Signal transmission method and apparatus, device, storage medium, and timing acquisition signal

Abstract

A signal transmission method and apparatus, a device, a storage medium, and a timing acquisition signal, relating to the technical field of communications. The method, which is performed by an A-IoT device, comprises: receiving a timing acquisition signal, the timing acquisition signal comprising an SIP and a CAP, the CAP being sent contiguously after the SIP, the SIP having a duration of 0.5 OFDM symbols, the CAP having a duration associated with a first value, the first value being a value of M used for OOK-4 modulation in R2D transmission, and the CAP at least comprising three chips (810). Provided is a timing acquisition signal, the timing acquisition signal comprising an SIP and a CAP, the CAP having a duration associated with a value of M used for OOK-4 modulation in R2D transmission, and a structure of the CAP being designed according to the value of M, so as to prevent a CP from impacting rising and falling edges of the CAP, thereby eliminating the impact of CPs on the reception of SIPs and CAPs by A-IoT devices.

Description

Signal transmission methods, devices, equipment, storage media, and time-based signal acquisition. Technical Field

[0001] This application relates to the field of communication technology, and in particular to a signal transmission method, apparatus, device, storage medium, and time acquisition signal. Background Technology

[0002] With the development of communication technology, the application of A-IoT (Ambient Internet of Things) devices is becoming increasingly widespread. In related technologies, R2D (Reader to Device) transmission uses DFT-s-OFDM (Discrete Fourier Transform-Spread OFDM) waveforms. Each OFDM (Orthogonal Frequency Division Multiplexing) symbol requires the addition of a CP (Cyclic Prefix). When receiving R2D transmissions, A-IoT devices rely on detecting rising / falling edges. The CP portion may introduce additional rising / falling edges, affecting the A-IoT device's ability to make correct decisions. How to reduce the impact of CP on A-IoT devices requires further discussion and research. Summary of the Invention

[0003] This application provides a signal transmission method, apparatus, device, storage medium, and time acquisition signal. The technical solution is as follows:

[0004] According to one aspect of the embodiments of this application, a signal transmission method is provided, the method being executed by an A-IoT device, the method comprising:

[0005] The receiver receives a time acquisition signal, which includes a SIP (Start-Indicator Part) and a CAP (Clock-Acquisition Part). The CAP is transmitted immediately after the SIP. The SIP occupies a duration of 0.5 OFDM symbols. The duration of the CAP is related to a first value, which is the M value used for OOK-4 modulation in R2D transmission. The CAP includes at least three chips.

[0006] According to one aspect of the embodiments of this application, a signal transmission method is provided, the method being executed by a reader, the method comprising:

[0007] A time acquisition signal is transmitted, which includes SIP and CAP. The CAP is transmitted adjacent to the SIP. The duration of the SIP is 0.5 OFDM symbol length. The duration of the CAP is related to a first value, which is the M value used for OOK-4 modulation in R2D transmission. The CAP includes at least three chips.

[0008] According to one aspect of the embodiments of this application, a time acquisition signal is provided, the time acquisition signal including SIP and CAP, the CAP being transmitted adjacent to the SIP, the duration of the SIP being 0.5 OFDM symbol length, the duration of the CAP being related to a first value, the first value being the M value used for OOK-4 modulation in R2D transmission, and the CAP including at least three chips.

[0009] According to one aspect of the embodiments of this application, a signal transmission device is provided, the device comprising:

[0010] A receiving module is used to receive a time acquisition signal, which includes a SIP and a CAP. The CAP is transmitted adjacent to the SIP. The duration of the SIP is 0.5 OFDM symbol lengths. The duration of the CAP is related to a first value, which is the M value used for OOK-4 modulation in R2D transmission. The CAP includes at least three chips.

[0011] According to one aspect of the embodiments of this application, a signal transmission device is provided, the device comprising:

[0012] The transmitting module is used to transmit a time acquisition signal, which includes SIP and CAP. The CAP is transmitted adjacent to the SIP. The duration of the SIP is 0.5 OFDM symbol length. The duration of the CAP is related to a first value, which is the M value used for OOK-4 modulation in R2D transmission. The CAP includes at least three chips.

[0013] According to one aspect of the embodiments of this application, a communication device is provided, the communication device including a processor and a memory, the memory storing a computer program, the processor executing the computer program to implement the above-described signal transmission method. The communication device is a terminal device, or the communication device is a network device.

[0014] According to one aspect of the embodiments of this application, a computer-readable storage medium is provided, the storage medium storing a computer program for execution by a processor to implement the above-described signal transmission method.

[0015] According to one aspect of the embodiments of this application, a chip is provided, the chip including programmable logic circuits and / or program instructions, which, when the chip is running, are used to implement the above-described signal transmission method.

[0016] According to one aspect of the embodiments of this application, a computer program product is provided, the computer program product including computer instructions stored in a computer-readable storage medium, and a processor reading from the computer-readable storage medium and executing the computer instructions to implement the above-described signal transmission method.

[0017] The technical solutions provided in this application embodiment may have the following beneficial effects:

[0018] A time acquisition signal is proposed, which includes SIP and CAP. The duration of CAP is related to the M value of OOK-4 modulation used in R2D transmission. The structure of CAP is designed according to the M value to avoid the influence of CP on the rising / falling edge in CAP, thereby eliminating the influence of CP on A-IoT reception of SIP and CAP. Attached Figure Description

[0019] Figure 1 is a schematic diagram of a network architecture provided in one embodiment of this application;

[0020] Figure 2 is a schematic diagram of a zero-power communication system provided in an embodiment of this application;

[0021] Figure 3 is a schematic diagram of the radio frequency energy harvesting principle provided in an embodiment of this application;

[0022] Figure 4 is a schematic diagram of the backscatter communication principle provided in an embodiment of this application;

[0023] Figure 5 is a schematic diagram of the circuit principle of resistive load modulation provided in one embodiment of this application;

[0024] Figure 6 is a schematic diagram of the topology in A-IoT WID (Work Item Description) provided in an embodiment of this application;

[0025] Figure 7 is a schematic diagram of an OOK-4 modulation scheme provided in an embodiment of this application;

[0026] Figure 8 is a flowchart of a signal transmission method provided in an embodiment of this application;

[0027] Figure 9 is a flowchart of a signal transmission method provided in another embodiment of this application;

[0028] Figure 10 is a schematic diagram of the time acquisition signal provided in an embodiment of this application when M=1;

[0029] Figure 11 is a schematic diagram of the time acquisition signal provided in an embodiment of this application when M=2;

[0030] Figure 12 is a schematic diagram of the time acquisition signal provided in another embodiment of this application when M=2;

[0031] Figure 13 is a schematic diagram of the time acquisition signal provided in an embodiment of this application when M=4;

[0032] Figure 14 is a schematic diagram of the time acquisition signal provided in an embodiment of this application when M=6;

[0033] Figure 15 is a schematic diagram of the time acquisition signal provided in an embodiment of this application when M=12;

[0034] Figure 16 is a block diagram of a signal transmission device provided in an embodiment of this application;

[0035] Figure 17 is a block diagram of a signal transmission device provided in another embodiment of this application;

[0036] Figure 18 is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0038] The network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0039] Please refer to Figure 1, which shows a schematic diagram of a network architecture 100 provided in one embodiment of this application. The network architecture 100 may include: a terminal device 10, an access network device 20, and a core network element 30.

