, for example, the series of the m-sequences, the primitive polynomial of the basic m-sequences, or their number. The number of m-sequences may be, for example, multiple consecutive m-sequences starting from one m-sequence. The m-sequences may be sorted according to certain rules, such as by cyclic shifting to the left or right with a certain offset. If the required number of m-sequences is not met after traversing all the sequences obtained by cyclic shifting a basic m-sequence with a certain offset, the above process can be repeated with the next basic m-sequence until the required number of m-sequences is found. The information of the Gold sequence group is associated with the preferred m-sequence pair. The Gold sequence group can be numbered according to the preferred m-sequence pair and indicated via a beacon frame. The Gold sequence generation method may include, for example, the preferred m-sequence pair used, the direction of the cyclic shift of the m-sequences, and the offset. The generated Gold sequences are sorted according to certain rules. The number of Gold sequences can be determined by starting with one Gold sequence from a Gold sequence group, and then taking multiple Gold sequences consecutively in sorted order. If the desired number of Gold sequences is not found after traversing all the sequences in a Gold sequence group, the process can be repeated in the next Gold sequence group until the desired number of Gold sequences is found.

[0164] The first signal includes delimiters.

[0165] A delimiter is a specific signal used to identify the beginning or end of a data packet, or as a separator between data fields. A delimiter is typically a short signal with a specific voltage level that appears at the beginning of a data packet so that the reader knows where to start parsing subsequent data bits. For example, in the EPC protocol, the delimiter is a 12.5 microsecond long signal with a tolerance of ±5%. The use of delimiters is crucial for ensuring proper synchronization and decoding of data packets. It not only helps the reader determine the start of a data packet but also serves as a time reference for subsequent signal processing and decoding. The design and use of delimiters may vary depending on specific application requirements and system parameters. For example, delimiters of different lengths or voltage levels are adapted to specific communication environments and performance requirements.

[0166] In this embodiment, carrying a delimiter signal in the second signal domain can help the first device determine the start time of the carrier signal and / or the backscattered signal. For example, the first device may start backscattering when the delimiter signal is detected to end, or start backscattering after a time interval T4 has elapsed since the delimiter signal was detected to end.

[0167] In some implementations, the modulation scheme of the signal carried in the second signal domain may include one or more of the following: binary amplitude shift keying (OOK), phase shift keying (PSK), frequency shift keying (FSK), and minimum shift keying (MSK). The modulation scheme of the signal carried in the second signal domain must be a modulation scheme supported by the first device. For AMP devices, due to their lower complexity, they can only support simple modulation schemes, such as OOK, PSK, FSK, and MSK.

[0168] The method embodiments of this application have been described in detail above with reference to Figures 1 to 15. The apparatus embodiments of this application will be described in detail below with reference to Figures 17 to 19. It should be understood that the descriptions of the method embodiments correspond to the descriptions of the apparatus embodiments; therefore, any parts not described in detail can be referred to the preceding method embodiments.

[0169] Figure 17 is a schematic diagram of the structure of a communication device provided in an embodiment of this application. The communication device 1600 shown in Figure 17 may include a transceiver unit 1610. The transceiver unit 1610 is used to receive a first physical layer protocol data unit (PPDU) sent by a second device, wherein the first PPDU includes a first signal field for carrying a carrier signal and a second signal field located before the first signal field and associated with the carrier signal.

[0170] In some implementations, the second signal domain is adjacent to the first signal domain.

[0171] In some implementations, the starting position for the first device to detect the second signal domain is located before the starting position of the second signal domain.

[0172] In some implementations, the second signal domain is associated with a trigger signal, which is used to trigger the first device to receive or send data frames.

[0173] In some implementations, the second signal field is associated with a trigger signal, including: the trigger signal being carried in the second signal field of the first PPDU; or, the trigger signal being carried in a second PPDU preceding the first PPDU, and the trigger signal being used to indicate that the first PPDU includes the second signal field.

