Communication method and communication apparatus

Abstract

The present application provides a communication method. The method can be applied to WLAN systems that support 802.11 series protocols such as a next generation of IEEE 802.11be, and Wi-Fi 8, and can also be applied to UWB-based wireless personal area network systems and perception systems. The method comprises: in a channel contention scenario, before sending a latency signal instructing another station to wait for a period of time before channel contention, a station calibrates a CFO on the basis of a finally received first PPDU before sending the latency signal. The CFO is calibrated on the basis of the finally received PPDU, so that in a scenario in which a plurality of stations all send latency signals, the plurality of latency signals can still be normally received by other stations in the case of an excessively large CFO offset.

Description

Communication method and communication device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 16, 2023, with application number 202311039104.9 and application name “Communication Method and Communication Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and more particularly, to a communication method and a communication device. Background Art

[0003] WLANs (wireless local area networks) have developed to date, with 802.11 being one of the current mainstream wireless access standards and having been widely used commercially for over a decade. Its common basic architecture consists of an access point (AP) that connects to the Internet via wired or wireless connections. The AP is associated with multiple stations (STAs), and uplink and downlink communications between the AP and associated STAs are performed using the 802.11 protocol. WLANs operate in unlicensed spectrum, and multiple STAs need to share the same channel. To resolve channel access conflicts between multiple STAs, a random backoff mechanism was introduced. However, if a STA continuously backs off to avoid channel access conflicts, this can result in excessive transmission delays for that STA.

[0004] One current latency reduction method involves sending a Defer Signal after a STA fails to transmit k times (e.g., four times) in a row. This signal is then allowed to wait for a certain period of time after the channel has been idle. This triggers other STAs to wait and resume transmission on the channel. However, if multiple STAs send Defer Signals simultaneously, variations in carrier frequency offset (CFO) between STAs may prevent other STAs from receiving these signals, leading to latency reduction failure. Therefore, improving the performance of this latency reduction method has become an urgent issue.

[0005] Summary of the Invention

[0006] The present application provides a communication method for reducing latency by avoiding CFO deviations between different sites.

[0007] In a first aspect, a communication method is provided. The method may be executed by a first station, or may be executed by a component (e.g., a chip or circuit) of the first station, without limitation. For ease of description, the following description will take the execution by the first station as an example.

[0008] The communication method includes: a first station sends a delay signal after a channel is idle for a first period of time, wherein the delay signal is used to trigger other stations to wait for a second period of time to compete for the channel; before sending the delay signal, the first station calibrates a carrier frequency offset (CFO) according to a first physical layer protocol data unit (PPDU), where the first PPDU is the last PPDU received before sending the delay signal.

[0009] Based on the above technical solution, before sending a delayed signal, the first station can calibrate the CFO based on the last received first PPDU. The delayed signal is used to trigger other stations to wait for a second period of time before competing for the channel, thereby increasing the probability of the first station successfully competing for the channel and thereby reducing the first station's latency. Furthermore, in this technical solution, before sending a delayed signal, the first station calibrates its own CFO based on the last received first PPD. This ensures that, in scenarios where multiple stations in the communication system are sending delayed signals, the delayed signals sent by the multiple stations will not be properly received by other stations due to excessive CFO deviations, thereby ensuring the normal transmission of the delayed signal and reducing the first station's latency.

[0010] In combination with the first aspect, in certain implementations of the first aspect, the first PPDU is a PPDU that is parsed successfully; and / or the duration between the moment of calibrating the CFO and the moment of sending the delayed signal is less than or equal to a first threshold; and / or the frame carried in the first PPDU is a response frame or a frame that does not trigger a response frame.

[0011] Based on the above technical solution, the first PPDU can be a PPDU that meets certain conditions, for example, the first PPDU can be a PPDU that is successfully parsed by the first station. This can prevent different stations from calibrating the CFO based on different PPDUs in a scenario where multiple stations in a communication system transmit delayed signals (for example, due to interference or differences in received signal-to-interference-and-noise ratios between different stations, some stations may experience received frame parsing errors, which may result in different stations calibrating the CFO based on different PPDUs).

[0012] The frame carried in the first PPDU is a response frame or a frame that does not trigger a response frame. By specifying that the frame used by the station to calibrate CFO is a response frame or a frame that does not trigger a response frame, it is possible to avoid different stations calibrating CFO based on different PPDUs in a scenario where multiple stations in the communication system all send delayed signals (for example, due to different physical locations, different stations can receive different frames, which may cause different stations to calibrate CFO based on different PPDUs).

[0013] Furthermore, after a station calibrates the CFO, the CFO will gradually increase over time. Therefore, in scenarios where multiple stations in a communication system transmit delay signals, even if multiple stations perform CFO calibration based on the same PPDU, the calibration time cannot be too far from the time the delay signal is transmitted. This technical solution prevents the CFO calibration time from being too far from the time the delay signal is transmitted by limiting the time between the CFO calibration time and the delay signal transmission time to less than or equal to a first threshold.

