Communication method and apparatus

Abstract

The present application relates to the technical field of communications. Provided are a communication method and apparatus. The method comprises: generating a first signal, wherein the first signal is used for calibrating a carrier frequency; and sending the first signal, wherein the first signal occupies X consecutive orthogonal frequency division multiplexing (OFDM) symbols and N frequency-domain resources, each frequency-domain resource occupies M consecutive subcarriers, the first signal occupies one of the N frequency-domain resources on any one of the X consecutive OFDM symbols, the N frequency-domain resources occupy NxM subcarriers, N is greater than or equal to 2, the value of M is 1 or 2, and X is greater than or equal to N. The first signal constructed in the present application does not occupy only one frequency-domain resource on the X consecutive OFDM symbols. The frequency-domain resources occupied by the first signal are constantly changing, and the constantly changing frequency may be relatively close to the deviation of a generated carrier frequency. On this basis, the efficiency of carrier frequency calibration can be improved. In addition, the complexity of carrier frequency calibration can be reduced.

Description

A communication method and apparatus

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411999551.3, filed with the State Intellectual Property Office of the People's Republic of China on December 31, 2024, entitled "A Communication Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0004] Low-power devices generate high-frequency carriers using crystal oscillators with very low accuracy and large carrier frequency errors, necessitating carrier frequency error calibration. However, calibrating the carrier frequency error using a carrier frequency calibration signal increases the power consumption and complexity of the low-power device if the carrier frequency calibration signal is applied to each time-domain symbol of the signal. Summary of the Invention

[0005] This application provides a communication method and apparatus to provide a signal for calibrating carrier frequency, thereby reducing the complexity and power consumption of low-power devices.

[0006] Firstly, this application provides a communication method that can be applied to a first device. For example, the executing entity may be the first device, a component within the first device (e.g., a communication module, processor, circuit, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the first device. For example, the first device may be a network device, a terminal device, or other device. Furthermore, the first device may also be referred to as a reader / writer; this application does not limit the specific form of the first device. The execution is as follows:

[0007] A first signal is generated and used to calibrate the carrier frequency; the first signal is then transmitted. The first signal occupies X consecutive orthogonal frequency division multiplexing (OFDM) symbols and N frequency domain resources. Each frequency domain resource occupies M consecutive subcarriers. The first signal occupies one of the N frequency domain resources on any one of the X consecutive OFDM symbols. The N frequency domain resources occupy N*M subcarriers, where N is greater than or equal to 2, M is 1 or 2, and X is greater than or equal to N.

[0008] Secondly, this application provides a communication method that can be applied to a second device. For example, the executing entity may be the second device, a component within the second device (e.g., a communication module, processor, circuit, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the second device. For example, the second device may be a terminal device or an Internet of Things (IoT) device. Furthermore, the second device may also be referred to as a tag; this application does not limit the specific form of the second device. The execution is as follows:

[0009] A first signal is received, which is used to calibrate the carrier frequency. The first signal occupies X consecutive OFDM symbols and N frequency domain resources. Each frequency domain resource occupies M consecutive subcarriers. The first signal occupies one of the N frequency domain resources on any one of the X consecutive OFDM symbols. The N frequency domain resources occupy N*M subcarriers, where N is greater than or equal to 2, M is 1 or 2, and X is greater than or equal to N. Carrier frequency error calibration is performed based on the first signal.

[0010] It should be noted that when X equals N, the first signal occupies N consecutive OFDM symbols and N frequency domain resources. The frequency domain resources occupied by any two OFDM symbols in the N consecutive OFDM symbols of the first signal do not overlap.

[0011] The first signal constructed in this application does not occupy only one frequency domain resource across X consecutive OFDM symbols; the frequency domain resource occupied by the first signal is continuously changing. This continuously changing frequency may be close to the deviation of the generated carrier frequency, thereby improving carrier frequency calibration efficiency. Furthermore, after the second device receives the first signal, it does not need to frequently calibrate the carrier frequency after each OFDM symbol mixing operation, thus reducing the complexity of carrier frequency calibration. Further, it reduces the power consumption of low-power devices.

[0012] In combination with the first or second aspect, in one alternative approach, X = L*N, the first signal occupies one of the N frequency domain resources on any one of the X consecutive OFDM symbols, including: the first signal occupies one frequency domain resource on every L consecutive OFDM symbols in the L*N consecutive OFDM symbols, where L is greater than 1.

[0013] Considering that the carrier frequency generated by the local crystal oscillator of the second device may be unstable, this application constructs the first signal by occupying the same frequency domain resources for L consecutive OFDM symbols, and the second device performs L mixing operations on the same frequency domain resources, which ensures the reliability of the frequency deviation obtained after mixing and improves the accuracy of carrier frequency calibration.

[0014] In an alternative manner, in conjunction with the first or second aspect, the first signal occupying one frequency domain resource per L consecutive OFDM symbols in L*N consecutive OFDM symbols includes: the frequency domain resource occupied by the first signal in the i-th consecutive L OFDM symbols is different from the frequency domain resource occupied in the j-th consecutive L OFDM symbols, i and j are different, i is greater than or equal to 1 and less than or equal to N, and j is greater than or equal to 1 and less than or equal to N.

[0015] When X is greater than N, the first signal occupies L*N consecutive OFDM symbols and N frequency domain resources. The frequency domain resources occupied by the first signal in the i-th consecutive L OFDM symbols are different from those occupied in the j-th consecutive L OFDM symbols, thus avoiding the overlap of frequency domain resources occupied by consecutive L OFDM symbols. Based on this, the N frequency domain resources are continuously distributed across L*N consecutive OFDM symbols at L OFDM symbol intervals. Therefore, the second device can guarantee the accuracy of carrier frequency calibration during the calibration process.

[0016] In combination with the first or second aspect, in one alternative approach, X = N, the first signal is spaced M subcarriers apart at the frequency start position of the frequency domain resources occupied by two adjacent OFDM symbols.

[0017] When the first signal occupies frequency domain resources in two adjacent OFDM symbols with a frequency start position interval of M subcarriers, the frequency domain resources occupied by the first signal on X consecutive OFDM symbols are continuous and exhibit a gradient distribution, which can be from high frequency to low frequency or from low frequency to high frequency. Based on this, the second device can improve the efficiency of carrier frequency calibration by referring to the time-frequency pattern of the first signal when performing carrier frequency calibration.

[0018] In conjunction with the second aspect, in one optional manner, X = N, when the second device determines that the carrier frequency offset error corresponding to the frequency domain resources occupied by the first signal in the Pth OFDM symbol meets the carrier frequency offset error threshold, it determines the frequency offset value between the frequency domain resources occupied by the first signal in the Pth OFDM symbol and the reference frequency of the first signal, where P is greater than or equal to 1 and less than or equal to N; and adjusts the carrier frequency according to the frequency offset value.

[0019] In an alternative approach, combining the first or second aspect, X = N, where the frequency starting position of the frequency domain resources occupied by the i-th OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the (i+1)-th OFDM symbol equals the bandwidth of the M subcarriers. Alternatively, the frequency starting position of the frequency domain resources occupied by the (i+1)-th OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the i-th OFDM symbol equals the bandwidth of the M subcarriers, where i is greater than or equal to 1 and less than or equal to N-1.

[0020] In one alternative approach, the frequency offset value is... SCS is the frequency spacing between adjacent subcarriers in an OFDM symbol.

[0021] In conjunction with either the first or second aspect, in one optional manner, the frequency starting position of the frequency domain resources occupied by the j-th OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the (j+1)-th OFDM symbol equals the bandwidth of M subcarriers, and the frequency starting position of the frequency domain resources occupied by the (k+1)-th OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the k-th OFDM symbol equals the bandwidth of M subcarriers. Alternatively, the frequency starting position of the frequency domain resources occupied by the (j+1)-th OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the j-th OFDM symbol equals the bandwidth of M subcarriers, and the frequency starting position of the frequency domain resources occupied by the k-th OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the (k+1)-th OFDM symbol equals the bandwidth of M subcarriers. Wherein, 1≤j≤Q-2, Q≤k≤N-1, 2≤Q≤N-2, the first position of the (Q-1)th OFDM symbol in X consecutive OFDM symbols is the same as the reference frequency of the first signal, wherein the first position is one of the following positions: the frequency start position of the frequency domain resource occupied by the (Q-1)th OFDM symbol, the frequency end position of the frequency domain resource occupied by the (Q-1)th OFDM symbol, or the frequency center position of the frequency domain resource occupied by the (Q-1)th OFDM symbol; and / or, the second position of the Qth OFDM symbol is the same as the reference frequency of the first signal, wherein the second position is one of the following positions: the frequency start position of the frequency domain resource occupied by the Qth OFDM symbol, the frequency end position of the frequency domain resource occupied by the Qth OFDM symbol, or the frequency center position of the frequency domain resource occupied by the Qth OFDM symbol.

[0022] In one alternative approach, when P is greater than Q, the frequency offset is (PQ)*SCS*M, and when P is less than Q, the frequency offset is (QP)*SCS*M, where SCS is the frequency spacing between adjacent subcarriers in an OFDM symbol.

[0023] In conjunction with the second aspect, in one optional manner, when the second device determines that the carrier frequency offset error corresponding to the frequency domain resources occupied by the first signal in the Pth consecutive L OFDM symbols meets the carrier frequency offset error threshold, it determines the frequency offset value between the frequency domain resources occupied by the first signal in the Pth consecutive L OFDM symbols and the reference frequency of the first signal. P is greater than or equal to 1 and less than or equal to N; the carrier frequency is adjusted according to the frequency offset value.

[0024] Based on this, after receiving the first signal, the second device does not need to frequently calibrate the carrier frequency after each OFDM symbol mixing operation. Carrier frequency calibration is only performed when the carrier frequency offset error corresponding to the frequency domain resources occupied by the first signal in a certain OFDM symbol meets the carrier frequency offset error threshold. This avoids frequent carrier frequency adjustments and reduces the complexity of carrier frequency calibration. Furthermore, it also saves power consumption for the second device.

[0025] In combination with the first or second aspect, in one alternative approach, X = L * N, the frequency starting position of the frequency domain resources occupied by the first signal in the i-th consecutive L OFDM symbols is spaced M subcarriers apart from the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols, where i is greater than or equal to 1 and less than or equal to N-1.

[0026] When X = L*N, and the frequency starting position of the frequency domain resources occupied by the first signal in the i-th consecutive L OFDM symbols is separated from the frequency starting position of the frequency domain resources occupied in the (i+1)-th consecutive L OFDM symbols by M subcarriers, the frequency domain resources occupied by the first signal in the X consecutive OFDM symbols are continuous and exhibit a gradient distribution, which can be from high frequency to low frequency or from low frequency to high frequency. Based on this, when the second device performs carrier frequency calibration, referring to the time-frequency pattern of the first signal can improve the efficiency of carrier frequency calibration.

[0027] In combination with the first or second aspect, in one alternative approach, the frequency offset value is SCS is the frequency spacing between adjacent subcarriers in an OFDM symbol. Each L frequency domain symbols occupies the same frequency domain resources, improving the accuracy of frequency calibration.

[0028] In an alternative approach, combining the first or second aspect, X = L * N, where the frequency starting position of the frequency domain resources occupied by the i-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols equals the bandwidth of the M subcarriers. Alternatively, the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the i-th consecutive L OFDM symbols equals the bandwidth of the M subcarriers.

[0029] In an optional approach, combining the first or second aspect, X = L*N, where the frequency starting position of the frequency domain resources occupied by the j-th consecutive L OFDM symbols minus the frequency starting position of the (j+1)-th consecutive L OFDM symbols equals the bandwidth of M subcarriers, and the frequency starting position of the frequency domain resources occupied by the (k+1)-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the k-th consecutive L OFDM symbols equals the bandwidth of M subcarriers. Alternatively, the frequency starting position of the frequency domain resources occupied by the (j+1)-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the j-th consecutive L OFDM symbols equals the bandwidth of M subcarriers, and the frequency starting position of the frequency domain resources occupied by the k-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the (k+1)-th consecutive L OFDM symbols equals the bandwidth of M subcarriers. Wherein, 1≤j≤Q-2, Q≤k≤N-1, 2≤Q≤N-2, the first position of the (Q-1)th OFDM symbol in X consecutive OFDM symbols is the same as the reference frequency of the first signal, wherein the first position is one of the following positions: the frequency start position of the frequency domain resource occupied by the (Q-1)th OFDM symbol, the frequency end position of the frequency domain resource occupied by the (Q-1)th OFDM symbol, or the frequency center position of the frequency domain resource occupied by the (Q-1)th OFDM symbol; and / or, the second position of the Qth OFDM symbol is the same as the reference frequency of the first signal, wherein the second position is one of the following positions: the frequency start position of the frequency domain resource occupied by the Qth OFDM symbol, the frequency end position of the frequency domain resource occupied by the Qth OFDM symbol, or the frequency center position of the frequency domain resource occupied by the Qth OFDM symbol.