[0040] Terminal device 10 can refer to UE (User Equipment), STA (Station), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, wireless communication device, user agent, or user equipment. In some embodiments, terminal device 10 can also be a cellular phone, cordless phone, SIP (Session Initiation Protocol) phone, WLL (Wireless Local Loop) station, PDA (Personal Digital Assistant), handheld device with wireless communication capabilities, computing device or other processing device connected to a wireless modem, vehicle-mounted device, wearable device, terminal device in 5GS (5th Generation System), or terminal device in the future evolved PLMN (Public Land Mobile Network), etc., and this application embodiment is not limited to these. For ease of description, the devices mentioned above are collectively referred to as terminal devices. The number of terminal devices 10 is usually multiple, and one or more terminal devices 10 can be distributed within the cell managed by each access network device 20. Terminal equipment can also be simply referred to as terminal or UE, the meaning of which can be understood by those skilled in the art.

[0041] Access network device 20 is a device deployed in an access network to provide wireless communication functionality to terminal device 10. Access network device 20 may include various forms of macro base stations, micro base stations, relay stations, APs (Access Points), etc. In systems employing different wireless access technologies, the name of the device with access network device functionality may differ; for example, in a 5G NR (New Radio) system, it is called gNodeB or gNB (Next Generation Node B). As communication technologies evolve, the name "access network device" may change. For ease of description, in this embodiment, the aforementioned devices providing wireless communication functionality to terminal device 10 are collectively referred to as access network devices. In some embodiments, a communication relationship can be established between terminal device 10 and core network element 30 through access network device 20. For example, in an LTE (Long Term Evolution) system, access network device 20 can be one or more eNodeBs within an EUTRAN (Evolved Universal Terrestrial Radio Access Network); in a 5G NR system, access network device 20 can be one or more gNBs within a RAN (Radio Access Network). In the embodiments of this application, unless otherwise specified, "network device" refers to access network device 20, such as a base station.

[0042] Core network element 30 is a network element deployed in the core network. Its main functions are to provide user connectivity, manage users, and bear services, serving as an interface to external networks. For example, core network elements in a 5G NR system may include AMF (Access and Mobility Management Function) entities, UPF (User Plane Function) entities, and SMF (Session Management Function) entities.

[0043] In some embodiments, the access network device 20 and the core network element 30 communicate with each other via some air interface technology, such as the NG interface in a 5G NR system. The access network device 20 and the terminal device 10 communicate with each other via some air interface technology, such as the Uu interface.

[0044] The "5G NR system" in this application embodiment can also be referred to as a 5G system or an NR system, but those skilled in the art will understand its meaning. The technical solutions described in this application embodiment can be applied to LTE systems, 5G NR systems, and subsequent evolution systems of 5G NR systems (such as B5G (Beyound 5G) systems, 6G systems (6th Generation System), and other communication systems such as NB-IoT (Narrow Band Internet of Things) systems. This application does not limit these applications.

[0045] In this embodiment, the network device can provide services to a cell. The terminal device communicates with the network device through the transmission resources (e.g., frequency domain resources, or spectrum resources) on the carrier used by the cell. The cell can be the cell corresponding to the network device (e.g., a base station). The cell can belong to a macro base station or to a base station corresponding to a small cell. The small cell can include: Metro Cell, Micro Cell, Pico Cell, Femto Cell, etc. These small cells have the characteristics of small coverage area and low transmission power, and are suitable for providing high-speed data transmission services.

[0046] Before introducing the technical solution of this application, some related technical knowledge involved in this application will be introduced and explained. The following related technologies are optional solutions and can be arbitrarily combined with the technical solutions of the embodiments of this application, all of which fall within the protection scope of the embodiments of this application. The embodiments of this application include at least some of the following contents.

[0047] 1. Zero-power technology principle

[0048] In recent years, the application of zero-power devices has become increasingly widespread. During standardization discussions, zero-power IoT can also be referred to as Ambient Power Enabled IoT or Ambient IoT, or simply Ambient IoT (Ambient Energy IoT). Some technical literature also refers to it as passive IoT. Ambient IoT devices refer to IoT devices that use various environmental energy sources, such as radio frequency energy, light energy, solar energy, thermal energy, and mechanical energy, to power themselves. These devices may have no energy storage capacity or very limited energy storage capacity (e.g., using capacitors with a capacitance of tens of microseconds). Compared to existing IoT devices, Ambient IoT devices have many advantages, including no need for conventional batteries, no maintenance, small size, low complexity and low cost, and long lifespan.

[0049] Zero-power communication employs energy harvesting and backscatter communication technologies. A zero-power communication network consists of network devices (also called readers) and zero-power devices, as shown in Figure 2. The network devices send wireless power signals and downlink communication signals to the zero-power devices and receive backscatter signals from them. A basic zero-power device includes an energy harvesting module, a backscatter communication module, and a low-power computing module. Furthermore, the zero-power device may also have a memory or sensor to store basic information (such as object identification) or acquire sensor data such as ambient temperature and humidity.

[0050] The key technologies for zero-power communication mainly include radio frequency energy harvesting and backscatter communication.

[0051] (1) Radio Frequency Power Harvesting

[0052] As shown in Figure 3, the radio frequency energy harvesting module harvests electromagnetic wave energy from space based on the principle of electromagnetic induction, thereby obtaining the energy required to drive zero-power devices, such as driving low-power demodulation and modulation modules, sensors, and memory reading. Therefore, zero-power devices do not require traditional batteries.

[0053] (2) Backscattering communication

[0054] As shown in Figure 4, the zero-power communication terminal receives wireless signals sent by the network, modulates the wireless signals, loads the information to be transmitted, and radiates the modulated signal from the antenna. This information transmission process is called backscatter communication. Backscatter and load modulation are inseparable. Load modulation adjusts and controls the circuit parameters of the zero-power device's oscillation circuit according to the data stream's rhythm, causing parameters such as the electronic tag's impedance to change accordingly, thus completing the modulation process. Load modulation technology mainly includes two methods: resistive load modulation and capacitive load modulation. In resistive load modulation, a resistor is connected in parallel with the load. This resistor is switched on or off based on the control of the binary data stream, as shown in Figure 5. The switching on and off of the resistor causes a change in the circuit voltage, thus realizing amplitude shift keying (ASK), that is, signal modulation and transmission are achieved by adjusting the amplitude of the backscatter signal from the zero-power device. Similarly, in capacitive load modulation, the resonant frequency of the circuit can be changed by switching the capacitor on and off, realizing frequency shift keying (FSK). That is, the modulation and transmission of the signal is achieved by adjusting the operating frequency of the backscattered signal of the zero-power device.

[0055] As can be seen, zero-power devices modulate the incoming signal using load modulation, thereby achieving backscatter communication. Therefore, zero-power devices have significant advantages:

[0056] (1) The terminal does not actively transmit signals, so it does not need complex radio frequency links, such as PA (Power Amplifier), radio frequency filters, etc.;

[0057] (2) The terminal does not need to actively generate high-frequency signals, therefore it does not need a high-frequency crystal oscillator;

[0058] (3) With the help of backscatter communication, the terminal signal transmission does not require the terminal to consume its own energy.

