Frequency calibration method, apparatus, device, and storage medium

Abstract

The application discloses a frequency calibration method, device, equipment and storage medium, and belongs to the field of mobile communication. The method comprises the following steps: receiving at least two reference signals; wherein the at least two reference signals are used for determining a first time domain interval, the first time domain interval is a measurement time domain interval between any two reference signals in the at least two reference signals, the first time domain interval and a second time domain interval are used for frequency calibration, and the second time domain interval is a reference time domain interval between the any two reference signals known by a low-power device. At least two reference signals are received by the low-power device, so that the first time domain interval between any two reference signals in the at least two reference signals can be determined, the first time domain interval is compared with the second time domain interval known by the low-power device, so that the low-power device can estimate a frequency offset and perform calibration, and an implementation manner of frequency calibration of the low-power device is provided.

Description

Frequency calibration method, device, equipment and storage medium Technical Field

[0001] The present application relates to the field of mobile communications, and in particular to a frequency calibration method, apparatus, device and storage medium. Background Art

[0002] With the continuous evolution of wireless communication technology, the Internet of Things (IoT) is being applied to all aspects of production and life. Low-power IoT devices, such as ambient power enabled IoT (A-IoT) devices, have simple radio frequency and baseband circuits, offering numerous advantages such as small size, light weight, low price, long service life, and maintenance-free operation.

[0003] Due to factors like cost and power consumption, low-power devices often lack crystal oscillators or have very low precision, which can lead to frequency drift. The specific implementation of frequency calibration for low-power devices requires further discussion and research.

[0004] Summary of the Invention

[0005] This application provides a frequency calibration method, apparatus, device, and storage medium. The technical solution is as follows:

[0006] According to one aspect of the present application, a frequency calibration method is provided, the method being performed by a low-power device, the method comprising:

[0007] receiving at least two reference signals;

[0008] In which, the at least two reference signals are used to determine a first time domain interval, the first time domain interval is the measurement time domain interval of any two reference signals among the at least two reference signals, the first time domain interval and the second time domain interval are used for frequency calibration, and the second time domain interval is the reference time domain interval between the any two reference signals known to the low-power device.

[0009] According to another aspect of the present application, a frequency calibration method is provided, the method being performed by a first device, the method comprising:

[0010] sending at least two reference signals to the low-power device;

[0011] In which, the at least two reference signals are used to determine a first time domain interval, the first time domain interval is the measurement time domain interval of any two reference signals among the at least two reference signals, the first time domain interval and the second time domain interval are used for frequency calibration, and the second time domain interval is the reference time domain interval between the any two reference signals known to the low-power device.

[0012] According to another aspect of the present application, a frequency calibration device is provided, comprising:

[0013] A receiving module, configured to receive at least two reference signals;

[0014] The at least two reference signals are used to determine a first time domain interval, the first time domain interval is a measurement time domain interval of any two reference signals among the at least two reference signals, the first time domain interval and the second time domain interval are used for frequency calibration, and the second time domain interval is a reference time domain interval between the any two reference signals known to the device.

[0015] According to another aspect of the present application, a frequency calibration device is provided, comprising:

[0016] A sending module, configured to send at least two reference signals to the low-power device;

[0017] In which, the at least two reference signals are used to determine a first time domain interval, the first time domain interval is the measurement time domain interval of any two reference signals among the at least two reference signals, the first time domain interval and the second time domain interval are used for frequency calibration, and the second time domain interval is the reference time domain interval between the any two reference signals known to the low-power device.

[0018] According to another aspect of the present application, a low-power device is provided, comprising: a processor; a transceiver connected to the processor; and a memory for storing executable instructions of the processor; wherein the low-power device is configured to load and execute the executable instructions to implement the frequency calibration method as described in the above aspects.

[0019] According to another aspect of the present application, a first device is provided, comprising: a processor; a transceiver connected to the processor; and a memory for storing executable instructions of the processor; wherein the first device is configured to load and execute the executable instructions to implement the frequency calibration method as described in the above aspects.

[0020] According to another aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores executable instructions, and the executable instructions are loaded and executed by a processor to implement the frequency calibration method as described in the above aspects.

[0021] According to another aspect of the present application, a chip is provided, which includes a programmable logic circuit and / or program instructions. When the chip runs on a computer device, it is used to implement the frequency calibration method described in the above aspects based on the programmable logic circuit and / or program instructions.

[0022] According to another aspect of the present application, a computer program product or computer program is provided, wherein the computer program product or computer program includes computer instructions, wherein the computer instructions are stored in a computer-readable storage medium, and a processor reads and executes the computer instructions from the computer-readable storage medium, so that a computer device performs the frequency calibration method described in the above aspects.

[0023] The technical solutions provided by the embodiments of the present application include at least the following beneficial effects:

[0024] By receiving at least two reference signals through a low-power device, a first time domain interval between any two reference signals of the at least two reference signals can be determined, and the first time domain interval is compared with a second time domain interval known to the low-power device, so that the low-power device can estimate the frequency deviation and perform calibration, providing an implementation method for frequency calibration of a low-power device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] FIG1 is a schematic diagram of a low-power communication system provided by an exemplary embodiment of the present application;

[0027] FIG2 is a schematic diagram of radio frequency energy harvesting provided by an exemplary embodiment of the present application;

[0028] FIG3 is a schematic diagram of a backscatter communication process provided by an exemplary embodiment of the present application;

[0029] FIG4 is a schematic diagram of resistive load modulation provided by an exemplary embodiment of the present application;

[0030] FIG5 is a schematic diagram of an encoding method provided by an exemplary embodiment of the present application;

[0031] FIG6 is a schematic diagram of a first topological structure provided by an exemplary embodiment of the present application;

[0032] FIG7 is a schematic diagram of a second topology structure provided by an exemplary embodiment of the present application;

[0033] FIG8 is a schematic diagram of a system architecture of a communication system provided by an exemplary embodiment of the present application;

[0034] FIG9 is a flow chart of a frequency calibration method provided by an exemplary embodiment of the present application;

[0035] FIG10 is a schematic diagram of a first time domain interval and a second time domain interval provided by an exemplary embodiment of the present application;

[0036] FIG11 is a flow chart of a frequency calibration method provided by an exemplary embodiment of the present application;

[0037] FIG12 is a flow chart of a frequency calibration method provided by an exemplary embodiment of the present application;

[0038] FIG13 is a schematic diagram of a reference signal provided by an exemplary embodiment of the present application;

[0039] FIG14 is a schematic diagram of a reference signal provided by an exemplary embodiment of the present application;

[0040] FIG15 is a schematic diagram of a reference signal provided by an exemplary embodiment of the present application;

[0041] FIG16 is a schematic diagram of a time domain structure of a reference signal provided by an exemplary embodiment of the present application;

[0042] FIG17 is a schematic diagram of a time domain structure of a reference signal provided by an exemplary embodiment of the present application;

[0043] FIG18 is a schematic diagram of a sequence corresponding to a reference signal provided by an exemplary embodiment of the present application;

[0044] FIG19 is a schematic diagram of a sequence corresponding to a reference signal provided by an exemplary embodiment of the present application;

[0045] FIG20 is a schematic diagram of a sequence corresponding to a reference signal provided by an exemplary embodiment of the present application;

[0046] FIG21 is a schematic diagram of a data packet associated with a reference signal provided by an exemplary embodiment of the present application;

[0047] FIG22 is a schematic diagram of a data packet associated with a reference signal provided by an exemplary embodiment of the present application;

[0048] FIG23 is a schematic diagram of a data packet associated with a reference signal provided by an exemplary embodiment of the present application;

[0049] FIG24 is a schematic diagram of a data packet associated with a reference signal provided by an exemplary embodiment of the present application;

[0050] FIG25 is a block diagram of a frequency calibration apparatus provided by an exemplary embodiment of the present application;

[0051] FIG26 is a block diagram of a frequency calibration apparatus provided by an exemplary embodiment of the present application;

[0052] FIG27 is a schematic structural diagram of a communication device provided by an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0053] To make the objectives, technical solutions, and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings. Exemplary embodiments will be described in detail herein, with examples shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0054] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0055] It should be understood that although the terms first, second, third, etc. may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0056] The technical solutions described in some embodiments of the present application can be applied to various communication systems, such as: Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS) system, Long Term Evolution (LTE) system, Advanced Long Term Evolution (LTE-A) system, New Radio (NR) system, NR system evolution system, LTE on unlicensed spectrum (LTE-U) system, NR on unlicensed spectrum (NR-based access to unlicensed spectrum, NR-U) system, Non-Terrestrial Networks (NTN) system, Universal Mobile Telecommunication System (UMTS), Wireless Local Area Networks (WLAN) system, Wireless Fidelity (Wireless Fidelity) system. The present invention is applicable to the fifth generation mobile communication technology (5G) system, the cellular Internet of Things system, the cellular passive Internet of Things system, and can also be applied to the subsequent evolution system of the 5G NR system, and can also be applied to the sixth generation mobile communication technology (6G) system and subsequent evolution systems.

[0057] It should be understood that in some embodiments of the present application, "5G" may also be referred to as "5G NR" or "NR".

[0058] It should be understood that in the description of the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and being indicated, configuration and being configured, etc.

[0059] Figure 1 shows a schematic diagram of a low-power communication system 100 provided by an exemplary embodiment of the present application, wherein the low-power communication system 100 includes a network device 120 and a low-power device 140. In some embodiments, the low-power device 140 includes a device (IoT device) that uses various environmental energies, such as wireless radio frequency energy, light energy, solar energy, thermal energy, mechanical energy, and other environmental energies to drive itself, and has the characteristics of low power consumption or zero power consumption. Such devices may have no energy storage capacity or may have very limited energy storage capacity (such as using a capacitor with a capacity of tens of uF). In some embodiments, the low-power device 140 includes at least one of a zero-power device, a zero-power IoT device, an ambient IoT device, and a passive IoT device. In some embodiments, the low-power communication in the present application is equivalent to / replaceable with zero-power communication, and the low-power IoT in the present application is equivalent to / replaceable with zero-power IoT.

[0060] The network device 120 is used to send wireless power supply signals, downlink communication signals and receive backscattered signals from the low-power device 140 to the low-power device 140. The low-power device 140 can also be called an ambient power enabled Internet of Things (Ambient IoT) device, which includes an energy collection module 141, a backscattered communication module 142 and a low-power computing module 143. The energy collection module 141 can collect energy carried by radio waves in space, which is used to drive the low-power computing module 143 of the low-power device 140 and realize backscattered communication. After obtaining energy, the low-power device 140 can receive control signaling from the network device 120 and send data to the network device 120 based on the backscattering method according to the control signaling. The sent data can come from data stored in the low-power device 140 itself (such as an identity or pre-written information, such as the production date, brand, manufacturer, etc. of the product).

[0061] Low-power device 140 may also include a sensor module 144 and a memory 145. Sensor module 144 may include various sensors, and low-power device 140 may report data collected by these sensors based on a low-power mechanism. Memory 145 is used to store basic information (such as item identification) or acquired sensor data such as ambient temperature and humidity.

[0062] The low-power device 140 itself does not require a battery, and at the same time, the low-power computing module 143 can perform simple signal demodulation, decoding or encoding, modulation and other simple calculation tasks. Therefore, the low-power device 140 only requires a very simple hardware design, making the low-power device 140 very low in cost and small in size.

[0063] The network device 120 includes but is not limited to: cellular network devices, such as 5G / 6G network devices, base station devices; WiFi / WLAN network devices, such as access points (APs), routers, mobile access points, etc., and the mobile access point is, for example, a mobile phone.

[0064] The low-power device 140 includes but is not limited to: handheld devices, wearable devices, vehicle-mounted devices and Internet of Things devices, etc. The low-power device 140 can be at least one of a mobile phone, a tablet computer, an e-book reader, a laptop computer, a desktop computer, a television, a game console, an augmented reality (AR) terminal, a virtual reality (VR) terminal and a mixed reality (MR) terminal, a wearable device, a handle, an electronic tag and a controller, etc.

[0065] Next, we will further introduce low-power communication:

[0066] Radio Frequency Power Harvesting

[0067] Figure 2 shows a schematic diagram of RF energy harvesting provided by an exemplary embodiment of the present application. RF energy harvesting is based on the principle of electromagnetic induction, using a radio frequency (RF) module to conduct electromagnetic induction and maintain a parallel relationship with a capacitor C and a load resistor R. L By connecting to the CMOS sensor, the energy from electromagnetic waves in space can be collected to generate the energy needed to drive low-power devices, such as demodulators, modulators, sensors, and memory readers. Therefore, low-power devices do not require traditional batteries.

[0068] Backscattering communication

[0069] Figure 3 shows a schematic diagram of a backscatter communication process provided by an exemplary embodiment of the present application. A low-power device 140 receives a wireless signal carrier 131 transmitted by a transmit (TX) module 121 of a network device 120 using an amplifier (AMP) 122, modulates the wireless signal carrier 131, loads the information to be transmitted using a logic processing module 147, and collects radio frequency energy using an energy harvesting module 141. The low-power device 140 uses an antenna 146 to radiate the modulated reflected signal 132. This information transmission process is called backscatter communication. The receive (RX) module 123 of the network device 120 uses a low-noise amplifier (LNA) 124 to receive the modulated reflected signal 132. Backscatter and load modulation functions are inseparable. Load modulation completes the modulation process by adjusting and controlling the circuit parameters of the oscillating circuit of the low-power device 140 according to the rhythm of the data stream, causing parameters such as the impedance of the electronic tag to change accordingly.

[0070] Load modulation technology mainly includes resistance load modulation and capacitance load modulation. FIG4 shows a schematic diagram of resistance load modulation provided by an exemplary embodiment of the present application. In resistance load modulation, the load resistor R L The third resistor R3 is connected in parallel, and the switch S based on the binary code control is turned on or off. The on and off of the third resistor R3 will cause the voltage on the circuit to change. The load resistor R L Maintaining a parallel connection relationship with the first capacitor C1, the load resistor R L Maintain a series connection relationship with the second resistor R2, and the second resistor R2 maintains a series connection relationship with the first inductor L1. The first inductor L1 is coupled to the second inductor L2, and the second inductor L2 maintains a series connection relationship with the second capacitor C2. Amplitude Shift Keying (ASK) modulation can be achieved, that is, the modulation and transmission of the signal is achieved by adjusting the amplitude of the backscattered signal of the low-power device. Similarly, in capacitive load modulation, the circuit resonant frequency can be changed by turning the capacitor on and off, and frequency shift keying (FSK) modulation can be achieved, that is, the modulation and transmission of the signal is achieved by adjusting the operating frequency of the backscattered signal of the low-power device.

[0071] Low-power devices use load modulation to modulate the incoming signal, thus achieving the backscatter communication process. Low-power devices have significant advantages: (1) They do not actively transmit signals, so they do not require complex RF links such as power amplifiers (PAs) and RF filters; (2) They do not need to actively generate high-frequency signals, so they do not require high-frequency crystal oscillators; (3) With backscatter communication, signal transmission does not consume the energy of the low-power device itself.

[0072] ·Extremely low power consumption active transmission technology.

[0073] Low-power devices can also use ultra-low-power active transmission technology. Unlike backscatter, when using ultra-low-power active transmission technology for data transmission, low-power devices use a relatively simple and low-power oscillator to generate the RF carrier, and then modulate the information to be transmitted onto the RF carrier. Based on current research, the power consumption of ultra-low-power active transmitters can be as low as hundreds of microwatts, thus achieving ultra-low-power data transmission.

[0074] Coding method for low-power communication.

[0075] FIG5 shows a schematic diagram of an encoding method provided by an exemplary embodiment of the present application. The data transmitted by the electronic tag can use different forms of codes to represent binary "1" and "0". The wireless radio frequency identification system usually uses one of the following encoding methods: Not Return to Zero (NRZ) encoding, Manchester encoding, Unipolar Return to Zero (URZ) encoding, Differential Binary Phase (DBP) encoding, Miller encoding and differential encoding. That is, different pulse signals can be used to represent 0 and 1.

[0076] (1) NRZ encoding: Non-return-to-zero encoding uses a high level to represent a binary "1" and a low level to represent a binary "0". Figure 5 shows a level diagram of encoding binary data: 101100101001011 using the NRZ method.

[0077] (2) Manchester coding: Manchester coding is also known as split-phase coding. In Manchester coding, the binary value is represented by the change in level (rising or falling) during half a bit period within the bit length. A negative jump during half a bit period represents a binary "1", and a positive jump during half a bit period represents a binary "0". The error in data transmission refers to the situation when the data bits sent by multiple electronic tags at the same time have different values. The received rising and falling edges cancel each other out, resulting in an uninterrupted carrier signal within the entire bit length. Manchester coding cannot have a state without change within the bit length. The reader can use this error to determine the specific location where the collision occurred. Manchester coding is conducive to detecting data transmission errors. When using carrier load modulation or backscatter modulation, it is usually used for data transmission from electronic tags to readers. Figure 5 shows a schematic diagram of the Manchester method to encode binary data: 101100101001011.

[0078] (3) URZ coding: The high level of unipolar return-to-zero coding in the first half bit period represents binary "1", while the low level signal that lasts throughout the entire bit period represents binary "1". Figure 5 shows the level diagram of URZ coding using the URZ method to encode binary data: 101100101001011.

[0079] (4) DBP encoding: Differential biphase encoding uses any edge within a half-bit period to represent a binary "0," while the absence of an edge represents a binary "1." Furthermore, the voltage level is inverted at the beginning of each bit period. This makes the bit beat easier to reconstruct for the receiver. Figure 5 shows a voltage level diagram of the binary data 101100101001011 encoded using the DBP method.

[0080] (5) Miller coding: In Miller coding, any edge within half a bit period represents a binary "1," while a constant level throughout the next bit period represents a binary "0." The level transition at the beginning of a bit period makes it easier for the receiver to reconstruct the bit beat. Figure 5 shows a schematic diagram of the levels of binary data 101100101001011 encoded using the Miller method.

[0081] (6) Differential coding: In differential coding, each binary "1" to be transmitted causes a change in the signal level, while for binary "0", the signal level remains unchanged.

[0082] Classification of low-power devices.

[0083] Low-power devices can be divided into the following types based on their energy sources and usage:

[0084] (1) Passive low-power devices.

[0085] Low-power devices do not require built-in batteries. When the low-power device approaches the network device, it is within the near field formed by the radiation of the network device's antenna. For example, the network device is a reader / writer of the Radio Frequency Identification (RFID) system. Therefore, the antenna of the low-power device generates an induced current through electromagnetic induction, and the induced current drives the low-power chip circuit of the low-power device. This realizes the demodulation of the forward link (downlink, the link from the network device to the low-power device) signal and the modulation of the backward link (uplink, the link from the low-power device to the network device) signal. For the backscatter link, the low-power device can use backscatter or extremely low-power active transmission to transmit signals.

[0086] Passive low-power devices require no internal batteries for either the forward or reverse link, making them truly low-power (zero-power) devices. They don't require batteries, and their RF and baseband circuits are very simple. For example, they don't require components like LNAs, PAs, crystal oscillators, or analog-to-digital converters (ADCs). These devices offer numerous advantages, including small size, light weight, very low price, and a long service life.

[0087] (2) Semi-passive low-power devices.