[0174] In some implementations, the start time of the backscattered signal based on the carrier signal is the end time of the second signal domain; or, there is a time interval between the start time of the backscattered signal and the end time of the second signal domain.

[0175] In some implementations, the time interval is a predetermined inter-frame interval; or, the time interval is determined based on indication information received by the first device; or, the time interval is determined based on the type of the first device; or, the time interval is determined based on the capabilities of the first device.

[0176] In some implementations, the indication information is carried in: the first PPDU; or, a trigger frame for triggering the first device to receive or send data frames; or, a beacon frame for discovering the Basic Service Set (BSS); or, a probe response frame during the scanning process of the first device; or, an authentication response frame during the authentication process of the first device; or, an association response frame during the association process of the first device.

[0177] In some implementations, the second signal domain is used to carry one or more of the following: a trigger signal; a synchronization signal; a reference signal; a first signal; wherein the first signal is used to determine the start time of the carrier signal and / or the start time of the backscattered signal based on the carrier signal.

[0178] In some implementations, the first signal includes a first sequence; or, the first signal includes a first group of sequences; or, the first signal includes a delimiter.

[0179] In some implementations, the first sequence group is further used to indicate the time interval between the start time of the backscattered signal based on the carrier signal and the end time of the second signal domain.

[0180] In some implementations, the first sequence and / or the sequences in the first sequence group include: an m-sequence; or, a Gold sequence.

[0181] In some implementations, the first sequence and / or the group of first sequences is associated with the BSS.

[0182] In some implementations, the first sequence and / or the first sequence group is carried in a beacon frame for discovering the BSS; or, the first sequence and / or the first sequence group is carried in a probe response frame during the scanning process of the first device; or, the first sequence and / or the first sequence group is carried in an authentication response frame during the authentication process of the first device; or, the first sequence and / or the first sequence group is carried in an association response frame during the association process of the first device; or, the first sequence and / or the first sequence group is determined based on the BSS identifier BSSID; or, the first sequence and / or the first sequence group is predefined.

[0183] In some implementations, the first sequence and / or the first sequence group is determined based on the BSS identifier BSSID, including: the number of the first sequence is determined based on the result of taking the number of candidate sequences modulo the BSSID; and / or, the number of the first sequence group is determined based on the result of taking the number of candidate sequence groups modulo the BSSID.

[0184] In some implementations, the modulation scheme of the signal carried in the second signal domain includes: OOK; or, PSK; or, FSK; or, MSK.

[0185] In some implementations, the first device is a STA, and the second device is an AP or a carrier source for providing a carrier signal; or, the first device is a STA or an AP, and the second device is the carrier source.

[0186] In some implementations, the transceiver unit 1610 is further configured to, when the first device is a STA, send a backscatter signal to the AP based on the second signal domain; and when the first device is an AP, receive a backscatter signal sent by the STA based on the second signal domain.

[0187] In some implementations, the first device and / or the second device are AMP devices.

[0188] It is understood that the transceiver unit 1610 may be, for example, a transceiver 1830. Additionally, the communication device 1600 may optionally include a processor 1810 and a memory 1820, as detailed in Figure 19.

[0189] Figure 18 is a schematic diagram of the structure of a communication device provided in an embodiment of this application. The communication device 1700 shown in Figure 18 may include a transceiver unit 1710. The transceiver unit 1710 is used to send a first physical layer protocol data unit (PPDU) to a first device, wherein the first PPDU includes a first signal field for carrying a carrier signal and a second signal field located before the first signal field and associated with the carrier signal.

[0190] In some implementations, the second signal domain is adjacent to the first signal domain.

[0191] In some implementations, the second signal domain is associated with a trigger signal, which is used to trigger the first device to receive or send data frames.

[0192] In some implementations, the second signal field is associated with a trigger signal, including: the trigger signal being carried in the second signal field of the first PPDU; or, the trigger signal being carried in a second PPDU preceding the first PPDU, and the trigger signal being used to indicate that the first PPDU includes the second signal field.