[0014] In combination with the first aspect, in certain implementations of the first aspect, before the first site sends the delayed signal, the method also includes: the first site determines that the channel is idle based on physical carrier sensing (physical carrier sensing) and virtual carrier sensing (virtual carrier sensing), and the network allocation vector (NAV) value corresponding to the virtual carrier sensing is set based on the duration field in the medium access control (MAC) frame header.

[0015] Based on the above technical solution, before sending the delay signal, the first station determines that the channel state is idle by calling the carrier sensing (CS) mechanism, wherein the carrier sensing mechanism includes physical carrier sensing and virtual carrier sensing. As for virtual carrier sensing, after receiving a frame whose receiving address is neither a broadcast address nor its own MAC address, the NAV timer is set, and then the countdown is performed until the countdown reaches 0. If the value of the network allocation vector (NAV) is not 0, the virtual carrier sensing is busy, and if the value of NAV is 0, the virtual carrier sensing is idle. In this embodiment, in order to avoid a large difference in the time when different stations determine that the channel state is idle through the carrier sensing mechanism in the scenario where multiple stations in the communication system all send delay signals, it can be set that the stations sending the delay signal all use Duration to set NAV.

[0016] In combination with the first aspect, in some implementations of the first aspect, a time synchronization function (TSF) value of a start time of sending the delayed signal is an integer multiple of 9 microseconds.

[0017] Based on the above technical solution, in order to avoid large differences between the starting times of sending delayed signals at different sites in a scenario where multiple sites in a communication system all send delayed signals, the time synchronization function TSF value of the starting time of sending delayed signals can be set to an integer multiple of 9 microseconds to maximize the alignment of the starting times of sending delayed signals at different sites.

[0018] In combination with the first aspect, in certain implementations of the first aspect, the delayed signal is generated based on a medium access control MAC frame, and the values ​​of a scrambling seed, a legacy signaling field (Legacy Signal Field, L-SIG), a duration field, and a receiving address (RA) field of the MAC frame are determined.

[0019] Based on the above technical solution, in order to enable a station receiving a delayed signal to correctly parse the delayed signal, the delayed signal may be generated based on MAC, and the fields in the MAC frame are determined.

[0020] In combination with the first aspect, in certain implementations of the first aspect, the rate (RATA) field in the L-SIG indicates 6 megabits per second Mbps; and / or the Duration field indicates 72 microseconds or 36 microseconds; and / or the RA field indicates a broadcast address or a determined MAC address.

[0021] In combination with the first aspect, in certain implementations of the first aspect, the first station is a station that fails to send wireless frames on the channel for k consecutive times, where k is a positive integer.

[0022] In a second aspect, a communication method is provided. The method may be executed by a first site, or may be executed by a component (e.g., a chip or circuit) of the first site, without limitation. For ease of description, the following description will take the execution by the first site as an example.

[0023] The communication method includes: a first station determines that the state of a channel is idle based on physical carrier sensing and virtual carrier sensing; if the network allocation vector NAV value corresponding to the virtual carrier sensing is set based on the duration field in the media access control MAC frame header, the first station determines to send a delay signal after the channel is idle for a first period of time; or, if the NAV value corresponding to the virtual carrier sensing is set based on the transmission opportunity TXOP field in the MAC frame header, the first station determines not to send the delay signal, and the delay signal is used to trigger other stations to wait for a second period of time to compete for the channel.

[0024] Based on the above technical solution, the first station determines that the channel status is idle by calling the CS mechanism, wherein the CS mechanism includes physical carrier sensing and virtual carrier sensing. As for virtual carrier sensing, after receiving a frame whose receiving address is neither a broadcast address nor its own MAC address, the NAV timer is set, and then the countdown is performed until the countdown reaches 0. If the NAV value is not 0, the virtual carrier sensing is busy; if the NAV value is 0, the virtual carrier sensing is idle. In this embodiment, if the NAV based on which the first station performs virtual carrier sensing is set based on the Duration field in the MAC frame header, the first station can send a delay signal after the channel is idle for a period of time; if the NAV based on which the first station performs virtual carrier sensing is set based on the TXOP field in the MAC frame header, the first station determines that the delay signal cannot be sent, so as to avoid the situation where multiple stations in the communication system all send delay signals. The time when different stations determine that the channel status is idle through the carrier sensing mechanism is too different.

[0025] In combination with the second aspect, in certain implementations of the second aspect, when the first site determines to send a delayed signal after the channel is idle for a first period of time, the method further includes: the first site sends the delayed signal after the channel is idle for the first period of time; before sending the delayed signal, the first site calibrates the carrier frequency offset CFO according to the first physical layer protocol data unit PPDU, and the first PPDU is the last PPDU received before sending the delayed signal.

[0026] Based on the above technical solution, before sending a delayed signal, the first station can calibrate the CFO based on the last received first PPDU. The delayed signal is used to trigger other stations to wait for a second period of time before competing for the channel, thereby increasing the probability of the first station successfully competing for the channel and thereby reducing the first station's latency. Furthermore, in this technical solution, before sending the delayed signal, the first station calibrates its own CFO based on the last received first PPD. This ensures that, in scenarios where multiple stations in the communication system are sending delayed signals, the delayed signals sent by the multiple stations will not be properly received by other stations due to excessive CFO deviations, thereby ensuring the normal transmission of the delayed signals and reducing the first station's latency.