[0030] Based on this, when performing carrier frequency calibration, the second device can improve the efficiency of carrier frequency calibration by referring to the time-frequency pattern of the first signal. This enables the device to find the corresponding frequency error and perform carrier frequency error calibration regardless of whether the carrier frequency error is positive or negative.

[0031] In combination with the first or second aspect, in one alternative approach, the frequency offset value is SCS is the frequency spacing between adjacent subcarriers in an OFDM symbol.

[0032] In conjunction with the first or second aspect, in one alternative approach, the reference frequency of the first signal is one of the following: the lowest frequency position of the N frequency domain resources, the highest frequency position of the N frequency domain resources, the corresponding synchronization grid frequency in the first signal, or the frequency corresponding to the channel grid in the first signal.

[0033] When the first signal uses different time-frequency patterns, the frequency domain position of the reference frequency of the first signal is also different. However, it is ensured that the frequency domain position of the first signal can cover the positive and negative frequency errors of the reference frequency. Under any carrier error situation, it is convenient for the second device to accurately determine the frequency deviation value of the carrier signal and ensure the reliability of carrier frequency calibration.

[0034] In conjunction with either the first or second aspect, in one optional manner, the third position of the frequency domain resource occupied by the S-th OFDM symbol among X consecutive OFDM symbols is the same as the reference frequency of the first signal, where S is a positive integer less than or equal to N. The third position is one of the following: the starting position of the frequency domain resource occupied by the S-th OFDM symbol, the ending position of the frequency domain resource occupied by the S-th OFDM symbol, or the center position of the frequency domain resource occupied by the S-th OFDM symbol.

[0035] Based on this, the time-domain symbol corresponding to the reference frequency of the first signal can be clearly identified, which facilitates the second device to calculate the frequency offset value based on the index of the time-domain symbol in the first signal.

[0036] Combining the first or second aspect, in one alternative way, S equals or Or 1 or X, To round down, This is for rounding up.

[0037] In conjunction with the first or second aspect, in one alternative manner, the first device sends first information, and correspondingly, the second device receives the first information, the first information being used to indicate the reference frequency of the first signal.

[0038] Based on this, the second device does not need to blindly detect multiple possible reference frequencies of the first signal, thus reducing the processing complexity of the second device.

[0039] Thirdly, embodiments of this application provide a communication device, which can be a first device or a second device. The communication device has the functions described in the first and second aspects above. For example, the communication device includes modules, units, or means that perform the steps involved in the first and second aspects above. These functions, units, or means can be implemented by software, hardware, or hardware executing corresponding software.

[0040] In one possible design, the communication device includes a processing unit and a transceiver unit. The transceiver unit can be used to send and receive signals to enable communication between the communication device and other devices. The processing unit can be used to perform some internal operations of the communication device. The transceiver unit can be called an input / output unit, a communication unit, etc., and can be a transceiver; the processing unit can be a processor. When the communication device is a module (e.g., a chip) in a communication device, the transceiver unit can be an input / output interface, input / output circuit, or input / output pins, etc., and can also be called an interface, communication interface, or interface circuit, etc.; the processing unit can be a processor, processing circuit, or logic circuit, etc.

[0041] In another possible design, the communication device includes a processor and may further include a transceiver for transmitting and receiving signals. The processor executes program instructions to perform the methods in any of the possible designs or implementations of the first to second aspects described above. The communication device may also include one or more memories coupled to the processor, which may store necessary computer programs or instructions for implementing the functions involved in the first to second aspects described above. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, the communication device implements the methods in any of the possible designs or implementations of the first to second aspects described above.

[0042] In another possible design, the communication device includes a processor that can be coupled to a memory. The memory can store necessary computer programs or instructions for implementing the functions described in the first to second aspects above. The processor can execute the computer programs or instructions stored in the memory, causing the communication device to implement the methods in any possible design or implementation of the first to second aspects above, when the computer programs or instructions are executed.

[0043] In another possible design, the communication device includes a processor and an interface circuit, wherein the processor is used to communicate with other devices through the interface circuit and to perform the methods in any possible design or implementation of the first to second aspects described above.

[0044] Understandably, in the third aspect described above, the processor can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, integrated circuit, etc.; when implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. Furthermore, there can be one or more processors, and one or more memories. The memory can be integrated with the processor or separated from it. In specific implementations, the memory can be integrated with the processor on the same chip or disposed on different chips. This application does not limit the type of memory or the arrangement of the memory and processor.

[0045] Fourthly, embodiments of this application provide a communication system, which includes the first device and the second device described above.

[0046] Fifthly, this application provides a chip system including a processor and potentially a memory, for implementing the methods described in the first to second aspects above. The chip system may be composed of chips or may include chips and other discrete devices.

[0047] Sixthly, this application also provides a computer-readable storage medium, which may be a volatile storage medium or a non-volatile storage medium, wherein the computer-readable storage medium stores computer-readable instructions, which, when executed on a computer, cause the computer to perform the methods as described in the first to second aspects.

[0048] In a seventh aspect, this application provides a computer program product containing instructions that, when run on a computer, cause the computer to perform the methods of the embodiments of the first to second aspects described above. Attached Figure Description

[0049] Figure 1 is a schematic diagram of the backscattering system.

[0050] Figures 2 and 3 are schematic diagrams of the communication system applicable to the embodiments of this application;

[0051] Figures 4A and 4B are schematic diagrams of the A-IoT structure;

[0052] Figure 5 is a flowchart illustrating a communication method provided in an embodiment of this application;

[0053] Figures 6 to 13 are schematic diagrams of the time-frequency pattern of a first signal provided in an embodiment of this application;

[0054] Figure 14 is a schematic diagram of a communication device provided in an embodiment of this application;

[0055] Figure 15 is a schematic diagram of another structure of the communication device provided in the embodiment of this application. Detailed Implementation

[0056] In the embodiments of this application, the solutions in each embodiment can be used in a reasonable combination, and the explanations or descriptions of various terms, similar operations, or steps appearing in the embodiments can be referenced or explained to each other in the embodiments, without limitation.

[0057] In the embodiments of this application, "transmission" includes "sending" and / or "receiving." "Sending" and "receiving" indicate the direction of signal transmission. For example, "sending information to XX" can be understood as the destination of the information being XX, which can include direct transmission via the air interface or indirect transmission by other units or modules via the air interface. "Receiving information from YY" can be understood as the source of the information being YY, which can include direct reception from YY via the air interface or indirect reception from YY by other units or modules via the air interface. "Sending" can also be understood as the "output" of a chip interface, and "receiving" can also be understood as the "input" of a chip interface. In other words, sending and receiving can occur between devices, such as between access network devices and terminal devices, or within a device, such as between components, modules, chips, software modules, or hardware modules within the device via a bus, wiring, or interface.

[0058] In this application embodiment, the number of nouns, unless otherwise specified, refers to "singular nouns or plural nouns," that is, "one or more." "At least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A / B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. For example, A / B means: A or B. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and / or c means the following combinations: a exists alone, b exists alone, c exists alone, a and b exist simultaneously, a and c exist simultaneously, b and c exist simultaneously, or a, b, and c exist simultaneously, where a, b, and c can be single or multiple.

[0059] In the embodiments of this application, "when," "if," and "if" all refer to the device taking corresponding actions under certain objective circumstances, and are not time-limited, nor do they require the device to perform a judgment action, nor do they imply any other limitations. Unless otherwise specified, "if" and "if" are interchangeable, and "when" and "in the case of" are interchangeable. "When" and "if" / "if" are interchangeable. "Associated" and "corresponding" are interchangeable.

[0060] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0061] In this application, the ordinal numbers such as "first" and "second" are used to distinguish multiple objects, and are not used to limit the size, content, order, timing, priority, or importance of the multiple objects. For example, the first parameter and the second parameter refer to two different parameters, and do not indicate a difference in the priority or importance of these two parameters.

[0062] The technical solutions provided in the embodiments of this application can be applied to various communication systems, such as cellular systems related to the 3rd Generation Partnership Project (3GPP), such as Long Term Evolution (LTE) communication systems, 5th Generation (5G) mobile communication systems / New Radio (NR) communication systems, or future-oriented evolution systems, or other similar communication systems. Other similar communication systems include Wireless Fidelity (WiFi), Vehicle-to-Everything (V2X), Spark Link systems, Bluetooth systems, Near Field Communication (NFC) systems, and Internet of Things (IoT) systems, such as Ambient IoT (A-IoT / A-IoT) and Narrow Band Internet of Things (NB-IoT). Alternatively, the solutions provided in the embodiments of this application can also be applied to communication systems that integrate two or more of the above systems. It should be understood that IoT technology is widely used in various industries; for example, IoT technology can be applied to scenarios such as logistics, warehousing, industrial manufacturing, identity recognition, or environmental monitoring.

[0063] The technical solution provided in this application is applicable to backscattering systems. A backscattering system generally consists of an exciter, a receiver, and a transmitter. Its communication link includes a downlink from the exciter to the reflector and an uplink from the reflector to the receiver. Figure 1 illustrates a backscattering system using a tag and a reader. The reader can send a carrier signal to the tag, which receives the carrier signal through an antenna. The solid line in Figure 1 represents the carrier signal sent by the reader, and the dashed line represents the reflected signal transmitted by the tag based on the carrier signal reflection. The tag can adjust the information to be transmitted in the reflected signal. Through this method, the tag uses a low-precision, low-power, mid-to-low frequency ring oscillator or a completely oscillator-free method to receive downlink signals, further reducing the power consumption of the tag's downlink reception. Optionally, the carrier can also be understood as an excitation signal, which can be sent by other devices besides the reader or devices integrated into the reader (e.g., external nodes).

[0064] For example, please refer to Figure 2, which illustrates a communication system to which this application embodiment applies. As shown in Figure 2, the communication system includes a network device and an A-IoT device. The A-IoT device can be a standalone device, or it can be integrated with a terminal device, i.e., the A-IoT device is part of the terminal device. In this communication system, the network device can communicate with the A-IoT device. It should be noted that Figure 1 uses the example of a network device communicating with the A-IoT device. In possible scenarios, the device communicating with the A-IoT device can be other than a network device, such as a terminal device.

[0065] For example, please refer to Figure 3, which shows a schematic diagram of another communication system applicable to embodiments of this application. As shown in Figure 3, the communication system includes a network device, an intermediate node, and an A-IoT device, wherein the intermediate node can forward information between the network device and the A-IoT device. Figure 2 uses a terminal device as an example of an intermediate node, that is, the terminal device acts as an intermediate node between the network device and the A-IoT device. The A-IoT device transmits information to the terminal device, and the terminal device forwards the information to the network device through the Uu interface; or, the network device transmits information to the terminal device, and the terminal device then forwards the information to the A-IoT device; or, based on resources pre-authorized or pre-configured by the network device, the terminal device conducts bidirectional communication with the A-IoT device through the A-IoT air interface.

[0066] Intermediate nodes can also be devices other than terminal devices, such as network devices. This network device can be located outdoors, while the terminal device and the A-IoT device can be located indoors. Essentially, the outdoor network device communicates with the indoor A-IoT device through an indoor intermediate node. Optionally, the intermediate node can be called an intermediate UE (User Equipment). For another example, an intermediate node can be an integrated access and backhaul (IAB) node. An IAB node can act as an intermediary between the network device and the A-IoT device. The A-IoT device transmits information to the IAB node, and the IAB node forwards this information to the network device via the Uu interface; alternatively, the network device transmits information to the IAB node, and the IAB node then forwards the information to the A-IoT device. Based on pre-authorized or pre-configured resources of the network device, the IAB node can also communicate bidirectionally with the A-IoT device via the A-IoT air interface. For yet another example, an intermediate node can be a relay node. Relay nodes can act as intermediary nodes between network devices and A-IoT devices. A-IoT devices transmit information to the relay node, and the relay node forwards this information to the network device via the Uu interface; alternatively, network devices transmit information to the relay node, and the relay node then forwards the information to the A-IoT device. Based on pre-authorized or pre-configured resources of the network device, relay nodes can also conduct bidirectional communication with A-IoT devices via the A-IoT air interface.