[0193] In some implementations, the start time of the backscattered signal based on the carrier signal is the end time of the second signal domain; or, there is a time interval between the start time of the backscattered signal and the end time of the second signal domain.

[0194] In some implementations, the time interval is a predetermined inter-frame interval; or, the time interval is determined based on indication information received by the first device; or, the time interval is determined based on the type of the first device; or, the time interval is determined based on the capabilities of the first device.

[0195] In some implementations, the indication information is carried in: the first PPDU; or, a trigger frame for triggering the first device to receive or send data frames; or, a beacon frame for discovering the Basic Service Set (BSS); or, a probe response frame during the scanning process of the first device; or, an authentication response frame during the authentication process of the first device; or, an association response frame during the association process of the first device.

[0196] In some implementations, the second signal domain is used to carry one or more of the following: a trigger signal; a synchronization signal; a reference signal; a first signal; wherein the first signal is used to determine the start time of the carrier signal and / or the start time of the backscattered signal based on the carrier signal.

[0197] In some implementations, the first signal includes a first sequence; or, the first signal includes a first group of sequences; or, the first signal includes a delimiter.

[0198] In some implementations, the first sequence group is further used to indicate the time interval between the start time of the backscattered signal based on the carrier signal and the end time of the second signal domain.

[0199] In some implementations, the first sequence and / or the sequences in the first sequence group include: an m-sequence; or, a Gold sequence.

[0200] In some implementations, the first sequence and / or the group of first sequences is associated with the BSS.

[0201] In some implementations, the first sequence and / or the first sequence group is carried in a beacon frame for discovering the BSS; or, the first sequence and / or the first sequence group is carried in a probe response frame during the scanning process of the first device; or, the first sequence and / or the first sequence group is carried in an authentication response frame during the authentication process of the first device; or, the first sequence and / or the first sequence group is carried in an association response frame during the association process of the first device; or, the first sequence and / or the first sequence group is determined based on the BSS identifier BSSID; or, the first sequence and / or the first sequence group is predefined.

[0202] In some implementations, the first sequence and / or the first sequence group is determined based on the BSS identifier BSSID, including: the number of the first sequence is determined based on the result of taking the number of candidate sequences modulo the BSSID; and / or, the number of the first sequence group is determined based on the result of taking the number of candidate sequence groups modulo the BSSID.

[0203] In some implementations, the modulation scheme of the signal carried in the second signal domain includes: OOK; or, PSK; or, FSK; or, MSK.

[0204] In some implementations, the first device is a STA, and the second device is an AP or a carrier source for providing a carrier signal; or, the first device is a STA or an AP, and the second device is the carrier source.

[0205] In some implementations, the first device and / or the second device are AMP devices.

[0206] It is understood that the transceiver unit 1710 may be, for example, a transceiver 830. Additionally, the communication device 700 may optionally include a processor 1810 and a memory 1820, as detailed in Figure 19.

[0207] Figure 19 is a schematic structural diagram of a communication apparatus according to an embodiment of this application. The dashed lines in Figure 19 indicate that the unit or module is optional. The apparatus 1800 can be used to implement the methods described in the above method embodiments. The apparatus 1800 may be, for example, a chip, a first device, or a second device.

[0208] Apparatus 1800 may include one or more processors 1810. Processor 1810 may support apparatus 1800 in implementing the methods described in the foregoing method embodiments. Processor 1810 may be a general-purpose processor or a special-purpose processor. For example, processor 1810 may be a central processing unit (CPU). Alternatively, processor 1810 may also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. General-purpose processors may be microprocessors or any conventional processor.

[0209] The apparatus 1800 may further include one or more memories 1820. The memories 1820 store programs that can be executed by the processor 1810, causing the processor 1810 to perform the methods described in the above method embodiments. The memories 1820 may be independent of the processor 1810, or they may be integrated into the processor 1810.

[0210] The device 1800 may also include a transceiver 1830. The processor 1810 can communicate with other devices or chips via the transceiver 1830. For example, the processor 1810 can send and receive data with other devices or chips via the transceiver 1830.