[0088] Semi-passive, low-power devices do not have conventional batteries installed. Instead, they use radio frequency energy harvesting modules to harvest radio wave energy, or energy harvesting modules corresponding to solar energy, light energy, thermal energy, kinetic energy, and other energies. The harvested energy is then stored in an energy storage unit, typically a capacitor. After the energy storage unit harvests energy, it drives the low-power chip circuits of the low-power device, performing tasks such as demodulating forward link signals and modulating backward link signals. For backscatter links, low-power devices can use backscatter or extremely low-power active transmission to transmit signals.

[0089] Semi-passive low-power devices require no internal battery for either forward or reverse link operation. Instead, the energy stored in capacitors is derived from radio energy harvested by RF energy harvesting modules, making them truly low-power (zero-power) devices. They inherit many of the advantages of passive low-power devices, including small size, light weight, very low price, and long service life.

[0090] (3) Active low-power devices.

[0091] Low-power devices used in some scenarios can also be active low-power devices. These devices may have built-in batteries (conventional batteries, such as dry cells or rechargeable lithium batteries, can be used). The batteries power the low-power chip circuitry within the low-power device, performing tasks such as demodulating forward link signals and modulating reverse link signals. For backscatter links, however, the low-power device can use backscatter or extremely low-power active transmission to transmit signals. Therefore, the low power consumption of active low-power devices is primarily due to the fact that reverse link signal transmission does not consume the low-power device's own power, but instead uses backscatter. Although active low-power devices use batteries, their ultra-low-power communication technology results in very low power consumption, significantly extending battery life. In active low-power devices, the built-in battery powers the RFID chip, increasing the tag's read and write range and improving communication reliability. Therefore, they are suitable for scenarios with relatively high requirements for communication range and read latency.

[0092] Classification of low-power devices based on transmitter type.

[0093] Low-power IoT services are similar to other IoT services, primarily focusing on uplink services. Low-power IoT devices can be categorized into the following types based on how they send data:

[0094] (1) Low-power devices based on backscattering.

[0095] These low-power devices use backscattering, as described above, for uplink data transmission. They lack active transmitters, only backscattering transmitters. Therefore, when these low-power devices transmit uplink data, they require network equipment to provide a carrier. These low-power devices use backscattering based on the carrier to achieve uplink data transmission.

[0096] (2) Low-power devices based on active transmitters.

[0097] These low-power devices use active transmitters with active transmission capabilities for uplink data transmission. Therefore, when sending uplink data, these low-power devices can use their own active transmitters to send uplink data without the need for network equipment to provide a carrier. Examples of active transmitters suitable for low-power devices include ultra-low-power ASK transmitters and ultra-low-power FSK transmitters. Based on current implementations, these transmitters can reduce overall power consumption to 400-600 microwatts when transmitting a 100-microwatt signal.

[0098] (3) Low-power devices that have both backscatter and active transmitters.

[0099] These low-power devices can support both backscatter and active transmitters. They can determine whether to use backscatter or active transmitters based on different circumstances (e.g., varying battery levels, available ambient energy), or based on network device scheduling.

[0100] Application scenarios of low-power communication.

[0101] Due to its significant advantages such as extremely low cost, low power consumption, and small size, low-power communication can be widely used in various industries, such as logistics for vertical industries, smart warehousing, smart agriculture, energy and electricity, industrial Internet, etc.; it can also be used in personal applications such as smart wearables and smart homes.

[0102] Cellular passive IoT.

[0103] The cellular Internet of Things (IoT) is booming. The 3rd Generation Partnership Project (3GPP) has standardized IoT technologies such as Narrowband-Internet of Things (NB-IoT), Machine-Type Communications (MTC), and Reduced Capability (RedCap). However, IoT communication needs in many scenarios remain unmet. For example:

[0104] Harsh communication environment.

[0105] Certain IoT scenarios may encounter extreme environments such as high temperature, extremely low temperature, high humidity, high voltage, high radiation, or high-speed movement. Examples include ultra-high voltage substations, high-speed train track monitoring, environmental monitoring in high-altitude cold regions, and industrial production lines. In these scenarios, existing IoT devices will not function due to the operating environment limitations of conventional power supplies. Furthermore, extreme operating environments are not conducive to IoT device maintenance, such as battery replacement.

[0106] Requirements for extremely small terminal form factors.

[0107] Certain IoT communication scenarios, such as food traceability, commodity distribution, and smart wearables, require terminals to be extremely small for ease of use. For example, IoT terminals used for commodity management in the distribution process often use electronic tags, which are embedded in the product packaging in a very compact form factor. Another example is lightweight wearable IoT terminals that can meet user needs while improving the user experience.

[0108] Extremely low-cost IoT communication needs.

[0109] Many IoT communication scenarios require IoT terminal devices to be sufficiently low-cost to enhance their competitiveness compared to alternative technologies. For example, in logistics or warehousing scenarios, IoT terminal devices can be attached to each item to facilitate the management of large quantities of circulating items. Communication between the IoT terminal device and the logistics network enables precise management of the entire logistics process and lifecycle. These scenarios require IoT terminal devices to be sufficiently competitively priced.

[0110] Therefore, in order to cover these unmet IoT communication needs, cellular IoT also needs to develop ultra-low-cost, extremely small-size, battery-free / maintenance-free IoT, and low-power IoT can just meet these needs.

[0111] The low-power Internet of Things (IoT), also known as the Ambient IoT (A-IoT) or the passive IoT, refers to devices that use various ambient energies, such as radio frequency energy, light, solar energy, thermal energy, and mechanical energy, to power themselves. These devices may have no energy storage capacity or very limited energy storage capacity (such as using capacitors with a capacity of tens of microfarads). Compared to other IoT devices, A-IoT devices offer many advantages, including the absence of conventional batteries, maintenance-free operation, compact size, low complexity, low cost, and a long lifespan.

[0112] Low-power IoT can be used in at least four scenarios:

[0113] (1) Object recognition, such as logistics, production line product management, and supply chain management;

[0114] (2) Environmental monitoring, such as temperature, humidity, and harmful gas monitoring of the working environment and natural environment;

[0115] (3) Positioning, such as indoor positioning, intelligent object search, and production line item positioning;

[0116] (4) Intelligent control, such as intelligent control of various electrical appliances in smart homes (turning on and off air conditioners, adjusting temperature), and intelligent control of various facilities in agricultural greenhouses (automatic irrigation and fertilization).

[0117] This section introduces the topology of low-power devices:

[0118] In some embodiments, low-power devices involve two topologies (deployment scenarios).

[0119] For example, FIG6 is a schematic diagram of a first topology structure provided by an exemplary embodiment of the present application. As shown in FIG6, the topology structure 1 can be represented as a base station (BS) 601. The low-power device 602 and the base station 601 directly perform two-way signaling and / or data communication with the low-power device 602. The base station 601 that sends information to the low-power device 602 and the base station 601 that receives information sent by the low-power device 602 may be two different base stations 601.

[0120] For example, FIG7 is a schematic diagram of a second topology structure provided by an exemplary embodiment of the present application. As shown in FIG7 , topology structure 2 can be represented as a base station 701 Intermediate node 702 Low-power device 703. Low-power device 703 performs bidirectional communication with intermediate node 702. Intermediate node 702 can relay signaling and / or data between base station 701 and low-power device 703. In some embodiments, intermediate node 702 is a terminal under network control and is located indoors.

[0121] Introduce the time-frequency synchronization process:

[0122] The communication system involving the wake-up receiver (WUR) adopts a simple multi-carrier on-off keying (MC-OOK) modulation method for data transmission. The MC-OOK symbol length corresponding to the data channel is 2us or 4us. Receiving such a signal requires low frequency accuracy for the terminal with WUR, and the terminal is usually equipped with a high-precision, high-energy main receiver (Main Radio, MR), which can be used to send uplink data and provide initial frequency information to the WUR. Therefore, the WUR does not have a special design for frequency calibration, and only introduces the WUR-Sync (synchronization) synchronization reference signal for the timing synchronization of the WUR.

[0123] WUR-Sync is used for time domain synchronization and indication of data transmission rate of terminals with WUR. The data transmission rate is divided into high data rate (HDR) and low data rate (LDR). The WUR-Sync corresponding to LDR is composed of two identical W sequences. The W sequence is 32 bits in length, and each bit corresponds to an MC-OOK symbol with a length of 2us. The WUR-Sync corresponding to HDR is based on the bitwise complement generation of the W sequence (each bit is opposite), which is also 32 bits in length, and each bit corresponds to a 2us MC-OOK symbol. According to the simulation results, the probability that the synchronization accuracy of WUR-Sync is within + / -250ns (one sampling point) is 90%, and the error accuracy is 0 in more than 70% of the cases. Such synchronization accuracy is sufficient for the subsequent reception of 2us MC-OOK symbols.

[0124] In the NR cellular system, when a terminal (such as a mobile phone) first accesses a network device (such as a base station), that is, during the initial access process of the terminal, time and frequency synchronization is performed through the primary synchronization signal (PSS) / secondary synchronization signal (SSS) of the synchronization signal block (SSB). A typical implementation method is that the terminal performs synchronization sequence correlation detection of the PSS in the time domain and obtains clock information (the starting position of the orthogonal frequency division multiplexing (OFDM) symbol) based on the position of the sequence correlation peak. In the process of time domain correlation based on the PSS, the approximate frequency deviation (frequency offset) can be estimated by blind search. This process can be called coarse frequency deviation estimation. The specific implementation method of coarse frequency offset estimation can be to preset some fixed frequency offset values ​​(called frequency bins, such as 0, + / -7.5kHz, + / -15kHz, etc.), compensate this frequency offset value to the local sequence of the terminal (or the received signal), and then perform correlation between the sequences (correlation analysis), and compare the size of the correlation peak under different frequency offset value assumptions. The larger the value, the closer the actual frequency offset value is to the preset frequency offset value used. The terminal can estimate the approximate frequency offset. After PSS detection, the terminal can determine the SSS signal and perform fine frequency offset estimation and calibration in the frequency domain. This keeps the frequency offset error within a smaller range and does not affect the subsequent data transmission and reception of the terminal.

[0125] Due to cost and power consumption constraints, low-power devices typically lack crystal oscillators or have very low precision, leading to frequency drift (offset). This can result in frequency deviation errors of 200 ppm or even higher. For example, the target frequency of a low-power device's RF component is 2.4 GHz, but the actual deviation may be within the range of [-480, +480] kHz. This large frequency deviation is very detrimental to low-power devices transmitting uplink data, especially low-power devices that use active transmission. This can cause strong interference between adjacent channels and between different low-power devices. Therefore, frequency synchronization and calibration of low-power devices are crucial.

[0126] However, low-power devices can usually only receive simple signals, such as signals modulated by On-Off Keying (OOK), Frequency Shift Keying (FSK), etc., and it is difficult to achieve In-phase Quadrature (IQ) demodulation. Therefore, the frequency offset estimation and calibration method based on complex operations in the above-mentioned cellular system is not suitable for low-power devices, and the above-mentioned system involving WUR does not involve a solution for frequency offset calibration.

[0127] The present application provides a frequency calibration (synchronization) method for a low-power device, in which the low-power device receives and detects the time domain positions of at least two reference signals, thereby determining a first time domain interval between any two reference signals of the at least two reference signals, and comparing the first time domain interval with a (fixed / indicated) second time domain interval known to the low-power device, so that the low-power device can estimate the frequency deviation and perform calibration.

[0128] 8 shows a schematic diagram of a system architecture of a communication system 800 provided in one embodiment of the present application. The system architecture may include: a terminal 10, an access network device 20, and a core network device 30.

[0129] The terminal 10 may refer to a UE (User Equipment), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a wireless communication device, a user agent, or a user apparatus. Alternatively, the terminal may also be a cellular phone, a cordless phone, a SIP (Session Initiation Protocol) phone, a WLL (Wireless Local Loop) station, a PDA (Personal Digital Assistant), a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal in a 5GS (5th Generation System) or a terminal in a future-evolved PLMN (Public Land Mobile Network), etc., and the embodiments of the present application are not limited thereto. For ease of description, the above-mentioned devices are collectively referred to as terminals. In some embodiments, a communication connection is established between the terminal 10 and a low-power device, thereby transmitting data and / or signaling with the low-power device.

[0130] It should be noted that there are usually multiple terminals 10. One or more terminals 10 can be distributed within each cell managed by the access network device 20. Furthermore, one or more terminals 10 can also be distributed outside the cell managed by the access network device 20. Different terminals 10 can communicate with each other based on sidelinks.

[0131] Access network equipment 20 is a device deployed in an access network to provide wireless communication capabilities for terminal 10. Access network equipment 20 may include various forms of macro base stations, micro base stations, relay stations, access points, and the like. In systems employing different wireless access technologies, the names of devices that provide access network equipment functions may vary. For example, in 5G NR systems, they are referred to as gNodeBs or gNBs. As communication technologies evolve, the term "access network equipment" may change. For ease of description, in the embodiments of this application, the aforementioned devices that provide wireless communication capabilities for terminal 10 are collectively referred to as access network equipment. Optionally, a communication relationship can be established between terminal 10 and core network equipment 30 through access network equipment 20. For example, in a Long Term Evolution (LTE) system, access network equipment 20 may be an Evolved Universal Terrestrial Radio Access Network (EUTRAN) or one or more eNodeBs in EUTRAN; in a 5G NR system, access network equipment 20 may be a RAN or one or more gNBs in the RAN.

[0132] The core network equipment 30 primarily provides user connectivity, user management, and service bearering, serving as a bearer network interface to external networks. For example, the core network equipment in a 5G NR system may include devices such as an AMF (Access and Mobility Management Function) entity, a UPF (User Plane Function) entity, and an SMF (Session Management Function) entity. The access network equipment 20 and the core network equipment 30 may be collectively referred to as network equipment.

[0133] In one example, the access network device 20 and the core network device 30 communicate with each other via an air technology, such as the NG interface in a 5G NR system. The access network device 20 and the terminal 10 communicate with each other via an air technology, such as the Uu interface. The terminals 10 communicate with each other via an air technology, such as the PC5 interface.

[0134] FIG9 is a flow chart of a frequency calibration method provided by an exemplary embodiment of the present application. The method can be performed by a low-power device. The method includes:

[0135] Step 902: Receive at least two reference signals.

[0136] In some embodiments, low-power devices include devices that use ambient energy, such as radio frequency energy, light energy, solar energy, thermal energy, mechanical energy, or other ambient energy for their operation. In some embodiments, low-power devices have no energy storage capability or have limited energy storage capability. In some embodiments, low-power devices are equivalent to or can be replaced by zero-power devices, zero-power IoT devices, Ambient-IoT (A-IoT) devices, or passive IoT devices.

[0137] In some embodiments, the reference signal in this application is equivalent to / can be replaced by a synchronization signal, a synchronization reference signal, or a reference synchronization signal. Receiving at least two reference signals is equivalent to / can be replaced by detecting at least two reference signals. At least two reference signals are equivalent to / can be replaced by multiple reference signals.

[0138] At least two reference signals received by a low-power device are used to determine a first time domain interval. The first time domain interval is a measured time domain interval between any two reference signals from the at least two reference signals. In some embodiments, the any two reference signals are any two adjacent reference signals from the at least two reference signals. In some embodiments, the any two reference signals are any two non-adjacent reference signals from the at least two reference signals. For example, the first time domain interval is a measured time domain interval between a first reference signal and a second reference signal from the at least two reference signals. The first reference signal is any reference signal from the at least two reference signals, and the second reference signal is any reference signal from the at least two reference signals that has a time domain position different from that of the first reference signal. The first reference signal and the second reference signal are adjacent (continuous) or non-adjacent in the time domain. In some embodiments, the low-power device detects the time domain position of the first reference signal and the time domain position of the second reference signal from the any two reference signals and calculates the difference between the two, thereby obtaining the measured time domain interval between the any two reference signals. In some embodiments, measuring the time domain interval is equivalent to or can be replaced by detecting the time domain interval or estimating the time domain interval.

[0139] The first time domain interval and the second time domain interval are used for frequency calibration. The second time domain interval is a reference time domain interval between any two reference signals known to the low-power device. In some embodiments, the second time domain interval known to the low-power device can be understood as the time domain interval when the low-power device sends the any two reference signals, the real time domain interval between the any two reference signals known to the low-power device, and the accurate time domain interval between the any two reference signals known to the low-power device. In some embodiments, the second time domain interval is a reference value, a standard value, or an ideal value of the time domain interval between the any two reference signals known to the low-power device. The reference time domain interval is equivalent to / can be replaced by a control time domain interval or an ideal time domain interval.

[0140] In some embodiments, the low-power device knows a third time domain interval between any adjacent reference signals of at least two reference signals, and the third time domain interval includes a configured time domain interval between adjacent reference signals of at least two reference signals. The second time domain interval between any two reference signals can be determined based on the third time domain interval, that is, the second time domain interval is determined based on the third time domain interval. In some embodiments, the configured time domain interval is equivalent to / replaceable with a fixed time domain interval, a predetermined time domain interval, a reference time domain interval, or a real time domain interval. In some embodiments, the first time domain interval and the second time domain interval are also used for clock calibration (time synchronization) of the low-power device.

[0141] It should be noted that the time domain intervals between reference signals involved in this application (first time domain interval, second time domain interval, third time domain interval) are determined based on any one of the starting position, ending position, or position between the starting position and the ending position of the reference signal in the time domain. The first time domain interval, the second time domain interval, and the third time domain interval are determined in the same manner.

[0142] In some embodiments, the reference signal is sent by a first device, where the first device includes at least one of the following:

[0143] Network equipment; intermediate node; access point (AP); a device that provides energy or carrier to low-power devices.

[0144] In some embodiments, the network device includes an access network device, such as the base station in the topology structure 1 shown in Figure 6. The intermediate node includes a node between the network device and the low-power device, and the intermediate node establishes a communication connection with the low-power device and the network device respectively. In some embodiments, the intermediate node is used to transfer signaling and / or data between the network device and the low-power device. In some embodiments, the intermediate node is a terminal, such as the terminal between the base station and the low-power device in the topology structure 2 shown in Figure 7. In some embodiments, the above-mentioned AP belongs to a WLAN system. In some embodiments, the energy or carrier provided to the low-power device is used for backscattering of the low-power device. The device that provides energy or carrier to the low-power device is different from the network device, the intermediate node and the AP, such as a device in a communication system other than a cellular system and a WLAN system, and the embodiments of the present application are not limited to this.

[0145] For reference signal generation and mapping:

[0146] In some embodiments, the at least two reference signals are identical or related reference signals. For example, the at least two reference signals are repetitions of the same reference signal. In some embodiments, the at least two reference signals are different or unrelated reference signals.

[0147] In some embodiments, at least two reference signals belong to the same candidate reference signal group. In some embodiments, at least two reference signals belong to different candidate reference signal groups. In some embodiments, the reference signals in the candidate reference signal group are generated using sequences. In some embodiments, the candidate reference signal group in this application is equivalent to / replaceable with a candidate reference signal sequence group, a candidate synchronization signal group, a candidate synchronization signal sequence group, a reference signal group, a synchronization signal group, a candidate synchronization reference signal group, or a candidate synchronization reference signal sequence group, and the aforementioned groups are equivalent to / replaceable with sets.

[0148] For example, the at least two reference signals include a first reference signal and a second reference signal, both of which are selected from the same candidate reference signal sequence group. Alternatively, the first reference signal is selected from candidate reference signal sequence group 1, and the second reference signal is selected from candidate reference signal sequence group 2. Different candidate reference signal sequence groups may be identical or different in one or more of sequence type, sequence length, and the number of sequences within a group. In some embodiments, the sequence type includes at least one of an m-sequence, a gold sequence, a ZC sequence, and a Walsh sequence. Using multiple sequences allows the reference signal to carry more information.