[0027] For example, the conditions satisfied by the first PPDU can refer to the description of the first PPDU in the first aspect above, and are not repeated here. In addition, the delayed signal can be generated based on a MAC frame, and the conditions satisfied by the MAC frame can refer to the description of the delayed signal in the first aspect above, and are not repeated here.

[0028] In combination with the second aspect, in some implementations of the second aspect, a time synchronization function TSF value of the start time of sending the delayed signal is an integer multiple of 9 microseconds.

[0029] Based on the above technical solution, in order to avoid large differences between the starting times of sending delayed signals at different sites in a scenario where multiple sites in a communication system all send delayed signals, the time synchronization function TSF value of the starting time of sending delayed signals can be set to an integer multiple of 9 microseconds to maximize the alignment of the starting times of sending delayed signals at different sites.

[0030] In a third aspect, a communication method is provided. The method may be executed by a first site, or by a component (e.g., a chip or circuit) of the first site, without limitation. For ease of description, the following description uses the first site as an example.

[0031] The communication method includes: a first station generates a delay signal based on a medium access control MAC frame, wherein the delay signal is used to trigger other stations to wait for a second period of time before competing for a channel, and the values ​​of the scrambling code seed, the traditional signaling field L-SIG, the continuous Duration field and the receiving address RA field of the MAC frame are determined; the first station sends the delay signal after the channel is idle for a first period of time.

[0032] Based on the above technical solution, in order to enable a station receiving a delayed signal to correctly parse the delayed signal, the delayed signal may be generated based on MAC, and the fields in the MAC frame are determined.

[0033] In combination with the third aspect, in certain implementations of the third aspect, the rate RATA field in the L-SIG indicates 6 megabits per second (Mbps); and / or, the Duration field indicates 72 microseconds or 36 microseconds; and / or, the RA field indicates a broadcast address or a determined MAC address.

[0034] In combination with the third aspect, in certain implementations of the third aspect, the first station is a station that fails to send wireless frames on the channel for k consecutive times, where k is a positive integer.

[0035] In combination with the third aspect, in certain implementations of the third aspect, before sending the delayed signal, the first site calibrates the carrier frequency offset CFO according to the first physical layer protocol data unit PPDU, where the first PPDU is the last PPDU received before sending the delayed signal.

[0036] Based on the above technical solution, before sending a delayed signal, the first station can calibrate the CFO based on the last received first PPDU. The delayed signal is used to trigger other stations to wait for a second period of time before competing for the channel, thereby increasing the probability of the first station successfully competing for the channel and thereby reducing the first station's latency. Furthermore, in this technical solution, before sending the delayed signal, the first station calibrates its own CFO based on the last received first PPD. This ensures that, in scenarios where multiple stations in the communication system are sending delayed signals, the delayed signals sent by the multiple stations will not be properly received by other stations due to excessive CFO deviations, thereby ensuring the normal transmission of the delayed signals and reducing the first station's latency.

[0037] Exemplarily, the conditions satisfied by the first PPDU may refer to the description of the first PPDU in the above-mentioned first aspect, which will not be repeated here.

[0038] In combination with the third aspect, in certain implementations of the third aspect, before the first site sends the delayed signal, the method also includes: the first site determines that the channel is idle based on physical carrier sensing and virtual carrier sensing, and the network allocation vector NAV value corresponding to the virtual carrier sensing is set based on the duration field in the media access control MAC frame header.

[0039] Based on the above technical solution, before sending the delay signal, the first station determines that the channel status is idle by calling the carrier sensing (CS) mechanism, wherein the carrier sensing mechanism includes physical carrier sensing and virtual carrier sensing. For virtual carrier sensing, after receiving a frame whose receiving address is neither a broadcast address nor its own MAC address, the NAV timer is set and then counts down until the countdown reaches 0. If the value of the network allocation vector (NAV) is not 0, the virtual carrier sensing is busy; if the value of NAV is 0, the virtual carrier sensing is idle. In this embodiment, in order to avoid a large difference in the time when different stations determine that the channel status is idle through the carrier sensing mechanism in the scenario where multiple stations in the communication system all send delay signals, it can be set that the stations sending the delay signal all use Duration to set NAV.

[0040] In combination with the third aspect, in certain implementations of the third aspect, a time synchronization function TSF value of the start time of sending the delayed signal is an integer multiple of 9 microseconds.

[0041] Based on the above technical solution, in order to avoid large differences between the starting times of sending delayed signals at different sites in a scenario where multiple sites in a communication system all send delayed signals, the time synchronization function TSF value of the starting time of sending delayed signals can be set to an integer multiple of 9 microseconds to maximize the alignment of the starting times of sending delayed signals at different sites.

[0042] In a fourth aspect, a communication device is provided, which is configured to execute the methods provided in aspects 1 to 3 above. Specifically, the device may include units and / or modules, such as a processing unit and / or a communication unit, configured to execute the methods provided in any one of the aforementioned implementations of aspects 1 to 3 above.