[0211] This application also provides a communication system. The communication system includes the first device and the second device described above. In some implementations, the system further includes other devices that interact with the first device and the second device.

[0212] This application also provides a computer-readable storage medium for storing a program. This computer-readable storage medium can be applied to the first or second device provided in this application, and the program causes a computer to perform the methods executed by the first or second device in various embodiments of this application.

[0213] This application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to the first device or the second device provided in the embodiments of this application, and the program causes a computer to perform the methods executed by the first device or the second device in the various embodiments of this application.

[0214] This application also provides a computer program. This computer program can be applied to the first or second device provided in this application, and causes the computer to execute the methods performed by the first or second device in various embodiments of this application.

[0215] It should be understood that the terms "system" and "network" in the embodiments of this application can be used interchangeably. Furthermore, the terminology used in this application is only for explaining specific embodiments of this application and is not intended to limit this application. The terms "first," "second," "third," and "fourth," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. In addition, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0216] In the embodiments of this application, the term "instruction" can be a direct instruction, an indirect instruction, or an indication of a relationship. For example, A instructing B can mean that A directly instructs B, such as B being able to obtain information through A; it can also mean that A indirectly instructs B, such as A instructing C, so B can obtain information through C; or it can mean that there is a relationship between A and B.

[0217] In the embodiments of this application, "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and / or other information.

[0218] In the embodiments of this application, the term "correspondence" can indicate a direct or indirect correspondence between two things, or an association between two things, or a relationship such as instruction and being instructed, configuration and being configured.

[0219] In this application embodiment, "predefined" or "preconfigured" can be implemented by pre-storing corresponding codes, tables, or other means that can be used to indicate relevant information in the device (e.g., including a first device and a second device). This application does not limit the specific implementation method. For example, predefined can refer to what is defined in the protocol.

[0220] In this application embodiment, the "protocol" may refer to a standard protocol in the field of communication, such as the LTE protocol, the NR protocol, and related protocols applied to future communication systems. This application does not limit this.

[0221] In the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0222] In the various embodiments of this application, the order of the above-mentioned processes does not imply 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 this application.

[0223] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0224] The units described as separate components may or may not be physically separate. 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 the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0225] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0226] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially 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, all or part of the processes or functions described in the embodiments of this application are generated. 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. 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 wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can read or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0227] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method of wireless communication, comprising: include: The first device receives a first physical layer protocol data unit (PPDU) sent by the second device, wherein the first PPDU includes a first signal field for carrying a carrier signal and a second signal field located before the first signal field and associated with the carrier signal.

2. The method of claim 1, wherein, The second signal domain is adjacent to the first signal domain.

3. The method according to claim 1 or 2, characterized in that, The starting position for the first device to detect the second signal domain is located before the starting position of the second signal domain.

4. The method according to any one of claims 1 to 3, characterized in that, The second signal domain is associated with a trigger signal, which is used to trigger the first device to receive or send data frames.

5. The method of claim 4, wherein, The second signal domain is associated with the trigger signal and includes: The trigger signal is carried in the second signal field of the first PPDU; or... The trigger signal is carried on a second PPDU preceding the first PPDU, and the trigger signal is used to indicate that the first PPDU includes the second signal field.

6. The method according to any one of claims 1 to 5, characterized in that, The start time of the backscattered signal based on the carrier signal is the end time of the second signal domain; or, There is a time interval between the start time of the backscattered signal and the end time of the second signal domain.

7. The method according to claim 6, characterized in that, The time interval is a predetermined inter-frame interval; or, The time interval is determined based on the indication information received by the first device; or, The time interval is determined based on the type of the first device; or... The time interval is determined based on the capabilities of the first device.

8. The method of claim 7, wherein, The indication information is carried in: The first PPDU; or, A trigger frame used to trigger the first device to receive or send data frames; or, Beacon frames used for discovering the Basic Service Set (BSS); or, The detection response frame during the scanning process of the first device; or, The authentication response frame during the authentication process of the first device; or, The association response frame during the association process of the first device.