[0149] In some embodiments, the reference signal carries information via a sequence. In some embodiments, the information includes at least one of the following:

[0150] Physical Cell Identifier (PCI); AP Identity Document (ID); intermediate node identifier; data transmission rate; data transmission mode; reference signal timing information.

[0151] In some embodiments, the time information of the reference signal is used to reflect the time domain position of the reference signal (the time corresponding to the reference signal). For example, the time information of the reference signal is used to indicate the position of the reference signal in the time domain, or the time information of the reference signal is used to indicate the position of the reference signal in the time domain compared to other reference signals, such as the offset in the time domain or the order in the time domain. For example, the at least two reference signals include signal 1 and signal 2, and signal 1 indicates, through the information carried by the sequence, that the starting position of signal 1 is located at 0ms, 10ms, or 20ms in an 80ms period, and signal 2 indicates, through the information carried by the sequence, that the starting position of signal 2 is located at a position offset by 5ms, 15ms, or 25ms after the starting position of signal 1. In some embodiments, the time information of the reference signal is used to determine the time domain interval between the reference signal and the previous reference signal and / or the next reference signal in the at least two reference signals. In some embodiments, the above-mentioned identifier carried by the reference signal is related to the sender of the reference signal. For example, the reference signal sent by the network device carries the PCI, the reference signal sent by the AP carries the AP ID, and the reference signal sent by the intermediate node carries the identifier of the intermediate node. The data transmission rate indicates the rate at which data is transmitted to the low-power device. The data transmission mode indicates the method by which data is transmitted to the low-power device.

[0152] In some embodiments, the reference signal carries information through any one of an m-sequence, a gold sequence, a ZC sequence, and a Walsh sequence. The sequence corresponding to the reference signal can be considered as the reference signal being generated by the above sequence, or as the reference signal being obtained by generating the above sequence, or as the reference signal being the above sequence. In some embodiments, the reference signal is obtained by adjusting or transforming the above sequence. For example, the length of the m-sequence is usually 2 n-1 For example, n=3 corresponds to an m-sequence of length 7. By performing zero padding on the m-sequence, the length of the m-sequence can be changed to 8, thereby obtaining a reference signal. Alternatively, the generated sequence is Manchester encoded to obtain a reference signal. Alternatively, the order or position of certain bits in the generated sequence is adjusted to obtain a reference signal. In some embodiments, the protocol may stipulate sequences corresponding to multiple reference signals, and these sequences can form a candidate reference signal sequence group, and each candidate reference signal sequence in the candidate reference signal sequence group represents corresponding information. For example, referring to the NR PSS, an m-sequence of length 127 is used. The protocol specifies the generating polynomial [x(i+7)=(x(i+4)+x(i))mod 2] for generating the m-sequence and the initial value of the register. The random sequence is cyclically shifted by 0, 43, and 86, respectively, to generate three different sequences, representing the network identifiers (NIDs) of three different cells.

[0153] In some embodiments, the sequence corresponding to the reference signal is mapped on a time domain unit. In some embodiments, the time domain unit includes any one of a time domain symbol and an OFDM symbol. For example, the sequence corresponding to the reference signal is expressed as [1 0 1 0 0 1 1], and the generated sequence may be zero-padded or coded adjusted to obtain a sequence corresponding to the reference signal. In some embodiments, the reference signal adopts OOK modulation, and the sequence corresponding to the reference signal is directly mapped on the time domain symbol (time domain OOK symbol), rather than mapping the random sequence to multiple resource elements (RE) in the frequency domain like LTE or NR, and then performing an inverse fast Fourier transform (IFFT) for time domain mapping.

[0154] For the first reference signal generation situation:

[0155] In some embodiments, at least two reference signals correspond to the same sequence; or, at least two reference signals correspond to related sequences. For example, at least two reference signals correspond to repetitions of the same sequence, i.e., at least two reference signals transmitted by the same device are identical. In some embodiments, at least two reference signals correspond to related sequences, including when the low-power device detects the sequence corresponding to the first reference signal of the at least two reference signals, it can determine the sequence of the second reference signal of the at least two reference signals. In some embodiments, the first reference signal and the second reference signal are adjacent reference signals of the at least two reference signals.

[0156] For example, the first candidate reference signal sequence group is {seq-1, seq-2, …, seq-8}, and the second candidate reference signal sequence group is {seq-A, seq-B, …, seq-H}. Although the first candidate reference signal sequence group and the second candidate reference signal sequence group are different, the sequences in these two candidate reference signal sequence groups are paired. For example, if the first reference signal is seq-1, the second reference signal must be seq-A, or if the second reference signal is seq-H, the first reference signal must be seq-8.

[0157] By making the sequences corresponding to at least two reference signals identical or correlated, the complexity of reference signal detection for low-power devices can be reduced, improving detection reliability. For example, after detecting the first reference signal, a low-power device can determine the sequence corresponding to the second reference signal without having to perform blind detection again. When channel conditions are poor, repeated or correlated reference signals can improve detection performance for low-power devices.

[0158] For the generation of the second reference signal:

[0159] In some embodiments, at least two reference signals correspond to sequences of the same type. In this case, the at least two reference signals correspond to the same sequence or different sequences, depending on the information carried by the sequence. In some embodiments, the sequences corresponding to the at least two reference signals belong to the same candidate reference signal sequence group. In some embodiments, the sequences in the same candidate reference signal sequence group are generated using the same generator polynomial and initial value.

[0160] For example, the sequences corresponding to the first reference signal and the second reference signal in at least two reference signals belong to the same candidate reference signal sequence group. For example, the candidate reference signal sequence group includes 8 m-sequences generated according to the same generating polynomial and initial value, recorded as {seq-1, seq-2, …, seq-8}. The first reference signal and the second reference signal are both selected from these 8 sequences. The sequences corresponding to the first reference signal and the second reference signal may be the same or different, depending on the information carried by the reference signals.

[0161] By ensuring that the sequences corresponding to at least two reference signals are of the same type, compared to the first scenario described above, using a combination of reference signals of the same sequence type can achieve the goal of carrying more information through the reference signals while reducing the number of blind detections by the low-power device. Compared to the third scenario described below, using a combination of reference signals of the same sequence type can reduce the number of local sequences required to be stored by the low-power device, making it suitable for low-power devices with smaller storage. In some embodiments, the local sequence of the low-power device is used to detect the sequence corresponding to the reference signal based on correlation.

[0162] Regarding the generation of the third reference signal:

[0163] In some embodiments, at least two reference signals correspond to different sequences. In this case, the at least two reference signals transmitted by the same device are different. In some embodiments, the sequences corresponding to the at least two reference signals belong to different candidate reference signal sequence groups. In some embodiments, the different candidate reference signal sequence groups differ in at least one of the following aspects:

[0164] Sequence type; sequence length; sequence generation parameters.

[0165] For example, the sequence corresponding to the first reference signal of the at least two reference signals belongs to a first candidate reference signal sequence group, represented as {seq-1, seq-2, …, seq-8}, and the sequence corresponding to the second reference signal of the at least two reference signals belongs to a second candidate reference signal sequence group, represented as {seq-A, seq-B, …, seq-H}. The first candidate reference signal sequence group and the second candidate reference signal sequence group are different. For example, the intersection of the first candidate reference signal sequence group and the second candidate reference signal sequence group is an empty set. The first candidate reference signal sequence group and the second candidate reference signal sequence group satisfy at least one of the following conditions:

[0166] The first candidate reference signal sequence group and the second candidate reference signal sequence group have different sequence types. For example, one is an m-sequence sequence group and the other is a gold-sequence sequence group.

[0167] The sequence lengths of the sequences in the first candidate reference signal sequence group and the second candidate reference signal sequence group are different. For example, the sequence lengths in one sequence group are 32 bits, and the sequence lengths in the other sequence group are 64 bits.

[0168] The generation parameters used to generate the sequences in the first candidate reference signal sequence group are different from the generation parameters used to generate the sequences in the second candidate reference signal sequence group. For example, both the first candidate reference signal sequence group and the second candidate reference signal sequence group are m-sequences, and their corresponding sequences differ in at least one of their generating polynomials, initial values, and cyclic shifts. Alternatively, both the first candidate reference signal sequence group and the second candidate reference signal sequence group are ZC sequences, and their corresponding ZC sequences differ in at least one of their roots and physical sequence numbers.

[0169] By making the sequences corresponding to at least two reference signals different, the combination of different reference signals can carry more information while reducing the number of blind detections by the low-power device. For example, the first reference signal corresponds to N sequences and the second reference signal corresponds to M sequences. The number of blind detections by the low-power device is N+M, but the amount of information that the first reference signal and the second reference signal can carry is N*M (or log2(N*M) bits). In addition, because the candidate reference signal sequence groups corresponding to at least two reference signals are different, the low-power device can determine the time domain position of the reference signal based on the sequences corresponding to the reference signals. For example, the period of the first reference signal and the second reference signal is 320ms and the interval is 10ms. After the low-power device is started, if it only detects the sequence in the candidate reference signal sequence group corresponding to the second reference signal, then the low-power device can determine that it has missed the first reference signal of the current period. In this case, the low-power device needs to wait for the transmission of the first reference signal (after 310ms) and the transmission of the second reference signal (after 320ms) in the next period to perform frequency calibration.

[0170] For the time domain structure of the reference signal:

[0171] In some embodiments, at least two reference signals are reference signals within the same reference signal period. In some embodiments, the reference signals within the same reference signal period collectively constitute a reference signal within the reference signal period (which can be considered as one reference signal) or a reference signal cluster (burst). In some embodiments, the time domain intervals between adjacent reference signals within the same reference signal period are the same. In some embodiments, the time domain intervals between adjacent reference signals within the same reference signal period are different. For example, the at least two reference signals include a first reference signal and a second reference signal, the reference signal period is 10 ms, and the first reference signal and the second reference signal are located within the 10 ms period.

[0172] In some embodiments, the at least two reference signals are reference signals transmitted in different reference signal periods. For example, the reference signal period (without distinguishing which reference signal's time domain resource) is 10 ms, and the at least two reference signals are transmitted alternately on this resource. For example, the first reference signal is transmitted in the first period, and the second reference signal is transmitted in the second period. In this case, the transmission period of each reference signal is 20 ms.

[0173] Determination of the second time domain interval:

[0174] In some embodiments, the third time domain interval is determined using at least one of the following methods. The third time domain interval includes a configured time domain interval between adjacent reference signals among at least two reference signals, where the configured time domain interval is a time domain interval known to the low-power device. In some embodiments, the low-power device knows the third time domain interval of any two adjacent reference signals among the at least two reference signals. The third time domain interval is used to determine the second time domain interval. If any two reference signals are adjacent, the low-power device directly determines the third time domain interval of the any two reference signals as the second time domain interval of the any two reference signals. If any two reference signals are adjacent among the at least two reference signals received by the low-power device, the configured time domain interval can be considered the reference time domain interval, and the third time domain interval can be considered the second time domain interval. In this case, the third time domain interval is equivalent to the second time domain interval. If any two reference signals are not adjacent, the low-power device determines the second time domain interval of the any two reference signals based on the third time domain interval corresponding to the any two reference signals and the reference signal between the any two reference signals. For example, a low-power device receives four reference signals, namely signal 1, signal 2, signal 3, and signal 4, and the time domain interval between any two reference signals is known to the low-power device. The low-power device can then select any two signals from signals 1-4, for example, signal 1 and signal 3, to determine the first time domain interval, and determine the second time domain interval between signals 1 and 3 based on the sum of the third time domain interval between signals 1 and 2 and the third time domain interval between signals 2 and 3.

[0175] The third time domain interval is predefined by the protocol; the third time domain interval is indicated by the power supply signal of the low-power device; the third time domain interval is indicated by the reference signal and / or the data packet associated with the reference signal.

[0176] Regarding the first determination of the third time domain interval:

[0177] In some embodiments, the third time domain interval is predefined by the protocol. For example, the protocol stipulates a fixed or default reference signal interval (third time domain interval), which can be denoted as X. The transmitter of the reference signal needs to send the reference signal according to the interval agreed upon by the protocol. The low-power device also uses this agreed X value for relevant calculations to perform frequency calibration. In some embodiments, the protocol stipulates a unified third time domain interval for the entire frequency band. In some embodiments, the protocol stipulates a third time domain interval for at least one of each frequency band, band, or carrier.

[0178] Regarding the determination of the second third time domain interval:

[0179] In some embodiments, the third time domain interval is indicated by a power supply signal of a low-power device. The device that sends the power supply signal to the low-power device is the same as or different from the device that sends the reference signal to the low-power device. In some embodiments, the low-power device is charged by receiving the power supply signal, and when the energy accumulation meets the conditions, the low-power device monitors the reference signal, as well as other control information and / or data information. In some embodiments, the value of the third time domain interval is indicated by the physical characteristics of the power supply signal, such as the waveform and frequency of the power supply signal. Alternatively, one of multiple candidate values ​​is indicated as the third time domain interval by the physical characteristics of the power supply signal. In some embodiments, the multiple candidate values ​​are predefined by the protocol.

[0180] In some embodiments, the energy supply signal and the reference signal have the same sender, for example, both are sent by a network device or an intermediate node in the topology shown in Figures 6 and 7, or by a device other than a network device and an intermediate node. In some embodiments, the energy supply signal and the reference signal have different senders. In this case, a connection is established between the sender of the energy supply signal and the sender of the reference signal via a wired or wireless (e.g., cellular communication) method, and relevant information is exchanged.

[0181] Regarding the determination of the third time domain interval:

[0182] In some embodiments, the third time domain interval is indicated by a reference signal and / or a data packet associated with the reference signal. The data packet associated with the reference signal includes a data packet sent to the low-power device in the same transmission direction as the reference signal. In some embodiments, each reference signal is associated with a data packet. In some embodiments, multiple reference signals are associated with a data packet. For example, each reference signal in the same reference signal period is associated with a data packet. In some embodiments, the data packet includes at least one of a Master Information Block (MIB) and a System Information Block (SIB).

[0183] In some embodiments, the reference signal and / or data packet carries a third time domain interval. In some embodiments, the reference signal and / or data packet carries the time corresponding to the reference signal, and the third time domain interval is determined based on the difference in time corresponding to adjacent reference signals in at least two reference signals. For example, the value X of the third time domain interval is directly indicated by the reference signal and / or data packet. Alternatively, the time Ti corresponding to the reference signal is indicated by the reference signal and / or data packet, and the time corresponding to two adjacent reference signals is subtracted to obtain the value of the third time domain interval X, for example, X=T2-T1. In some embodiments, the time corresponding to the reference signal includes at least one of the time domain starting position of the reference signal, the time domain ending position of the reference signal, and the position between the time domain starting position and the time domain ending position of the reference signal.

[0184] In some embodiments, the reference signal and / or data packet carries a first value, the first value being used to indicate a third time domain interval among multiple candidate time domain intervals. In some embodiments, the multiple candidate time domain intervals are predefined by a protocol. In some embodiments, the reference signal and / or data packet carries a second value, the second value being used to indicate a time corresponding to the reference signal among multiple candidate times, and the third time domain interval is determined based on a difference between times corresponding to adjacent reference signals among at least two reference signals. In some embodiments, the multiple candidate times are predefined by a protocol.

[0185] In some embodiments, the value of the third time domain interval is carried by a sequence corresponding to the reference signal, for example, the first value is carried by the sequence corresponding to the reference signal. In some embodiments, the value of the time corresponding to the reference signal is carried by a sequence corresponding to the reference signal, for example, the second value is carried by the sequence corresponding to the reference signal.

[0186] It should be noted that, for the case where the reference signal and / or data packet carries the time corresponding to the reference signal, and the reference signal and / or data packet carries a second value, the low-power device can directly determine the second time domain interval based on the difference between the times corresponding to any two of the above reference signals. Alternatively, the low-power device first determines the third time domain interval of adjacent reference signals in at least two reference signals based on the time corresponding to each reference signal in the at least two received reference signals, and then determines the second time domain interval based on the third time domain interval. This embodiment of the present application is not limited to this.

[0187] For example, considering that the amount of information carried by the sequence is usually small, multiple candidate values ​​of the third time domain interval X or the time Ti corresponding to the reference signal can be determined by protocol agreement, such as X = {10, 15, 20, 25} ms, and then the sequences corresponding to different reference signals are used to indicate the value of X or Ti, so that the low-power device can determine the third time domain interval, that is, the third time domain interval is implicitly indicated by the {sequence-value} mapping method.

[0188] In some embodiments, the value of the third time domain interval is carried by a data packet associated with the reference signal, for example, the data packet carries the first value. In some embodiments, the value of the time corresponding to the reference signal is carried by a data packet associated with the reference signal, for example, the data packet carries the second value.

[0189] For example, multiple reference signals within the same reference signal period are each associated with a data packet, and each data packet carries the time (timestamp) Ti corresponding to its corresponding reference signal, or carries the time domain interval X or -X between adjacent reference signals within the reference signal period, or carries the time domain distance between its corresponding reference signal and the next reference signal. Alternatively, all reference signals within the same reference signal period are associated with the same data packet, which carries the time domain interval X between adjacent reference signals within the reference signal period. In addition, if the data packet can carry more information, the above-mentioned X or the above-mentioned Ti can be directly carried in the data packet through explicit signaling. If the data packet is only allowed to carry less information, multiple candidate values ​​of X or Ti can be determined by protocol agreement, such as X = {10, 15, 20, 25} ms, and then the value of X or Ti is indicated by the information carried by the data packet. For example, the above-mentioned 4 values ​​of X correspond to two bits of information {00, 01, 10, 11} respectively.

[0190] Frequency calibration process:

[0191] In some embodiments, the low-power device can calculate the deviation between the local clock of the low-power device and the ideal clock based on the first time domain interval of the detected reference signal and the known second time domain interval, thereby calibrating the local clock of the low-power device and further calibrating the frequency of the low-power device. For example, Figure 10 is a schematic diagram of the first time domain interval and the second time domain interval provided by an exemplary embodiment of the present application. Taking at least two reference signals including the first reference signal and the second reference signal as an example, the frequency calibration process of the low-power device is introduced in conjunction with Figure 10:

[0192] Assume that the network devices or intermediate nodes in the topology shown in Figures 6 and 7 periodically send a first reference signal (signal 1) and a second reference signal (signal 2), and the third time domain interval (which can be regarded as the second time domain interval in this case) of the two signals is 10ms and is known. It should be noted that the second time domain interval shown in Figure 10 refers to the time domain interval of the starting points of the two signals, and can also be replaced by the time domain interval of the end points of the two signals, or the time domain interval of the midpoints of the two signals, or the interval from the end point of the previous signal to the starting point of the next signal. The embodiments of the present application do not limit this. However, no matter which interval definition method is used, the low-power device also needs to use or convert to the same interval definition method to determine the first time domain interval between the first reference signal and the second reference signal when calibrating the timing error.

[0193] The low-power device performs correlation detection / analysis on the received first reference signal and the received second reference signal based on locally generated signals 1 and 2. Ideally, when the locally generated signal 1 is fully aligned with the received first reference signal, and the locally generated signal 2 is fully aligned with the received second reference signal, a correlation peak will appear between the signals, as shown by the arrows in Figure 10(b). Figure 10 shows the correlation peak at the starting point of the signal, but after obtaining the starting point and signal length of the signal, other time domain positions of the signal, such as the end point and midpoint, can be inferred.