[0043] Exemplarily, when the communication device is the first site in the above-mentioned first aspect, the communication unit is used to send a delay signal after the channel is idle for a first period of time, and the delay signal is used to trigger other sites to wait for a second period of time to compete for the channel; the processing unit is also used to calibrate the carrier frequency offset CFO according to the first physical layer protocol data unit PPDU before the communication unit sends the delay signal, and the first PPDU is the last PPDU received before sending the delay signal.

[0044] Exemplarily, when the communication device is the first site in the second aspect above, the processing unit is used to determine that the state of the channel is idle based on physical carrier sensing and virtual carrier sensing; if the network allocation vector NAV value corresponding to the virtual carrier sensing is set based on the duration field in the media access control MAC frame header, the processing unit is used to determine to send a delay signal after the channel is idle for a first period of time; or, if the NAV value corresponding to the virtual carrier sensing is set based on the transmission opportunity TXOP field in the MAC frame header, the processing unit is used to determine not to send the delay signal, and the delay signal is used to trigger other sites to wait for a second period of time to compete for the channel.

[0045] Exemplarily, when the communication device is the first site in the third aspect above, the processing unit is used to generate a delay signal based on the medium access control MAC frame, and the delay signal is used to trigger other sites to wait for a second period of time to compete for the channel, and the values ​​of the scrambling code seed, traditional signaling field L-SIG, continuous Duration field and receiving address RA field of the MAC frame are determined; the communication unit is used to send the delay signal after the channel is idle for a first period of time.

[0046] In one implementation, the apparatus is a terminal device. When the apparatus is a terminal device, the communication unit may be a transceiver or an input / output interface; and the processing unit may be at least one processor. Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0047] Exemplarily, when the communication device is the first site in the first aspect above, the transceiver is used to send a delay signal after the channel is idle for a first period of time, and the delay signal is used to trigger other sites to wait for a second period of time to compete for the channel; the processing unit is also used to calibrate the carrier frequency offset CFO according to the first physical layer protocol data unit PPDU before the communication unit sends the delay signal, and the first PPDU is the last PPDU received before sending the delay signal.

[0048] Exemplarily, when the communication device is the first site in the second aspect above, the processor is used to determine that the state of the channel is idle based on physical carrier sensing and virtual carrier sensing; if the network allocation vector NAV value corresponding to the virtual carrier sensing is set based on the duration field in the media access control MAC frame header, the processor is used to determine to send a delay signal after the channel is idle for a first period of time; or, if the NAV value corresponding to the virtual carrier sensing is set based on the transmission opportunity TXOP field in the MAC frame header, the processor is used to determine not to send the delay signal, and the delay signal is used to trigger other sites to wait for a second period of time to compete for the channel.

[0049] Exemplarily, when the communication device is the first station in the third aspect above, the processor is used to generate a delay signal based on the medium access control MAC frame, and the delay signal is used to trigger other stations to wait for a second period of time to compete for the channel, and the values ​​of the scrambling code seed, traditional signaling field L-SIG, continuous Duration field and receiving address RA field of the MAC frame are determined; the transceiver is used to send the delay signal after the channel is idle for a first period of time.

[0050] In another implementation, the device is a chip, chip system, or circuit used in a terminal device. When the device is a chip, chip system, or circuit used in a terminal device, the communication unit may be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip, chip system, or circuit; and the processing unit may be at least one processor, processing circuit, or logic circuit.

[0051] In a fifth aspect, a communication device is provided, which includes: a memory for storing programs; and at least one processor for executing computer programs or instructions stored in the memory to execute any one of the above-mentioned implementations of the first to third aspects, or the method provided by any one of the above-mentioned implementations of the second to third aspects.

[0052] In a sixth aspect, the present application provides a processor for executing the methods provided in the above aspects.

[0053] For the operations such as sending and acquiring / receiving involved in the processor, unless otherwise specified, or if they do not conflict with their actual functions or internal logic in the relevant descriptions, they can be understood as processor output, reception, input and other operations, and can also be understood as sending and receiving operations performed by the radio frequency circuit and antenna. This application does not limit this.

[0054] In a seventh aspect, a computer-readable storage medium is provided, which stores a program code for execution by a device, and the program code includes a method for executing any one of the above-mentioned implementation methods of the first to third aspects.

[0055] In an eighth aspect, a computer program product comprising instructions is provided, which, when run on a computer, enables the computer to execute the method provided in any one of the above-mentioned implementations of the first to third aspects.

[0056] In the ninth aspect, a chip is provided, which includes a processor and a communication interface. The processor reads instructions stored in a memory through the communication interface and executes the method provided by any one of the above-mentioned implementation methods of the first to third aspects.

[0057] Optionally, as an implementation method, the chip also includes a memory, in which a computer program or instruction is stored, and the processor is used to execute the computer program or instruction stored in the memory. When the computer program or instruction is executed, the processor is used to execute the method provided in any one of the above implementation methods.

[0058] In a tenth aspect, a communication system is provided, comprising the first site of the first aspect, or the first site of the second aspect, or the first site of the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] FIG1 is a schematic diagram of an application scenario to which an embodiment of the present application is applicable.

[0060] FIG2 shows a schematic diagram of the structure of a device provided in this application.

[0061] FIG3 is a schematic diagram of a PPDU format.