[0059] 2. Application scenarios of zero-power communication

[0060] Zero-power communication (ZHW) has significant advantages such as extremely low cost, zero power consumption, and small size, and can be widely used in various industries, such as logistics, smart warehousing, smart agriculture, energy and power, and industrial internet for vertical industries; it can also be used in personal applications such as smart wearables and smart homes.

[0061] 3. Classification of zero-power devices

[0062] Based on the energy source and usage method of zero-power devices, zero-power devices can be classified into the following types:

[0063] 1) Passive zero-power devices

[0064] Zero-power devices do not require an internal battery. When a zero-power device approaches a network device (such as a reader in an RFID (Radio Frequency Identification) system), it falls within the near-field range of the network device's antenna radiation. Therefore, the zero-power device's antenna generates an induced current through electromagnetic induction, which drives the device's low-power chip circuitry. This enables demodulation of the forward link signal (downlink, from the network device to the zero-power device) and modulation of the backward link signal (uplink, from the zero-power device to the network device). For backscatter links, the zero-power device uses backscattering to transmit signals.

[0065] As can be seen, passive zero-power devices do not require built-in batteries to drive either the forward or reverse link, making them truly zero-power devices.

[0066] Passive zero-power devices do not require batteries, and their radio frequency and baseband circuits are very simple. For example, they do not require LNA (Low Noise Amplifier), PA (Power Amplifier), crystal oscillator, ADC (Analog-to-Digital Converter), etc. Therefore, they have many advantages such as small size, light weight, very low price, and long service life.

[0067] 2) Semi-passive zero-power devices

[0068] Semi-passive zero-power devices do not have conventional batteries installed, but they can harvest radio wave energy using RF energy harvesting modules, or harvest energy using solar / photovoltaic / thermal / kinetic energy harvesting modules, storing the harvested energy in an energy storage unit (such as a capacitor). Once the energy storage unit receives energy, it can drive the low-power chip circuitry of the zero-power device, enabling demodulation of forward link signals and modulation of backward link signals. For backscatter links, the zero-power device uses backscattering to transmit signals.

[0069] As can be seen, semi-passive zero-power devices do not require built-in batteries to drive either the forward or reverse link. Although they use energy stored in capacitors during operation, the energy comes from the radio energy collected by the energy harvesting module, making them a true zero-power device.

[0070] Semi-passive zero-power devices inherit many advantages of passive zero-power devices, and therefore have many advantages such as small size, light weight, very low price, and long service life.

[0071] 3) Active zero-power devices

[0072] In some scenarios, zero-power devices can also be active zero-power devices. These terminals can have a built-in battery (a conventional battery, such as a dry cell battery or a rechargeable lithium battery). The battery powers the low-power chip circuitry of the zero-power device, enabling demodulation of the forward link signal and modulation of the backward link signal. However, for the backscatter link, the zero-power device uses backscattering to transmit the signal. Therefore, the zero power consumption of this type of terminal is mainly reflected in the fact that the signal transmission of the backward link does not require the terminal's own power, but instead uses backscattering. Although active zero-power devices use batteries, their power consumption is extremely low due to ultra-low power communication sampling technology, thus significantly improving battery life compared to existing technologies.

[0073] Active zero-power devices use a built-in battery to power the RFID chip, increasing the tag's read / write distance and improving communication reliability. Therefore, they are used in scenarios with relatively high requirements for communication distance and read latency.

[0074] Classification of zero-power devices based on transmitter type.

[0075] As is well known, the business types of zero-power IoT, along with other IoT business types, will primarily focus on upstream services. Therefore, based on the way zero-power terminals transmit data, they can be categorized as follows:

[0076] 1) Zero-power devices based on backscattering

[0077] These zero-power devices transmit uplink data using the backscattering method described above. These devices do not have an active transmitter for active transmission, but only a backscattering transmitter. Therefore, when this type of terminal transmits data, a network device needs to provide a carrier wave, and the terminal device uses this carrier wave for backscattering to achieve data transmission.

[0078] 2) Zero-power devices based on active transmitters

[0079] These zero-power devices use active transmitters with active transmission capabilities for uplink data transmission. Therefore, when sending data, these devices can transmit data using their own active transmitters without requiring a carrier wave from network equipment. Suitable active transmitters for zero-power devices include, for example, ultra-low-power ASK or ultra-low-power FSK transmitters. Based on current implementations, these transmitters can reduce overall power consumption to 400–600 µW when transmitting a 100 µW signal.

[0080] 3) Zero-power devices that simultaneously feature backscattering and active transmitters.

[0081] These terminals can support both backscatter and active transmitters. The terminal can determine which uplink signal transmission method to use based on different conditions (such as battery level and available ambient energy) or the scheduling of network devices: whether to use backscatter or active transmitter for active transmission.

[0082] 4. Cellular Passive Internet of Things

[0083] Cellular IoT is booming, with 3GPP standardizing IoT technologies such as NB-IoT, MTC, and RedCap. However, there are still many IoT communication needs in various scenarios that cannot be met using existing technologies, such as:

[0084] - Harsh communication environment

[0085] Some IoT scenarios may face extreme environments such as high temperatures, extremely low temperatures, high humidity, high pressure, high radiation, or high-speed movement. Examples include ultra-high-voltage substations, high-speed train track monitoring, environmental monitoring in frigid regions, and industrial production lines. In these scenarios, existing IoT terminals will be unable to function due to the limitations of conventional power supplies. Furthermore, extreme working environments are also detrimental to IoT maintenance, such as battery replacement.

[0086] - Minimal size terminal form factor requirements

[0087] In certain IoT communication scenarios, such as food traceability, commodity distribution, and smart wearables, terminals require extremely small sizes for convenient use in these environments. For example, IoT terminals used for commodity management in the distribution process typically use electronic tags, embedded in very small packages. Furthermore, lightweight wearable devices can enhance the user experience while meeting user needs.

[0088] - Extremely low-cost IoT communication needs

[0089] Numerous IoT communication scenarios require IoT terminals to be sufficiently inexpensive to enhance their competitiveness compared to other alternative technologies. For example, in logistics or warehousing scenarios, to facilitate the management of large quantities of goods in circulation, IoT terminals can be attached to each item, enabling precise management of the entire logistics process and lifecycle through communication between the terminal and the logistics network. These scenarios necessitate that IoT terminals be priced competitively.

[0090] With the increasing application of 5G in various industries, the types of connected devices and application scenarios are also increasing, which will place higher demands on the price and power consumption of communication terminals. The application of battery-free, low-cost passive IoT devices has become a key technology for cellular IoT, enriching the types and number of terminals connected by 5G networks and truly realizing the Internet of Everything.

[0091] Based on the discussion of Ambient IoT application scenarios in 3GPP SA1, Ambient IoT can be used in at least the following four scenarios:

[0092] Object recognition, such as in logistics, production line product management, and supply chain management;

[0093] Environmental monitoring, such as monitoring of temperature, humidity, and harmful gases in the work environment and natural environment;

[0094] Location services, such as indoor positioning, smart item finding, and production line item positioning;

[0095] Intelligent control, such as the intelligent control of various electrical appliances in smart homes (turning on and off air conditioners, adjusting temperature), and the intelligent control of various facilities in agricultural greenhouses (automatic irrigation, fertilization).