[0194] When performing signal correlation detection, the low-power device estimates the time domain interval between the peaks of the two detected signals (the first reference signal and the second reference signal) based on its own local counter or timer, and then compares it with the known ideal time domain interval (the second time domain interval). This allows the low-power device to determine its time-frequency error and perform calibration. For example, as shown in Figure 10, the ideal time domain interval X = 10ms, and the time domain interval (the first time domain interval) X' estimated by the low-power device based on the local oscillator is 10.1ms. The difference between the two is Δx = X-X' = -0.1ms. By comparing this difference with the ideal time domain interval, the frequency error of the low-power device can be determined as Δf = -1 / 100 = -1%. A positive Δf indicates that the frequency of the low-power device needs to be increased, while a negative ratio indicates that the frequency of the low-power device needs to be decreased.

[0195] The time domain interval X' estimated by the low-power device is related to the pulse generated by the oscillator of the low-power device itself.

[0196] For example, the low-power device has a frequency of f = 0.1 MHz and a pulse interval of T = 1 / f = 0.01 ms. By counting the number of pulses between two correlation peaks, N = 1010, we can determine X' = 1010 * 0.01 = 10.1 ms. Based on the above method, we can determine Δf = -1 / 100 = -1%, so the low-power device frequency should be reduced by 1% * 0.1M = 0.001 MHz. Since the ideal time domain interval X = 10 ms is known, we can calculate the actual pulse interval of the low-power device, T = 10 ms / 1010 = 9.9 us, which translates to a frequency of 0.10101 MHz. If reduced by 1%, the low-power device frequency is approximately 0.10101 - 0.10 * 0.01 = 0.1 MHz.

[0197] For example, if the low-power device has a frequency of f = 200 MHz and a pulse interval of T = 1 / f = 5 ns, and the number of pulses between two correlation peaks is counted (N = 2020000), we can determine X' = 2020000 * 5 ns = 10.1 ms. Based on the above method, we can determine Δf = -1 / 100 = -1%, so the low-power device frequency should be reduced by 1% * 200M = 2 MHz. Since the ideal time domain interval X = 10 ms is known, we can calculate the actual pulse interval of the low-power device to be T = 10 ms / 202000 = 4.9505 ns, which translates to a frequency of 202 MHz. If the frequency is reduced by 1%, the low-power device frequency is approximately 202 - 200 * 0.1 = 200 MHz.

[0198] To summarize, the method provided in this embodiment receives at least two reference signals through a low-power device, thereby determining the first time domain interval between any two reference signals of the at least two reference signals, and comparing the first time domain interval with the second time domain interval known to the low-power device, so that the low-power device can estimate the frequency deviation and perform calibration, providing an implementation method for frequency calibration of a low-power device.

[0199] The method provided in this embodiment also reduces the complexity of reference signal detection by low-power devices and improves detection reliability by ensuring that the sequences corresponding to at least two reference signals are identical or correlated. When channel conditions are poor, repeated or correlated reference signals can improve detection performance for low-power devices. By ensuring that the sequences corresponding to at least two reference signals are of the same type, more information can be carried by the reference signals while minimizing the number of blind detections by low-power devices. Combining reference signals of the same sequence type requires fewer local sequences to be stored by low-power devices, making it suitable for low-power devices with smaller storage requirements. By ensuring that the sequences corresponding to at least two reference signals are different, the combination of different reference signals can carry more information while minimizing the number of blind detections by low-power devices. Furthermore, since the candidate reference signal sequence groups corresponding to at least two reference signals are different, the low-power device can determine the time domain location of the reference signal based on the sequences corresponding to the reference signals. By carrying information through the reference signal sequences, information can be transmitted to the low-power device via the reference signals. By directly mapping the sequences corresponding to the reference signals onto time domain units, the complexity of the time domain mapping of the reference signals can be reduced. By transmitting the reference signals according to the reference signal period, the time domain scheduling of the reference signals is clarified. Indicating the third time domain interval in a protocol-predefined manner can reduce the implementation cost of indicating the third time domain interval. Indicating the third time domain interval in a power supply signal provides a method for reusing existing signals to indicate the third time domain interval. Indicating the third time domain interval in multiple ways using reference signals and / or data packets provides a flexible method for indicating the third time domain interval, enabling indication of the third time domain interval based on resource constraints of reference signals and / or data packets.

[0200] FIG11 is a flow chart of a frequency calibration method provided by an exemplary embodiment of the present application. The method may be executed by a first device. The method includes:

[0201] Step 1102: Send at least two reference signals to the low-power device.

[0202] In some embodiments, low-power devices include devices that use ambient energy, such as radio frequency energy, light energy, solar energy, thermal energy, mechanical energy, or other ambient energy for their operation. In some embodiments, low-power devices have no energy storage capability or have limited energy storage capability. In some embodiments, low-power devices are equivalent to or can be replaced by zero-power devices, zero-power IoT devices, ambient-energy IoT (A-IoT) devices, or passive IoT devices.

[0203] In some embodiments, the reference signal in this application is equivalent to / can be replaced by a synchronization signal, a synchronization reference signal, or a reference synchronization signal. Receiving at least two reference signals is equivalent to / can be replaced by detecting at least two reference signals. At least two reference signals are equivalent to / can be replaced by multiple reference signals.

[0204] At least two reference signals received by a low-power device are used to determine a first time domain interval. The first time domain interval is a measured time domain interval between any two reference signals from the at least two reference signals. In some embodiments, the any two reference signals are any two adjacent reference signals from the at least two reference signals. In some embodiments, the any two reference signals are any two non-adjacent reference signals from the at least two reference signals. For example, the first time domain interval is a measured time domain interval between a first reference signal and a second reference signal from the at least two reference signals. The first reference signal is any reference signal from the at least two reference signals, and the second reference signal is any reference signal from the at least two reference signals that has a time domain position different from that of the first reference signal. The first reference signal and the second reference signal are adjacent (continuous) or non-adjacent in the time domain. In some embodiments, the low-power device detects the time domain position of the first reference signal and the time domain position of the second reference signal from the any two reference signals and calculates the difference between the two, thereby obtaining the measured time domain interval between the any two reference signals. In some embodiments, measuring the time domain interval is equivalent to or can be replaced by detecting the time domain interval or estimating the time domain interval.

[0205] The first time domain interval and the second time domain interval are used for frequency calibration. The second time domain interval is a reference time domain interval between any two reference signals known to the low-power device. In some embodiments, the second time domain interval known to the low-power device can be understood as the time domain interval when the low-power device sends the any two reference signals, the real time domain interval between the any two reference signals known to the low-power device, and the accurate time domain interval between the any two reference signals known to the low-power device. In some embodiments, the second time domain interval is a reference value, a standard value, or an ideal value of the time domain interval between the any two reference signals known to the low-power device. The reference time domain interval is equivalent to / can be replaced by a control time domain interval or an ideal time domain interval.

[0206] In some embodiments, the low-power device knows a third time domain interval between any adjacent reference signals of at least two reference signals, and the third time domain interval includes a configured time domain interval between adjacent reference signals of at least two reference signals. The second time domain interval between any two reference signals can be determined based on the third time domain interval, that is, the second time domain interval is determined based on the third time domain interval. In some embodiments, the configured time domain interval is equivalent to / replaceable with a fixed time domain interval, a predetermined time domain interval, a reference time domain interval, or a real time domain interval. In some embodiments, the first time domain interval and the second time domain interval are also used for clock calibration (time synchronization) of the low-power device.

[0207] In some embodiments, the first device includes at least one of the following:

[0208] Network equipment; intermediate node; AP; a device that provides energy or carrier to low-power devices.

[0209] In some embodiments, the network device includes an access network device, such as the base station in the topology structure 1 shown in Figure 6. The intermediate node includes a node between the network device and the low-power device, and the intermediate node establishes a communication connection with the low-power device and the network device respectively. In some embodiments, the intermediate node is used to transfer signaling and / or data between the network device and the low-power device. In some embodiments, the intermediate node is a terminal, such as the terminal between the base station and the low-power device in the topology structure 2 shown in Figure 7. In some embodiments, the above-mentioned AP belongs to a WLAN system. In some embodiments, the energy or carrier provided to the low-power device is used for backscattering of the low-power device. The device that provides energy or carrier to the low-power device is different from the network device, the intermediate node and the AP, such as a device in a communication system other than a cellular system and a WLAN system, and the embodiments of the present application are not limited to this.

[0210] For reference signal generation and mapping:

[0211] In some embodiments, the at least two reference signals are identical or related reference signals. For example, the at least two reference signals are repetitions of the same reference signal. In some embodiments, the at least two reference signals are different or unrelated reference signals.

[0212] In some embodiments, at least two reference signals belong to the same candidate reference signal group. In some embodiments, at least two reference signals belong to different candidate reference signal groups. In some embodiments, the reference signals in the candidate reference signal group are generated using sequences. In some embodiments, the candidate reference signal group in this application is equivalent to / replaceable with a candidate reference signal sequence group, a candidate synchronization signal group, a candidate synchronization signal sequence group, a reference signal group, a synchronization signal group, a candidate synchronization reference signal group, or a candidate synchronization reference signal sequence group, and the aforementioned groups are equivalent to / replaceable with sets.

[0213] In some embodiments, the reference signal carries information via a sequence. In some embodiments, the information includes at least one of the following:

[0214] PCI; AP ID; intermediate node identification; data transmission rate; data transmission method; reference signal timing information.

[0215] In some embodiments, the time information of the reference signal is used to reflect the time domain position of the reference signal (the time corresponding to the reference signal). In some embodiments, the above-mentioned identifier carried by the reference signal is related to the sender of the reference signal. For example, the reference signal sent by the network device carries the PCI, the reference signal sent by the AP carries the AP ID, and the reference signal sent by the intermediate node carries the identifier of the intermediate node. The data transmission rate is used to indicate the rate of data transmission with the low-power device. The data transmission mode is used to indicate the method of data transmission with the low-power device.

[0216] In some embodiments, the reference signal carries information using any one of an m-sequence, a gold sequence, a ZC sequence, and a Walsh sequence. The sequence corresponding to the reference signal can be considered to be generated by the above sequence, or to be obtained by generating the above sequence, or to be the above sequence. In some embodiments, the reference signal is obtained by adjusting or transforming the above sequence. In some embodiments, the protocol may specify sequences corresponding to multiple reference signals. These sequences can form a candidate reference signal sequence group, and each candidate reference signal sequence in the candidate reference signal sequence group represents corresponding information.

[0217] In some embodiments, the sequence corresponding to the reference signal is mapped onto a time domain unit. In some embodiments, the time domain unit includes any one of a time domain symbol and an OFDM symbol. In some embodiments, the reference signal is OOK modulated, and the sequence corresponding to the reference signal is directly mapped onto the time domain symbol (time domain OOK symbol).

[0218] For the first reference signal generation situation:

[0219] In some embodiments, at least two reference signals correspond to the same sequence; or, at least two reference signals correspond to related sequences. For example, at least two reference signals correspond to repetitions of the same sequence, i.e., at least two reference signals transmitted by the same device are identical. In some embodiments, at least two reference signals correspond to related sequences, including when the low-power device detects the sequence corresponding to the first reference signal of the at least two reference signals, it can determine the sequence of the second reference signal of the at least two reference signals. In some embodiments, the first reference signal and the second reference signal are adjacent reference signals of the at least two reference signals.

[0220] For the generation of the second reference signal:

[0221] In some embodiments, at least two reference signals correspond to sequences of the same type. In this case, the at least two reference signals correspond to the same sequence or different sequences, depending on the information carried by the sequence. In some embodiments, the sequences corresponding to the at least two reference signals belong to the same candidate reference signal sequence group. In some embodiments, the sequences in the same candidate reference signal sequence group are generated using the same generator polynomial and initial value.

[0222] Regarding the generation of the third reference signal:

[0223] In some embodiments, at least two reference signals correspond to different sequences. In this case, the at least two reference signals transmitted by the same device are different. In some embodiments, the sequences corresponding to the at least two reference signals belong to different candidate reference signal sequence groups. In some embodiments, the different candidate reference signal sequence groups differ in at least one of the following aspects:

[0224] Sequence type; sequence length; sequence generation parameters.

[0225] For the time domain structure of the reference signal:

[0226] In some embodiments, at least two reference signals are reference signals within the same reference signal period. In some embodiments, the reference signals within the same reference signal period collectively constitute a reference signal within the reference signal period (which can be considered as one reference signal) or a reference signal cluster (burst). In some embodiments, the time domain intervals between adjacent reference signals within the same reference signal period are the same. In some embodiments, the time domain intervals between adjacent reference signals within the same reference signal period are different. For example, the at least two reference signals include a first reference signal and a second reference signal, the reference signal period is 10 ms, and the first reference signal and the second reference signal are located within the 10 ms period.

[0227] In some embodiments, the at least two reference signals are reference signals transmitted in different reference signal periods. For example, the reference signal period (without distinguishing which reference signal's time domain resource) is 10 ms, and the at least two reference signals are transmitted alternately on this resource. For example, the first reference signal is transmitted in the first period, and the second reference signal is transmitted in the second period. In this case, the transmission period of each reference signal is 20 ms.

[0228] Determination of the second time domain interval:

[0229] In some embodiments, the third time domain interval is determined using at least one of the following methods. The third time domain interval includes a configured time domain interval between adjacent reference signals among at least two reference signals, where the configured time domain interval is a time domain interval known to the low-power device. In some embodiments, the low-power device knows the third time domain interval of any two adjacent reference signals among the at least two reference signals. The third time domain interval is used to determine the second time domain interval. If any two reference signals are adjacent, the low-power device directly determines the third time domain interval of the any two reference signals as the second time domain interval of the any two reference signals. If any two reference signals are adjacent among the at least two reference signals received by the low-power device, the configured time domain interval can be considered the reference time domain interval, and the third time domain interval can be considered the second time domain interval. In this case, the third time domain interval is equivalent to the second time domain interval. If any two reference signals are not adjacent, the low-power device determines the second time domain interval of the any two reference signals based on the third time domain interval corresponding to the any two reference signals and the reference signal between the any two reference signals.

[0230] The third time domain interval is predefined by the protocol; the third time domain interval is indicated by the power supply signal of the low-power device; the third time domain interval is indicated by the reference signal and / or the data packet associated with the reference signal.

[0231] Regarding the first determination of the third time domain interval:

[0232] In some embodiments, the third time domain interval is predefined by the protocol. For example, the protocol stipulates a fixed or default reference signal interval (third time domain interval), which can be denoted as X. The transmitter of the reference signal needs to send the reference signal according to the interval agreed upon by the protocol. The low-power device also uses this agreed X value for relevant calculations to perform frequency calibration. In some embodiments, the protocol stipulates a unified third time domain interval for the entire frequency band. In some embodiments, the protocol stipulates a third time domain interval for at least one of each frequency band, band, or carrier.

[0233] Regarding the determination of the second third time domain interval:

[0234] In some embodiments, the third time domain interval is indicated by a power supply signal of a low-power device. The device that sends the power supply signal to the low-power device is the same as or different from the device that sends the reference signal to the low-power device. In some embodiments, the low-power device is charged by receiving the power supply signal, and when the energy accumulation meets the conditions, the low-power device monitors the reference signal, as well as other control information and / or data information. In some embodiments, the value of the third time domain interval is indicated by the physical characteristics of the power supply signal, such as the waveform and frequency of the power supply signal. Alternatively, one of multiple candidate values ​​is indicated as the third time domain interval by the physical characteristics of the power supply signal. In some embodiments, the multiple candidate values ​​are predefined by the protocol.

[0235] In some embodiments, the energy supply signal and the reference signal have the same sender, for example, both are sent by a network device or an intermediate node in the topology shown in Figures 6 and 7, or by a device other than a network device and an intermediate node. In some embodiments, the energy supply signal and the reference signal have different senders. In this case, a connection is established between the sender of the energy supply signal and the sender of the reference signal via a wired or wireless (e.g., cellular communication) method, and relevant information is exchanged.

[0236] Regarding the determination of the third time domain interval:

[0237] In some embodiments, the third time domain interval is indicated by a reference signal and / or a data packet associated with the reference signal. Data packets associated with reference signals include data packets sent to the low-power device from the same transmission direction as the reference signal. In some embodiments, each reference signal is associated with a data packet. In some embodiments, multiple reference signals are associated with a data packet. For example, each reference signal in the same reference signal period is associated with a data packet. In some embodiments, the data packet includes at least one of a MIB and a SIB.

[0238] In some embodiments, the reference signal and / or data packet carries a third time domain interval. In some embodiments, the reference signal and / or data packet carries the time corresponding to the reference signal, and the third time domain interval is determined based on the difference in time corresponding to adjacent reference signals in at least two reference signals. For example, the value X of the third time domain interval is directly indicated by the reference signal and / or data packet. Alternatively, the time Ti corresponding to the reference signal is indicated by the reference signal and / or data packet, and the time corresponding to two adjacent reference signals is subtracted to obtain the value of the third time domain interval X, for example, X=T2-T1. In some embodiments, the time corresponding to the reference signal includes at least one of the time domain starting position of the reference signal, the time domain ending position of the reference signal, and the position between the time domain starting position and the time domain ending position of the reference signal.

[0239] In some embodiments, the reference signal and / or data packet carries a first value, the first value being used to indicate a third time domain interval among multiple candidate time domain intervals. In some embodiments, the multiple candidate time domain intervals are predefined by a protocol. In some embodiments, the reference signal and / or data packet carries a second value, the second value being used to indicate a time corresponding to the reference signal among multiple candidate times, and the third time domain interval is determined based on a difference between times corresponding to adjacent reference signals among at least two reference signals. In some embodiments, the multiple candidate times are predefined by a protocol.

[0240] In some embodiments, the value of the third time domain interval is carried by a sequence corresponding to the reference signal, for example, the first value is carried by the sequence corresponding to the reference signal. In some embodiments, the value of the time corresponding to the reference signal is carried by a sequence corresponding to the reference signal, for example, the second value is carried by the sequence corresponding to the reference signal.

[0241] It should be noted that, for the case where the reference signal and / or data packet carries the time corresponding to the reference signal, and the reference signal and / or data packet carries a second value, the low-power device can directly determine the second time domain interval based on the difference between the times corresponding to any two of the above reference signals. Alternatively, the low-power device first determines the third time domain interval of adjacent reference signals in at least two reference signals based on the time corresponding to each reference signal in the at least two received reference signals, and then determines the second time domain interval based on the third time domain interval. This embodiment of the present application is not limited to this.

[0242] In some embodiments, the value of the third time domain interval is carried by a data packet associated with the reference signal, for example, the data packet carries the first value. In some embodiments, the value of the time corresponding to the reference signal is carried by a data packet associated with the reference signal, for example, the data packet carries the second value.

[0243] To summarize, the method provided in this embodiment sends at least two reference signals to a low-power device, so that the low-power device can determine a first time domain interval between any two reference signals of the at least two reference signals, and compares the first time domain interval with a second time domain interval known to the low-power device, so that the low-power device can estimate the frequency deviation and perform calibration, thereby providing an implementation method for frequency calibration of a low-power device.