9. The method according to any one of claims 1 to 8, characterized in that, The second signal field is used to carry one or more of the following: Trigger signal; Synchronization signal; Reference signal; First signal; The first signal is used to determine the start time of the carrier signal and / or the start time of the backscattered signal based on the carrier signal.

10. The method according to claim 9, characterized in that, The first signal includes a first sequence; or, The first signal includes a first sequence group; or, The first signal includes a delimiter.

11. The method of claim 10, wherein, The first sequence group is also used to indicate the time interval between the start time of the backscattered signal based on the carrier signal and the end time of the second signal domain.

12. The method according to claim 10 or 11, characterized in that, The first sequence and / or the sequences in the first sequence group include: m-sequence; or, Gold sequence.

13. The method according to any one of claims 10 to 12, characterized in that, The first sequence and / or the first sequence group are associated with the BSS.

14. The method according to any one of claims 10 to 13, characterized in that, The first sequence and / or the group of first sequences is carried in a beacon frame for BSS discovery; or, The first sequence and / or the first sequence group carries a probe response frame during the scanning process of the first device; or, The first sequence and / or the first sequence group are carried in the authentication response frame during the authentication process of the first device; or, The first sequence and / or the first sequence group are carried in the association response frame during the association process of the first device; or, The first sequence and / or the first sequence group is determined based on the BSS identifier BSSID; or, The first sequence and / or the first sequence group are predefined.

15. The method of claim 14, wherein, The first sequence and / or the first sequence group are determined based on the BSS identifier BSSID, including: The number of the first sequence is determined based on the result of modulo the number of candidate sequences using the BSSID; and / or, The number of the first sequence group is determined based on the result of modulo the number of candidate sequence groups using the BSSID.

16. The method according to any one of claims 1 to 15, characterized in that, The modulation methods of the signals carried in the second signal domain include: Binary amplitude keying OOK; or, Phase Shift Keying (PSK); or, Frequency Shift Keying (FSK); or, Minimum Frequency Shift Keying (MSK) 17. The method according to any one of claims 1 to 16, characterized in that, The first device is a station (STA), and the second device is an access point (AP) or a carrier source for providing carrier signals; or, The first device is a STA or AP, and the second device is the carrier source.

18. The method of any one of claims 1 to 17, wherein, The method further includes: When the first device is a STA, the first device sends a backscatter signal to the AP based on the second signal domain; When the first device is an AP, the first device receives the backscattered signal sent by the STA based on the second signal domain.

19. The method of any one of claims 1 to 18, wherein, The first device and / or the second device are environmental power supply (AMP) devices.

20. A method of wireless communication, comprising: include: The second device sends a first physical layer protocol data unit (PPDU) to the first device, wherein the first PPDU includes a first signal field for carrying a carrier signal and a second signal field located before the first signal field and associated with the carrier signal.

21. The method of claim 20, wherein, The second signal domain is adjacent to the first signal domain.

22. The method of claim 20 or 21, wherein, The second signal domain is associated with a trigger signal, which is used to trigger the first device to receive or send data frames.

23. The method of claim 22, wherein, The second signal domain is associated with the trigger signal and includes: The trigger signal is carried in the second signal field of the first PPDU; or... The trigger signal is carried on a second PPDU preceding the first PPDU, and the trigger signal is used to indicate that the first PPDU includes the second signal field.

24. The method according to any one of claims 20 to 23, characterized in that, The start time of the backscattered signal based on the carrier signal is the end time of the second signal domain; or, There is a time interval between the start time of the backscattered signal and the end time of the second signal domain.

25. The method according to claim 24, characterized in that, The time interval is a predetermined inter-frame interval; or, The time interval is determined based on the indication information received by the first device; or, The time interval is determined based on the type of the first device; or... The time interval is determined based on the capabilities of the first device.