[0067] Optionally, the energy required for the A-IoT device to transmit information is provided by an excitation signal, which can come from an exciter. This exciter can be a network device, a terminal device, or a device other than a network device or a terminal device. In possible scenarios, the functions of the device communicating with the A-IoT device (e.g., a reader / writer) can be further separated. Functionally, the reader / writer can be divided into a receiver and an exciter, which can be deployed on different network devices. For example, the receiver is deployed on a first network device, and the exciter on a second network device. The first network device performs the reader / writer's receiving function. The second network device performs the reader / writer's transmitting function. The receiver is also called a receiving end or receiving unit, and the exciter is also called an excitation end or excitation unit.

[0068] In this embodiment, network equipment refers to radio access network (RAN) equipment / RAN node. In this embodiment, (R)AN and RAN are interchangeable; for ease of description, RAN is used as an example below. RAN can be a cellular system related to the 3rd generation partnership project (3GPP). RAN can also be an open RAN (O-RAN or ORAN), a cloud radio access network (CRAN), a virtualized RAN (vRAN), a non-terrestrial network (NTN), etc. RAN can also be a communication system that integrates two or more of the above systems. RAN equipment can also be called a RAN node, RAN entity, or access node, etc.

[0069] In one possible scenario, a RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), or a base station in a future mobile communication system. RAN nodes can also be macro base stations, micro base stations, indoor stations, relay nodes, donor / host nodes, or radio controllers. RAN nodes can also be servers, wearable devices, vehicles, or in-vehicle equipment. For example, in V2X technology, the RAN node can be a roadside unit (RSU).

[0070] In another possible scenario, the RAN node can be a module or unit that performs some of the functions of the base station; or multiple RAN nodes can cooperate to assist terminal equipment in achieving wireless access, with different RAN nodes performing some of the functions of the base station. For example, the RAN node can be a central unit (CU), a distributed unit (DU), or a remote unit (RU). The function of the CU can be implemented by a single entity or by different entities. For example, the function of the CU can be further divided, that is, the control plane and the user plane can be separated and implemented by different entities, namely the control plane CU entity (i.e., CU-control plane (CP) entity) and the user plane CU entity (i.e., CU-user plane (UP) entity). The CU-CP entity and the CU-UP entity can be coupled with the DU to jointly complete the function of the RAN node. The CU and DU can be set up separately or included in the same network element, such as in the baseband unit (BBU). Any of the units among the CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented by software modules, hardware modules, or a combination of software modules and hardware modules.

[0071] The CU and DU can be configured according to the protocol layer functions of the wireless network they implement: for example, the CU can be configured to implement the functions of the Packet Data Convergence Protocol (PDCP) layer and above (such as the Radio Resource Control (RRC) layer and / or the Service Data Adaptation Protocol (SDAP) layer); the DU can be configured to implement the functions of the protocol layers below the PDCP layer (such as the Radio Link Control (RLC) layer, the Media Access Control (MAC) layer, and / or the Physical (PHY) layer). For specific descriptions of the above protocol layers, please refer to the relevant 3GPP technical specifications or the technical specifications of other applicable communication protocols.

[0072] The above division of the processing functions of CU and DU according to protocol layers is merely an example; other division methods are also possible, and this application does not limit this. For example, in one design, CU or DU can be further divided into processing functions with protocol layers. In one design, some functions of the RLC layer and the functions of the protocol layer above the RLC layer are located in the CU, while the remaining functions of the RLC layer and the functions of the protocol layer below the RLC layer are located in the DU.

[0073] When the RAN is O-RAN, it can also have artificial intelligence (AI) capabilities. For example, O-RAN includes an intelligent controller. The intelligent controller can be a non-real-time RAN intelligent controller (RIC / non-RT RIC / NRT RIC) or a near-real-time RAN intelligent controller (RIC / nRT RIC / nRT RIC). A non-real-time RIC can be used to implement non-real-time intelligent management of RAN functions, enabling workflows including model training and model updates, and guiding applications / functions in the nRT RIC based on policies. A near-real-time RIC can be used to implement near-real-time intelligent management of the RAN. Through data collection and related operations on the E2 interface, near-real-time control and optimization of O-RAN modules and resources are achieved.

[0074] In the embodiments of this application, the means for implementing the functions of the network device can be the network device itself, or it can be a means that supports the network device in implementing the functions, such as a chip system or a combination of devices or components that can implement the functions of the network device. This means can be installed in the network device. The embodiments of this application do not limit the specific technology or specific device form used in the network device.

[0075] In this application embodiment, anything capable of data communication with a base station can be considered a terminal device. Terminal devices are also called terminals, terminal equipment, user equipment (UE), mobile stations, or mobile terminals, etc. Terminal devices can be widely used in various scenarios. For example, terminal devices can be: mobile phones, computers, mobile internet devices (MID), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, stations (STA), robotic arms, cameras, robots, vehicles, drones, helicopters, airplanes, ships, or smart home devices (such as televisions, air conditioners, robot vacuums, speakers, set-top boxes), relays, customer premises equipment (CPE), etc.

[0076] Furthermore, in this embodiment, the terminal device can also be a terminal device in an IoT system, such as a water meter, electricity meter, electronic tag / label, etc. IoT is an important component of future information technology development. Its main technical characteristic is connecting objects to networks through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection.

[0077] When the terminal device is applied to V2X, it can also be called a V2X device, such as a smart car, an unmanned car, a driverless car, a pilotless car, or an automobile, or a roadside unit (RSU). All the terminal devices described above, if located on a vehicle (e.g., placed / installed inside the vehicle), can be considered in-vehicle terminal devices. In-vehicle terminal devices can be built into a vehicle's in-vehicle module, in-vehicle component, in-vehicle chip, or in-vehicle unit as one or more components or units. The vehicle can implement the methods of this application through the built-in in-vehicle module, in-vehicle component, in-vehicle chip, or in-vehicle unit. Vehicle-mounted terminal equipment can be vehicle equipment, vehicle-mounted modules, vehicles, on-board units (OBU), RSUs, vehicle infotainment systems (or on-board transmitting units) (telematics boxes, T-boxes), chips, or systems on chips (SoCs), etc. The aforementioned chips or SoCs can be installed in vehicles, OBUs, RSUs, or T-boxes.

[0078] In the embodiments of this application, the device for implementing the functions of the terminal device can be the network device itself, or it can be a device that supports the terminal device in implementing the functions, such as a chip system or a combination of devices or components that can implement the functions of the terminal device. This device can be installed in the terminal device. The embodiments of this application do not limit the specific technology or specific device form used in the terminal device.

[0079] The Internet of Things (IoT) can encompass a variety of devices, including smart water meters, shared bicycles, and devices for sensing and data collection in areas such as smart cities, environmental monitoring, smart homes, and forest fire prevention. To increase the number of devices that can be accommodated in IoT scenarios, reducing the size of IoT devices is generally a trend. However, due to various factors, the size of IoT devices cannot be minimized; for example, IoT devices require high-capacity batteries. Therefore, for IoT devices with limited size, it is not feasible to incorporate high-capacity batteries, and the goal is to reduce the power consumption of IoT devices to extend their battery life.

[0080] Compared to NR terminal devices (e.g., NR terminal devices of release (R) 15, R16, R17), A-IoT devices have at least one of the following characteristics:

[0081] 1) Maximum Bandwidth: The maximum bandwidth of an A-IoT device can be less than the maximum bandwidth of R15 and R16 terminal devices (e.g., 100MHz). The maximum bandwidth of an A-IoT device can also be less than the maximum bandwidth of the reduced capability (RedCap) in R17 terminal devices (e.g., 20MHz). For example, the maximum bandwidth of an A-IoT device is 1 resource block (RB), 1.44MHz, 1.5MHz, 2.88MHz, 3MHz, etc.

[0082] 2) Number of antennas supported: A-IoT devices support one transmit antenna and one receive antenna, or A-IoT devices support one transmit antenna and two receive antennas.

[0083] 3) The transmission channels of A-IoT devices and readers are not aligned with the start and / or boundaries of NR time slots, frames, symbols, etc.

[0084] 4) The transmission between A-IoT devices and readers uses a single-carrier waveform.

[0085] 5) The transmission channel from the reader to the A-IoT device is not aligned with the start and / or end boundaries of the NR's time slots, frames, etc.; the transmission channel from the reader to the A-IoT device is aligned with the start and / or end boundaries of the NR's OFDM symbols.

[0086] 6) The transmission from the reader to the A-IoT device uses OFDM waveform.

[0087] 7) A-IoT devices support at least one of the following modulation methods: binary on-off keying (OOK), frequency-shift keying (FSK), binary phase shift keying (BPSK), and minimum shift keying (MSK). FSK can also be called binary frequency shift keying (BFSK), 2FSK, or OOK-FSK.

[0088] IoT devices include those requiring batteries (also known as IoT devices with energy storage or active IoT devices), those without batteries (also known as IoT devices without energy storage or passive IoT devices), and those with limited energy storage (also known as semi-passive IoT devices). IoT devices with limited energy storage do not require manual battery replacement or charging. Active IoT devices can independently generate signals and have active radio frequency components for transmission. Passive IoT devices have no energy storage, cannot independently generate signals, and transmit based on backscatter communications. Semi-passive IoT devices have energy storage but cannot independently generate signals and transmit based on backscatter communications. Passive or semi-passive IoT devices can also be called A-IoT devices; A-IoT devices can provide services and communicate by harvesting energy from the environment.

[0089] A typical IoT device is a tag. Tags can also be called RFID tags, electronic tags, or IoT tags. In this embodiment, the tag can function as a terminal device to communicate with network devices. The term "tag" is merely an optional designation and may change; for example, "A-IoT tag" may be replaced with other names. This embodiment does not limit the name used. For ease of description, the term "tag" will continue to be used as an example below.

[0090] The tag uses a low-precision, low-power mid-to-low frequency ring oscillator or a completely oscillator-less receiver to receive downlink signals. When the tag is operating, the energy and / or carrier for communication are supplied by the reader, and communication is based on a reflected carrier.

[0091] A tag is a miniature wireless transceiver device, mainly consisting of a built-in antenna, coupling element, and chip. The tag's chip contains storage space that enables a reader to read or write tag data. After receiving radio frequency (RF) signals from the reader via its antenna, the tag can couple these signals through the coupling element. This coupling channel allows power to be supplied to the tag's chip, and the data stored in the chip can be fed back to the reader via the antenna. A communication network based on cellular network infrastructure, including readers and tags, can be called A-IoT.

[0092] There are various types of A-IoT devices, and this application does not limit the methods for classifying A-IoT device types. Several methods for classifying A-IoT device types are illustrated below.

[0093] In classification method 1, A-IoT devices can be divided into three categories: Type 1 (also known as device1), Type 2 (also known as device2a), and Type 3 (also known as device2b). Type 1 A-IoT devices do not support uplink or downlink amplification, and their uplink transmission relies on an externally provided carrier wave using backscatter, rather than generating its own signal. Type 2 A-IoT devices support either uplink or downlink amplification, and their uplink transmission relies on an externally provided carrier wave using backscatter, also without generating its own signal. Type 3 A-IoT devices support either uplink or downlink amplification, and their uplink transmission relies on an internally generated carrier wave.

[0094] Optionally, Type 1 A-IoT devices have an output power consumption of approximately 1 μW and some energy storage capacity. Type 2 A-IoT devices have a peak power of no more than several hundred μW. Type 3 A-IoT devices have a peak power of no more than several hundred μW.

[0095] Optionally, the initial sampling frequency offset (SFO) of Type 1 A-IoT devices is at most 10. X1 ppm, X1 can be 5, 4, 3, or 2. The maximum initial sampling clock skew for Type 2 A-IoT devices is 10. X2 ppm, X2 can be 5, 4, 3, or 2. The maximum initial sampling clock skew for Type 3 A-IoT devices is 10. X3 ppm, X3 can be 5, 4, 3 or 2.

[0096] As shown in Figure 4A, Type 1 A-IoT devices include:

[0097] 1. Antenna: It can be shared or separated for receiving radio frequency (RF) energy and for receiving / transmitting.