[0062] FIG4 is a schematic diagram of sending a Defer Signal according to an embodiment of the present application.

[0063] FIG5 is a schematic flowchart of a communication method provided in an embodiment of the present application.

[0064] FIG6 is a schematic flowchart of a communication method provided in an embodiment of the present application.

[0065] FIG7 is a schematic block diagram of a communication device provided in an embodiment of the present application.

[0066] FIG8 is a schematic diagram of another communication device provided in an embodiment of the present application.

[0067] FIG9 is a schematic diagram of a chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0068] In order to facilitate understanding of the embodiments of the present application, the following points are first explained.

[0069] First, in this application, "used to indicate" can include being used for direct indication and being used for indirect indication. When describing that a certain indication information is used to indicate A, it can include that the indication information directly indicates A or indirectly indicates A, but it does not mean that the indication information must carry A.

[0070] The information indicated by the indication information is called the information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated, such as but not limited to, directly indicating the information to be indicated, such as the information to be indicated itself or the index of the information to be indicated. The information to be indicated can also be indirectly indicated by indicating other information, wherein there is an association between the other information and the information to be indicated. It is also possible to indicate only a part of the information to be indicated, while the other parts of the information to be indicated are known or agreed in advance. For example, it is also possible to use the arrangement order of each piece of information agreed in advance (such as specified in the protocol) to achieve the indication of specific information, thereby reducing the indication overhead to a certain extent. At the same time, it is also possible to identify the common parts of each piece of information and indicate them uniformly to reduce the indication overhead caused by indicating the same information separately.

[0071] Second, "at least one" shown in the present application refers to one or more, and "multiple" refers to two or more. In addition, in the embodiments of the present application, "first", "second" and various digital numbers (for example, "#1", "#2", etc.) are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of each process below does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. It should be understood that the objects described in this way can be interchangeable under appropriate circumstances so as to be able to describe solutions other than the embodiments of the present application. In addition, in the embodiments of the present application, words such as "S510" are only for the convenience of description and are not used to limit the order of execution of steps.

[0072] Third, in the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0073] Fourth, the term "storage" used in the embodiments of this application may refer to storage in one or more memories. The one or more memories may be provided separately or integrated into an encoder or decoder, a processor, or a communication device. The one or more memories may also be partially provided separately and partially integrated into a decoder, a processor, or a communication device. The type of memory may be any form of storage medium, and this application is not limited thereto.

[0074] Fifth, in the implementation of this application, "protocol" may refer to a standard protocol in the field of communications, for example, it may include the NR protocol and related protocols used in future communication systems, and this application does not limit this.

[0075] Sixth, in the embodiments of the present application, the terms “of”, “corresponding, relevant”, “corresponding” and “associate” can sometimes be used interchangeably. It should be noted that when the distinction between them is not emphasized, the meanings they intend to express are consistent.

[0076] Seventh, in the embodiments of the present application, "under the circumstances", "when", and "if" can sometimes be used interchangeably. It should be pointed out that when the distinction between them is not emphasized, the meanings they intend to express are consistent.

[0077] Eighth, the term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0078] The technical solution in this application will be described below with reference to the accompanying drawings.

[0079] The technical solution provided in the embodiments of the present application can be applicable to wireless local area network (WLAN) scenarios, for example, supporting the Institute of Electrical and Electronics Engineers (IEEE) 802.11 related standards, such as 802.11a / b / g standards, 802.11n standards, 802.11ac standards, 802.11ax standards, IEEE 802.11ax next-generation Wi-Fi protocols, such as 802.11be, Wi-Fi 7, extremely high throughput (EHT), 802.11ad, 802.11ay or 802.11bf, such as the next generation of 802.11be, Wi-Fi 8, etc., and can also be applied to wireless personal area network systems based on ultra-wide band (UWB), such as the 802.15 series standards, and can also be applied to sensing systems, such as the 802.11bf series standards. The 802.11n standard is known as the high throughput (HT) standard, the 802.11ac standard is known as the very high throughput (VHT) standard, the 802.11ax standard is known as the high efficiency (HE) standard, and the 802.11be standard is known as the extremely high throughput (EHT) standard. 802.11bf includes two major categories of standards: low-frequency (e.g., sub7 GHz) and high-frequency (e.g., 60 GHz). The sub7 GHz implementation primarily relies on 802.11ac, 802.11ax, 802.11be, and their next-generation standards, while the 60 GHz implementation primarily relies on 802.11ad, 802.11ay, and their next-generation standards. 802.11ad may also be called a directional multi-gigabit (DMG) standard, and 802.11ay may also be called an enhanced directional multi-gigabit (EDMG) standard.

[0080] Although the embodiments of the present application are primarily described using the deployment of a WLAN network, particularly a network using the IEEE 802.11 system standard, as an example, those skilled in the art will readily appreciate that the various aspects of the embodiments of the present application can be extended to other networks using various standards or protocols, such as a high-performance wireless local area network (HIPERLAN), a wireless wide area network (WWAN), a wireless personal area network (WPAN), or other networks now known or developed in the future. Therefore, regardless of the coverage area and wireless access protocol used, the various aspects provided in the embodiments of the present application can be applied to any suitable wireless network.