[0096] 5. A-IoT projects in 3GPP

[0097] 3GPP RAN Ambient-IoT Rel-19 Project Overview

[0098] The 3GPP RAN#106 plenary meeting discussed and approved the A-IoT WID (Work Item Description). The Rel-19 A-IoT WI phase will only standardize one type of A-IoT device:

[0099] - Category 1 A-IoT devices: ~1uW peak power consumption. These A-IoT devices have energy storage, an initial sampling frequency offset of 10X ppm, no uplink or downlink power amplifiers, and transmit uplink data by backscattering an external carrier.

[0100] Rel-19Ambient-IoT is deployed in the following scenarios / topologies, as shown in Figure 6:

[0101] -Deployment scenario 1with Topology 1(D1T1):BS Ambient IoT devices (A-IoT devices) involve direct two-way signaling and / or data communication between the base station and the A-IoT device. The carrier used for backscattering by the A-IoT device is provided by a third-party node.

[0102] In Ambient-IoT, the reader sends R2D (Reader-to-device) transmissions to the A-IoT device, and the device sends D2R (Device-to-reader) transmissions to the reader. The reader includes the base station in Topology 1, and the device includes the first type of device.

[0103] Based on existing conclusions, R2D transmission consists of two parts: Timing Acquisition Signal (TAS) and Physical Reader-to-Device Channel (PRDCH). The Timing Acquisition Signal is used by the device to determine the start time of R2D transmission and the OOK chip width of the PRDCH transmission. The PRDCH is used to carry control and / or data information. The transmission of control and / or data information uses OOK modulation, with a high level representing {1} and a low level representing {0}. The duration of the level can be understood as one OOK chip. The transition between high and low levels will generate rising / falling edges, which the device can detect. The aforementioned time acquisition signal comprises two parts: a start indication part and a clock acquisition part. The SIP is used to indicate the start time of R2D. For example, the SIP employs a special structure that is distinguishable from CAP and PRDCH. When the device detects a signal with this structure, it can determine that R2D transmission has begun. CAP is used to determine the OOK chip width used by PRDCH. For example, CAP includes at least two edges in the same direction, and the length between the two edges is equal to the width of two OOK chips. When the device detects the edges of CAP, it can determine the OOK chip width.

[0104] R2D transmission uses DFT-s-OFDM waveforms and OOK-4 modulation. This modulation method indicates that one OFDM symbol carries M OOK chips. The method for generating an OOK-4 signal based on DFT-s-OFDM is shown in Figure 7. Specifically, firstly, a time-domain signal with N' sampling points is generated based on the M bits to be transmitted. This time-domain signal is then transformed using DFT to generate an N'-point frequency-domain signal. This frequency-domain signal is further transformed to obtain an N-point frequency-domain signal. The N-point frequency-domain signal is mapped onto N subcarriers in the frequency domain after IFFT transformation. After IFFT transformation and the addition of CP, the desired time-domain signal is obtained.

[0105] The length and structure of SIP and CAP are currently undetermined. Designing these two parts requires considering both how to achieve their required functionality and how to handle the impact of CP (Cyclic prefix). R2D transmission uses DFT-s-OFDM waveforms, and a CP needs to be added to each OFDM symbol. A-IoT devices rely on detecting rising / falling edges when receiving R2D transmissions; the CP section may introduce additional rising / falling edges, affecting the device's ability to make correct decisions.

[0106] Please refer to Figure 8, which shows a flowchart of a signal transmission method provided in one embodiment of this application, which is performed by an A-IoT device. The method includes the following step 810.

[0107] Step 810: The A-IoT device receives a time acquisition signal, which includes SIP and CAP. CAP is sent adjacent to SIP. The duration of SIP is 0.5 OFDM symbol length. The duration of CAP is related to a first value, which is the M value used for OOK-4 modulation in R2D transmission. CAP includes at least three chips.

[0108] In some embodiments, the A-IoT device receives a time acquisition signal sent by the reader for time synchronization with the reader.

[0109] In some embodiments, the timing acquisition signal includes SIP and CAP, with CAP adjacent to SIP and following SIP. In some embodiments, SIP occupies 1 / 2 OFDM symbol length, where OFDM symbol length refers to the duration occupied by one OFDM symbol. In some embodiments, the OFDM symbol length is the symbol length corresponding to a subcarrier spacing of 15 kHz.

[0110] In some embodiments, the duration of CAP is related to a first value, which is the M value used for OOK-4 modulation in R2D transmission. As described in the above embodiments, OOK-4 modulation means that one OFDM symbol carries M OOK chips. The detailed structure of CAP will be described in subsequent embodiments.

[0111] In some embodiments, the CAP includes at least three chips because A-IoT devices detect R2D transmission signals based on rising / falling edges, thus requiring at least three chips to ensure the presence of at least two rising / falling edges. The A-IoT device determines the chip length based on the distance (or time-domain offset) between two rising edges (two falling edges).

[0112] In some embodiments, OFDM symbols do not include a CP. In some embodiments, a CP is added before each OFDM symbol.

[0113] The technical solution provided in this application proposes a time acquisition signal, which includes SIP and CAP. The duration of CAP is related to the M value of OOK-4 modulation used in R2D transmission. The structure of CAP is designed according to the M value to avoid the influence of CP on the rising / falling edge in CAP, thereby eliminating the influence of CP on A-IoT reception of SIP and CAP.

[0114] Please refer to Figure 9, which shows a flowchart of a signal transmission method provided in one embodiment of this application, the method being performed by a reader. The method includes the following step 910.

[0115] Step 910: The reader sends a time acquisition signal, which includes SIP and CAP. CAP is sent adjacent to SIP. The duration of SIP is 0.5 OFDM symbol length. The duration of CAP is related to a first value, which is the M value used for OOK-4 modulation in R2D transmission. CAP includes at least three chips.

[0116] In some embodiments, the reader sends a time acquisition signal to the A-IoT device to establish time synchronization with the reader.

[0117] In some embodiments, the time acquisition signal includes SIP and CAP, with CAP adjacent to SIP and located after SIP. In some embodiments, SIP occupies 1 / 2 OFDM symbol length, where OFDM symbol length refers to the duration occupied by one OFDM symbol.

[0118] In some embodiments, the duration of CAP is related to a first value, which is the M value used for OOK-4 modulation in R2D transmission. As described in the above embodiments, OOK-4 modulation means that one OFDM symbol carries M OOK chips. The detailed structure of CAP will be described in subsequent embodiments.

[0119] In some embodiments, the CAP includes at least three chips because A-IoT devices detect R2D transmission signals based on rising / falling edges, thus requiring at least three chips to ensure the presence of at least two rising / falling edges. The A-IoT device determines the chip length based on the distance (or time-domain offset) between two rising edges (two falling edges).

[0120] In some embodiments, OFDM symbols do not include a CP. In some embodiments, each OFDM symbol is followed by a CP.

[0121] The technical solution provided in this application proposes a time acquisition signal, which includes SIP and CAP. The duration of CAP is related to the M value of OOK-4 modulation used in R2D transmission. The structure of CAP is designed according to the M value to avoid the influence of CP on the rising / falling edge in CAP, thereby eliminating the influence of CP on A-IoT reception of SIP and CAP.