[0098] 2. Matching network: Matches the impedance between the antenna and other components (including modules related to the RF energy harvester and receiver).

[0099] 3. RF energy harvester: including rectifiers used to convert radio frequency signals (AC) into DC.

[0100] 4. Energy storage device (e.g., capacitor): Stores the collected energy from the RF energy receiver.

[0101] 5. Power Management Unit (PMU): Manages the energy stored in the energy harvester and provides energy to active modules that require energy supply.

[0102] 6. Digital baseband logic: This includes functional modules such as encoders, decoders, and controllers.

[0103] 7. Memory: Includes two types of memory: 1) Non-volatile memory, such as electrically erasable programmable read-only memory (EEPROM, EEPROM); 2) Registers that temporarily store information, which can only store information when there is sufficient energy in the energy storage.

[0104] 8. Clock generator: Provides clock signals.

[0105] 9. Receive related modules, such as:

[0106] 1) RF bandpass filter (BPF): Improves frequency selectivity.

[0107] 2) RF envelope detector: Converts RF signals to baseband.

[0108] 3) Baseband low-pass filter (LPF): Filters out harmonics and high-frequency components, improving the signal quality input to the comparator.

[0109] 4) Comparator: determines the high / low (level) of the input signal.

[0110] 10. Transmit-related modules, such as: backscatter modulator: switch impedance to modulate the backscatter signal with the transmit signal from the baseband logic.

[0111] 11. Clock generator: Provides clock signals.

[0112] As shown in Figure 4B, Type 2 A-IoT devices include:

[0113] 1. Antenna: The RF energy reception and receiver / transmitter can be shared or separated.

[0114] 2. Matching network: Matches the impedance between the antenna and other components (including modules related to the RF energy harvester and receiver).

[0115] 3. RF energy harvester: includes a rectifier that converts radio frequency signals (AC) into DC.

[0116] 4. Energy Management Unit (PMU): Manages the energy stored from the energy harvester and provides energy to the active modules that need energy supply.

[0117] 5. Digital baseband logic: This includes functional modules such as encoders, decoders, and controllers.

[0118] 6. Memory: Includes two types of memory: 1) Non-volatile memory, such as EEPROM. 2) Registers that temporarily store information, which can only store information when there is sufficient energy in the energy storage.

[0119] 7. Clock generator: Provides clock signals.

[0120] 8. Local oscillator (LO): Generates the carrier frequency for the transmitter or the carrier frequency offset for the intermediate frequency (IF) receiver.

[0121] 9. Receiving relevant modules, such as:

[0122] 1) RF bandpass filter (BPF): Improves frequency selectivity.

[0123] 2) Mixer: Converts RF signals to intermediate frequency signals.

[0124] 3) Intermediate frequency (IF) amplifier (amf): amplifies intermediate frequency signals.

[0125] 4) Intermediate Frequency (IF) Filter: The intermediate frequency filter removes unwanted RF and LO signals.

[0126] 5) Intermediate frequency (IF) envelope demodulation (ED): Detecting the envelope from the intermediate frequency signal.

[0127] 6) Baseband circuit test board (bread board, BB) amplifier (amf): depending on the implementation, may or may not be present.

[0128] 7) Baseband BB low-pass filter LPF: Filters out harmonics and high-frequency components, improving the signal quality input to the comparator / analog-to-digital converter (ADC).

[0129] 8) Comparator / N-bit ADC.

[0130] 10. Launch-related modules, such as:

[0131] 1) Transmit modulation: Modulate baseband bits according to the modulation method. This part can be part of the baseband logic module.

[0132] 2) Digital-to-analog converter (DAC): Converts digital signals into analog signals.

[0133] 3) Low-pass filter (LPF): Filters out unwanted signals.

[0134] 4) Mixer: Upconverts baseband signals to the RF frequency range.

[0135] 5) Power amplifier (PA): If present, amplifies the transmitted signal.

[0136] 11. Energy storage device (e.g., capacitor): Stores the collected energy from the RF energy receiver.

[0137] In addition, the chip shown in Figure 4B also includes a low noise amplifier (LNA) and an energy harvester (other than RF).

[0138] In classification method 2, A-IoT devices can be divided into three categories: passive A-IoT devices, semi-passive A-IoT devices, and active A-IoT devices. Among them, passive A-IoT devices and semi-passive A-IoT devices can use reflection-based communication methods, while active A-IoT devices use actively generated carrier communication methods.

[0139] In classification method 3, A-IoT devices can also be divided into three categories: device A, device B, and device C. Device A has no energy storage and cannot generate signals independently; it uses backscattering to transmit signals. Device B has energy storage but cannot generate signals independently; it also uses backscattering to transmit signals, and the energy stored in device B can amplify the reflected signal. Device C has energy storage, can generate carrier signals internally, and has a local high-frequency oscillator for transmission.

[0140] The A-IoT devices in this application embodiment can be classified according to classification method 1, classification method 2, or classification method 3. This application embodiment is applicable to type 3 (also known as device2b) in classification method 1 or device C (device C) in classification method 3. Alternatively, the A-IoT tags in this application embodiment may have other classification methods or may not be classified at all; this is not limited.

[0141] The above describes several communication systems applicable to the embodiments of this application. To better understand the technical solutions of the embodiments of this application, some terms and concepts related to the embodiments of this application are first introduced.

[0142] To better illustrate the solution of this application, the technical terms involved in this application are explained below:

[0143] 1) Carrier frequency calibration signal

[0144] To ensure signal synchronization between the tag and the reader, a carrier calibration signal is introduced, primarily for carrier frequency offset (CFO) calibration. The carrier calibration signal may also be called a carrier frequency calibration signal, CFO calibration signal, or frequency synchronization signal (FSS), etc., without specific limitations here.

[0145] When downlink communication occurs between the reader and the tag (taking Device C as an example), also known as R2D, the downlink signal transmitted by the reader is modulated by OOK. The tag processes the downlink signal through an intermediate frequency or zero intermediate frequency filter, then performs envelope detection, and finally demodulates the OOK modulation to obtain the information bits.

[0146] Due to power consumption limitations of the tag, the crystal oscillator used by Device C to generate the high-frequency carrier has very low accuracy, with an initial accuracy of only [100-200] parts per million (ppm) (error measurement). In the frequency division duplex (FDD) band, taking a downlink carrier frequency of 900MHz as an example, the initial frequency offset-induced CFO can reach 90kHz-180kHz. This level of CFO necessitates maintaining sufficient guard-bandwidth in both downlink and uplink transmissions to ensure that even with CFO, effective signals can still be received after filtering in either the downlink or uplink, avoiding performance loss. However, a large guard-bandwidth leads to significant system frequency domain resource overhead, drastically reducing the spectral efficiency of downlink or uplink transmissions. Therefore, downlink transmission needs to consider sending a CFO calibration signal (i.e., a carrier calibration signal) for device CFO calibration. In this case, the guard-bandwidth can be reduced, effectively improving the spectral efficiency of the transmission.

[0147] 2) Carrier frequency calibration process

[0148] Assuming the carrier calibration signal is a single-tone signal (i.e., a signal occupying one subcarrier), the tag's receiver mixes the received carrier calibration signal with the single-tone signal generated by the local crystal oscillator. The mixed signal is then filtered by the intermediate frequency (IF). The mixing process can be understood using the following formula 1:

[0149] in, For the signal components after mixing and intermediate frequency filtering, sin(2πf) c t) represents the carrier synchronization signal received by the tag's receiver, sin(2π(f) c +Δf)t) is the mixed signal, f c f is the frequency of the carrier synchronization signal. c +Δf is the frequency of the Single-tone signal generated by the local crystal oscillator, and Δf is the residual frequency offset (that is, the frequency difference between the carrier synchronization signal and the Single-tone signal generated by the local crystal oscillator).

[0150] If Δf is within the range required by CFO, such as ≤20ppm or ≤40ppm, then the carrier frequency (i.e., the signal frequency generated by the local crystal oscillator) is confirmed to be successfully calibrated.

[0151] Carrier calibration signals typically occupy N OFDM symbols. For example, the carrier calibration signal on each OFDM symbol can be OOK modulated. Related technologies propose that after the tag receives the carrier calibration signal, it performs a carrier frequency calibration once after each OFDM symbol (i.e., after receiving the carrier calibration signal in one OFDM symbol). This method requires the tag to frequently adjust its local oscillator to adjust the carrier frequency of the signal generated by the local crystal oscillator, which not only increases the tag's power consumption but also increases the processing complexity of the tag device.

[0152] Based on this, this application provides a communication method to clarify how to construct a carrier calibration signal that can reduce tag processing complexity while balancing spectrum utilization. This communication method is applicable to the communication systems illustrated in Figures 1-3 above. It can be applied to a first device, a second device, or based on the interaction between the first and second devices. The first device can be the first device itself, a component within the first device (e.g., a communication module, processor, circuit, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the first device. For example, the first device can be a reader / writer, a network device, or other device; this application does not limit the specific form of the first device. The second device can be the second device itself, a component within the second device (e.g., a communication module, processor, circuit, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the second device. For example, the second device can be an IoT device, a tag, etc.; this application does not limit the specific form of the second device. Depending on the specific application, multiple second devices may be involved; this is not specifically limited here. The number of second devices is only illustrated using one as an example. Referring to Figure 5, the following is executed:

[0153] Step 501: The first device generates a first signal, which is used to calibrate the carrier frequency.

[0154] The first signal can be referred to as the carrier calibration signal mentioned in 1) above.

[0155] In this configuration, the first signal occupies X consecutive OFDM symbols and N frequency domain resources. Each frequency domain resource occupies M consecutive subcarriers. The first signal occupies one of the N frequency domain resources on any OFDM symbol among the X consecutive OFDM symbols. The N frequency domain resources occupy N*M subcarriers, where N is greater than or equal to 2, M is 1 or 2, and X is greater than or equal to N.

[0156] It should be noted that the X consecutive OFDM symbols occupied by the first signal can be consecutive OFDM symbols within the same time slot. For example, if X is 3, the first signal occupies OFDM symbols 3 to 5 in slot 1. Alternatively, the X consecutive OFDM symbols occupied by the first signal can be adjacent OFDM symbols in adjacent time slots. For example, if X is 5, the first signal occupies OFDM symbols 12 to 13 in slot 1 and OFDM symbols 0 to 2 in slot 2. Here, slot 1 and slot 2 are adjacent time slots, and one slot includes 14 OFDM symbols. This is merely an illustrative example and does not specifically limit how the X consecutive OFDM symbols should be interpreted. The first signal occupies N frequency domain resources, each frequency domain resource occupies M consecutive subcarriers, and the N frequency domain resources occupy N*M subcarriers. That is, the N frequency domain resources occupied by the first signal do not overlap. For example, if the first signal occupies 5 frequency domain resources, and each frequency domain resource occupies 1 subcarrier, then the 5 frequency domain resources occupy 5 (1*5) subcarriers. Or, if the first signal occupies 5 frequency domain resources, and each frequency domain resource occupies 2 subcarriers, then the 5 frequency domain resources occupy 10 (2*5) subcarriers. This is only an example and is not a specific limitation.

[0157] For example, let's take the case where the time-domain resource occupied by the first signal is one OFDM symbol in one slot, and the frequency-domain resource occupied by the first signal is one subcarrier in one RB. When X equals N, the first signal occupies N consecutive OFDM symbols and N frequency-domain resources. The frequency-domain resources occupied by any two OFDM symbols in the N consecutive OFDM symbols do not overlap. As shown in Figure 6(a), the first signal occupies 8 consecutive OFDM symbols and 8 frequency-domain resources (i.e., X = N = 8). The first signal occupies OFDM symbols 2 to 9, and the 8 frequency-domain resources correspond to subcarrier numbers 2 to 9. Each frequency-domain resource occupies one subcarrier. The subcarrier numbers corresponding to OFDM symbol 2 are 2, OFDM symbol 3 is 5, OFDM symbol 4 is 7, OFDM symbol 5 is 9, OFDM symbol 6 is 3, OFDM symbol 7 is 4, OFDM symbol 8 is 6, and OFDM symbol 9 is 8. As shown in Figure 6(b), the first signal occupies 4 consecutive OFDM symbols and 4 frequency domain resources (i.e., X = N = 4). The first signal occupies OFDM symbols 2 to 5, and the 4 frequency domain resources correspond to subcarrier numbers 2 to 9. Each frequency domain resource occupies 2 consecutive subcarriers. The subcarrier numbers corresponding to OFDM symbol 2 are 2 and 3, OFDM symbol 3 is 4 and 5, OFDM symbol 4 is 6 and 7, and OFDM symbol 5 is 8 and 9. This is merely an illustrative example and does not specifically limit how the time-frequency resources of the first signal are arranged when X=N, as long as the frequency domain resources occupied by the two OFDM symbols do not overlap.