[0244] The method provided in this embodiment also reduces the complexity of reference signal detection by low-power devices and improves detection reliability by ensuring that the sequences corresponding to at least two reference signals are identical or correlated. When channel conditions are poor, repeated or correlated reference signals can improve detection performance for low-power devices. By ensuring that the sequences corresponding to at least two reference signals are of the same type, more information can be carried by the reference signals while minimizing the number of blind detections by low-power devices. Combining reference signals of the same sequence type requires fewer local sequences to be stored by low-power devices, making it suitable for low-power devices with smaller storage requirements. By ensuring that the sequences corresponding to at least two reference signals are different, the combination of different reference signals can carry more information while minimizing the number of blind detections by low-power devices. Furthermore, since the candidate reference signal sequence groups corresponding to at least two reference signals are different, the low-power device can determine the time domain location of the reference signal based on the sequences corresponding to the reference signals. By carrying information through the reference signal sequences, information can be transmitted to the low-power device via the reference signals. By directly mapping the sequences corresponding to the reference signals onto time domain units, the complexity of the time domain mapping of the reference signals can be reduced. By transmitting the reference signals according to the reference signal period, the time domain scheduling of the reference signals is clarified. Indicating the third time domain interval in a protocol-predefined manner can reduce the implementation cost of indicating the third time domain interval. Indicating the third time domain interval in a power supply signal provides a method for reusing existing signals to indicate the third time domain interval. Indicating the third time domain interval in multiple ways using reference signals and / or data packets provides a flexible method for indicating the third time domain interval, enabling indication of the third time domain interval based on resource constraints of reference signals and / or data packets.

[0245] This application receives and detects the time domain positions of at least two reference signals through a low-power device, thereby determining a first time domain interval between any two of the at least two reference signals, and comparing the first time domain interval with a second time domain interval known to the low-power device, so that the low-power device can estimate the frequency offset and perform calibration. In order to enable the low-power device to detect the above-mentioned first time domain interval and estimate and calibrate the frequency in combination with the second time domain interval, this application provides a transmission implementation method for the reference signal related to the above-mentioned low-power device, including:

[0246] (1) Generation and mapping method of the sequence corresponding to the reference signal;

[0247] (2) The time domain structure of the reference signal;

[0248] (3) Determination / indication method of the time parameter (second time domain interval) of the reference signal.

[0249] FIG12 is a flow chart of a frequency calibration method provided by an exemplary embodiment of the present application. The method can be used in the system shown in FIG8. The method includes:

[0250] Step 1202: The low-power device receives at least two reference signals sent by the first device.

[0251] In some embodiments, low-power devices include devices that use ambient energy, such as radio frequency energy, light energy, solar energy, thermal energy, mechanical energy, or other ambient energy for their operation. In some embodiments, low-power devices have no energy storage capability or have limited energy storage capability. In some embodiments, low-power devices are equivalent to or can be replaced by zero-power devices, zero-power IoT devices, ambient-energy IoT (A-IoT) devices, or passive IoT devices.

[0252] In some embodiments, the reference signal in this application is equivalent to / can be replaced by a synchronization signal, a synchronization reference signal, or a reference synchronization signal. Receiving at least two reference signals is equivalent to / can be replaced by detecting at least two reference signals. At least two reference signals are equivalent to / can be replaced by multiple reference signals.

[0253] At least two reference signals received by a low-power device are used to determine a first time domain interval. The first time domain interval is a measured time domain interval between any two reference signals from the at least two reference signals. In some embodiments, the any two reference signals are any two adjacent reference signals from the at least two reference signals. In some embodiments, the any two reference signals are any two non-adjacent reference signals from the at least two reference signals. For example, the first time domain interval is a measured time domain interval between a first reference signal and a second reference signal from the at least two reference signals. The first reference signal is any reference signal from the at least two reference signals, and the second reference signal is any reference signal from the at least two reference signals that has a time domain position different from that of the first reference signal. The first reference signal and the second reference signal are adjacent (continuous) or non-adjacent in the time domain. In some embodiments, the low-power device detects the time domain position of the first reference signal and the time domain position of the second reference signal from the any two reference signals and calculates the difference between the two, thereby obtaining the measured time domain interval between the any two reference signals. In some embodiments, measuring the time domain interval is equivalent to or can be replaced by detecting the time domain interval or estimating the time domain interval.

[0254] The first time domain interval and the second time domain interval are used for frequency calibration. The second time domain interval is a reference time domain interval between any two reference signals known to the low-power device. In some embodiments, the second time domain interval known to the low-power device can be understood as the time domain interval when the low-power device sends the any two reference signals, the real time domain interval between the any two reference signals known to the low-power device, and the accurate time domain interval between the any two reference signals known to the low-power device. In some embodiments, the second time domain interval is a reference value, a standard value, or an ideal value of the time domain interval between the any two reference signals known to the low-power device. The reference time domain interval is equivalent to / can be replaced by a control time domain interval or an ideal time domain interval.

[0255] In some embodiments, the low-power device knows a third time domain interval between any adjacent reference signals of at least two reference signals, and the third time domain interval includes a configured time domain interval between adjacent reference signals of at least two reference signals. The second time domain interval between any two reference signals can be determined based on the third time domain interval, that is, the second time domain interval is determined based on the third time domain interval. In some embodiments, the configured time domain interval is equivalent to / replaceable with a fixed time domain interval, a predetermined time domain interval, a reference time domain interval, or a real time domain interval. In some embodiments, the first time domain interval and the second time domain interval are also used for clock calibration (time synchronization) of the low-power device.

[0256] In some embodiments, the first device includes at least one of the following:

[0257] Network equipment; intermediate node; AP; a device that provides energy or carrier to low-power devices.

[0258] In some embodiments, the network device includes an access network device, such as the base station in the topology structure 1 shown in Figure 6. The intermediate node includes a node between the network device and the low-power device, and the intermediate node establishes a communication connection with the low-power device and the network device respectively. In some embodiments, the intermediate node is used to transfer signaling and / or data between the network device and the low-power device. In some embodiments, the intermediate node is a terminal, such as the terminal between the base station and the low-power device in the topology structure 2 shown in Figure 7. In some embodiments, the above-mentioned AP belongs to a WLAN system. In some embodiments, the energy or carrier provided to the low-power device is used for backscattering of the low-power device. The device that provides energy or carrier to the low-power device is different from the network device, the intermediate node and the AP, such as a device in a communication system other than a cellular system and a WLAN system, and the embodiments of the present application are not limited to this.

[0259] For reference signal generation and mapping:

[0260] In some embodiments, the at least two reference signals are identical or related reference signals. For example, the at least two reference signals are repetitions of the same reference signal. In some embodiments, the at least two reference signals are different or unrelated reference signals.

[0261] In some embodiments, at least two reference signals belong to the same candidate reference signal group. In some embodiments, at least two reference signals belong to different candidate reference signal groups. In some embodiments, the reference signals in the candidate reference signal group are generated using sequences. In some embodiments, the candidate reference signal group in this application is equivalent to / replaceable with a candidate reference signal sequence group, a candidate synchronization signal group, a candidate synchronization signal sequence group, a reference signal group, a synchronization signal group, a candidate synchronization reference signal group, or a candidate synchronization reference signal sequence group, and the aforementioned groups are equivalent to / replaceable with sets.

[0262] In some embodiments, the reference signal carries information via a sequence. In some embodiments, the information includes at least one of the following:

[0263] PCI; AP ID; intermediate node identification; data transmission rate; data transmission method; reference signal timing information.

[0264] In some embodiments, the time information of the reference signal is used to reflect the time domain position of the reference signal (the time corresponding to the reference signal). In some embodiments, the above-mentioned identifier carried by the reference signal is related to the sender of the reference signal. For example, the reference signal sent by the network device carries the PCI, the reference signal sent by the AP carries the AP ID, and the reference signal sent by the intermediate node carries the identifier of the intermediate node. The data transmission rate is used to indicate the rate of data transmission with the low-power device. The data transmission mode is used to indicate the method of data transmission with the low-power device.

[0265] In some embodiments, the reference signal carries information using any one of an m-sequence, a gold sequence, a ZC sequence, and a Walsh sequence. The sequence corresponding to the reference signal can be considered to be generated by the above sequence, or to be obtained by generating the above sequence, or to be the above sequence. In some embodiments, the reference signal is obtained by adjusting or transforming the above sequence. In some embodiments, the protocol may specify sequences corresponding to multiple reference signals. These sequences can form a candidate reference signal sequence group, and each candidate reference signal sequence in the candidate reference signal sequence group represents corresponding information.

[0266] In some embodiments, the sequence corresponding to the reference signal is mapped onto a time domain unit. In some embodiments, the time domain unit includes any one of a time domain symbol and an OFDM symbol. In some embodiments, the reference signal is OOK modulated, and the sequence corresponding to the reference signal is directly mapped onto the time domain symbol (time domain OOK symbol).

[0267] For the first reference signal generation situation:

[0268] In some embodiments, at least two reference signals correspond to the same sequence; or, at least two reference signals correspond to related sequences. For example, at least two reference signals correspond to repetitions of the same sequence, i.e., at least two reference signals transmitted by the same device are identical. In some embodiments, at least two reference signals correspond to related sequences, including when the low-power device detects the sequence corresponding to the first reference signal of the at least two reference signals, it can determine the sequence of the second reference signal of the at least two reference signals. In some embodiments, the first reference signal and the second reference signal are adjacent reference signals of the at least two reference signals.

[0269] For example, Figure 13 is a schematic diagram of a reference signal provided by an exemplary embodiment of the present application. As shown in Figure 13, the at least two reference signals received by the low-power device during the reference signal period include signal 1 and signal 2. The sequences corresponding to signal 1 and signal 2 both belong to a candidate reference signal sequence group including N candidate sequences, and the sequence corresponding to signal 1 is the same as the sequence corresponding to signal 2.

[0270] For the generation of the second reference signal:

[0271] In some embodiments, at least two reference signals correspond to sequences of the same type. In this case, the at least two reference signals correspond to the same sequence or different sequences, depending on the information carried by the sequence. In some embodiments, the sequences corresponding to the at least two reference signals belong to the same candidate reference signal sequence group. In some embodiments, the sequences in the same candidate reference signal sequence group are generated using the same generator polynomial and initial value.

[0272] For example, Figure 14 is a schematic diagram of a reference signal provided by an exemplary embodiment of the present application. As shown in Figure 14, the at least two reference signals received by the low-power device within the reference signal period include signal 1 and signal 2. The sequences corresponding to signal 1 and signal 2 are of the same type, both belong to a candidate reference signal sequence group including N candidate sequences, and the sequence corresponding to signal 1 and signal 2 are the same or different.

[0273] Regarding the generation of the third reference signal:

[0274] In some embodiments, at least two reference signals correspond to different sequences. In this case, the at least two reference signals transmitted by the same device are different. In some embodiments, the sequences corresponding to the at least two reference signals belong to different candidate reference signal sequence groups. In some embodiments, the different candidate reference signal sequence groups differ in at least one of the following aspects:

[0275] Sequence type; sequence length; sequence generation parameters.

[0276] For example, Figure 15 is a schematic diagram of a reference signal provided by an exemplary embodiment of the present application. As shown in Figure 15, the at least two reference signals received by the low-power device within the reference signal period include signal 1 and signal 2. The sequence corresponding to signal 1 belongs to a candidate reference signal sequence group including N candidate sequences 1, and the sequence corresponding to signal 2 belongs to a candidate reference signal sequence group including M candidate sequences 2. Candidate sequences 1 and 2 are different.

[0277] For the time domain structure of the reference signal:

[0278] In some embodiments, at least two reference signals are reference signals within the same reference signal period. In some embodiments, the reference signals within the same reference signal period collectively constitute a reference signal within the reference signal period (which can be considered as one reference signal) or a reference signal cluster (burst). In some embodiments, the time domain intervals between adjacent reference signals within the same reference signal period are the same. In some embodiments, the time domain intervals between adjacent reference signals within the same reference signal period are different. For example, the at least two reference signals include a first reference signal and a second reference signal, the reference signal period is 10 ms, and the first reference signal and the second reference signal are located within the 10 ms period.

[0279] In some embodiments, the at least two reference signals are reference signals transmitted in different reference signal periods. For example, the reference signal period (without distinguishing which reference signal's time domain resource) is 10 ms, and the at least two reference signals are transmitted alternately on this resource. For example, the first reference signal is transmitted in the first period, and the second reference signal is transmitted in the second period. In this case, the transmission period of each reference signal is 20 ms.

[0280] For example, Figure 16 is a schematic diagram of the time domain structure of a reference signal provided by an exemplary embodiment of the present application. Figure 17 is a schematic diagram of the time domain structure of a reference signal provided by an exemplary embodiment of the present application. As shown in Figures 16 and 17, the reference signal within the same reference signal period includes at least two reference signals. In this case, each reference signal can be called a sub-reference signal. For example, Figures 16 and 17 show the case where the reference signal within the same reference signal period includes two reference signals. In Figure 16, the reference signal period is 80ms, which means that two sub-reference signals will be sent every 80ms, or the period of each sub-reference signal is also 80ms, but the time domain offset value is different. A special case corresponding to Figure 16 is shown in Figure 17, that is, the reference signal period is 80ms, and the interval between the two sub-reference signals is 40ms, which is half of the entire period. This case is equivalent to sending two different sub-reference signals in an interleaved manner according to a time domain resource with a period of 40ms, and the interval between the sub-reference signals is equal to the period of 40ms. In this case, the low-power device combines the two groups of sub-reference signals across the period, estimates the time domain interval, and performs clock calibration and / or frequency calibration according to the method provided in the embodiments of the present application. In addition, for the case where the same reference signal period includes K sub-reference signals, the above special case occurs when the interval between each two adjacent sub-reference signals is one-Kth of the entire period.

[0281] Determination of the second time domain interval:

[0282] In some embodiments, the third time domain interval is determined using at least one of the following methods. The third time domain interval includes a configured time domain interval between adjacent reference signals among at least two reference signals, where the configured time domain interval is a time domain interval known to the low-power device. In some embodiments, the low-power device knows the third time domain interval of any two adjacent reference signals among the at least two reference signals. The third time domain interval is used to determine the second time domain interval. If any two reference signals are adjacent, the low-power device directly determines the third time domain interval of the any two reference signals as the second time domain interval of the any two reference signals. If any two reference signals are adjacent among the at least two reference signals received by the low-power device, the configured time domain interval can be considered the reference time domain interval, and the third time domain interval can be considered the second time domain interval. In this case, the third time domain interval is equivalent to the second time domain interval. If any two reference signals are not adjacent, the low-power device determines the second time domain interval of the any two reference signals based on the third time domain interval corresponding to the any two reference signals and the reference signal between the any two reference signals.

[0283] The third time domain interval is predefined by the protocol; the third time domain interval is indicated by the power supply signal of the low-power device; the third time domain interval is indicated by the reference signal and / or the data packet associated with the reference signal.

[0284] Regarding the first determination of the third time domain interval:

[0285] In some embodiments, the third time domain interval is predefined by the protocol. For example, the protocol stipulates a fixed or default reference signal interval (third time domain interval), which can be denoted as X. The transmitter of the reference signal needs to send the reference signal according to the interval agreed upon by the protocol. The low-power device also uses this agreed X value for relevant calculations to perform frequency calibration. In some embodiments, the protocol stipulates a unified third time domain interval for the entire frequency band. In some embodiments, the protocol stipulates a third time domain interval for at least one of each frequency band, band, or carrier.

[0286] Regarding the determination of the second third time domain interval:

[0287] In some embodiments, the third time domain interval is indicated by a power supply signal of a low-power device. The device that sends the power supply signal to the low-power device is the same as or different from the device that sends the reference signal to the low-power device. In some embodiments, the low-power device is charged by receiving the power supply signal, and when the energy accumulation meets the conditions, the low-power device monitors the reference signal, as well as other control information and / or data information. In some embodiments, the value of the third time domain interval is indicated by the physical characteristics of the power supply signal, such as the waveform and frequency of the power supply signal. Alternatively, one of multiple candidate values ​​is indicated as the third time domain interval by the physical characteristics of the power supply signal. In some embodiments, the multiple candidate values ​​are predefined by the protocol.

[0288] In some embodiments, the energy supply signal and the reference signal have the same sender, for example, both are sent by a network device or an intermediate node in the topology shown in Figures 6 and 7, or by a device other than a network device and an intermediate node. In some embodiments, the energy supply signal and the reference signal have different senders. In this case, a connection is established between the sender of the energy supply signal and the sender of the reference signal via a wired or wireless (e.g., cellular communication) method, and relevant information is exchanged.

[0289] Regarding the determination of the third time domain interval:

[0290] In some embodiments, the third time domain interval is indicated by a reference signal and / or a data packet associated with the reference signal. Data packets associated with reference signals include data packets sent to the low-power device from the same transmission direction as the reference signal. In some embodiments, each reference signal is associated with a data packet. In some embodiments, multiple reference signals are associated with a data packet. For example, each reference signal in the same reference signal period is associated with a data packet. In some embodiments, the data packet includes at least one of a MIB and a SIB.

[0291] In some embodiments, the reference signal and / or data packet carries a third time domain interval. In some embodiments, the reference signal and / or data packet carries the time corresponding to the reference signal, and the third time domain interval is determined based on the difference in time corresponding to adjacent reference signals in at least two reference signals. For example, the value X of the third time domain interval is directly indicated by the reference signal and / or data packet. Alternatively, the time Ti corresponding to the reference signal is indicated by the reference signal and / or data packet, and the time corresponding to two adjacent reference signals is subtracted to obtain the value of the third time domain interval X, for example, X=T2-T1. In some embodiments, the time corresponding to the reference signal includes at least one of the time domain starting position of the reference signal, the time domain ending position of the reference signal, and the position between the time domain starting position and the time domain ending position of the reference signal.

[0292] In some embodiments, the reference signal and / or data packet carries a first value, the first value being used to indicate a third time domain interval among multiple candidate time domain intervals. In some embodiments, the multiple candidate time domain intervals are predefined by a protocol. In some embodiments, the reference signal and / or data packet carries a second value, the second value being used to indicate a time corresponding to the reference signal among multiple candidate times, and the third time domain interval is determined based on a difference between times corresponding to adjacent reference signals among at least two reference signals. In some embodiments, the multiple candidate times are predefined by a protocol.

[0293] In some embodiments, the value of the third time domain interval is carried by a sequence corresponding to the reference signal, for example, the first value is carried by the sequence corresponding to the reference signal. In some embodiments, the value of the time corresponding to the reference signal is carried by a sequence corresponding to the reference signal, for example, the second value is carried by the sequence corresponding to the reference signal.

[0294] It should be noted that, for the case where the reference signal and / or data packet carries the time corresponding to the reference signal, and the reference signal and / or data packet carries a second value, the low-power device can directly determine the second time domain interval based on the difference between the times corresponding to any two of the above reference signals. Alternatively, the low-power device first determines the third time domain interval of adjacent reference signals in at least two reference signals based on the time corresponding to each reference signal in the at least two received reference signals, and then determines the second time domain interval based on the third time domain interval. This embodiment of the present application is not limited to this.

[0295] In some embodiments, the value of the third time domain interval is carried by a data packet associated with the reference signal, for example, the data packet carries the first value. In some embodiments, the value of the time corresponding to the reference signal is carried by a data packet associated with the reference signal, for example, the data packet carries the second value.