[0122] In this embodiment of the application, a time acquisition signal is provided, which includes SIP and CAP. CAP is sent adjacent to SIP. The duration of SIP is 0.5 OFDM symbol length. The duration of CAP is related to a first value, which is the M value used for OOK-4 modulation in R2D transmission. CAP includes at least three chips.

[0123] The time acquisition signal will be described in detail below.

[0124] Regarding time acquisition signals

[0125] 1. The first value is 1

[0126] In some embodiments, when the first value is 1, CAP includes three chips with the same chip length, wherein the chip length of one chip is equal to the length of one OFDM symbol.

[0127] In some embodiments, the SIP starts at the middle of an OFDM symbol. In some embodiments, a dummy signal precedes the SIP, and the dummy signal occupies a duration of 0.5 OFDM symbol lengths. In some embodiments, the dummy signal is different from the SIP.

[0128] In some embodiments, the three chips are represented as {ON,OFF,ON}; or, the three chips are represented as {1,0,1}.

[0129] As shown in Figure 10, if the first value is 1, SIP begins in the middle of the OFDM symbol. Within the OFDM symbol where SIP is located but before SIP, the network device sends a dummy signal. The dummy signal only needs to be different from the SIP part; the specific implementation depends on the reader / writer. CAP occupies a duration of 3 OFDM symbols. CAP includes three chips, each with the same length equal to the length of one OFDM symbol. The three chips of CAP are represented as {ON, OFF, ON}, or as {1, 0, 1}.

[0130] Adding CPs before the three OFDM symbols occupied by CAP does not introduce additional transition edges. The device can determine the OOK chip width by detecting two rising edges. After adding CPs, the width between the two rising edges is greater than the width of two OOK chips. However, from the perspective of A-IoT devices, since the OOK chip width is longest when M=1, the device can determine that M is 1 when it detects that the width between the two rising edges is greater than the length of one OFDM symbol. Therefore, adding CPs does not affect the device's determination that M=1.

[0131] 2. The first value is 2.

[0132] In one example, with the first value being 2, CAP consists of three chips of equal length, wherein the chip length of one chip is equal to 0.5 OFDM symbol length.

[0133] In some embodiments, the starting position of the SIP is the OFDM symbol boundary.

[0134] In some embodiments, the three chips are represented as {ON,OFF,ON}; or, the three chips are represented as {1,0,1}.

[0135] As shown in Figure 11, if the first value is 2, SIP starts at the OFDM symbol boundary, the duration of CAP is 1.5 OFDM symbols, CAP includes three chips, each chip has the same length and is equal to 0.5 OFDM symbol length, the three chips of CAP are represented as {ON, OFF, ON}, or the three chips of CAP are represented as {1, 0, 1}.

[0136] Since the SIP starts at the OFDM symbol boundary and occupies 1 / 2 of the OFDM symbol, the CAP portion starts in the middle of the OFDM symbol. The CP will not affect the A-IoT device's detection of the CAP start. After adding the CP, the width between the two rising edges detected by the device will be greater than the width of two OOK chips, but not greater than the length of two OFDM symbols. Therefore, it will not affect the device's determination that M=2.

[0137] In another example, when the first value is 2, CAP comprises four chips, the sum of which is equal to 1.5 OFDM symbol lengths. The fourth chip is represented as OFF or 0. In some embodiments, the four chips are referred to sequentially as the first chip, second chip, third chip, and fourth chip. In some embodiments, the first and third chips have the same length, and the second and fourth chips have the same length. In some embodiments, the chip length of the first and third chips is 0.5 OFDM symbol lengths, and the sum of the chip lengths of the second and fourth chips is 0.5 OFDM symbol lengths.

[0138] In some embodiments, the starting position of the SIP is the OFDM symbol boundary.

[0139] In some embodiments, the four chips are represented as {ON,OFF,ON,OFF}; or, the four chips are represented as {1,0,1,0}.

[0140] As shown in Figure 12, if the first value is 2, SIP starts at the OFDM symbol boundary, the duration of CAP is 1.5 OFDM symbols, CAP includes four chips, the length of the four chips can be the same or different, the four chips of CAP are represented as {ON,OFF,ON,OFF}, or the four chips of CAP are represented as {1,0,1,0}.

[0141] Since the SIP starts at the OFDM symbol boundary and occupies 1 / 2 of the OFDM symbol, the CAP portion starts in the middle of the OFDM symbol. Because the last chip in the CAP is an off-chip, the added CP has the same level as the SIP end. However, the CP does not affect the A-IoT device's detection of the CAP start. After adding the CP, the width between the two rising edges detected by the device will be greater than the width of two OOK chips, but not greater than the length of two OFDM symbols. Therefore, it will not affect the device's determination that M=2.

[0142] 3. The first value is 4

[0143] In some embodiments, when the first value is 4, the CAP includes four chips of the same length, wherein the chip length of one chip is equal to 0.25 OFDM symbol lengths.

[0144] In some embodiments, the four chips are represented as {ON,OFF,ON,OFF}; or, the four chips are represented as {1,0,1,0}.

[0145] In some embodiments, the starting position of the SIP is the middle position of the OFDM symbol.

[0146] In some embodiments, a dummy signal is included before the SIP, and the dummy signal occupies a duration of 0.5 OFDM symbol length. In some embodiments, the dummy signal is different from the SIP.

[0147] As shown in Figure 13, if the first value is 4, SIP begins in the middle of the OFDM symbol. Within the OFDM symbol where SIP is located but before SIP, the network device sends a dummy signal. The dummy signal only needs to be different from the SIP part; the specific implementation depends on the network device. CAP occupies the duration of one OFDM symbol. CAP includes four chips, each with the same length equal to 1 / 4 of the OFDM symbol length. The four chips of CAP are represented as {ON, OFF, ON, OFF}, or as {1, 0, 1, 0}.

[0148] The CAP section begins at the OFDM symbol boundary. Since the last chip in the CAP is an OFF-chip, the added CP is at the same level as the SIP end level, so it will not affect the start of the CAP section in A-IoT. Furthermore, the width between the two rising edges of the CAP is the width of two OOK chips, which is not affected by the CP.

[0149] 4. The first value is greater than 4

[0150] In some embodiments, when the first value is greater than 4, CAP includes three chips with the same chip length, wherein the chip length of one chip is equal to 3 / M OFDM symbol length.

[0151] In some embodiments, the first value is any one of 6, 8, 12, 16, 24, and 32.

[0152] In some embodiments, the starting position of the SIP is the OFDM symbol boundary.

[0153] In some embodiments, the three chips are represented as {ON,OFF,ON}; or, the three chips are represented as {1,0,1}.

[0154] If the first value is any one of 6, 8, 12, 16, 24, or 32, the SIP begins at the OFDM symbol boundary, and the duration of CAP is 3 * 1 / M OFDM symbols. CAP consists of three chips, each with the same length equal to 1 / M OFDM symbol length. The three chips in CAP are represented as {ON, OFF, ON}, or {1, 0, 1}. The OFDM symbol does not include CP. Figures 14 and 15 show the time acquisition signal schematics for M=6 and M=12, respectively. Since the SIP begins at the OFDM symbol boundary and occupies 1 / 2 OFDM symbol, and the length of CAP is less than or equal to 1 / 2 OFDM symbol, CAP will not cross OFDM symbols, and CP will not have any impact on the CAP part.