[0158] When X is greater than N, the first signal occupies X consecutive OFDM symbols and N frequency domain resources. The first signal occupies one of the N frequency domain resources on any one of the X consecutive OFDM symbols, as shown in Figure 6(c). The first signal occupies 8 consecutive OFDM symbols and 4 frequency domain resources (i.e., X = 8, N = 4). The first signal occupies OFDM symbols 2 to 9, and the subcarrier numbers corresponding to the 4 frequency domain resources are 2 to 5, with each frequency domain resource occupying one subcarrier. The subcarrier numbers corresponding to OFDM symbols 2 to 5 are 2, OFDM symbol 6 is 3, OFDM symbols 7 to 8 are 4, and OFDM symbol 9 is 5. As shown in Figure 6(d), the first signal occupies 7 consecutive OFDM symbols and 4 frequency domain resources (i.e., X = 8, N = 4). The first signal occupies OFDM symbols 2 to 8, and the 4 frequency domain resources correspond to subcarrier numbers 2 to 5, with each frequency domain resource occupying one subcarrier. The subcarrier number corresponding to OFDM symbols 2 to 5 is 2, the subcarrier number corresponding to OFDM symbol 6 is 3, the subcarrier number corresponding to OFDM symbol 7 is 4, and the subcarrier number corresponding to OFDM symbol 8 is 5. This is only an example and does not specifically limit which OFDM symbols in the time-frequency resources of the first signal occupy the same frequency domain resources when X is greater than N.

[0159] In one possible implementation, X = N, and the frequency starting positions of the frequency domain resources occupied by the first signal in two adjacent OFDM symbols are spaced by M subcarriers. When the frequency starting positions of the frequency domain resources occupied by the first signal in two adjacent OFDM symbols are spaced by M subcarriers, the frequency domain resources occupied by the first signal in X consecutive OFDM symbols are continuous and exhibit a gradient distribution, which can be from high frequency to low frequency or from low frequency to high frequency. Based on this, the second device can improve the efficiency of carrier frequency calibration by referring to the time-frequency pattern of the first signal when performing carrier frequency calibration. Here, the frequency starting position of the frequency domain resources occupied by the i-th OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the (i+1)-th OFDM symbol equals the bandwidth of the M subcarriers, where i is greater than or equal to 1 and less than or equal to N-1. For example, as shown in Figure 7(a), the first signal occupies 11 consecutive OFDM symbols and 11 frequency domain resources (i.e., X = N = 11). The first signal occupies OFDM symbols 2 to 12, and the 11 frequency domain resources correspond to subcarrier numbers 1 to 11. Each frequency domain resource occupies one subcarrier (i.e., M = 1). The subcarrier number corresponding to OFDM symbol 2 is 11, the subcarrier number corresponding to OFDM symbol 3 is 10, the subcarrier number corresponding to OFDM symbol 4 is 9, the subcarrier number corresponding to OFDM symbol 5 is 8, the subcarrier number corresponding to OFDM symbol 6 is 7, the subcarrier number corresponding to OFDM symbol 7 is 6, the subcarrier number corresponding to OFDM symbol 8 is 5, the subcarrier number corresponding to OFDM symbol 9 is 4, the subcarrier number corresponding to OFDM symbol 10 is 3, the subcarrier number corresponding to OFDM symbol 11 is 2, and the subcarrier number corresponding to OFDM symbol 12 is 1. Alternatively, the frequency starting position of the frequency domain resources occupied by the (i+1)th OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the ith OFDM symbol equals the bandwidth of M subcarriers, where i is greater than or equal to 1 and less than or equal to N-1. For example, as shown in Figure 7(b), the first signal occupies 11 consecutive OFDM symbols and 11 frequency domain resources (i.e., X = N = 11). The first signal occupies OFDM symbols 2 to 12, and the 11 frequency domain resources correspond to subcarrier numbers 1 to 11. Each frequency domain resource occupies one subcarrier (i.e., M = 1).The subcarrier numbers corresponding to OFDM symbol 2 are 1, OFDM symbol 3 is 2, OFDM symbol 4 is 3, OFDM symbol 5 is 4, OFDM symbol 6 is 5, OFDM symbol 7 is 6, OFDM symbol 8 is 7, OFDM symbol 9 is 8, OFDM symbol 10 is 9, OFDM symbol 11 is 10, and OFDM symbol 12 is 11. This is merely an example and not a specific limitation.

[0160] Considering that the carrier frequency generated by the local crystal oscillator of the second device may be unstable, this application constructs the first signal by occupying the same frequency domain resources for L consecutive OFDM symbols. The second device performs L mixing operations on the same frequency domain resources, ensuring the reliability of the frequency deviation obtained after mixing and improving the accuracy of carrier frequency calibration. In one possible implementation, X = L*N, the first signal occupies one frequency domain resource for every L consecutive OFDM symbols in L*N consecutive OFDM symbols, where L is greater than 1. For example, as shown in Figure 8, the first signal occupies 8 consecutive OFDM symbols and 4 frequency domain resources (i.e., X = 8, N = 4, L = 2). The first signal occupies OFDM symbols 2 to 9, and the subcarrier numbers corresponding to the 4 frequency domain resources are 2 to 5, with each frequency domain resource occupying one subcarrier. The subcarrier numbers corresponding to OFDM symbols 2 to 3 are 2, OFDM symbols 4 to 5 are 5, OFDM symbols 6 to 7 are 4, and OFDM symbols 8 to 9 are 3.

[0161] In this configuration, the frequency domain resources occupied by the first signal in the i-th consecutive L OFDM symbols are different from those occupied in the j-th consecutive L OFDM symbols. i and j are different, and i is greater than or equal to 1 and less than or equal to N. This difference in frequency domain resources avoids overlap between consecutive L OFDM symbols. Based on this, N frequency domain resources are continuously distributed across L*N consecutive OFDM symbols at L-symbol intervals. Therefore, the second device can guarantee the accuracy of carrier frequency calibration during this process. For example, in Figure 8 above, OFDM symbols 2 to 3 are the first two consecutive OFDM symbols, and the frequency domain resources they occupy are the frequency domain resources corresponding to subcarrier number 2. OFDM symbols 8 to 9 are the fourth two consecutive OFDM symbols, and the frequency domain resources they occupy are the frequency domain resources corresponding to subcarrier number 3. The frequency domain resources corresponding to subcarrier number 2 are different from those corresponding to subcarrier number 3.

[0162] In one possible implementation, when X = L*N, the frequency starting position of the frequency domain resources occupied by the first signal in the i-th consecutive L OFDM symbols is spaced M subcarriers apart from the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols, where i is greater than or equal to 1 and less than or equal to N-1. When X = L*N, and the frequency starting position of the first signal in the i-th consecutive L OFDM symbols is spaced M subcarriers apart from the frequency starting position of the frequency domain resources occupied by the first signal in the (i+1)-th consecutive L OFDM symbols, the frequency domain resources occupied by the first signal in the X consecutive OFDM symbols are continuous and exhibit a gradient distribution, which can be from high frequency to low frequency or from low frequency to high frequency. Based on this, when performing carrier frequency calibration, the second device can improve the efficiency of carrier frequency calibration by referring to the time-frequency pattern of the first signal. The frequency starting position of the frequency domain resources occupied by the i-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols equals the bandwidth of the M subcarriers. For example, as shown in Figure 9(a), the first signal occupies 12 consecutive OFDM symbols and 4 frequency domain resources (i.e., X = 12, N = 4, L = 3). The first signal occupies OFDM symbols 2 to 13, and the subcarrier numbers corresponding to the 4 frequency domain resources are 2 to 5. Each frequency domain resource occupies 1 subcarrier (i.e., M = 1). The subcarrier numbers corresponding to OFDM symbols 2 to 4 are 5, those corresponding to OFDM symbols 5 to 7 are 4, those corresponding to OFDM symbols 8 to 10 are 3, and those corresponding to OFDM symbols 11 to 13 are 2. Alternatively, the frequency starting position of the frequency domain resources occupied by the (i+1)th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the ith consecutive L OFDM symbols equals the bandwidth of M subcarriers. For example, as shown in Figure 9(b), the first signal occupies 12 consecutive OFDM symbols and 4 frequency domain resources (i.e., X = 12, N = 4, L = 3). The first signal occupies OFDM symbols 2 to 13, and the subcarrier numbers corresponding to the 4 frequency domain resources are 2 to 5. Each frequency domain resource occupies 1 subcarrier (i.e., M = 1). The subcarrier numbers corresponding to OFDM symbols 2 to 4 are 2, those corresponding to OFDM symbols 5 to 7 are 3, those corresponding to OFDM symbols 8 to 10 are 4, and those corresponding to OFDM symbols 11 to 13 are 5. This is merely an illustrative example and not a specific limitation.

[0163] The time-frequency pattern of the first signal also involves a reference frequency for the first signal. This reference frequency can be one of the following: the lowest frequency position among N frequency domain resources, the highest frequency position among N frequency domain resources, the corresponding synchronization grid frequency in the first signal, or the frequency corresponding to the channel grid in the first signal. The corresponding synchronization grid frequency or the frequency corresponding to the channel grid in the first signal is also known as the Sync Raster frequency. When the first signal uses different time-frequency patterns, the frequency domain position of the reference frequency of the first signal is also different, which facilitates the second device in accurately determining the frequency deviation value of the carrier signal and ensuring the reliability of carrier frequency calibration. The frequency domain position of a frequency domain resource can be understood as the lowest frequency (also called the frequency start position) in the frequency range corresponding to that frequency domain resource, the highest frequency (also called the frequency end position) in the frequency range corresponding to that frequency domain resource, or the center frequency in the frequency range corresponding to that frequency domain resource. For example, one frequency domain resource corresponds to one subcarrier, and the bandwidth (also called the subcarrier spacing) corresponding to one subcarrier is 15kHz, 30kHz, or 60kHz, etc. If the bandwidth corresponding to one subcarrier is 15kHz, frequency domain resource A corresponds to subcarrier A, and the frequency range corresponding to subcarrier A is 600MHz to 600.015MHz. The frequency domain position of frequency domain resource A can be the frequency position corresponding to 600MHz, 600.015MHz, or 600.0075MHz; these are merely illustrative examples and not specific limitations. For example, the first signal occupies N frequency domain resources. The starting position of the first frequency domain resource can be the lowest frequency position among the N frequency domain resources, and the ending position of the Nth frequency domain resource is the highest frequency position among the N frequency domain resources. For example, the synchronization grid frequency or the frequency corresponding to the channel grid in the first signal is the frequency of the N frequency domain resources. One frequency domain resource or the first The frequency start position or frequency end position of each frequency domain resource. For example, if the frequency of the start position of the lowest frequency domain position of N frequency domain resources is 899.91MHz, and the frequency of the start position of the highest frequency domain position of N frequency domain resources is 900.09MHz, then the frequency of the corresponding synchronization grid in the first signal or the frequency of the corresponding channel grid in the first signal is 900MHz ((899.91+900.09) / 2).