[0081] The technical solutions of the embodiments of the present application can also be applied to various communication systems, such as: WLAN communication system, wireless fidelity (Wi-Fi) system, long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), universal mobile telecommunication system (UMTS), world-wide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system or new radio (NR), sixth generation (6G) system, Internet of Things (IoT) network or vehicle to x (V2X), etc.

[0082] The above-mentioned communication system applicable to the present application is only an example, and the communication system applicable to the present application is not limited to this. It is described uniformly here and will not be repeated below.

[0083] FIG1 is a schematic diagram of an application scenario applicable to an embodiment of the present application. As shown in FIG1 , the communication method provided by the present application is applicable to data communication between an access point (AP) and a station (STA), wherein the station may be a non-AP station (none access point station, non-AP STA), referred to as a non-AP station or STA for short. Specifically, the scheme of the present application is applicable to data communication between an AP and one or more non-AP stations (for example, data communication between AP1 and non-AP STA1, non-AP STA2), and is also applicable to data communication between APs (for example, data communication between AP1 and AP2), as well as data communication between non-AP STAs and non-AP STAs (for example, data communication between non-AP STA2 and non-AP STA3).

[0084] An access point is a node that allows terminals (such as mobile phones) to access a wired (or wireless) network. It is primarily deployed in homes, buildings, and campuses, with a typical coverage radius of tens to hundreds of meters. It can also be deployed outdoors. An access point acts as a bridge between wired and wireless networks, connecting wireless network clients and then connecting the wireless network to the Ethernet.

[0085] Specifically, the access point can be a terminal or network device with a Wi-Fi chip, and the network device can be a server, a router, a switch, a bridge, a computer, a mobile phone, a relay station, a vehicle-mounted device, a wearable device, a network device in a 5G network, a network device in a 6G network, or a network device in a public land mobile network (PLMN), etc., and the embodiments of the present application are not limited thereto. The access point can be a device that supports the Wi-Fi standard. For example, the access point can also support one or more standards of the IEEE 802.11 series, such as 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.11ax, 802.11be, 802.11ad, and 802.11ay.

[0086] A non-AP site may be a wireless communication chip, a wireless sensor, or a wireless communication terminal, and may also be referred to as a user, user equipment (UE), access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. A non-AP site may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, an Internet of Things device, a wearable device, a terminal device in a 5G network, a terminal device in a 6G network, or a terminal device in a PLMN, and the embodiments of the present application are not limited thereto. A non-AP site may be a device that supports the WLAN standard. For example, a non-AP station may support one or more standards in the IEEE 802.11 series, such as 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.11ax, 802.11be, 802.11ad, and 802.11ay.

[0087] For example, non-AP sites can be mobile phones, tablets, set-top boxes, smart TVs, smart wearable devices, in-vehicle communication devices, computers, Internet of Things (IoT) nodes, sensors, smart homes such as smart cameras, smart remote controls, smart water and electricity meters, and sensors in smart cities.

[0088] The above-mentioned AP or non-AP site may include a transmitter, a receiver, a memory, a processor, etc., wherein the transmitter and the receiver are used for sending and receiving packet structures respectively, the memory is used to store signaling information and store preset values ​​agreed in advance, etc., and the processor is used to parse signaling information, process related data, etc.

[0089] For example, Figure 2 shows a communication device provided by the present application. The device shown in Figure 2 can be an AP or a non-AP site. Among them, a medium access control (MAC) layer processing module, a physical (PHY) layer processing module, a radio frequency / antenna, etc. are used to implement the relevant functions of the above-mentioned transmitter and receiver. As shown in Figure 2, in addition to the MAC layer processing module, the PHY layer processing module, the radio frequency / antenna, the memory, and the processor, the device can also include a controller and a scheduler.

[0090] It should be understood that FIG2 is merely an example of a device provided in the present application and does not constitute a limitation of the present application. For example, the device may not include a controller and / or a scheduler.

[0091] In order to facilitate understanding of the technical solutions of the embodiments of the present application, some terms or concepts that may be involved in the embodiments of the present application are first briefly described.

[0092] 1. Physical Protocol Data Unit (PPDU): Figure 3 is a schematic diagram of the PPDU format. The PPDU includes the Legacy Short Training Field (L-STF), the Legacy Long Training Field (L-LTF), the Legacy Signal Field (L-SIG), the Repeat Legacy-Signal Field (RL-SIG), the Universal Signal Field (U-SIG), the Extremely High Throughput Signaling Field (EHT-SIG), the EHT-short training field (EHT-STF), the EHT-long training field (EHT-LTF), the Data field, and the Package Extension (PE) field. Among them, L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-SIG, EHT-STF, and EHT-LTF are partial structures in the physical layer header (or preamble) of PPDU.

[0093] L-STF, L-LTF, and L-SIG can be understood as legacy preamble fields, used to ensure the coexistence of new devices with legacy devices. RL-SIG is used to enhance the reliability of legacy signaling fields.

[0094] U-SIG and EHT-SIG are signaling fields. U-SIG is used to carry common information, such as PPDU version, uplink / downlink information, PPDU frequency bandwidth, and puncturing information. EHT-SIG includes information indicating resource allocation and data demodulation.