[0296] For example, Figure 18 is a schematic diagram of reference signal sequences provided by an exemplary embodiment of the present application. As shown in Figure 18, a low-power device receives reference signal 1 and reference signal 2 within the same reference signal period. The sequence corresponding to reference signal 1 belongs to a candidate reference signal sequence group that includes N candidate sequences, and the sequence corresponding to reference signal 2 belongs to a candidate reference signal sequence group that includes M candidate sequences. Reference signal 1 carries its corresponding time T1, and reference signal 2 carries its corresponding time T2.

[0297] For example, Figure 19 is a schematic diagram of sequences corresponding to reference signals provided by an exemplary embodiment of the present application. As shown in Figure 19, a low-power device receives reference signal 1 and reference signal 2 within the same reference signal period. The sequence corresponding to reference signal 1 belongs to a candidate reference signal sequence group that includes N candidate sequences, and the sequence corresponding to reference signal 2 belongs to a candidate reference signal sequence group that includes M candidate sequences. Reference signal 1 carries its corresponding second time domain interval X, and reference signal 2 carries its corresponding second time domain interval X or -X.

[0298] For example, Figure 20 is a schematic diagram of sequences corresponding to reference signals provided by an exemplary embodiment of the present application. As shown in Figure 20, a low-power device receives reference signal 1 and reference signal 2 within the same reference signal period. The sequence corresponding to reference signal 1 belongs to a candidate reference signal sequence group including N candidate sequences, and the sequence corresponding to reference signal 2 belongs to a candidate reference signal sequence group including M candidate sequences. Reference signal 1 and reference signal 2 jointly carry a second time domain interval. That is, the sequence corresponding to reference signal 1 and the sequence corresponding to reference signal 2 are combined to obtain the second time domain interval X between reference signal 1 and reference signal 2.

[0299] For example, Figure 21 is a schematic diagram of data packets associated with reference signals, provided by an exemplary embodiment of the present application. As shown in Figure 21, a low-power device receives reference signal 1 and reference signal 2 within the same reference signal period. Reference signal 1 and reference signal 2 are each associated with a data packet: reference signal 1 is associated with data 1, and reference signal 2 is associated with data 2. Data 1 carries time T1 corresponding to reference signal 1, and data 2 carries time T2 corresponding to reference signal 2.

[0300] For example, Figure 22 is a schematic diagram of a data packet associated with a reference signal provided by an exemplary embodiment of the present application. As shown in Figure 22, a low-power device receives reference signal 1 and reference signal 2 within the same reference signal period. Reference signal 1 and reference signal 2 are each associated with a data packet: reference signal 1 is associated with data 1, and reference signal 2 is associated with data 2. Data 1 carries the second time domain interval X corresponding to reference signal 1, and data 2 carries the second time domain interval X or -X corresponding to reference signal 2.

[0301] For example, Figure 23 is a schematic diagram of a data packet associated with a reference signal provided by an exemplary embodiment of the present application. As shown in Figure 23, a low-power device receives reference signal 1 and reference signal 2 within the same reference signal period. Reference signal 1 and reference signal 2 are each associated with a data packet: reference signal 1 is associated with data 1, and reference signal 2 is associated with data 2. Data 1 carries the time domain interval between reference signal 1 and the next reference signal in the time domain, while data 2 carries the time domain interval between reference signal 2 and the next reference signal in the time domain.

[0302] For example, Figure 24 is a schematic diagram of a data packet associated with a reference signal provided by an exemplary embodiment of the present application. As shown in Figure 24, a low-power device receives reference signal 1 and reference signal 2 within the same reference signal period. Reference signal 1 and reference signal 2 are associated with a data packet, which is the data shown in Figure 24. This data packet carries the second time domain interval X corresponding to reference signal 1 and reference signal 2.

[0303] Step 1204: The low-power device performs frequency calibration according to the first time domain interval and the second time domain interval.

[0304] In some embodiments, the low-power device can calculate the deviation between the local clock of the low-power device and the ideal clock based on the detected first time domain interval of the reference signal and the known second time domain interval, thereby calibrating the local clock of the low-power device and further calibrating the frequency of the low-power device. For the specific implementation of frequency calibration of the low-power device, please refer to the relevant content of the aforementioned embodiments and will not be described in detail in this embodiment of the present application.

[0305] In this embodiment, step 1202 and step 1204 are optional. In different embodiments, one or more of these steps may be omitted or replaced.

[0306] Step 1202 can be implemented as an independent embodiment, such as a receiving method on the low-power device side or a sending method on the first device side. Step 1204 can be implemented as an independent embodiment, such as a frequency calibration method on the low-power device side.

[0307] To summarize, the method provided in this embodiment sends at least two reference signals to a low-power device, so that the low-power device can determine a first time domain interval between any two reference signals of the at least two reference signals, and compares the first time domain interval with a second time domain interval known to the low-power device, so that the low-power device can estimate the frequency deviation and perform calibration, thereby providing an implementation method for frequency calibration of a low-power device.

[0308] The method provided in this embodiment also reduces the complexity of reference signal detection by low-power devices and improves detection reliability by ensuring that the sequences corresponding to at least two reference signals are identical or correlated. When channel conditions are poor, repeated or correlated reference signals can improve detection performance for low-power devices. By ensuring that the sequences corresponding to at least two reference signals are of the same type, more information can be carried by the reference signals while minimizing the number of blind detections by low-power devices. Combining reference signals of the same sequence type requires fewer local sequences to be stored by low-power devices, making it suitable for low-power devices with smaller storage requirements. By ensuring that the sequences corresponding to at least two reference signals are different, the combination of different reference signals can carry more information while minimizing the number of blind detections by low-power devices. Furthermore, since the candidate reference signal sequence groups corresponding to at least two reference signals are different, the low-power device can determine the time domain location of the reference signal based on the sequences corresponding to the reference signals. By carrying information through the reference signal sequences, information can be transmitted to the low-power device via the reference signals. By directly mapping the sequences corresponding to the reference signals onto time domain units, the complexity of the time domain mapping of the reference signals can be reduced. By transmitting the reference signals according to the reference signal period, the time domain scheduling of the reference signals is clarified. Indicating the third time domain interval in a protocol-predefined manner can reduce the implementation cost of indicating the third time domain interval. Indicating the third time domain interval in a power supply signal provides a method for reusing existing signals to indicate the third time domain interval. Indicating the third time domain interval in multiple ways using reference signals and / or data packets provides a flexible method for indicating the third time domain interval, enabling indication of the third time domain interval based on resource constraints of reference signals and / or data packets.

[0309] It should be noted that the order of the method steps provided in the embodiments of the present application can be appropriately adjusted, the steps can also be increased or decreased accordingly according to the circumstances, and different steps can be freely combined to form new embodiments. Any person skilled in the art who is familiar with the present invention can easily think of the method of variation within the technical scope disclosed in this application, and should be included in the protection scope of this application, so it will not be repeated here. In addition, the order of the above-mentioned different situations does not have a preferred meaning, but is only for the convenience of expression.

[0310] FIG25 is a block diagram of a frequency calibration device provided by an exemplary embodiment of the present application, which can be implemented as a low-power device or as a part of a low-power device through software or hardware or a combination of both.

[0311] The receiving module 2501 is configured to receive at least two reference signals.

[0312] In some embodiments, the apparatus includes a device that uses ambient energy, such as radio frequency energy, light energy, solar energy, thermal energy, mechanical energy, or other ambient energy for its operation. In some embodiments, the apparatus has no energy storage capability or has limited energy storage capability. In some embodiments, the apparatus is equivalent to or can be replaced by a zero-power device, a zero-power IoT device, an Ambient-IoT (A-IoT) device, or a passive IoT device.

[0313] In some embodiments, the reference signal in this application is equivalent to / can be replaced by a synchronization signal, a synchronization reference signal, or a reference synchronization signal. Receiving at least two reference signals is equivalent to / can be replaced by detecting at least two reference signals. At least two reference signals are equivalent to / can be replaced by multiple reference signals.

[0314] At least two reference signals received by the device are used to determine a first time domain interval. The first time domain interval is a measured time domain interval between any two reference signals from the at least two reference signals. In some embodiments, the any two reference signals are any two adjacent reference signals from the at least two reference signals. In some embodiments, the any two reference signals are any two non-adjacent reference signals from the at least two reference signals. For example, the first time domain interval is a measured time domain interval between a first reference signal and a second reference signal from the at least two reference signals. The first reference signal is any reference signal from the at least two reference signals, and the second reference signal is any reference signal from the at least two reference signals that has a time domain position different from that of the first reference signal. The first reference signal and the second reference signal are adjacent (continuous) or non-adjacent in the time domain. In some embodiments, the device detects the time domain position of the first reference signal and the time domain position of the second reference signal from the any two reference signals and calculates the difference between the two, thereby obtaining the measured time domain interval between the any two reference signals. In some embodiments, measuring the time domain interval is equivalent to or can be replaced by detecting the time domain interval or estimating the time domain interval.

[0315] The first time domain interval and the second time domain interval are used for frequency calibration. The second time domain interval is a reference time domain interval between any two reference signals known to the device. In some embodiments, the second time domain interval known to the device can be understood as the time domain interval when the device sends the any two reference signals, the real time domain interval between the any two reference signals known to the device, and the accurate time domain interval between the any two reference signals known to the device. In some embodiments, the second time domain interval is a reference value, a standard value, or an ideal value of the time domain interval between the any two reference signals known to the device. The reference time domain interval is equivalent to / can be replaced by a control time domain interval or an ideal time domain interval.

[0316] In some embodiments, the device knows a third time domain interval between any adjacent reference signals among at least two reference signals, where the third time domain interval includes a configured time domain interval between adjacent reference signals among the at least two reference signals. The second time domain interval between any two reference signals can be determined based on the third time domain interval, i.e., the second time domain interval is determined based on the third time domain interval. In some embodiments, the configured time domain interval is equivalent to / replaceable with a fixed time domain interval, a predetermined time domain interval, a reference time domain interval, or a real time domain interval. In some embodiments, the first time domain interval and the second time domain interval are also used for clock calibration (time synchronization) of the device.

[0317] In some embodiments, the first device includes at least one of the following:

[0318] Network equipment; intermediate node; AP; equipment that provides energy or carrier to devices.

[0319] In some embodiments, the network device includes an access network device, such as the base station in the topology structure 1 shown in Figure 6. The intermediate node includes a node between the network device and the device, and the intermediate node establishes a communication connection with the device and the network device respectively. In some embodiments, the intermediate node is used to transfer signaling and / or data between the network device and the device. In some embodiments, the intermediate node is a terminal, such as the terminal between the base station and the device in the topology structure 2 shown in Figure 7. In some embodiments, the above-mentioned AP belongs to a WLAN system. In some embodiments, the energy or carrier provided to the device is used for backscattering by the device. The device that provides energy or carrier to the device is different from the network device, the intermediate node and the AP, for example, it is a device in a communication system other than a cellular system and a WLAN system, and the embodiments of the present application are not limited to this.

[0320] For reference signal generation and mapping:

[0321] In some embodiments, the at least two reference signals are identical or related reference signals. For example, the at least two reference signals are repetitions of the same reference signal. In some embodiments, the at least two reference signals are different or unrelated reference signals.

[0322] In some embodiments, at least two reference signals belong to the same candidate reference signal group. In some embodiments, at least two reference signals belong to different candidate reference signal groups. In some embodiments, the reference signals in the candidate reference signal group are generated using sequences. In some embodiments, the candidate reference signal group in this application is equivalent to / replaceable with a candidate reference signal sequence group, a candidate synchronization signal group, a candidate synchronization signal sequence group, a reference signal group, a synchronization signal group, a candidate synchronization reference signal group, or a candidate synchronization reference signal sequence group, and the aforementioned groups are equivalent to / replaceable with sets.

[0323] In some embodiments, the reference signal carries information via a sequence. In some embodiments, the information includes at least one of the following:

[0324] PCI; AP ID; intermediate node identification; data transmission rate; data transmission method; reference signal time information.

[0325] In some embodiments, the time information of the reference signal is used to reflect the time domain location of the reference signal (the time corresponding to the reference signal). In some embodiments, the identifier carried by the reference signal is related to the sender of the reference signal. For example, the reference signal sent by the network device carries the PCI, the reference signal sent by the AP carries the AP ID, and the reference signal sent by the intermediate node carries the identifier of the intermediate node. The data transmission rate is used to indicate the rate of data transmission with the device. The data transmission mode is used to indicate the method of data transmission with the device.

[0326] In some embodiments, the reference signal carries information using any one of an m-sequence, a gold sequence, a ZC sequence, and a Walsh sequence. The sequence corresponding to the reference signal can be considered to be generated by the above sequence, or to be obtained by generating the above sequence, or to be the above sequence. In some embodiments, the reference signal is obtained by adjusting or transforming the above sequence. In some embodiments, the protocol may specify sequences corresponding to multiple reference signals. These sequences can form a candidate reference signal sequence group, and each candidate reference signal sequence in the candidate reference signal sequence group represents corresponding information.

[0327] In some embodiments, the sequence corresponding to the reference signal is mapped onto a time domain unit. In some embodiments, the time domain unit includes any one of a time domain symbol and an OFDM symbol. In some embodiments, the reference signal is OOK modulated, and the sequence corresponding to the reference signal is directly mapped onto the time domain symbol (time domain OOK symbol).

[0328] For the first reference signal generation situation:

[0329] In some embodiments, at least two reference signals correspond to the same sequence; or, at least two reference signals correspond to related sequences. For example, at least two reference signals correspond to repetitions of the same sequence, i.e., at least two reference signals transmitted by the same device are identical. In some embodiments, at least two reference signals correspond to related sequences, including when a device detects a sequence corresponding to a first reference signal of at least two reference signals, thereby determining a sequence of a second reference signal of the at least two reference signals. In some embodiments, the first reference signal and the second reference signal are adjacent reference signals of the at least two reference signals.

[0330] For the generation of the second reference signal:

[0331] In some embodiments, at least two reference signals correspond to sequences of the same type. In this case, the at least two reference signals correspond to the same sequence or different sequences, depending on the information carried by the sequence. In some embodiments, the sequences corresponding to the at least two reference signals belong to the same candidate reference signal sequence group. In some embodiments, the sequences in the same candidate reference signal sequence group are generated using the same generator polynomial and initial value.

[0332] Regarding the generation of the third reference signal:

[0333] In some embodiments, at least two reference signals correspond to different sequences. In this case, the at least two reference signals transmitted by the same device are different. In some embodiments, the sequences corresponding to the at least two reference signals belong to different candidate reference signal sequence groups. In some embodiments, the different candidate reference signal sequence groups differ in at least one of the following aspects:

[0334] Sequence type; sequence length; sequence generation parameters.

[0335] For the time domain structure of the reference signal:

[0336] In some embodiments, at least two reference signals are reference signals within the same reference signal period. In some embodiments, the reference signals within the same reference signal period collectively constitute a reference signal within the reference signal period (which can be considered as one reference signal) or a reference signal cluster (burst). In some embodiments, the time domain intervals between adjacent reference signals within the same reference signal period are the same. In some embodiments, the time domain intervals between adjacent reference signals within the same reference signal period are different. For example, the at least two reference signals include a first reference signal and a second reference signal, the reference signal period is 10 ms, and the first reference signal and the second reference signal are located within the 10 ms period.

[0337] In some embodiments, the at least two reference signals are reference signals transmitted in different reference signal periods. For example, the reference signal period (without distinguishing which reference signal's time domain resource) is 10 ms, and the at least two reference signals are transmitted alternately on this resource. For example, the first reference signal is transmitted in the first period, and the second reference signal is transmitted in the second period. In this case, the transmission period of each reference signal is 20 ms.

[0338] Determination of the second time domain interval:

[0339] In some embodiments, the third time domain interval is determined using at least one of the following methods. The third time domain interval includes a configured time domain interval between adjacent reference signals among at least two reference signals, where the configured time domain interval is a time domain interval known to the device. In some embodiments, the device knows the third time domain interval between any two adjacent reference signals among the at least two reference signals. The third time domain interval is used to determine the second time domain interval. If any two reference signals are adjacent, the device directly determines the third time domain interval between the any two reference signals as the second time domain interval between the any two reference signals. If any two reference signals are adjacent among the at least two reference signals received by the device, the configured time domain interval can be considered the reference time domain interval, and the third time domain interval can be considered the second time domain interval. In this case, the third time domain interval is equivalent to the second time domain interval. If any two reference signals are not adjacent, the device determines the second time domain interval between the any two reference signals based on the third time domain interval corresponding to the any two reference signals and the reference signal between the any two reference signals.

[0340] The third time domain interval is predefined by the protocol; the third time domain interval is indicated by a power supply signal of the device; the third time domain interval is indicated by a reference signal and / or a data packet associated with the reference signal.

[0341] Regarding the first determination of the third time domain interval:

[0342] In some embodiments, the third time domain interval is predefined by the protocol. For example, the protocol stipulates a fixed or default reference signal interval (third time domain interval), which can be denoted as X. The transmitter of the reference signal needs to send the reference signal according to the interval agreed upon by the protocol. The device also uses this agreed X value to perform relevant calculations for frequency calibration. In some embodiments, the protocol stipulates a unified third time domain interval for the entire frequency band. In some embodiments, the protocol stipulates a third time domain interval for each frequency band, band, or at least one of the carriers.

[0343] Regarding the determination of the second third time domain interval:

[0344] In some embodiments, the third time domain interval is indicated by the power supply signal of the device. The device that sends the power supply signal to the device is the same as or different from the device that sends the reference signal to the device. In some embodiments, the device is charged by receiving the power supply signal, and when the energy accumulation meets the conditions, the device monitors the reference signal, as well as other control information and / or data information. In some embodiments, the value of the third time domain interval is indicated by the physical characteristics of the power supply signal, such as the waveform and frequency of the power supply signal. Alternatively, one of multiple candidate values ​​is indicated as the third time domain interval based on the physical characteristics of the power supply signal. In some embodiments, the multiple candidate values ​​are predefined by the protocol.

[0345] In some embodiments, the energy supply signal and the reference signal have the same sender, for example, both are sent by a network device or an intermediate node in the topology shown in Figures 6 and 7, or by a device other than a network device and an intermediate node. In some embodiments, the energy supply signal and the reference signal have different senders. In this case, a connection is established between the sender of the energy supply signal and the sender of the reference signal via a wired or wireless (e.g., cellular communication) method, and relevant information is exchanged.

[0346] Regarding the determination of the third time domain interval:

[0347] In some embodiments, the third time domain interval is indicated by a reference signal and / or a data packet associated with the reference signal. Data packets associated with a reference signal include data packets sent to a device in the same transmission direction as the reference signal. In some embodiments, each reference signal is associated with a data packet. In some embodiments, multiple reference signals are associated with a data packet. For example, each reference signal in the same reference signal period is associated with a data packet. In some embodiments, the data packet includes at least one of a MIB and a SIB.

[0348] In some embodiments, the reference signal and / or data packet carries a third time domain interval. In some embodiments, the reference signal and / or data packet carries the time corresponding to the reference signal, and the third time domain interval is determined based on the difference in time corresponding to adjacent reference signals in at least two reference signals. For example, the value X of the third time domain interval is directly indicated by the reference signal and / or data packet. Alternatively, the time Ti corresponding to the reference signal is indicated by the reference signal and / or data packet, and the time corresponding to two adjacent reference signals is subtracted to obtain the value of the third time domain interval X, for example, X=T2-T1. In some embodiments, the time corresponding to the reference signal includes at least one of the time domain starting position of the reference signal, the time domain ending position of the reference signal, and the position between the time domain starting position and the time domain ending position of the reference signal.