26. The method of claim 25, wherein, The indication information is carried in: The first PPDU; or, A trigger frame used to trigger the first device to receive or send data frames; or, Beacon frames used for discovering the Basic Service Set (BSS); or, The detection response frame during the scanning process of the first device; or, The authentication response frame during the authentication process of the first device; or, The association response frame during the association process of the first device.

27. The method of any one of claims 20-26, wherein, The second signal domain is used to carry one or more of the following: Trigger signal; Synchronization signal; Reference signal; First signal; The first signal is used to determine the start time of the carrier signal and / or the start time of the backscattered signal based on the carrier signal.

28. The method according to claim 27, characterized in that, The first signal includes a first sequence; or, The first signal includes a first sequence group; or, The first signal includes a delimiter.

29. The method of claim 28, wherein, The first sequence group is also used to indicate the time interval between the start time of the backscattered signal based on the carrier signal and the end time of the second signal domain.

30. The method of claim 28 or 29, wherein, The first sequence and / or the sequences in the first sequence group include: m-sequence; or, Gold sequence.

31. The method of any one of claims 28-30, wherein, The first sequence and / or the first sequence group are associated with the BSS.

32. The method according to any one of claims 28 to 31, characterized in that, The first sequence and / or the group of first sequences is carried in a beacon frame for BSS discovery; or, The first sequence and / or the first sequence group carries a probe response frame during the scanning process of the first device; or, The first sequence and / or the first sequence group are carried in the authentication response frame during the authentication process of the first device; or, The first sequence and / or the first sequence group are carried in the association response frame during the association process of the first device; or, The first sequence and / or the first sequence group is determined based on the BSS identifier BSSID; or, The first sequence and / or the first sequence group are predefined.

33. The method of claim 32, wherein, The first sequence and / or the first sequence group are determined based on the BSS identifier BSSID, including: The number of the first sequence is determined based on the result of modulo the number of candidate sequences using the BSSID; and / or, The number of the first sequence group is determined based on the result of modulo the number of candidate sequence groups using the BSSID.

34. The method of any one of claims 20-33, wherein, The modulation methods of the signals carried in the second signal domain include: Binary amplitude keying OOK; or, Phase Shift Keying (PSK); or, Frequency Shift Keying (FSK); or, Minimum Frequency Shift Keying (MSK) 35. The method according to any one of claims 20 to 34, characterized in that, The first device is a station (STA), and the second device is an access point (AP) or a carrier source for providing carrier signals; or, The first device is a STA or AP, and the second device is the carrier source.

36. The method of any one of claims 20-35, wherein, The first device and / or the second device are environmental power supply (AMP) devices.

37. A communications device, characterized by The communication device is a first device, comprising: The transceiver unit is configured to receive a first physical layer protocol data unit (PPDU) sent by a second device, wherein the first PPDU includes a first signal field for carrying a carrier signal and a second signal field located before the first signal field and associated with the carrier signal.

38. The communication device of claim 37, wherein, The second signal domain is adjacent to the first signal domain.

39. The communication device of claim 37 or 38, wherein, The starting position for the first device to detect the second signal domain is located before the starting position of the second signal domain.

40. The communication device of any one of claims 37 to 39, wherein, The second signal domain is associated with a trigger signal, which is used to trigger the first device to receive or send data frames.

41. The communication device of claim 40, wherein, The second signal domain is associated with the trigger signal and includes: The trigger signal is carried in the second signal field of the first PPDU; or... The trigger signal is carried on a second PPDU preceding the first PPDU, and the trigger signal is used to indicate that the first PPDU includes the second signal field.

42. The communication device according to any one of claims 37 to 41, characterized in that, The start time of the backscattered signal based on the carrier signal is the end time of the second signal domain; or, There is a time interval between the start time of the backscattered signal and the end time of the second signal domain.

43. The communication device according to claim 42, characterized in that, The time interval is a predetermined inter-frame interval; or, The time interval is determined based on the indication information received by the first device; or, The time interval is determined based on the type of the first device; or... The time interval is determined based on the capabilities of the first device.