[0095] It should be noted that in the embodiments of the present application, the fields in the PPDU in the 802.11be scenario are used as an example. The various fields in the PPDU mentioned in the embodiments of the present application are not limited to fields related to 802.11be. The various fields in the PPDU mentioned in the embodiments of the present application may also be fields related to standard versions after 802.11be, including but not limited to the PPDU signaling field in the next generation protocol as ultra-high reliability signaling (UHR-SIG).

[0096] 2. Distributed Coordination Function (DCF): WLAN operates in unlicensed spectrum, and multiple stations need to share the same channel. To resolve channel access conflicts between multiple stations, a random backoff mechanism, also known as the DCF mechanism, is introduced. Before a station wants to send data or management frames, it must first use the carrier sensing (CS) mechanism to determine whether the channel is idle or busy. If the channel is busy, the station must postpone channel access for a specified period of time.

[0097] Exemplarily, the specific time is divided into two cases: when a frame is detected but not received successfully, the specific time is the extended interframe space (EIFS); in other cases (such as, no frame is detected, or a frame is detected and received successfully, etc.), the specific time is the distributed interframe space (DIFS).

[0098] Specifically, the durations of DIFS and EIFS are:

[0099] DIFS=aSIFSTime+2*aSlotTime;

[0100] EIFS=aSIFSTime+AckTxTime+DIFS.

[0101] Typically, aSIFSTime is 16 microseconds and aSlotTime is 9 microseconds. Specific values ​​may vary depending on the spectrum and protocol, and this application does not limit the specific values ​​of aSIFSTime and aSlotTime. AckTxTime is the transmission duration of the acknowledgment (Ack) frame.

[0102] After waiting for the channel to be idle for DIFS or EIFS, a station must back off before sending data or management frames. For ease of description, the following uses the specific time as DIFS as an example.

[0103] For example, a station implements the DCF mechanism as follows: the station randomly selects a backoff number from the window [0, contention window (CW)] as the counter value. After waiting for the channel to be idle for DIFS, the counter value is decremented by 1 every time the channel remains idle for aSlotTime. When the counter value reaches 0, the station transmits data or management frames. The initial value of CW is the minimum contention window (CWmin). [0, CW] indicates that the counter value range is greater than or equal to 0 and less than or equal to CW.

[0104] If the station data or management frame is sent successfully, CW is set to CWmin, and the counter value is randomly selected from [0, CWmin] when the station competes for the channel next time.

[0105] If a station fails to send data or management frames, CW is set to 2*CW+1. The counter value is randomly selected from [0, 2*CW+1] when the station competes for the channel next time.

[0106] If a station fails to send packets continuously, CW is set to CWmax and remains at CWmax until it succeeds, at which point CW is set to CWmin.

[0107] From the above, we can see that in the scenario where multiple sites share the same channel, the DCF mechanism can be used to avoid channel access conflicts.

[0108] Alternatively, two stations generating the same random backoff counter value may simultaneously back off to 0, allowing both stations to transmit data or management frames simultaneously. This can cause transmission failure for both stations due to a channel access conflict. After the transmission fails, the two stations will randomly select a counter value within a larger contention window to access the channel, thereby reducing the probability of channel access conflicts. As more stations initiate contention simultaneously, the probability of channel access conflicts increases, and the contention window is continuously expanded. This means that the actual contention window is dynamically adjusted based on the number of competing stations, supporting channel contention for varying numbers of competing stations.

[0109] 3. Enhanced distributed channel access (EDCA): EDCA is derived from DCF.

[0110] In the DCF mechanism, each station corresponds to a contention queue, and its data to be transmitted is cached in the same queue. In the EDCA mechanism, a station supports four access categories (ACs) to distinguish data of different priorities. Each access category maintains a separate set of channel contention parameters. The four access categories, from highest to lowest priority, are AC_VO, AC_VI, AC_BE, and AC_BK.

[0111] During the random backoff process for each AC, the system no longer waits for the DIFS duration, but instead waits for the Arbitration Interframe Space (AIFS) duration: AIFS[AC] = AIFSN[AC] * aSlotTime + aSIFSTime. Each AC also corresponds to a different CWmin[AC] and CWmax[AC]. High-priority access categories can be assigned smaller AIFSN, CWmin, and CWmax parameters, while low-priority access categories can be assigned larger AIFSN, CWmin, and CWmax parameters. This increases the chances of high-priority services being sent and reduces the chances of low-priority services being sent. The minimum AIFSN value is 2.

[0112] 4. Defer Signal: When a station fails to send a message k times (for example, 4 times) in a row, it is allowed to send a Defer Signal after the channel is idle for DIFS time.

[0113] An example of a Defer Signal is a legacy preamble, consisting of the L-STF, L-LTF, and L-SIG fields. Because a Defer Signal lacks a payload, a receiving station will interpret it as an error frame, triggering an EIFS wait. Within the EIFS, the station sending the Defer Signal can initiate a backoff again. Once the backoff is complete, the station can resume sending data. Backoff can resolve collisions caused by multiple stations sending Defer Signals simultaneously.