[0155] It should be noted that, in the above method embodiments, the steps performed by the A-IoT device can be implemented separately as a signal transmission method on the A-IoT device side; the steps performed by the reader can be implemented separately as a signal transmission method on the reader side.

[0156] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0157] Please refer to Figure 16, which shows a block diagram of a signal transmission device according to an embodiment of this application. This device has the functionality to implement the above-described signal transmission method example; this functionality can be implemented in hardware or by hardware executing corresponding software. This device can be an A-IoT device as described above, or it can be installed within an A-IoT device. As shown in Figure 16, the device 1600 may include a receiving module 1610.

[0158] The receiving module 1610 is used to receive a time acquisition signal, which includes a start indication part (SIP) and a clock acquisition part (CAP). The CAP is transmitted adjacent to the SIP. The duration of the SIP is 0.5 times the length of an orthogonal frequency division multiplexing (OFDM) symbol. The duration of the CAP is related to a first value, which is the M value used for on / off keying (OOK-4) modulation in the reader-to-device R2D transmission. The CAP includes at least three chips.

[0159] In some embodiments, the OFDM symbol does not include the cyclic prefix CP.

[0160] 1. The first value is 1

[0161] In some embodiments, when the first value is 1, the CAP includes three chips of the same length, wherein the chip length of one chip is equal to the length of one OFDM symbol.

[0162] In some embodiments, the starting position of the SIP is the middle position of the OFDM symbol.

[0163] In some embodiments, a virtual signal is included before the SIP, the virtual signal having a duration of 0.5 OFDM symbol length.

[0164] In some embodiments, the three chips are represented as {ON, OFF, ON}; or, the three chips are represented as {1, 0, 1}.

[0165] 2. The first value is 2.

[0166] In one example, when the first value is 2, the CAP comprises three chips of equal length, wherein the chip length of one chip is equal to 0.5 OFDM symbol length.

[0167] In some embodiments, the starting position of the SIP is the OFDM symbol boundary.

[0168] In some embodiments, the three chips are represented as {ON, OFF, ON}; or, the three chips are represented as {1, 0, 1}.

[0169] In another example, when the first value is 2, the CAP comprises four chips whose chip lengths are equal to 1.5 OFDM symbol lengths, and the fourth chip is represented as OFF or 0.

[0170] In some embodiments, the starting position of the SIP is the OFDM symbol boundary.

[0171] In some embodiments, the four chips are represented as {ON,OFF,ON,OFF}; or, the four chips are represented as {1,0,1,0}.

[0172] 3. The first value is 4

[0173] In some embodiments, when the first value is 4, the CAP includes four chips of equal length, wherein the chip length of one chip is equal to 0.25 OFDM symbol lengths.

[0174] In some embodiments, the four chips are represented as {ON,OFF,ON,OFF}; or, the four chips are represented as {1,0,1,0}.

[0175] In some embodiments, the starting position of the SIP is the middle position of the OFDM symbol.

[0176] In some embodiments, a virtual signal is included before the SIP, the virtual signal having a duration of 0.5 OFDM symbol length.

[0177] 4. The first value is greater than 4

[0178] In some embodiments, when the first value is greater than 4, the CAP includes three chips, the three chips having the same chip length, wherein the chip length of one chip is equal to 3 / M OFDM symbol lengths.

[0179] In some embodiments, the first value is any one of 6, 8, 12, 16, 24, and 32.

[0180] In some embodiments, the starting position of the SIP is the OFDM symbol boundary.

[0181] In some embodiments, the three chips are represented as {ON, OFF, ON}; or, the three chips are represented as {1, 0, 1}.

[0182] The technical solution provided in this application proposes a time acquisition signal, which includes SIP and CAP. The duration of CAP is related to the M value of OOK-4 modulation used in R2D transmission. The structure of CAP is designed according to the M value to avoid the influence of CP on the rising / falling edge in CAP, thereby eliminating the influence of CP on A-IoT reception of SIP and CAP.

[0183] Please refer to Figure 17, which shows a block diagram of a signal transmission device according to an embodiment of this application. This device has the function of implementing the above-described signal transmission method example; the function can be implemented in hardware or by hardware executing corresponding software. The device can be the reader described above, or it can be located within a reader. As shown in Figure 17, the device 1700 may include a transmitting module 1710.

[0184] The transmitting module 1710 is used to receive a time acquisition signal, which includes a start indication part (SIP) and a clock acquisition part (CAP). The CAP is transmitted adjacent to the SIP. The duration of the SIP is 0.5 times the length of an orthogonal frequency division multiplexing (OFDM) symbol. The duration of the CAP is related to a first value, which is the M value used for on / off keying (OOK-4) modulation in the reader-to-device R2D transmission. The CAP includes at least three chips.

[0185] In some embodiments, the OFDM symbol does not include the cyclic prefix CP.

[0186] 1. The first value is 1

[0187] In some embodiments, when the first value is 1, the CAP includes three chips of the same length, wherein the chip length of one chip is equal to the length of one OFDM symbol.

[0188] In some embodiments, the starting position of the SIP is the middle position of the OFDM symbol.

[0189] In some embodiments, a virtual signal is included before the SIP, the virtual signal having a duration of 0.5 OFDM symbol length.

[0190] In some embodiments, the three chips are represented as {ON, OFF, ON}; or, the three chips are represented as {1, 0, 1}.

[0191] 2. The first value is 2.

[0192] In one example, when the first value is 2, the CAP comprises three chips of equal length, wherein the chip length of one chip is equal to 0.5 OFDM symbol length.

[0193] In some embodiments, the starting position of the SIP is the OFDM symbol boundary.

[0194] In some embodiments, the three chips are represented as {ON, OFF, ON}; or, the three chips are represented as {1, 0, 1}.

[0195] In another example, when the first value is 2, the CAP comprises four chips whose chip lengths are equal to 1.5 OFDM symbol lengths, and the fourth chip is represented as OFF or 0.

[0196] In some embodiments, the starting position of the SIP is the OFDM symbol boundary.

[0197] In some embodiments, the four chips are represented as {ON,OFF,ON,OFF}; or, the four chips are represented as {1,0,1,0}.

[0198] 3. The first value is 4

[0199] In some embodiments, when the first value is 4, the CAP includes four chips of equal length, wherein the chip length of one chip is equal to 0.25 OFDM symbol lengths.

[0200] In some embodiments, the four chips are represented as {ON,OFF,ON,OFF}; or, the four chips are represented as {1,0,1,0}.

[0201] In some embodiments, the starting position of the SIP is the middle position of the OFDM symbol.

[0202] In some embodiments, a virtual signal is included before the SIP, the virtual signal having a duration of 0.5 OFDM symbol length.

[0203] 4. The first value is greater than 4

[0204] In some embodiments, when the first value is greater than 4, the CAP includes three chips, the three chips having the same chip length, wherein the chip length of one chip is equal to 3 / M OFDM symbol lengths.

[0205] In some embodiments, the first value is any one of 6, 8, 12, 16, 24, and 32.