44. The communication device of claim 43, wherein, The indication information is carried in: The first PPDU; or, A trigger frame used to trigger the first device to receive or send data frames; or, Beacon frames used for discovering the Basic Service Set (BSS); or, The detection response frame during the scanning process of the first device; or, The authentication response frame during the authentication process of the first device; or, The association response frame during the association process of the first device.

45. The communication device according to any one of claims 37 to 44, characterized by, The second signal field is used to carry one or more of the following: Trigger signal; Synchronization signal; Reference signal; First signal; The first signal is used to determine the start time of the carrier signal and / or the start time of the backscattered signal based on the carrier signal.

46. ​​The communication device according to claim 45, characterized in that, The first signal includes a first sequence; or, The first signal includes a first sequence group; or, The first signal includes a delimiter.

47. The communication device of claim 46, wherein, The first sequence group is also used to indicate the time interval between the start time of the backscattered signal based on the carrier signal and the end time of the second signal domain.

48. The communication device of claim 46 or 47, wherein, The first sequence and / or the sequences in the first sequence group include: m-sequence; or, Gold sequence.

49. The communication device of any one of claims 46-48, wherein, The first sequence and / or the first sequence group are associated with the BSS.

50. The communication device according to any one of claims 46 to 49, characterized in that, The first sequence and / or the group of first sequences is carried in a beacon frame for BSS discovery; or, The first sequence and / or the first sequence group carries a probe response frame during the scanning process of the first device; or, The first sequence and / or the first sequence group are carried in the authentication response frame during the authentication process of the first device; or, The first sequence and / or the first sequence group are carried in the association response frame during the association process of the first device; or, The first sequence and / or the first sequence group is determined based on the BSS identifier BSSID; or, The first sequence and / or the first sequence group are predefined.

51. The communication device of claim 50, wherein, The first sequence and / or the first sequence group are determined based on the BSS identifier BSSID, including: The number of the first sequence is determined based on the result of modulo the number of candidate sequences using the BSSID; and / or, The number of the first sequence group is determined based on the result of modulo the number of candidate sequence groups using the BSSID.

52. The communication device of any one of claims 37 to 51, wherein, The modulation methods of the signals carried in the second signal domain include: Binary amplitude keying OOK; or, Phase Shift Keying (PSK); or, Frequency Shift Keying (FSK); or, Minimum Frequency Shift Keying (MSK) 53. The communication device according to any one of claims 37 to 52, characterized in that, The first device is a station (STA), and the second device is an access point (AP) or a carrier source for providing carrier signals; or, The first device is a STA or AP, and the second device is the carrier source.

54. The communication device of any one of claims 37 to 53, wherein, The transceiver unit is also used for: When the first device is a STA, a backscatter signal is sent to the AP based on the second signal domain; When the first device is an AP, the backscattered signal sent by the STA is received based on the second signal domain.

55. The communication device according to any one of claims 37-54, wherein, The first device and / or the second device are environmental power supply (AMP) devices.

56. A communications device, comprising: The communication device is a second device, including: The transceiver unit is configured to send a first physical layer protocol data unit (PPDU) to a first device, wherein the first PPDU includes a first signal field for carrying a carrier signal and a second signal field located before the first signal field and associated with the carrier signal.

57. The communication device of claim 56, wherein, The second signal domain is adjacent to the first signal domain.

58. The communication device of claim 56 or 57, wherein, The second signal domain is associated with a trigger signal, which is used to trigger the first device to receive or send data frames.

59. The communication device of claim 58, wherein, The second signal domain is associated with the trigger signal and includes: The trigger signal is carried in the second signal field of the first PPDU; or... The trigger signal is carried on a second PPDU preceding the first PPDU, and the trigger signal is used to indicate that the first PPDU includes the second signal field.

60. The communication device according to any one of claims 56 to 59, characterized in that, The start time of the backscattered signal based on the carrier signal is the end time of the second signal domain; or, There is a time interval between the start time of the backscattered signal and the end time of the second signal domain.