[0164] In one possible implementation, X = N, the frequency starting position of the frequency domain resources occupied by the j-th OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the (j+1)-th OFDM symbol equals the bandwidth of M subcarriers, and the frequency starting position of the frequency domain resources occupied by the (k+1)-th OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the k-th OFDM symbol equals the bandwidth of M subcarriers, where 1 ≤ j ≤ Q-2, Q ≤ k ≤ N-1, 2 ≤ Q ≤ N-2, and the first position of the (Q-1)-th OFDM symbol in X consecutive OFDM symbols is the same as the reference frequency of the first signal, where the... The first position is one of the following: the frequency start position of the frequency domain resources occupied by the (Q-1)th OFDM symbol, the frequency end position of the frequency domain resources occupied by the (Q-1)th OFDM symbol, and the frequency center position of the frequency domain resources occupied by the (Q-1)th OFDM symbol; and / or, the second position of the Qth OFDM symbol is the same as the reference frequency of the first signal, wherein the second position is one of the following: the frequency start position of the frequency domain resources occupied by the Qth OFDM symbol, the frequency end position of the frequency domain resources occupied by the Qth OFDM symbol, and the frequency center position of the frequency domain resources occupied by the Qth OFDM symbol. For example, as shown in FIG10(a), the first signal occupies 11 consecutive OFDM symbols and 10 frequency domain resources (i.e., X = 11, N = 10), the first signal occupies OFDM symbols 2 to 12, the 11 frequency domain resources correspond to subcarrier numbers 1 to 10, and each frequency domain resource occupies 1 subcarrier (i.e., M = 1). Q = 6 (corresponding to OFDM symbol 7). Q-1 = 5 (corresponding to OFDM symbol 6). OFDM symbol 6 corresponds to the lowest frequency position of N frequency domain resources. OFDM symbol 7 corresponds to the synchronization grid frequency or the frequency corresponding to the channel grid in the first signal. The subcarrier number corresponding to OFDM symbol 2 is 5, the subcarrier number corresponding to OFDM symbol 3 is 4, the subcarrier number corresponding to OFDM symbol 4 is 3, the subcarrier number corresponding to OFDM symbol 5 is 2, the subcarrier number corresponding to OFDM symbol 6 is 1, the subcarrier number corresponding to OFDM symbol 7 is 5, the subcarrier number corresponding to OFDM symbol 8 is 6, the subcarrier number corresponding to OFDM symbol 9 is 7, the subcarrier number corresponding to OFDM symbol 10 is 8, the subcarrier number corresponding to OFDM symbol 11 is 9, and the subcarrier number corresponding to OFDM symbol 12 is 10. This is only an example and is not specifically limited. Alternatively, the frequency starting position of the frequency domain resources occupied by the (j+1)th OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the jth OFDM symbol equals the bandwidth of M subcarriers, and the frequency starting position of the frequency domain resources occupied by the kth OFDM symbol minus the frequency starting position of the frequency domain resources occupied by the (k+1)th OFDM symbol equals the bandwidth of M subcarriers.For example, as shown in Figure 10(b), the first signal occupies 11 consecutive OFDM symbols and 10 frequency domain resources (i.e., X = 11, N = 10). The first signal occupies OFDM symbols 2 to 12, and the 11 frequency domain resources correspond to subcarrier numbers 1 to 10. Each frequency domain resource occupies one subcarrier (i.e., M = 1). Q = 7 (corresponding to OFDM symbol 8). Q-1 = 6 (corresponding to OFDM symbol 7). OFDM symbol 7 corresponds to the highest frequency domain position of the N frequency domain resources, and OFDM symbol 8 corresponds to the synchronization grid frequency or the frequency corresponding to the channel grid in the first signal. The subcarrier numbers corresponding to OFDM symbol 2 are 5, 3, 4, 5, 6, 7, 8, 9, 10, 5, 4, 3, 2, 11, and 1, respectively. This is merely an example and not a specific limitation.

[0165] In one possible implementation, X = L * N, where the frequency starting position of the frequency domain resources occupied by the j-th consecutive L OFDM symbols minus the frequency starting position of the (j+1)-th consecutive L OFDM symbols equals the bandwidth of M subcarriers, and the frequency starting position of the frequency domain resources occupied by the (k+1)-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the k-th consecutive L OFDM symbols equals the bandwidth of M subcarriers, where 1 ≤ j ≤ Q-2, Q ≤ k ≤ N-1, 2 ≤ Q ≤ N-2, and the first position of the (Q-1)-th OFDM symbol in X consecutive OFDM symbols is related to the reference of the first signal. The frequencies are the same, wherein the first position is one of the following: the frequency start position of the frequency domain resource occupied by the (Q-1)th OFDM symbol, the frequency end position of the frequency domain resource occupied by the (Q-1)th OFDM symbol, and the frequency center position of the frequency domain resource occupied by the (Q-1)th OFDM symbol; and / or, the second position of the Qth OFDM symbol is the same as the reference frequency of the first signal, wherein the second position is one of the following: the frequency start position of the frequency domain resource occupied by the Qth OFDM symbol, the frequency end position of the frequency domain resource occupied by the Qth OFDM symbol, and the frequency center position of the frequency domain resource occupied by the Qth OFDM symbol. For example, as shown in Figure 11(a), the first signal occupies 12 consecutive OFDM symbols and 5 frequency domain resources (i.e., X = 12, N = 5, L = 2), the first signal occupies OFDM symbols 2 to 13, the 5 frequency domain resources correspond to subcarrier numbers 1 to 5, and each frequency domain resource occupies 1 subcarrier (i.e., M = 1). Q = 4 (corresponding to OFDM symbols 8 and 9). Q-1 = 3 (corresponding to OFDM symbols 6 and 7). OFDM symbols 6 and 7 correspond to the lowest frequency domain position of N frequency domain resources. OFDM symbols 8 and 9 correspond to the synchronization grid frequency or the channel grid frequency in the first signal. The subcarrier numbers corresponding to OFDM symbols 2 to 3 are 3, those corresponding to OFDM symbols 4 to 5 are 2, those corresponding to OFDM symbols 6 to 7 are 1, those corresponding to OFDM symbols 8 to 9 are 3, those corresponding to OFDM symbols 10 to 11 are 4, and those corresponding to OFDM symbols 12 to 13 are 5. Alternatively, the frequency starting position of the frequency domain resources occupied by the (j+1)th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the jth consecutive L OFDM symbols equals the bandwidth of M subcarriers, and the frequency starting position of the frequency domain resources occupied by the kth consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the (k+1)th consecutive L OFDM symbols equals the bandwidth of M subcarriers.For example, as shown in Figure 11(b), the first signal occupies 12 consecutive OFDM symbols and 5 frequency domain resources (i.e., X=12, N=5, L=2). The first signal occupies OFDM symbols 2 to 13, and the 5 frequency domain resources correspond to subcarrier numbers 1 to 5. Each frequency domain resource occupies 1 subcarrier (i.e., M=1). Q=4 (corresponding to OFDM symbols 8 and 9). Q-1=3 (corresponding to OFDM symbols 6 and 7). OFDM symbols 6 and 7 correspond to the highest frequency domain position of the N frequency domain resources, and OFDM symbols 8 and 9 correspond to the corresponding synchronization grid frequency or the frequency corresponding to the channel grid in the first signal. The subcarrier numbers corresponding to OFDM symbols 2 to 3 are 3, those corresponding to OFDM symbols 4 to 5 are 4, those corresponding to OFDM symbols 6 to 7 are 5, those corresponding to OFDM symbols 8 to 9 are 3, those corresponding to OFDM symbols 10 to 11 are 2, and those corresponding to OFDM symbols 12 to 13 are 1. This is only an example and is not specifically limited.

[0166] It is important to note that the second position of the frequency domain resource occupied by the S-th OFDM symbol in the X consecutive OFDM symbols is the same as the reference frequency of the first signal, where S is a positive integer less than or equal to N. The second position is one of the following: the starting position of the frequency domain resource occupied by the S-th OFDM symbol, the ending position of the frequency domain resource occupied by the S-th OFDM symbol, or the center position of the frequency domain resource occupied by the S-th OFDM symbol. Based on this, the time domain symbol corresponding to the reference frequency of the first signal can be clearly identified, facilitating the calculation of the frequency offset value by the second device based on this time domain symbol. For example, one frequency domain resource corresponds to one consecutive subcarrier. If the subcarrier interval is 15kHz, the frequency domain resource occupied by the S-th OFDM symbol corresponds to the S-th subcarrier, and the frequency range corresponding to the S-th subcarrier is 900MHz to 900.015MHz. Wherein, the starting position of the frequency domain resource occupied by the S-th OFDM symbol is the frequency position corresponding to 900MHz, the ending position of the frequency domain resource occupied by the S-th OFDM symbol is the frequency position corresponding to 900.015MHz, and the center position of the frequency domain resource occupied by the S-th OFDM symbol is the frequency position corresponding to 900.0075MHz ((900+900.015) / 2). This is only an example and is not specifically limited.

[0167] In one possible implementation, S equals or Or 1 or X, To round down, Rounding up. For example, as shown in Figure 12, which is derived from Figure 7(a) above, the reference frequency of the first signal is the lowest frequency position of the N frequency domain resources, i.e., the position corresponding to subcarrier 1. S equals X, which is the reference frequency of the first signal corresponding to OFDM symbol 12 in Figure 12(a). Figure 12(a) uses the center frequency of subcarrier 1 corresponding to OFDM symbol 12 as an example of the lowest frequency position of the N frequency domain resources. The reference frequency of the first signal can also be the highest frequency position of the N frequency domain resources, i.e., the position corresponding to subcarrier 11. S equals 1, which is the reference frequency of the first signal corresponding to OFDM symbol 2 in Figure 12(b). Figure 12(b) uses the lowest frequency of subcarrier 11 corresponding to OFDM symbol 2 as an example of the highest frequency position of the N frequency domain resources. The reference frequency of the first signal is the corresponding synchronization grid frequency in the first signal. Wherein, the corresponding synchronization grid frequency in the first signal is the lowest frequency of the N frequency domain resources... The end position of the frequency of each frequency domain resource, that is, the 5th The frequency end position of each frequency domain resource (i.e., the position corresponding to subcarrier 7), S equals That is, 5, which is the OFDM symbol 6 in Figure 12(c) above, corresponding to the reference frequency of the first signal. The reference frequency of the first signal is the corresponding synchronization grid frequency in the first signal. Wherein, the corresponding synchronization grid frequency in the first signal is the _th_ ... The starting position of the frequency of each frequency domain resource, that is, the 6th The starting position of the frequency of each frequency domain resource (i.e., the position corresponding to subcarrier 6), S equals That is, 6, which is the reference frequency of the first signal corresponding to OFDM symbol 7 in Figure 12(d) above. This is only an example and is not specifically limited.

[0168] In another possible implementation, S may take multiple values. For example, as shown in Figure 13, which is derived from Figure 9(a) above, the reference frequency of the first signal is the lowest frequency position of the N frequency domain resources, i.e., the position corresponding to subcarrier 2. S is 10, 11, or 12, meaning that OFDM symbols 11, 12, or 13 in Figure 13(a) correspond to the reference frequency of the first signal. Figure 13(a) uses the lowest frequency of subcarrier 2 corresponding to OFDM symbols 11, 12, or 13 as an example of the lowest frequency position of the N frequency domain resources. The reference frequency of the first signal is the highest frequency position of the N frequency domain resources, i.e., the position corresponding to subcarrier 5. S is 1, 2, or 3, meaning that OFDM symbols 2, 3, or 4 in Figure 13(b) correspond to the reference frequency of the first signal. Figure 13(b) uses the highest frequency of subcarrier 5 corresponding to OFDM symbols 2, 3, or 4 as an example of the highest frequency position of the N frequency domain resources. The reference frequency of the first signal is the corresponding synchronization grid frequency in the first signal. That is, position 6, which corresponds to subcarrier 4. S is 4, 5, or 6, which means that OFDM symbols 5, 6, or 7 in Figure 13(c) above correspond to the reference frequency of the first signal. Figure 13(c) takes the center frequency of subcarrier 4 corresponding to OFDM symbols 5, 6, or 7 as the corresponding synchronization grid frequency in the first signal as an example. This is only an example and is not specifically limited.

[0169] Step 502: The first device sends a first signal.

[0170] Accordingly, the second device receives the first signal. The second device can obtain the reference frequency of the first signal through blind detection.

[0171] Furthermore, the first device may also send a reference frequency of the first signal used when constructing the first signal, so that the second device can obtain the reference frequency of the first signal. The specific method by which the second device obtains the reference frequency of the first signal is not limited here. Specifically, the first device sends first information to the second device, which indicates the reference frequency of the first signal. Exemplarily, the first information includes the reference frequency of the first signal, or an index of the reference frequency of the first signal, etc. Optionally, the first information may also include other information, such as the transmission period of the first signal, etc., which is not specifically limited here and is only exemplified.

[0172] Step 503: The second device performs carrier frequency error calibration based on the first signal.

[0173] Specifically, the second device can be executed by referring to the carrier frequency calibration procedure in 2) above.