[0206] In some embodiments, the starting position of the SIP is the OFDM symbol boundary.

[0207] In some embodiments, the three chips are represented as {ON, OFF, ON}; or, the three chips are represented as {1, 0, 1}.

[0208] The technical solution provided in this application proposes a time acquisition signal, which includes SIP and CAP. The duration of CAP is related to the M value of OOK-4 modulation used in R2D transmission. The structure of CAP is designed according to the M value to avoid the influence of CP on the rising / falling edge in CAP, thereby eliminating the influence of CP on A-IoT reception of SIP and CAP.

[0209] It should be noted that the device provided in the above embodiments is only illustrated by the division of the above functional modules when implementing its functions. In actual applications, the above functions can be assigned to different functional modules according to actual needs, that is, the content structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0210] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0211] Please refer to Figure 18, which shows a schematic diagram of a communication device provided in one embodiment of this application. The communication device can be an A-IoT device or a reader as described above. The communication device 1800 may include a processor 1801, a transceiver 1802, and a memory 1803. The transceiver 1802 is used to implement sending or receiving functions, such as implementing the functions of the receiving module 1610 or the sending module 1710 described above. The processor 1801 can be used to implement other processing functions or control sending and / or receiving.

[0212] The processor 1801 includes one or more processing cores, and the processor 1801 executes various functional applications and information processing by running software programs and modules.

[0213] The transceiver 1802 may include a receiver and a transmitter, for example, the receiver and transmitter may be implemented as the same wireless communication component, which may include a wireless communication chip and a radio frequency antenna.

[0214] The memory 1803 can be connected to the processor 1801 and the transceiver 1802.

[0215] The memory 1803 can be used to store a computer program executed by the processor, and the processor 1801 is used to execute the computer program to implement the various steps in the above method embodiments.

[0216] In some embodiments, when the communication device 1800 is an A-IoT device, the transceiver 1802 is used to receive a time acquisition signal, the time acquisition signal including SIP and CAP, the CAP being transmitted adjacent to the SIP, the SIP having a duration of 0.5 OFDM symbol length, the CAP having a duration related to a first value, the first value being the M value used for OOK-4 modulation in R2D transmission, and the CAP including at least three chips.

[0217] In some embodiments, when the communication device 1800 is a reader, the transceiver 1802 is used to transmit a time acquisition signal, the time acquisition signal including SIP and CAP, the CAP being transmitted adjacent to the SIP, the SIP having a duration of 0.5 OFDM symbol length, the CAP having a duration related to a first value, the first value being the M value used for OOK-4 modulation in R2D transmission, and the CAP including at least three chips.

[0218] For details not described in this embodiment, please refer to the embodiments above, which will not be repeated here.

[0219] Furthermore, the memory can be implemented by any type of volatile or non-volatile storage device or a combination thereof, including but not limited to: magnetic disks or optical disks, electrically erasable programmable read-only memory, erasable programmable read-only memory, statically accessible memory, read-only memory, magnetic memory, flash memory, and programmable read-only memory.

[0220] This application embodiment also provides a computer-readable storage medium storing a computer program for execution by a processor to implement the signal transmission method on the A-IoT device side or the signal transmission method on the reader side. Optionally, the computer-readable storage medium may include ROM (Read-Only Memory), RAM (Random-Access Memory), SSD (Solid State Drives), or optical disc, etc. The random access memory may include ReRAM (Resistance Random Access Memory) and DRAM (Dynamic Random Access Memory).

[0221] This application also provides a chip, which includes programmable logic circuits and / or program instructions. When the chip is running, it is used to implement the above-mentioned signal transmission method on the A-IoT device side or the above-mentioned signal transmission method on the reader side.

[0222] This application also provides a computer program product, which includes a computer program stored in a computer-readable storage medium. A processor reads and executes the computer program from the computer-readable storage medium to implement the above-described signal transmission method on the A-IoT device side or the above-described signal transmission method on the reader side.

[0223] It should be understood that the term "instruction" mentioned in the embodiments of this application 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.

[0224] In the description of the embodiments of this application, the term "correspondence" may indicate that there is a direct or indirect correspondence between two things, or that there is an association between two things, or that there is a relationship of instruction and being instructed, configuration and being configured, etc.

[0225] In some embodiments of this application, "predefined" 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 terminal devices and APs). This application does not limit the specific implementation method. For example, predefined can refer to what is defined in the protocol.

[0226] In some embodiments of this application, the term "protocol" may refer to standard protocols in the field of communications, such as LTE protocols, NR protocols, and related protocols applied in future communication systems. This application does not limit the scope of these protocols.

[0227] In this article, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0228] In this article, "greater than or equal to" can mean greater than or equal to, and "less than or equal to" can mean less than or equal to.

[0229] Furthermore, the step numbers described herein are merely illustrative of one possible execution order between steps. In some other embodiments, the steps may not be executed in the order of their numbers, such as two steps with different numbers being executed simultaneously, or two steps with different numbers being executed in the reverse order of the illustration. This application does not limit this.

[0230] Those skilled in the art will recognize that the functions described in the embodiments of this application in one or more of the above examples can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0231] The above description is merely an exemplary embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A signal transmission method, characterized in that, The method is executed by an environmental Internet of Things (A-IoT) device, and the method includes: The receiver receives a time acquisition signal, which includes a start indication part (SIP) and a clock acquisition part (CAP). The CAP is transmitted adjacent to the SIP. The duration of the SIP is 0.5 times the length of an orthogonal frequency division multiplexing (OFDM) symbol. The duration of the CAP is related to a first value, which is the M value used for on / off keying (OOK-4) modulation in the reader-to-device R2D transmission. The CAP includes at least three chips.

2. The method according to claim 1, characterized in that, When the first value is 1, the CAP includes three chips, the three chips have the same chip length, wherein the chip length of one chip is equal to the length of one OFDM symbol.

3. The method according to claim 1, characterized in that, When the first value is 2, the CAP includes three chips, all of which have the same chip length, wherein the chip length of one chip is equal to 0.5 OFDM symbol length.

4. The method according to claim 1, characterized in that, When the first value is 2, the CAP includes four chips, the sum of the chip lengths of the four chips is equal to 1.5 OFDM symbol lengths, and the fourth chip of the four chips is represented as OFF, or the fourth chip is represented as 0.

5. The method according to claim 1, characterized in that, When the first value is 4, the CAP includes four chips, all of which have the same chip length, wherein the chip length of one chip is equal to 0.25 OFDM symbol lengths.

6. The method according to claim 5, characterized in that, The four chips are represented as {ON,OFF,ON,OFF}; or, the four chips are represented as {1,0,1,0}.

7. The method according to claim 2, 5 or 6, characterized in that, The starting position of the SIP is the middle position of the OFDM symbol.

8. The method according to claim 7, characterized in that, A virtual signal precedes the SIP, and the duration of the virtual signal is 0.5 OFDM symbol length.

9. The method according to claim 1, characterized in that, When the first value is greater than 4, the CAP includes three chips, the three chips have the same chip length, wherein the chip length of one chip is equal to 3 / M OFDM symbol length.

10. The method according to claim 9, characterized in that, The first value is any one of 6, 8, 12, 16, 24, and 32.

11. The method according to claim 3, 4, 9 or 10, characterized in that, The starting position of the SIP is the OFDM symbol boundary.