61. The communication device according to claim 60, characterized in that, The time interval is a predetermined inter-frame interval; or, The time interval is determined based on the indication information received by the first device; or, The time interval is determined based on the type of the first device; or... The time interval is determined based on the capabilities of the first device.

62. The communication device of claim 61, wherein, The indication information is carried in: The first PPDU; or, A trigger frame used to trigger the first device to receive or send data frames; or, Beacon frames used for discovering the Basic Service Set (BSS); or, The detection response frame during the scanning process of the first device; or, The authentication response frame during the authentication process of the first device; or, The association response frame during the association process of the first device.

63. The communication device of any one of claims 56-62, wherein, The second signal domain is used to carry one or more of the following: Trigger signal; Synchronization signal; Reference signal; First signal; The first signal is used to determine the start time of the carrier signal and / or the start time of the backscattered signal based on the carrier signal.

64. The communication device according to claim 63, characterized in that, The first signal includes a first sequence; or, The first signal includes a first sequence group; or, The first signal includes a delimiter.

65. The communication device of claim 64, wherein, The first sequence group is also used to indicate the time interval between the start time of the backscattered signal based on the carrier signal and the end time of the second signal domain.

66. The communication device of claim 64 or 65, wherein, The first sequence and / or the sequences in the first sequence group include: m-sequence; or, Gold sequence.

67. The communication device of any one of claims 64 to 66, wherein, The first sequence and / or the first sequence group are associated with the BSS.

68. The communication device according to any one of claims 64 to 67, characterized in that, The first sequence and / or the group of first sequences is carried in a beacon frame for BSS discovery; or, The first sequence and / or the first sequence group carries a probe response frame during the scanning process of the first device; or, The first sequence and / or the first sequence group are carried in the authentication response frame during the authentication process of the first device; or, The first sequence and / or the first sequence group are carried in the association response frame during the association process of the first device; or, The first sequence and / or the first sequence group is determined based on the BSS identifier BSSID; or, The first sequence and / or the first sequence group are predefined.

69. The communication device of claim 68, wherein, The first sequence and / or the first sequence group are determined based on the BSS identifier BSSID, including: The number of the first sequence is determined based on the result of modulo the number of candidate sequences using the BSSID; and / or, The number of the first sequence group is determined based on the result of modulo the number of candidate sequence groups using the BSSID.

70. The communication device of any one of claims 56-69, wherein, The modulation methods of the signals carried in the second signal domain include: Binary amplitude keying OOK; or, Phase Shift Keying (PSK); or, Frequency Shift Keying (FSK); or, Minimum Frequency Shift Keying (MSK) 71. The communication device according to any one of claims 56 to 70, characterized in that, The first device is a station (STA), and the second device is an access point (AP) or a carrier source for providing carrier signals; or, The first device is a STA or AP, and the second device is the carrier source.

72. The communication device of any one of claims 56 to 71, wherein, The first device and / or the second device are environmental power supply (AMP) devices.

73. A communications device, characterized by The device includes a transceiver, a memory, and a processor. The memory stores a program, and the processor invokes the program in the memory and controls the transceiver to receive or transmit signals so that the communication device performs the method according to any one of claims 1 to 19.

74. A communications device, characterized by The device includes a transceiver, a memory, and a processor. The memory stores a program, and the processor invokes the program in the memory and controls the transceiver to receive or transmit signals so that the communication device performs the method according to any one of claims 20 to 36.

75. An apparatus comprising: Includes a processor for calling a program from memory to cause the apparatus to perform the method according to any one of claims 1 to 36.

76. A chip, comprising: Includes a processor for calling a program from memory, causing a device on which the chip is mounted to perform the method according to any one of claims 1 to 36.

77. A computer-readable storage medium, comprising: It contains a program that causes a computer to perform the method according to any one of claims 1 to 36.

78. A computer program product, characterized in that, Includes a program that causes a computer to perform the method according to any one of claims 1 to 36.

79. A computer program, characterized in that, The computer program causes the computer to perform the method according to any one of claims 1 to 36.

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