[0174] When X = N, if the second device determines that the carrier frequency offset error corresponding to the frequency domain resources occupied by the first signal in the Pth OFDM symbol meets the carrier frequency offset error threshold, it determines the frequency offset value between the frequency domain resources occupied by the first signal in the Pth OFDM symbol and the reference frequency of the first signal, where P is greater than or equal to 1 and less than or equal to N; and adjusts the carrier frequency according to the frequency offset value. Here, the frequency offset value is P*SCS*M, where SCS is the frequency spacing between adjacent subcarriers in an OFDM symbol. For example, when the time-frequency pattern of the first signal is as shown in Figure 7(b), the carrier frequency offset error threshold is 40ppm, the reference frequency of the first signal is the lowest frequency domain position of N frequency domain resources (the reference frequency of the first signal corresponds to the first OFDM symbol), and the reference frequency of the first signal is 899.91MHz. The second device performs mixing to determine the frequency offset error in each OFDM symbol. In the fifth OFDM symbol, the frequency offset error is determined to be less than 40ppm, and the SCS is 15kHz. Therefore, P is 5, and P*SCS*1 is 75kHz. The second device can adjust its local oscillator to 899.91MHz+75kHz. This is merely an illustrative example and not a specific limitation on how to adjust the local oscillator of the second device. Where P is greater than Q, the frequency offset value is (PQ)*SCS*M; when P is less than Q, the frequency offset value is (QP)*SCS*M. For example, when the time-frequency pattern of the first signal is as shown in Figure 10(a), the carrier frequency offset error threshold is 40ppm. The reference frequency of the first signal is the corresponding synchronization grid frequency in the first signal (the reference frequency of the first OFDM symbol corresponds to the first signal), and the reference frequency of the first signal is 900MHz. The second device performs mixing to determine the frequency offset error in each OFDM symbol. In the 7th OFDM symbol, the frequency offset error is determined to be less than 40ppm, and SCS is 15kHz. Then P is 7, Q = 6, P is greater than Q, and (PQ)*SCS*1 is 15kHz. The second device can adjust the local oscillator to 900MHz-15kHz. This is only an illustrative example and not a specific limitation on how to adjust the local oscillator of the second device. This is only an illustrative example. This is only an illustrative example.

[0175] When X = L*N, if the second device determines that the carrier frequency offset error corresponding to the frequency domain resources occupied by the first signal in the Pth consecutive L OFDM symbols meets the carrier frequency offset error threshold, it determines the frequency offset value between the frequency domain resources occupied by the first signal in the Pth consecutive L OFDM symbols and the reference frequency of the first signal, where P is greater than or equal to 1 and less than or equal to N; and adjusts the carrier frequency according to the frequency offset value. The frequency offset value is... SCS is the frequency spacing between adjacent subcarriers in an OFDM symbol. For example, when the time-frequency pattern of the first signal is as shown in Figure 9(b), the carrier frequency offset error threshold is 40ppm, the reference frequency of the first signal is the lowest frequency position among N frequency domain resources (the reference frequency of the first signal corresponds to the first OFDM symbol), and the reference frequency of the first signal is 899.91MHz. The second device performs mixing to determine the frequency offset error in each OFDM symbol, L=3, and determines that the frequency offset error is less than 40ppm in the 5th OFDM symbol. With SCS of 15kHz, P is 5. The value is 2, 2*SCS*1 is 30kHz, and the second device can adjust the local oscillator to 899.91MHz+30kHz. This is only an illustrative example and not a specific limitation on how to adjust the local oscillator of the second device. This is only an illustrative example. Where P is greater than Q, the frequency offset value is... When *SCS*M, P is less than Q, the frequency offset value is... For example, when the time-frequency pattern of the first signal is as shown in Figure 11(b), the carrier frequency offset error threshold is 40ppm, the reference frequency of the first signal is the corresponding synchronization grid frequency in the first signal (the reference frequency of the first signal corresponds to the first and second OFDM symbols), the reference frequency of the first signal is 900MHz, the second device performs mixing to determine the frequency offset error in each OFDM symbol, and determines that the frequency offset error is less than 40ppm in the 7th OFDM symbol, the SCS is 15kHz, then P is 9, Q = 4, L = 2, P is greater than Q. The local oscillator of the second device can be adjusted from 900MHz to 15kHz. This is merely an illustrative example and not a specific limitation on how to adjust the local oscillator of the second device. This is merely an illustrative example.

[0176] After the first signal constructed according to this application is received, the second device, upon receiving the first signal, does not need to frequently calibrate the carrier frequency after each OFDM symbol mixing operation. Carrier frequency calibration is only performed when the carrier frequency offset error corresponding to the frequency domain resources occupied by the first signal in a certain OFDM symbol meets the carrier frequency offset error threshold. This avoids frequent carrier frequency adjustments and reduces the complexity of carrier frequency calibration. Furthermore, it also saves power consumption of the second device.

[0177] The foregoing primarily describes the solutions provided by the embodiments of this application from the perspective of device interaction. It is understood that, in order to achieve the above functions, each device may include corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, the embodiments of this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0178] The embodiments of this application can divide the device into functional units according to the above method examples. For example, each function can be divided into a separate functional unit, or two or more functions can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0179] Figure 14 illustrates a possible exemplary block diagram of a communication device according to an embodiment of this application, using an integrated unit. As shown in Figure 14, the communication device 1400 may include a processing module 1410 and a transceiver module 1420. The processing module 1410 is used to control and manage the operation of the communication device 1400. The transceiver module 1420 is used to support communication between the communication device 1400 and other devices. Optionally, the transceiver module 1420 may include a receiving unit and / or a transmitting unit, respectively used to perform receiving and transmitting operations. Optionally, the communication device 1400 may also include a storage unit for storing the program code and / or data of the communication device 1400. The transceiver module may be referred to as an input / output module, a communication module, etc., and may be a transceiver; the processing module may be a processor. When the communication device is a module (e.g., a chip) in a communication device, the transceiver module may be an input / output interface, an input / output circuit, or an input / output pin, etc., and may also be referred to as an interface, a communication interface, or an interface circuit, etc.; the processing module may be a processor, a processing circuit, or a logic circuit, etc. Specifically, the communication device can be the aforementioned A-IoT terminal, reader, etc.

[0180] Optionally, a storage module may also be included, which can be used to store instructions (code or program) and / or data. This storage module may be, for example, a memory. The processing module 1410 and the transceiver module 1420 may be coupled to this storage module. For example, the processing module 1410 can read instructions (code or program) and / or data from the storage module to implement corresponding methods. For example, when the communication device 1400 is a chip in an A-IoT device, the storage module may be an internal storage module within the chip, such as a register or cache. Alternatively, the storage module may be an external storage module within the A-IoT device, such as a read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions, such as random access memory (RAM). The aforementioned units may be configured independently or partially or completely integrated.

[0181] Processing module 1410 may be a processor or controller, such as a general-purpose central processing unit (CPU), a general-purpose processor, a digital signal processing unit (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor may also be a combination that implements computational functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc. Transceiver module 1420 is a transceiver, interface circuit, bus, pin, or other possible communication interface for receiving signals from other devices. For example, when the device is implemented as a chip, transceiver module 1420 is an interface circuit for the chip to receive signals from other chips or devices, or an interface circuit for the chip to send signals to other chips or devices.

[0182] In one implementation, the communication device 1400 can correspondingly implement the behavior and functions of the network device in the above method embodiments. The communication device 1400 can be a first device, a component (e.g., a chip or circuit) within the first device, a part of a chip or chipset in the first device used to execute the relevant method functions, or a software module in the first device capable of implementing the above communication method; there are no limitations. Optionally, the network device has some or all of the functions of a reader / writer. For details, please refer to the relevant content of the foregoing method embodiments; further details will not be repeated here.

[0183] For example, processing module 1410 is used to generate a first signal, which is used to calibrate the carrier frequency; and to transmit the first signal. The first signal occupies X consecutive OFDM symbols and N frequency domain resources, each frequency domain resource occupies M consecutive subcarriers. The first signal occupies one of the N frequency domain resources on any one of the X consecutive OFDM symbols, and the N frequency domain resources occupy N*M subcarriers, where N is greater than or equal to 2, M is 1 or 2, and X is greater than or equal to N. Optionally, transceiver module 1420 is also used to transmit the first signal.

[0184] In one implementation, the communication device 1400 can correspondingly implement the behavior and functions of the second device in the above method embodiments. The communication device 1400 can be an A-IoT device, a component (e.g., a chip or circuit) within an A-IoT device, a part of a chip or chipset in an A-IoT device used to execute related method functions, or a software module in the second device capable of implementing the above communication method; there are no limitations. For details, please refer to the relevant content of the foregoing method embodiments, which will not be repeated here.

[0185] For example, the transceiver module 1420 is used to receive a first signal, which is used to calibrate the carrier frequency. The first signal occupies X consecutive OFDM symbols and N frequency domain resources. Each frequency domain resource occupies M consecutive subcarriers. The first signal occupies one of the N frequency domain resources on any OFDM symbol among the X consecutive OFDM symbols. The N frequency domain resources occupy N*M subcarriers, where N is greater than or equal to 2, M is 1 or 2, and X is greater than or equal to N.

[0186] Optionally, the processing module 1410 is used to perform carrier frequency error calibration based on the first signal.

[0187] When the communication device 1400 is a chip-based device or circuit, the transceiver module can be an input / output circuit and / or a communication interface; the processing module is an integrated processor, microprocessor, or integrated circuit.

[0188] Figure 15 is a schematic block diagram of a communication device 1500 provided in an embodiment of this application. The communication device 1500 can be a first terminal device or a network device as described in the above embodiments. For example, the communication device 1500 can be an A-IoT device or a chip (system) within an A-IoT device as shown in Figure 2 or Figure 3. As another example, the communication device 1500 can be a network device or a chip (system) within a network device as shown in Figure 2 or Figure 3. In this embodiment, the chip system can be composed of chips or may include chips and other discrete devices. Specific functions can be found in the descriptions of the above method embodiments.

[0189] The communication device 1500 includes one or more processors 1501, used to implement or support the communication device 1500 in implementing the functions of the first terminal device or network device in the methods provided in the embodiments of this application. For details, please refer to the detailed description in the method examples, which will not be repeated here. The processor 1501 can also be called a processing unit or processing module, and can implement certain control functions. The processor 1501 can be a general-purpose processor or a dedicated processor, etc. For example, it includes: a baseband processor, a central processing unit, an application processor, a modem processor, a graphics processor, an image signal processor, a digital signal processor, a video codec processor, a controller, a memory, and / or a neural network processor, etc. The baseband processor can be used to process communication protocols and communication data. The central processing unit can be used to control the communication device 1500 (e.g., a terminal device or a network device), execute software programs and / or process data. Different processors can be independent devices or integrated into one or more processors, for example, integrated on one or more application-specific integrated circuits.

[0190] In one design, processor 1501 may include program 1503 (sometimes also referred to as code or instructions), which can be executed on processor 1501 to cause communication device 1500 to perform the methods described in the embodiments below. In yet another possible design, communication device 1500 includes circuitry (not shown in FIG15) for implementing the functions of the first terminal device or network device in the above embodiments.

[0191] In one design, the communication device 1500 may include one or more memories 1502 storing a program 1504 (sometimes referred to as code or instructions), which can be run on the processor 1501 to cause the communication device 1500 to perform the methods described in the above method embodiments.

[0192] In one possible design, the processor 1501 and / or memory 1502 may also store data. The processor and memory may be configured separately or integrated together.

[0193] In one possible design, the communication device 1500 may further include a transceiver 1505 and / or an antenna 1506. The processor 1501, sometimes referred to as a processing unit, controls the communication device 1500. The transceiver 1505, sometimes referred to as a transceiver unit, transceiver, transceiver circuit, or transceiver, is used to realize the transmission and reception functions of the communication device 1500 through the antenna 1506.

[0194] In one possible design, the communication device 1500 may further include one or more of the following components: a wireless communication module, an audio module, an external memory interface, internal memory, a universal serial bus (USB) interface, a power management module, an antenna, a speaker, a microphone, an input / output module, a sensor module, a motor, a camera, or a display screen, etc. It is understood that in some embodiments, the communication device 1500 may include more or fewer components, or some components may be integrated, or some components may be separated. These components may be implemented in hardware, software, or a combination of software and hardware.