[0349] In some embodiments, the reference signal and / or data packet carries a first value, the first value being used to indicate a third time domain interval among multiple candidate time domain intervals. In some embodiments, the multiple candidate time domain intervals are predefined by a protocol. In some embodiments, the reference signal and / or data packet carries a second value, the second value being used to indicate a time corresponding to the reference signal among multiple candidate times, and the third time domain interval is determined based on a difference between times corresponding to adjacent reference signals among at least two reference signals. In some embodiments, the multiple candidate times are predefined by a protocol.

[0350] In some embodiments, the value of the third time domain interval is carried by a sequence corresponding to the reference signal, for example, the first value is carried by the sequence corresponding to the reference signal. In some embodiments, the value of the time corresponding to the reference signal is carried by a sequence corresponding to the reference signal, for example, the second value is carried by the sequence corresponding to the reference signal.

[0351] It should be noted that, in the case where the reference signal and / or data packet carries the time corresponding to the reference signal, and the reference signal and / or data packet carries the second value, the device can directly determine the second time domain interval based on the difference between the times corresponding to any two of the above reference signals. Alternatively, the device first determines the third time domain interval of adjacent reference signals in at least two reference signals based on the time corresponding to each reference signal in the at least two received reference signals, and then determines the second time domain interval based on the third time domain interval. This embodiment of the present application is not limited to this.

[0352] In some embodiments, the value of the third time domain interval is carried by a data packet associated with the reference signal, for example, the data packet carries the first value. In some embodiments, the value of the time corresponding to the reference signal is carried by a data packet associated with the reference signal, for example, the data packet carries the second value.

[0353] Frequency calibration process:

[0354] In some embodiments, a device can calculate a deviation between a local clock of the device and an ideal clock based on the detected first time domain interval of the reference signal and the known second time domain interval, thereby calibrating the local clock of the device and, in turn, the frequency of the device. For the specific implementation of frequency calibration by the device, reference can be made to the relevant content in the aforementioned embodiments and will not be further described in detail in this embodiment of the present application.

[0355] In some embodiments, the apparatus provided by the embodiments of the present application includes a receiving module 2501, which supports the execution of all reception-related steps performed by the low-power device in each of the above embodiments.

[0356] In some embodiments, the apparatus provided by the embodiments of the present application includes multiple receiving modules 2501, and the multiple receiving modules 2501 respectively support the execution of some reception-related steps performed by the low-power device in each of the above embodiments.

[0357] In some embodiments, the steps performed by different receiving modules 2501 are exactly the same, partially the same, or completely different.

[0358] To summarize, the device provided in this embodiment receives at least two reference signals through the device, thereby determining the first time domain interval between any two reference signals among the at least two reference signals, and comparing the first time domain interval with the second time domain interval known to the device, so that the device can estimate the frequency deviation and perform calibration, providing an implementation method for the device to perform frequency calibration.

[0359] FIG26 is a block diagram of a frequency calibration apparatus provided by an exemplary embodiment of the present application, which can be implemented as a first device or as a part of a first device through software or hardware or a combination of both.

[0360] The sending module 2601 is configured to send at least two reference signals to a low-power consumption device.

[0361] In some embodiments, low-power devices include devices that use ambient energy, such as radio frequency energy, light energy, solar energy, thermal energy, mechanical energy, or other ambient energy for their operation. In some embodiments, low-power devices have no energy storage capability or have limited energy storage capability. In some embodiments, low-power devices are equivalent to or can be replaced by zero-power devices, zero-power IoT devices, ambient-energy IoT (A-IoT) devices, or passive IoT devices.

[0362] In some embodiments, the reference signal in this application is equivalent to / can be replaced by a synchronization signal, a synchronization reference signal, or a reference synchronization signal. Receiving at least two reference signals is equivalent to / can be replaced by detecting at least two reference signals. At least two reference signals are equivalent to / can be replaced by multiple reference signals.

[0363] At least two reference signals received by a low-power device are used to determine a first time domain interval. The first time domain interval is a measured time domain interval between any two reference signals from the at least two reference signals. In some embodiments, the any two reference signals are any two adjacent reference signals from the at least two reference signals. In some embodiments, the any two reference signals are any two non-adjacent reference signals from the at least two reference signals. For example, the first time domain interval is a measured time domain interval between a first reference signal and a second reference signal from the at least two reference signals. The first reference signal is any reference signal from the at least two reference signals, and the second reference signal is any reference signal from the at least two reference signals that has a time domain position different from that of the first reference signal. The first reference signal and the second reference signal are adjacent (continuous) or non-adjacent in the time domain. In some embodiments, the low-power device detects the time domain position of the first reference signal and the time domain position of the second reference signal from the any two reference signals and calculates the difference between the two, thereby obtaining the measured time domain interval between the any two reference signals. In some embodiments, measuring the time domain interval is equivalent to or can be replaced by detecting the time domain interval or estimating the time domain interval.

[0364] The first time domain interval and the second time domain interval are used for frequency calibration. The second time domain interval is a reference time domain interval between any two reference signals known to the low-power device. In some embodiments, the second time domain interval known to the low-power device can be understood as the time domain interval when the low-power device sends the any two reference signals, the real time domain interval between the any two reference signals known to the low-power device, and the accurate time domain interval between the any two reference signals known to the low-power device. In some embodiments, the second time domain interval is a reference value, a standard value, or an ideal value of the time domain interval between the any two reference signals known to the low-power device. The reference time domain interval is equivalent to / can be replaced by a control time domain interval or an ideal time domain interval.

[0365] In some embodiments, the low-power device knows a third time domain interval between any adjacent reference signals of at least two reference signals, and the third time domain interval includes a configured time domain interval between adjacent reference signals of at least two reference signals. The second time domain interval between any two reference signals can be determined based on the third time domain interval, that is, the second time domain interval is determined based on the third time domain interval. In some embodiments, the configured time domain interval is equivalent to / replaceable with a fixed time domain interval, a predetermined time domain interval, a reference time domain interval, or a real time domain interval. In some embodiments, the first time domain interval and the second time domain interval are also used for clock calibration (time synchronization) of the low-power device.

[0366] In some embodiments, the apparatus comprises at least one of the following:

[0367] Network equipment; intermediate node; AP; a device that provides energy or carrier to low-power devices.

[0368] In some embodiments, the network device includes an access network device, such as the base station in the topology structure 1 shown in Figure 6. The intermediate node includes a node between the network device and the low-power device, and the intermediate node establishes a communication connection with the low-power device and the network device respectively. In some embodiments, the intermediate node is used to transfer signaling and / or data between the network device and the low-power device. In some embodiments, the intermediate node is a terminal, such as the terminal between the base station and the low-power device in the topology structure 2 shown in Figure 7. In some embodiments, the above-mentioned AP belongs to a WLAN system. In some embodiments, the energy or carrier provided to the low-power device is used for backscattering of the low-power device. The device that provides energy or carrier to the low-power device is different from the network device, the intermediate node and the AP, such as a device in a communication system other than a cellular system and a WLAN system, and the embodiments of the present application are not limited to this.

[0369] For reference signal generation and mapping:

[0370] In some embodiments, the at least two reference signals are identical or related reference signals. For example, the at least two reference signals are repetitions of the same reference signal. In some embodiments, the at least two reference signals are different or unrelated reference signals.

[0371] In some embodiments, at least two reference signals belong to the same candidate reference signal group. In some embodiments, at least two reference signals belong to different candidate reference signal groups. In some embodiments, the reference signals in the candidate reference signal group are generated using sequences. In some embodiments, the candidate reference signal group in this application is equivalent to / replaceable with a candidate reference signal sequence group, a candidate synchronization signal group, a candidate synchronization signal sequence group, a reference signal group, a synchronization signal group, a candidate synchronization reference signal group, or a candidate synchronization reference signal sequence group, and the aforementioned groups are equivalent to / replaceable with sets.

[0372] In some embodiments, the reference signal carries information via a sequence. In some embodiments, the information includes at least one of the following:

[0373] PCI; AP ID; intermediate node identification; data transmission rate; data transmission method; reference signal time information.

[0374] In some embodiments, the time information of the reference signal is used to reflect the time domain position of the reference signal (the time corresponding to the reference signal). In some embodiments, the above-mentioned identifier carried by the reference signal is related to the sender of the reference signal. For example, the reference signal sent by the network device carries the PCI, the reference signal sent by the AP carries the AP ID, and the reference signal sent by the intermediate node carries the identifier of the intermediate node. The data transmission rate is used to indicate the rate of data transmission with the low-power device. The data transmission mode is used to indicate the method of data transmission with the low-power device.

[0375] In some embodiments, the reference signal carries information using any one of an m-sequence, a gold sequence, a ZC sequence, and a Walsh sequence. The sequence corresponding to the reference signal can be considered to be generated by the above sequence, or to be obtained by generating the above sequence, or to be the above sequence. In some embodiments, the reference signal is obtained by adjusting or transforming the above sequence. In some embodiments, the protocol may specify sequences corresponding to multiple reference signals. These sequences can form a candidate reference signal sequence group, and each candidate reference signal sequence in the candidate reference signal sequence group represents corresponding information.

[0376] In some embodiments, the sequence corresponding to the reference signal is mapped onto a time domain unit. In some embodiments, the time domain unit includes any one of a time domain symbol and an OFDM symbol. In some embodiments, the reference signal is OOK modulated, and the sequence corresponding to the reference signal is directly mapped onto the time domain symbol (time domain OOK symbol).

[0377] For the first reference signal generation situation:

[0378] In some embodiments, at least two reference signals correspond to the same sequence; or, at least two reference signals correspond to related sequences. For example, at least two reference signals correspond to repetitions of the same sequence, i.e., at least two reference signals transmitted by the same device are identical. In some embodiments, at least two reference signals correspond to related sequences, including when the low-power device detects the sequence corresponding to the first reference signal of the at least two reference signals, it can determine the sequence of the second reference signal of the at least two reference signals. In some embodiments, the first reference signal and the second reference signal are adjacent reference signals of the at least two reference signals.

[0379] For the generation of the second reference signal:

[0380] In some embodiments, at least two reference signals correspond to sequences of the same type. In this case, the at least two reference signals correspond to the same sequence or different sequences, depending on the information carried by the sequence. In some embodiments, the sequences corresponding to the at least two reference signals belong to the same candidate reference signal sequence group. In some embodiments, the sequences in the same candidate reference signal sequence group are generated using the same generator polynomial and initial value.

[0381] Regarding the generation of the third reference signal:

[0382] In some embodiments, at least two reference signals correspond to different sequences. In this case, the at least two reference signals transmitted by the same device are different. In some embodiments, the sequences corresponding to the at least two reference signals belong to different candidate reference signal sequence groups. In some embodiments, the different candidate reference signal sequence groups differ in at least one of the following aspects:

[0383] Sequence type; sequence length; sequence generation parameters.

[0384] For the time domain structure of the reference signal:

[0385] In some embodiments, at least two reference signals are reference signals within the same reference signal period. In some embodiments, the reference signals within the same reference signal period collectively constitute a reference signal within the reference signal period (which can be considered as one reference signal) or a reference signal cluster (burst). In some embodiments, the time domain intervals between adjacent reference signals within the same reference signal period are the same. In some embodiments, the time domain intervals between adjacent reference signals within the same reference signal period are different. For example, the at least two reference signals include a first reference signal and a second reference signal, the reference signal period is 10 ms, and the first reference signal and the second reference signal are located within the 10 ms period.

[0386] In some embodiments, the at least two reference signals are reference signals transmitted in different reference signal periods. For example, the reference signal period (without distinguishing which reference signal's time domain resource) is 10 ms, and the at least two reference signals are transmitted alternately on this resource. For example, the first reference signal is transmitted in the first period, and the second reference signal is transmitted in the second period. In this case, the transmission period of each reference signal is 20 ms.

[0387] Determination of the second time domain interval:

[0388] In some embodiments, the third time domain interval is determined using at least one of the following methods. The third time domain interval includes a configured time domain interval between adjacent reference signals among at least two reference signals, where the configured time domain interval is a time domain interval known to the low-power device. In some embodiments, the low-power device knows the third time domain interval of any two adjacent reference signals among the at least two reference signals. The third time domain interval is used to determine the second time domain interval. If any two reference signals are adjacent, the low-power device directly determines the third time domain interval of the any two reference signals as the second time domain interval of the any two reference signals. If any two reference signals are adjacent among the at least two reference signals received by the low-power device, the configured time domain interval can be considered the reference time domain interval, and the third time domain interval can be considered the second time domain interval. In this case, the third time domain interval is equivalent to the second time domain interval. If any two reference signals are not adjacent, the low-power device determines the second time domain interval of the any two reference signals based on the third time domain interval corresponding to the any two reference signals and the reference signal between the any two reference signals.

[0389] The third time domain interval is predefined by the protocol; the third time domain interval is indicated by the power supply signal of the low-power device; the third time domain interval is indicated by the reference signal and / or the data packet associated with the reference signal.

[0390] Regarding the first determination of the third time domain interval:

[0391] In some embodiments, the third time domain interval is predefined by the protocol. For example, the protocol stipulates a fixed or default reference signal interval (third time domain interval), which can be denoted as X. The transmitter of the reference signal needs to send the reference signal according to the interval agreed upon by the protocol. The low-power device also uses this agreed X value for relevant calculations to perform frequency calibration. In some embodiments, the protocol stipulates a unified third time domain interval for the entire frequency band. In some embodiments, the protocol stipulates a third time domain interval for at least one of each frequency band, band, or carrier.

[0392] Regarding the determination of the second third time domain interval:

[0393] In some embodiments, the third time domain interval is indicated by a power supply signal of a low-power device. The device that sends the power supply signal to the low-power device is the same as or different from the device that sends the reference signal to the low-power device. In some embodiments, the low-power device is charged by receiving the power supply signal, and when the energy accumulation meets the conditions, the low-power device monitors the reference signal, as well as other control information and / or data information. In some embodiments, the value of the third time domain interval is indicated by the physical characteristics of the power supply signal, such as the waveform and frequency of the power supply signal. Alternatively, one of multiple candidate values ​​is indicated as the third time domain interval by the physical characteristics of the power supply signal. In some embodiments, the multiple candidate values ​​are predefined by the protocol.

[0394] In some embodiments, the energy supply signal and the reference signal have the same sender, for example, both are sent by a network device or an intermediate node in the topology shown in Figures 6 and 7, or by a device other than a network device and an intermediate node. In some embodiments, the energy supply signal and the reference signal have different senders. In this case, a connection is established between the sender of the energy supply signal and the sender of the reference signal via a wired or wireless (e.g., cellular communication) method, and relevant information is exchanged.

[0395] Regarding the determination of the third time domain interval:

[0396] In some embodiments, the third time domain interval is indicated by a reference signal and / or a data packet associated with the reference signal. Data packets associated with reference signals include data packets sent to the low-power device from the same transmission direction as the reference signal. In some embodiments, each reference signal is associated with a data packet. In some embodiments, multiple reference signals are associated with a data packet. For example, each reference signal in the same reference signal period is associated with a data packet. In some embodiments, the data packet includes at least one of a MIB and a SIB.

[0397] In some embodiments, the reference signal and / or data packet carries a third time domain interval. In some embodiments, the reference signal and / or data packet carries the time corresponding to the reference signal, and the third time domain interval is determined based on the difference in time corresponding to adjacent reference signals in at least two reference signals. For example, the value X of the third time domain interval is directly indicated by the reference signal and / or data packet. Alternatively, the time Ti corresponding to the reference signal is indicated by the reference signal and / or data packet, and the time corresponding to two adjacent reference signals is subtracted to obtain the value of the third time domain interval X, for example, X=T2-T1. In some embodiments, the time corresponding to the reference signal includes at least one of the time domain starting position of the reference signal, the time domain ending position of the reference signal, and the position between the time domain starting position and the time domain ending position of the reference signal.

[0398] In some embodiments, the reference signal and / or data packet carries a first value, the first value being used to indicate a third time domain interval among multiple candidate time domain intervals. In some embodiments, the multiple candidate time domain intervals are predefined by a protocol. In some embodiments, the reference signal and / or data packet carries a second value, the second value being used to indicate a time corresponding to the reference signal among multiple candidate times, and the third time domain interval is determined based on a difference between times corresponding to adjacent reference signals among at least two reference signals. In some embodiments, the multiple candidate times are predefined by a protocol.

[0399] In some embodiments, the value of the third time domain interval is carried by a sequence corresponding to the reference signal, for example, the first value is carried by the sequence corresponding to the reference signal. In some embodiments, the value of the time corresponding to the reference signal is carried by a sequence corresponding to the reference signal, for example, the second value is carried by the sequence corresponding to the reference signal.

[0400] It should be noted that, for the case where the reference signal and / or data packet carries the time corresponding to the reference signal, and the reference signal and / or data packet carries a second value, the low-power device can directly determine the second time domain interval based on the difference between the times corresponding to any two of the above reference signals. Alternatively, the low-power device first determines the third time domain interval of adjacent reference signals in at least two reference signals based on the time corresponding to each reference signal in the at least two received reference signals, and then determines the second time domain interval based on the third time domain interval. This embodiment of the present application is not limited to this.

[0401] In some embodiments, the value of the third time domain interval is carried by a data packet associated with the reference signal, for example, the data packet carries the first value. In some embodiments, the value of the time corresponding to the reference signal is carried by a data packet associated with the reference signal, for example, the data packet carries the second value.

[0402] In some embodiments, the apparatus provided by the embodiments of the present application includes a sending module 2601, which supports the execution of all sending-related steps performed by the first device in each of the above embodiments.

[0403] In some embodiments, the apparatus provided by the embodiments of the present application includes multiple sending modules 2601, and the multiple sending modules 2601 respectively support the execution of some of the sending-related steps performed by the first device in each of the above embodiments.

[0404] In some embodiments, the steps performed by different sending modules 2601 are exactly the same, partially the same, or completely different.

[0405] To summarize, the apparatus provided in this embodiment sends at least two reference signals to a low-power device, thereby enabling the low-power device to determine a first time domain interval between any two reference signals among the at least two reference signals, and compares the first time domain interval with a second time domain interval known to the low-power device, thereby enabling the low-power device to estimate the frequency deviation and perform calibration, thereby providing an implementation method for frequency calibration of a low-power device.

[0406] It should be noted that the device provided in the above embodiment only uses the division of the above-mentioned functional modules as an example to implement its functions. In actual applications, the above-mentioned 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.

[0407] Regarding the apparatus in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0408] Figure 27 is a structural diagram of a communication device provided by an exemplary embodiment of the present application. The communication device is a low-power device or a first device. The communication device 2700 includes: a processor 2701, a receiver 2702, a transmitter 2703, a memory 2704 and a bus 2705.

[0409] The processor 2701 includes one or more processing cores. The processor 2701 executes various functional applications and information processing by running software programs and modules.

[0410] The receiver 2702 and the transmitter 2703 may be implemented as a communication component, which may be a communication chip.

[0411] The memory 2704 is connected to the processor 2701 via a bus 2705. The memory 2704 may be used to store at least one instruction, and the processor 2701 may be used to execute the at least one instruction to implement each step in the above method embodiment.