12. The method according to any one of claims 2, 3, 9 to 11, characterized in that, The three chips are represented as {ON, OFF, ON}; or, the three chips are represented as {1, 0, 1}.

13. The method according to any one of claims 1 to 12, characterized in that, The OFDM symbol does not include the cyclic prefix CP.

14. A signal transmission method, characterized in that, The method is executed by the reader, and the method includes: A time acquisition signal is transmitted, which includes a start indication part (SIP) and a clock acquisition part (CAP). The CAP is transmitted adjacent to the SIP. The duration of the SIP is 0.5 OFDM symbol lengths. The duration of the CAP is related to a first value, which is the M value used for on / off keying OOK-4 modulation in reader-to-device R2D transmission. The CAP includes at least three chips.

15. The method according to claim 14, characterized in that, When the first value is 1, the CAP includes three chips, the three chips have the same chip length, wherein the chip length of one chip is equal to the length of one OFDM symbol.

16. The method according to claim 14, characterized in that, When the first value is 2, the CAP includes three chips, all of which have the same chip length, wherein the chip length of one chip is equal to 0.5 OFDM symbol length.

17. The method according to claim 14, characterized in that, When the first value is 2, the CAP includes four chips, the sum of the chip lengths of the four chips is equal to 1.5 OFDM symbol lengths, and the fourth chip of the four chips is represented as OFF, or the fourth chip is represented as 0.

18. The method according to claim 14, characterized in that, When the first value is 4, the CAP includes four chips, all of which have the same chip length, wherein the chip length of one chip is equal to 0.25 OFDM symbol lengths.

19. The method according to claim 18, characterized in that, The four chips are represented as {ON,OFF,ON,OFF}; or, the four chips are represented as {1,0,1,0}.

20. The method according to claim 15, 18 or 19, characterized in that, The starting position of the SIP is the middle position of the OFDM symbol.

21. The method according to claim 20, characterized in that, A virtual signal precedes the SIP, and the duration of the virtual signal is 0.5 OFDM symbol length.

22. The method according to claim 14, characterized in that, When the first value is greater than 4, the CAP includes three chips, the three chips have the same chip length, wherein the chip length of one chip is equal to 3 / M OFDM symbol length.

23. The method according to claim 22, characterized in that, The first value is any one of 6, 8, 12, 16, 24, and 32.

24. The method according to claim 16, 17, 22 or 23, characterized in that, The starting position of the SIP is the OFDM symbol boundary.

25. The method according to any one of claims 15, 16, 22 to 24, characterized in that, The three chips are represented as {ON, OFF, ON}; or, the three chips are represented as {1, 0, 1}.

26. The method according to any one of claims 14 to 25, characterized in that, The OFDM symbol does not include the cyclic prefix CP.

27. A time-acquisition signal, characterized in that, The time acquisition signal includes a start indication section (SIP) and a clock acquisition section (CAP). The CAP is transmitted adjacent to the SIP. The duration of the SIP is 0.5 times the length of an orthogonal frequency division multiplexing (OFDM) symbol. The duration of the CAP is related to a first value, which is the M value used for on / off keying (OOK-4) modulation in the reader-to-device R2D transmission. The CAP includes at least three chips.

28. The time acquisition signal according to claim 27, characterized in that, When the first value is 1, the CAP includes three chips, the three chips have the same chip length, wherein the chip length of one chip is equal to the length of one OFDM symbol.

29. The time acquisition signal according to claim 27, characterized in that, When the first value is 2, the CAP includes three chips, all of which have the same chip length, wherein the chip length of one chip is equal to 0.5 OFDM symbol length.

30. The time acquisition signal according to claim 27, characterized in that, When the first value is 2, the CAP includes four chips, the sum of the chip lengths of the four chips is equal to 1.5 OFDM symbol lengths, and the fourth chip of the four chips is represented as OFF, or the fourth chip is represented as 0.

31. The time acquisition signal according to claim 27, characterized in that, When the first value is 4, the CAP includes four chips, all of which have the same chip length, wherein the chip length of one chip is equal to 0.25 OFDM symbol lengths.

32. The time acquisition signal according to claim 31, characterized in that, The four chips are represented as {ON,OFF,ON,OFF}; or, the four chips are represented as {1,0,1,0}.

33. The time acquisition signal according to claim 28, 31 or 32, characterized in that, The starting position of the SIP is the middle position of the OFDM symbol.

34. The time acquisition signal according to claim 33, characterized in that, A virtual signal precedes the SIP, and the duration of the virtual signal is 0.5 OFDM symbol length.

35. The time acquisition signal according to claim 27, characterized in that, When the first value is greater than 4, the CAP includes three chips, the three chips have the same chip length, wherein the chip length of one chip is equal to 3 / M OFDM symbol length.

36. The time acquisition signal according to claim 35, characterized in that, The first value is any one of 6, 8, 12, 16, 24, and 32.

37. The time acquisition signal according to claim 29, 30, 35 or 36, characterized in that, The starting position of the SIP is the OFDM symbol boundary.

38. The time acquisition signal according to any one of claims 28, 29, 35 to 37, characterized in that, The three chips are represented as {ON, OFF, ON}; or, the three chips are represented as {1, 0, 1}.

39. The time acquisition signal according to any one of claims 27 to 38, characterized in that, The OFDM symbol does not include the cyclic prefix CP.

40. A signal transmission device, characterized in that, The device includes: The receiving module is used to receive a time acquisition signal, which includes a start indication part (SIP) and a clock acquisition part (CAP). The CAP is transmitted adjacent to the SIP. The duration of the SIP is 0.5 times the length of an orthogonal frequency division multiplexing (OFDM) symbol. The duration of the CAP is related to a first value, which is the M value used for on / off keying (OOK-4) modulation in the reader-to-device R2D transmission. The CAP includes at least three chips.

41. A signal transmission device, characterized in that, The device includes: The transmitting module is used to transmit a time acquisition signal, which includes a start indication part (SIP) and a clock acquisition part (CAP). The CAP is transmitted adjacent to the SIP. The duration of the SIP is 0.5 times the length of an orthogonal frequency division multiplexing (OFDM) symbol. The duration of the CAP is related to a first value, which is the M value used for on / off keying (OOK-4) modulation in the reader-to-device R2D transmission. The CAP includes at least three chips.

42. A communication device, characterized in that, The communication device includes a processor and a memory, the memory storing a computer program, the processor executing the computer program to implement the method as claimed in any one of claims 1 to 13, or to implement the method as claimed in any one of claims 14 to 26.

43. A computer-readable storage medium, characterized in that, The storage medium stores a computer program that is executed by a processor to implement the method as described in any one of claims 1 to 13, or the method as described in any one of claims 14 to 26.

44. A chip, characterized in that, The chip includes programmable logic circuitry and / or program instructions, which, when the chip is running, are used to implement the method as described in any one of claims 1 to 13, or to implement the method as described in any one of claims 14 to 26.

45. A computer program product, characterized in that, The computer program product includes computer instructions stored in a computer-readable storage medium, which a processor reads from and executes to implement the method as claimed in any one of claims 1 to 13, or the method as claimed in any one of claims 14 to 26.

Images