[0195] The communication device in the above embodiments can be a first terminal device or a network device, a circuit, a chip applied in a terminal device or network device, or other combined devices or components having the aforementioned first terminal device or network device. When the communication device is a terminal device, the transceiver module can be a transceiver, which may include an antenna and radio frequency circuits, etc., and the processing module can be a processor, such as a CPU. When the communication device is a chip system, the communication device can be an FPGA, a dedicated ASIC, a SoC, a CPU, a network processor (NP), a DSP, a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips. The processing module can be the processor of the chip system. The transceiver module or communication interface can be the input / output interface or interface circuit of the chip system. For example, the interface circuit can be a code / data read / write interface circuit. The interface circuit can be used to receive code instructions (the code instructions are stored in memory and can be read directly from memory or through other devices) and transmit them to the processor; the processor can be used to run the code instructions to execute the methods in the above method embodiments. For example, the interface circuit can also be a signal transmission interface circuit between the communication processor and the transceiver.

[0196] This application also provides a communication system, which includes at least one terminal device and at least one network device. The terminal device is a terminal device used to implement the functions related to the above-described communication method, and the network device is a network device used to implement the functions related to the above-described communication method.

[0197] This application also provides a computer-readable storage medium including instructions that, when run on a computer, cause the method executed by the first terminal device or network device in the above-described communication method to be executed.

[0198] This application also provides a computer program product, including computer program code, which, when executed, causes the method executed by the first terminal device or network device in the above-described communication method to be executed.

[0199] This application provides a chip system including a processor and potentially a memory, for implementing the functions of the first terminal device or network device in the aforementioned communication method. The chip system may be composed of chips or may include chips and other discrete components.

[0200] To achieve the functions of the communication devices shown in Figures 13-15, this application embodiment also provides a chip, including a processor, for supporting the communication device in implementing the functions involved in the first terminal device or network device in the above method embodiments. In one possible design, the chip is connected to a memory or the chip includes a memory for storing necessary computer programs, instructions, and data for the communication device.

[0201] It should be understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0202] Those skilled in the art will recognize that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0203] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0204] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

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

[0206] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the essential contributing part of the technical solution of this application, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, external hard drives, ROM, RAM, magnetic disks, or optical disks.

[0207] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A communication method, characterized in that, Applied to the first device, including: A first signal is generated, which is used to calibrate the carrier frequency; The first signal is transmitted, which occupies X consecutive orthogonal frequency division multiplexing (OFDM) symbols and N frequency domain resources. Each frequency domain resource occupies M consecutive subcarriers. The first signal occupies one of the N frequency domain resources on any one of the X consecutive OFDM symbols. The N frequency domain resources occupy N*M subcarriers, where N is greater than or equal to 2, M is 1 or 2, and X is greater than or equal to N.

2. The method according to claim 1, characterized in that, Where X = L*N, the first signal occupies one frequency domain resource out of the N frequency domain resources in any one of the X consecutive OFDM symbols, including: The first signal occupies one frequency domain resource in every L consecutive OFDM symbols out of the L*N consecutive OFDM symbols, where L is greater than 1.

3. The method according to claim 2, characterized in that, The first signal occupies one frequency domain resource in each L consecutive OFDM symbols out of the L*N consecutive OFDM symbols, including: The frequency domain resources occupied by the first signal in the i-th consecutive L OFDM symbols are different from those occupied in the j-th consecutive L OFDM symbols. The i and j are different, i is greater than or equal to 1 and less than or equal to N, and j is greater than or equal to 1 and less than or equal to N.

4. The method according to any one of claims 1-3, characterized in that, Where X = N, the first signal is spaced M subcarriers apart at the frequency start position of the frequency domain resources occupied by two adjacent OFDM symbols.

5. The method according to claim 2 or 3, characterized in that, X = L * N, where the frequency starting position of the frequency domain resources occupied by the first signal in the i-th consecutive L OFDM symbols is spaced M subcarriers apart from the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols, and i is greater than or equal to 1 and less than or equal to N-1.

6. The method according to claim 5, characterized in that, The frequency starting position of the frequency domain resources occupied by the first signal in the i-th consecutive L OFDM symbols is spaced M subcarriers apart from the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols, including: The frequency starting position of the frequency domain resources occupied by the i-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols equals the bandwidth of M subcarriers, or the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the i-th consecutive L OFDM symbols equals the bandwidth of M subcarriers.

7. The method according to claim 2 or 3, characterized in that, The frequency starting position of the frequency domain resources occupied by the j-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the (j+1)-th consecutive L OFDM symbols equals the bandwidth of M subcarriers; the frequency starting position of the frequency domain resources occupied by the (k+1)-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the k-th consecutive L OFDM symbols equals the bandwidth of M subcarriers; or, The frequency starting position of the frequency domain resources occupied by the (j+1)th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the jth consecutive L OFDM symbols equals the bandwidth of M subcarriers; the frequency starting position of the frequency domain resources occupied by the kth consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the (k+1)th consecutive L OFDM symbols equals the bandwidth of M subcarriers. Wherein, 1≤j≤Q-2, Q≤k≤N-1, 2≤Q≤N-2, the first position of the (Q-1)th OFDM symbol in the X consecutive OFDM symbols is the same as the reference frequency of the first signal, and the first position is one of the following positions: The frequency start position of the frequency domain resource occupied by the (Q-1)th OFDM symbol, the frequency end position of the frequency domain resource occupied by the (Q-1)th OFDM symbol, and the frequency center position of the frequency domain resource occupied by the (Q-1)th OFDM symbol; and / or, The second position of the Qth OFDM symbol is the same as the reference frequency of the first signal, wherein the second position is one of the following positions: The frequency start position of the frequency domain resources occupied by the Qth OFDM symbol, the frequency end position of the frequency domain resources occupied by the Qth OFDM symbol, and the frequency center position of the frequency domain resources occupied by the Qth OFDM symbol.

8. The method according to any one of claims 1-7, characterized in that, The reference frequency of the first signal is one of the following: The lowest frequency domain position of the N frequency domain resources, the highest frequency domain position of the N frequency domain resources, the corresponding synchronization grid frequency in the first signal, or the frequency corresponding to the channel grid in the first signal.

9. The method according to claim 8, characterized in that, The third position of the frequency domain resources occupied by the S-th OFDM symbol in the X consecutive OFDM symbols is the same as the reference frequency of the first signal, where S is a positive integer less than or equal to N. The third position is one of the following positions: The frequency start position of the frequency domain resources occupied by the Sth OFDM symbol, the frequency end position of the frequency domain resources occupied by the Sth OFDM symbol, and the frequency center position of the frequency domain resources occupied by the Sth OFDM symbol.

10. The method according to claim 9, characterized in that, The S equals or Or 1 or X, the stated To round down, the This is for rounding up.

11. The method according to any one of claims 8-10, characterized in that, The method further includes: Send a first message, which indicates the reference frequency of the first signal.

12. A communication method, characterized in that, Applied to a second device, including: The first signal is received. The first signal is used to calibrate the carrier frequency. The first signal occupies X consecutive orthogonal frequency division multiplexing (OFDM) symbols and N frequency domain resources. Each frequency domain resource occupies M consecutive subcarriers. The first signal occupies one of the N frequency domain resources on any one of the X consecutive OFDM symbols. The N frequency domain resources occupy N*M subcarriers. The N is greater than or equal to 2. The M takes the value of 1 or 2. The X is greater than or equal to the N. Carrier frequency error calibration is performed based on the first signal.

13. The method according to claim 12, characterized in that, Where X = L*N, the first signal occupies one frequency domain resource out of the N frequency domain resources in any one of the X consecutive OFDM symbols, including: The first signal occupies one frequency domain resource in every L consecutive OFDM symbols out of the L*N consecutive OFDM symbols, where L is greater than 1.

14. The method according to claim 13, characterized in that, The first signal occupies one frequency domain resource in each L consecutive OFDM symbols out of the L*N consecutive OFDM symbols, including: The frequency domain resources occupied by the first signal in the i-th consecutive L OFDM symbols are different from those occupied in the j-th consecutive L OFDM symbols, where i and j are different, i is greater than or equal to 1 and less than or equal to N, and i is greater than or equal to 1 and less than or equal to N.

15. The method according to any one of claims 12-14, characterized in that, Where X = N, the first signal is spaced M subcarriers apart at the frequency start position of the frequency domain resources occupied by two adjacent OFDM symbols.

16. The method according to claim 13 or 14, characterized in that, X = L * N, where the frequency starting position of the frequency domain resources occupied by the first signal in the i-th consecutive L OFDM symbols is spaced M subcarriers apart from the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols, and i is greater than or equal to 1 and less than or equal to N-1.

17. The method according to any one of claims 12-16, characterized in that, The method further includes: When it is determined that the carrier frequency offset error corresponding to the frequency domain resources occupied by the first signal in the Pth consecutive L OFDM symbols meets the carrier frequency offset error threshold, the frequency offset value between the frequency domain resources occupied by the first signal in the Pth consecutive L OFDM symbols and the reference frequency of the first signal is determined, wherein P is greater than or equal to 1 and less than or equal to N. The carrier frequency error calibration based on the first signal includes: Adjust the carrier frequency according to the frequency offset value.

18. The method according to claim 17, characterized in that, The frequency starting position of the frequency domain resources occupied by the i-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols equals the bandwidth of M subcarriers, or the frequency starting position of the frequency domain resources occupied by the (i+1)-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the i-th consecutive L OFDM symbols equals the bandwidth of M subcarriers.

19. The method according to claim 18, characterized in that, The frequency offset value is The SCS is the frequency spacing between adjacent subcarriers in an OFDM symbol.

20. The method according to claim 17, characterized in that, The frequency starting position of the frequency domain resources occupied by the j-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the (j+1)-th consecutive L OFDM symbols equals the bandwidth of M subcarriers; the frequency starting position of the frequency domain resources occupied by the (k+1)-th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the k-th consecutive L OFDM symbols equals the bandwidth of M subcarriers; or, The frequency starting position of the frequency domain resources occupied by the (j+1)th consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the jth consecutive L OFDM symbols equals the bandwidth of M subcarriers; the frequency starting position of the frequency domain resources occupied by the kth consecutive L OFDM symbols minus the frequency starting position of the frequency domain resources occupied by the (k+1)th consecutive L OFDM symbols equals the bandwidth of M subcarriers. Wherein, 1≤j≤Q-2, Q≤k≤N-1, 2≤Q≤N-2, the first position of the (Q-1)th OFDM symbol in the X consecutive OFDM symbols is the same as the reference frequency of the first signal, and the first position is one of the following positions: The frequency start position of the frequency domain resource occupied by the (Q-1)th OFDM symbol, the frequency end position of the frequency domain resource occupied by the (Q-1)th OFDM symbol, and the frequency center position of the frequency domain resource occupied by the (Q-1)th OFDM symbol; and / or, The second position of the Qth OFDM symbol is the same as the reference frequency of the first signal, wherein the second position is one of the following positions: The frequency start position of the frequency domain resources occupied by the Qth OFDM symbol, the frequency end position of the frequency domain resources occupied by the Qth OFDM symbol, and the frequency center position of the frequency domain resources occupied by the Qth OFDM symbol.

21. The method according to claim 20, characterized in that, The frequency offset value is or The SCS is the frequency spacing between adjacent subcarriers in an OFDM symbol.

22. The method according to any one of claims 17-21, characterized in that, The reference frequency of the first signal is located at the lowest frequency position of the N frequency domain resources, the highest frequency position of the N frequency domain resources, the synchronization grid frequency corresponding to the first signal, or the frequency corresponding to the channel grid in the first signal.

23. The method according to claim 22, characterized in that, The third position of the frequency domain resources occupied by the S-th OFDM symbol in the X consecutive OFDM symbols is the same as the reference frequency of the first signal, where S is a positive integer less than or equal to N. The third position is one of the following positions: The frequency start position of the frequency domain resources occupied by the Sth OFDM symbol, the frequency end position of the frequency domain resources occupied by the Sth OFDM symbol, and the frequency center position of the frequency domain resources occupied by the Sth OFDM symbol.

24. The method according to claim 23, characterized in that, The S equals or Or 1 or X, the stated To round down, the This is for rounding up.

25. The method according to any one of claims 17-24, characterized in that, The method further includes: Receive first information, which indicates the reference frequency of the first signal.

26. A communication device, characterized in that, include: At least one processor; Used to run part or all of a computer program or data so that the method of any one of claims 1-11 or any one of claims 12-25 is performed.

27. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed by a computer, cause the method as described in any one of claims 1-25 to be performed.

28. A computer program product comprising a computer program or instructions, characterized in that, When the computer program or instructions are run on a computer, the method as described in any one of claims 1-25 is performed.

Images