[0412] In addition, the memory 2704 can be implemented by any type of volatile or non-volatile storage device or a combination thereof. Volatile or non-volatile storage devices include but are not limited to: magnetic disks or optical disks, electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), static random-access memory (SRAM), read-only memory (ROM), magnetic memory, flash memory, and programmable read-only memory (PROM).

[0413] In some embodiments, when the communication device is implemented as a low-power device, the processor 2701 is configured to receive at least two reference signals; wherein the at least two reference signals are used to determine a first time domain interval, the first time domain interval being a measurement time domain interval between any two reference signals of the at least two reference signals, the first time domain interval and the second time domain interval being used for frequency calibration, and the second time domain interval being a reference time domain interval between the any two reference signals known to the low-power device. In some embodiments, the processor 2701 is further configured to perform other processing-related steps in the above method embodiments.

[0414] In some embodiments, when the communication device is implemented as a first device, the processor 2701 is configured to send at least two reference signals to the low-power device; wherein the at least two reference signals are used to determine a first time domain interval, the first time domain interval being a measurement time domain interval of any two reference signals among the at least two reference signals, the first time domain interval and the second time domain interval being used for frequency calibration, and the second time domain interval being a reference time domain interval between the any two reference signals known to the low-power device. In some embodiments, the processor 2701 is further configured to perform other processing-related steps in the above method embodiments.

[0415] In some embodiments, the receiver 2702 receives signals / data independently, or the processor 2701 controls the receiver 2702 to receive signals / data, or the processor 2701 requests the receiver 2702 to receive signals / data, or the processor 2701 cooperates with the receiver 2702 to receive signals / data.

[0416] In some embodiments, the transmitter 2703 independently sends signals / data, or the processor 2701 controls the transmitter 2703 to send signals / data, or the processor 2701 requests the transmitter 2703 to send signals / data, or the processor 2701 cooperates with the transmitter 2703 to send signals / data.

[0417] In some embodiments, the processor 2701 and the receiver 2702 may be implemented as one module, or the processor 2701 may be implemented as a part of the receiver 2702 .

[0418] In some embodiments, the receiver 2702 may be implemented as a receiver. Optionally, the receiver includes the processor 2701 or does not include the processor 2701.

[0419] In some embodiments, the processor 2701 and the transmitter 2703 may be implemented as one module, or the processor 2701 may be implemented as a part of the transmitter 2703 .

[0420] In some embodiments, the transmitter 2703 may be implemented as a transmitter. Optionally, the receiver includes the processor 2701 or does not include the processor 2701.

[0421] In an exemplary embodiment, a computer-readable storage medium is also provided, in which at least one instruction, at least one program, code set or instruction set is stored. The at least one instruction, the at least one program, the code set or instruction set is loaded and executed by a processor to implement the frequency calibration method provided by the above-mentioned various method embodiments.

[0422] In an exemplary embodiment, a chip is also provided, which includes a programmable logic circuit and / or program instructions. When the chip runs on a communication device, it is used to implement the frequency calibration method provided by the above-mentioned various method embodiments based on the programmable logic circuit and / or program.

[0423] In an exemplary embodiment, a computer program product is further provided. When the computer program product is run on a processor of a computer device, the computer device is caused to perform the above-mentioned frequency calibration method.

[0424] In an exemplary embodiment, a computer program is further provided. The computer program includes computer instructions. A processor of a computer device executes the computer instructions, so that the computer device performs the above-mentioned frequency calibration method.

[0425] Those skilled in the art will appreciate that in one or more of the above examples, the functions described in the embodiments of the present application 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 codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any media that facilitates the transmission of computer programs from one place to another. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0426] The above description is merely an exemplary embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A frequency calibration method, characterized in that: The method is performed by a low-power consumption device, and includes: receiving at least two reference signals; In which, the at least two reference signals are used to determine a first time domain interval, the first time domain interval is the measurement time domain interval of any two reference signals among the at least two reference signals, the first time domain interval and the second time domain interval are used for frequency calibration, and the second time domain interval is the reference time domain interval between the any two reference signals known to the low-power device.

2. The method according to claim 1, characterized in that The at least two reference signals are identical or related reference signals.

3. The method according to claim 1 or 2, characterized in that The at least two reference signals are different or unrelated reference signals.

4. The method according to claim 2, characterized in that The at least two reference signals correspond to the same sequence; or, the at least two reference signals correspond to related sequences.

5. The method according to claim 2 or 3, characterized in that The at least two reference signals correspond to sequences of the same type.

6. The method according to claim 5, characterized in that The sequences corresponding to the at least two reference signals belong to the same candidate reference signal sequence group.

7. The method according to claim 3, characterized in that The at least two reference signals correspond to different sequences.

8. The method according to claim 7, characterized in that The sequences corresponding to the at least two reference signals belong to different candidate reference signal sequence groups.

9. The method according to claim 8, characterized in that The different candidate reference signal sequence groups differ in at least one of the following aspects: Sequence type; sequence length; sequence generation parameters.

10. The method according to any one of claims 1 to 9, characterized in that: The reference signal carries information via a sequence.

11. The method according to claim 10, characterized in that The information includes at least one of the following: Physical cell identifier PCI; access point identifier AP ID; intermediate node identifier; data transmission rate; data transmission mode; time information of the reference signal; The intermediate node includes a node between the network device and the low-power device.

12. The method according to claim 10 or 11, characterized in that The sequence corresponding to the reference signal is mapped on the time domain unit.

13. The method according to any one of claims 1 to 12, characterized in that: The at least two reference signals are reference signals within the same reference signal period.

14. The method according to any one of claims 1 to 13, characterized in that: The at least two reference signals are reference signals sent respectively in different reference signal periods.

15. The method according to any one of claims 1 to 14, characterized in that: The third time domain interval is determined by at least one of the following methods, where the third time domain interval includes a configured time domain interval between adjacent reference signals among the at least two reference signals, and the third time domain interval is used to determine the second time domain interval: The third time domain interval is predefined by the protocol; the third time domain interval is indicated by the power supply signal of the low-power device; the third time domain interval is indicated by the reference signal and / or the data packet associated with the reference signal.

16. The method according to claim 15, characterized in that The reference signal and / or the data packet carries the third time domain interval.

17. The method according to claim 15 or 16, characterized in that The reference signal and / or the data packet carries a first value, where the first value is used to indicate the third time domain interval among multiple candidate time domain intervals.

18. The method according to claim 17, characterized in that The multiple candidate time domain intervals are predefined by the protocol.

19. The method according to any one of claims 15 to 18, characterized in that: The reference signal and / or the data packet carries the time corresponding to the reference signal, and the third time domain interval is determined according to the difference between the times corresponding to adjacent reference signals.

20. The method according to any one of claims 15 to 19, characterized in that The reference signal and / or the data packet carries a second value, which is used to indicate the time corresponding to the reference signal among multiple candidate times, and the third time domain interval is determined according to the difference between the times corresponding to adjacent reference signals.

21. The method according to claim 20, characterized in that The multiple candidate times are predefined by the protocol.

22. The method according to any one of claims 1 to 21, characterized in that The reference signal is sent by a first device, where the first device includes at least one of the following: Network device; intermediate node; AP; device providing energy or carrier to the low-power device; The intermediate node includes a node between the network device and the low-power device.

23. A frequency calibration method, characterized in that: The method is performed by a first device, and includes: sending at least two reference signals to the low-power device; In which, the at least two reference signals are used to determine a first time domain interval, the first time domain interval is the measurement time domain interval of any two reference signals among the at least two reference signals, the first time domain interval and the second time domain interval are used for frequency calibration, and the second time domain interval is the reference time domain interval between the any two reference signals known to the low-power device.

24. The method according to claim 23, wherein The at least two reference signals are identical or related reference signals.

25. The method according to claim 23 or 24, characterized in that The at least two reference signals are different or unrelated reference signals.

26. The method according to claim 24, characterized in that The at least two reference signals correspond to the same sequence; or, the at least two reference signals correspond to related sequences.

27. The method according to claim 24 or 25, characterized in that The at least two reference signals correspond to sequences of the same type.

28. The method according to claim 27, characterized in that The sequences corresponding to the at least two reference signals belong to the same candidate reference signal sequence group.

29. The method according to claim 25, characterized in that The at least two reference signals correspond to different sequences.

30. The method according to claim 29, wherein The sequences corresponding to the at least two reference signals belong to different candidate reference signal sequence groups.

31. The method according to claim 30, wherein The different candidate reference signal sequence groups differ in at least one of the following aspects: Sequence type; sequence length; sequence generation parameters.

32. The method according to any one of claims 23 to 31, characterized in that The reference signal carries information via a sequence.

33. The method according to claim 32, characterized in that The information includes at least one of the following: PCI; AP ID; intermediate node identification; data transmission rate; data transmission mode; time information of the reference signal; The intermediate node includes a node between the network device and the low-power device.

34. The method according to claim 32 or 33, characterized in that The sequence corresponding to the reference signal is mapped on the time domain unit.

35. The method according to any one of claims 23 to 34, characterized in that The at least two reference signals are reference signals within the same reference signal period.

36. The method according to any one of claims 23 to 35, characterized in that The at least two reference signals are reference signals sent respectively in different reference signal periods.

37. The method according to any one of claims 23 to 36, characterized in that The third time domain interval is determined by at least one of the following methods, where the third time domain interval includes a configured time domain interval between adjacent reference signals among the at least two reference signals, and the third time domain interval is used to determine the second time domain interval: The third time domain interval is predefined by the protocol; the third time domain interval is indicated by the power supply signal of the low-power device; the third time domain interval is indicated by the reference signal and / or the data packet associated with the reference signal.

38. The method according to claim 37, wherein The reference signal and / or the data packet carries the third time domain interval.

39. The method according to claim 37 or 38, characterized in that The reference signal and / or the data packet carries a first value, where the first value is used to indicate the third time domain interval among multiple candidate time domain intervals.

40. The method according to claim 39, wherein The multiple candidate time domain intervals are predefined by the protocol.

41. The method according to any one of claims 37 to 40, characterized in that The reference signal and / or the data packet carries the time corresponding to the reference signal, and the third time domain interval is determined according to the difference between the times corresponding to adjacent reference signals.

42. The method according to any one of claims 37 to 41, characterized in that The reference signal and / or the data packet carries a second value, which is used to indicate the time corresponding to the reference signal among multiple candidate times, and the third time domain interval is determined according to the difference between the times corresponding to adjacent reference signals.

43. The method according to claim 42, characterized in that The multiple candidate times are predefined by the protocol.

44. The method according to any one of claims 23 to 43, characterized in that The first device includes at least one of the following: Network device; intermediate node; AP; device providing energy or carrier to the low-power device; The intermediate node includes a node between the network device and the low-power device.

45. A frequency calibration device, characterized in that: The device comprises: A receiving module, configured to receive at least two reference signals; The at least two reference signals are used to determine a first time domain interval, the first time domain interval is a measurement time domain interval of any two reference signals among the at least two reference signals, the first time domain interval and the second time domain interval are used for frequency calibration, and the second time domain interval is a reference time domain interval between the any two reference signals known to the device.

46. A frequency calibration device, characterized in that The device comprises: A sending module, configured to send at least two reference signals to the low-power device; In which, the at least two reference signals are used to determine a first time domain interval, the first time domain interval is the measurement time domain interval of any two reference signals among the at least two reference signals, the first time domain interval and the second time domain interval are used for frequency calibration, and the second time domain interval is the reference time domain interval between the any two reference signals known to the low-power device.

47. A low power consumption device, characterized in that: The low-power consumption device includes: processor; a transceiver connected to the processor; a memory for storing executable instructions for the processor; Wherein, the low-power consumption device is configured to receive at least two reference signals; In which, the at least two reference signals are used to determine a first time domain interval, the first time domain interval is the measurement time domain interval of any two reference signals among the at least two reference signals, the first time domain interval and the second time domain interval are used for frequency calibration, and the second time domain interval is the reference time domain interval between the any two reference signals known to the low-power device.

48. The low-power consumption device according to claim 47, characterized in that: The at least two reference signals are identical or related reference signals.

49. The low-power consumption device according to claim 47 or 48, characterized in that: The at least two reference signals are different or unrelated reference signals.

50. The low-power consumption device according to claim 48, wherein: The at least two reference signals correspond to the same sequence; or, the at least two reference signals correspond to related sequences.

51. The low-power consumption device according to claim 48 or 49, characterized in that: The at least two reference signals correspond to sequences of the same type.

52. The low-power consumption device according to claim 51, characterized in that: The sequences corresponding to the at least two reference signals belong to the same candidate reference signal sequence group.

53. The low-power consumption device according to claim 49, characterized in that The at least two reference signals correspond to different sequences.

54. The low-power consumption device according to claim 53, characterized in that: The sequences corresponding to the at least two reference signals belong to different candidate reference signal sequence groups.

55. The low-power consumption device according to claim 54, characterized in that: The different candidate reference signal sequence groups differ in at least one of the following aspects: Sequence type; sequence length; sequence generation parameters.

56. The low-power consumption device according to any one of claims 47 to 55, characterized in that: The reference signal carries information via a sequence.

57. The low-power consumption device according to claim 56, characterized in that The information includes at least one of the following: PCI; AP ID; intermediate node identification; data transmission rate; data transmission mode; time information of the reference signal; The intermediate node includes a node between the network device and the low-power device.

58. The low-power consumption device according to claim 56 or 57, characterized in that: The sequence corresponding to the reference signal is mapped on the time domain unit.

59. The low-power consumption device according to any one of claims 47 to 58, characterized in that: The at least two reference signals are reference signals within the same reference signal period.

60. The low-power consumption device according to any one of claims 47 to 59, characterized in that: The at least two reference signals are reference signals sent respectively in different reference signal periods.

61. The low-power consumption device according to any one of claims 47 to 60, characterized in that: The third time domain interval is determined by at least one of the following methods, where the third time domain interval includes a configured time domain interval between adjacent reference signals among the at least two reference signals, and the third time domain interval is used to determine the second time domain interval: The third time domain interval is predefined by the protocol; the third time domain interval is indicated by the power supply signal of the low-power device; the third time domain interval is indicated by the reference signal and / or the data packet associated with the reference signal.

62. The low-power consumption device according to claim 61, characterized in that: The reference signal and / or the data packet carries the third time domain interval.

63. The low-power consumption device according to claim 61 or 62, characterized in that: The reference signal and / or the data packet carries a first value, where the first value is used to indicate the third time domain interval among multiple candidate time domain intervals.

64. The low-power consumption device according to claim 63, characterized in that: The multiple candidate time domain intervals are predefined by the protocol.

65. The low-power consumption device according to any one of claims 61 to 64, characterized in that: The reference signal and / or the data packet carries the time corresponding to the reference signal, and the third time domain interval is determined according to the difference between the times corresponding to adjacent reference signals.

66. The low-power consumption device according to any one of claims 61 to 65, characterized in that: The reference signal and / or the data packet carries a second value, which is used to indicate the time corresponding to the reference signal among multiple candidate times, and the third time domain interval is determined according to the difference between the times corresponding to adjacent reference signals.

67. The low-power consumption device according to claim 66, characterized in that: The multiple candidate times are predefined by the protocol.

68. The low-power consumption device according to any one of claims 47 to 67, characterized in that: The reference signal is sent by a first device, where the first device includes at least one of the following: Network device; intermediate node; AP; device providing energy or carrier to the low-power device; The intermediate node includes a node between the network device and the low-power device.

69. A first device, characterized in that The first device includes: processor; a transceiver connected to the processor; a memory for storing executable instructions for the processor; The first device is configured to send at least two reference signals to the low-power device; In which, the at least two reference signals are used to determine a first time domain interval, the first time domain interval is the measurement time domain interval of any two reference signals among the at least two reference signals, the first time domain interval and the second time domain interval are used for frequency calibration, and the second time domain interval is the reference time domain interval between the any two reference signals known to the low-power device.

70. The first device according to claim 69, characterized in that The at least two reference signals are identical or related reference signals.

71. The first device according to claim 69 or 70, characterized in that The at least two reference signals are different or unrelated reference signals.

72. The first device according to claim 70, characterized in that The at least two reference signals correspond to the same sequence; or, the at least two reference signals correspond to related sequences.

73. The first device according to claim 70 or 71, characterized in that The at least two reference signals correspond to sequences of the same type.

74. The first device according to claim 73, characterized in that The sequences corresponding to the at least two reference signals belong to the same candidate reference signal sequence group.

75. The first device according to claim 71, characterized in that The at least two reference signals correspond to different sequences.

76. The first device according to claim 75, characterized in that The sequences corresponding to the at least two reference signals belong to different candidate reference signal sequence groups.

77. The first device according to claim 76, characterized in that The different candidate reference signal sequence groups differ in at least one of the following aspects: Sequence type; sequence length; sequence generation parameters.

78. The first device according to any one of claims 69 to 77, characterized in that The reference signal carries information via a sequence.

79. The first device according to claim 78, characterized in that The information includes at least one of the following: PCI; AP ID; intermediate node identification; data transmission rate; data transmission mode; time information of the reference signal; The intermediate node includes a node between the network device and the low-power device.

80. The first device according to claim 78 or 79, characterized in that The sequence corresponding to the reference signal is mapped on the time domain unit.

81. The first device according to any one of claims 69 to 80, characterized in that The at least two reference signals are reference signals within the same reference signal period.

82. The first device according to any one of claims 69 to 81, characterized in that The at least two reference signals are reference signals sent respectively in different reference signal periods.

83. The first device according to any one of claims 69 to 82, characterized in that The third time domain interval is determined by at least one of the following methods, where the third time domain interval includes a configured time domain interval between adjacent reference signals among the at least two reference signals, and the third time domain interval is used to determine the second time domain interval: The third time domain interval is predefined by the protocol; the third time domain interval is indicated by the power supply signal of the low-power device; the third time domain interval is indicated by the reference signal and / or the data packet associated with the reference signal.

84. The first device according to claim 83, characterized in that The reference signal and / or the data packet carries the third time domain interval.

85. The first device according to claim 83 or 84, characterized in that The reference signal and / or the data packet carries a first value, where the first value is used to indicate the third time domain interval among multiple candidate time domain intervals.

86. The first device according to claim 85, characterized in that The multiple candidate time domain intervals are predefined by the protocol.

87. The first device according to any one of claims 83 to 86, characterized in that The reference signal and / or the data packet carries the time corresponding to the reference signal, and the third time domain interval is determined according to the difference between the times corresponding to adjacent reference signals.

88. The first device according to any one of claims 83 to 87, characterized in that The reference signal and / or the data packet carries a second value, which is used to indicate the time corresponding to the reference signal among multiple candidate times, and the third time domain interval is determined according to the difference between the times corresponding to adjacent reference signals.

89. The first device according to claim 88, characterized in that The multiple candidate times are predefined by the protocol.

90. The first device according to any one of claims 69 to 89, characterized in that The first device includes at least one of the following: Network device; intermediate node; AP; device providing energy or carrier to the low-power device; The intermediate node includes a node between the network device and the low-power device.

91. A computer-readable storage medium, characterized in that The readable storage medium stores executable instructions, which are loaded and executed by a processor to implement the frequency calibration method according to any one of claims 1 to 44.

92. A chip, characterized in that: The chip includes a programmable logic circuit or a program, and the chip is used to implement the frequency calibration method according to any one of claims 1 to 44 based on the programmable logic circuit or the program.

93. A computer program product, characterized in that The computer program product includes computer instructions, which are stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device performs the frequency calibration method according to any one of claims 1 to 44.

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