[0114] The above, in conjunction with Figure 1, briefly introduces the scenarios in which the communication method provided in the embodiment of the present application can be applied, as well as the basic concepts that may be involved in the embodiment of the present application, and introduces the Defer Signal in the basic concepts. From the above introduction to the Defer Signal, it can be seen that a site can reduce its own latency by sending a Defer Signal.

[0115] For ease of understanding, FIG4 is used to illustrate how a station sends a Defer Signal.

[0116] When a transmission opportunity (TXOP) on a channel ends, other stations determine the end time of the previous TXOP based on physical carrier sensing and virtual carrier sensing. In Figure 4, STA#1 obtains the previous TXOP (TXOP#1 shown in Figure 4). After exchanging A-MPDU1 and BA1 frames, the current TXOP ends some time later (as shown at the start of xIFS in Figure 4). At this point, STA#3 and STA#4 have experienced several consecutive contention failures and meet the basic conditions for sending a Defer Signal. STA#3 and STA#4 send a Defer Signal xIFS after the channel becomes idle. Upon receiving the Defer Signal, STA#1 and STA#2 interpret it as an erroneous frame and wait for the EIFS time after receiving the Defer Signal before competing for the channel again.

[0117] To make STA#1 and STA#2 treat the Defer Signal as an erroneously received frame, the physical layer frame header (i.e., L-STF, L-LTF, and L-SIG) is used as the Defer Signal. This prevents STA#1 and STA#2 from parsing the payload, which was never sent, and therefore treats the Defer Signal as an erroneous frame. Because multiple stations may send Defer Signals simultaneously, STA#3 and STA#4 cannot transmit immediately after sending the Defer Signal. Instead, they must go through a backoff process (as shown in Backoff #1 and Backoff #2 in Figure 4) to avoid collisions between STA#3 and STA#4.

[0118] The Defer Signal sending process shown in Figure 4 has the following problems:

[0119] 1) Each station has a different carrier frequency offset (CFO). When multiple stations send Defer Signals simultaneously, the CFO offset may be too large, causing third stations to be unable to receive them properly. For example, if the CFO offset between STA#3 and STA#4 is too large, as shown in Figure 4, the Defer Signals sent by STA#3 and STA#4 may not be received by STA#1 and STA#2.

[0120] 2) Different stations may determine different channel idle times, so the Defer Signal transmission times cannot be aligned. For example, as shown in Figure 4, if STA#3 and STA#4 need to confirm that the channel is idle before sending the Defer Signal, if STA#3 and STA#4 determine different channel idle times, the Defer Signals sent by STA#3 and STA#4 may not be received by STA#1 and STA#2.

[0121] 3) When using L-STF, L-LTF, and L-SIG as Defer signals, traditional STAs may behave inconsistently after receiving them. Some stations, due to a lack of received energy after the Defer signal, no longer treat the Defer signal as a received PPDU and immediately initiate channel contention. For example, STA#1 and STA#2 shown in Figure 4 do not wait for the EIFS time to initiate channel contention after receiving the Defer signal, but instead initiate channel contention directly.

[0122] In order to solve the problems existing in the Defer Signal sending process shown in Figure 4, the present application provides a communication method to reduce latency by avoiding CFO deviation between different sites.

[0123] The technical solution provided by the present application will be described in detail below with reference to the accompanying drawings. The embodiments of the present application can be applied to a variety of different scenarios, including the scenario shown in FIG1 , but is not limited to this scenario.

[0124] It should be understood that the embodiments shown below do not particularly limit the specific structure of the execution subject of the method provided by the embodiments of the present application. As long as it is possible to communicate according to the method provided by the embodiments of the present application by running a program that records the code of the method provided by the embodiments of the present application, for example, the execution subject of the method provided by the embodiments of the present application can be a receiving device or a sending device, or a functional module in the receiving device or the sending device that can call and execute the program.

[0125] Below, without loss of generality, the communication method provided in the embodiment of the present application is described in detail by taking the interaction between the first station and the second station as an example. The first station involved in the embodiment of the present application can be an access point AP, and the second station can be a non-access point non-AP (such as STA); or, the first station can be an access point STA, and the second station can be a non-access point AP; or, the first station and the second station are access points AP; or, the first station and the second station are non-access points non-AP.

[0126] FIG5 is a schematic flow chart of a communication method provided in an embodiment of the present application, comprising the following steps:

[0127] S510: The first station sends a delay signal.

[0128] The first station may be any station that needs to compete for a channel. For example, if a WLAN operates in an unlicensed spectrum and multiple stations need to share the same channel, the first station may be one of the multiple stations that need to share the same channel for transmission.

[0129] As a possible implementation, the first station may be a station that has failed to transmit radio frames on the channel for k consecutive times, where k is a positive integer. When k is equal to 1, the first station's failure to transmit radio frames on the channel for k consecutive times means that the first station has failed to transmit radio frames on the channel once. This embodiment does not impose any restrictions on the form of radio frames transmitted on the channel, and may be data frames, control frames, or management frames.

[0130] As another possible implementation, the first station may be any station that needs to send a delayed signal.

[0131] It should be understood that in this embodiment, there is no limitation on the conditions for the first station to send the delayed signal. It can be a station that fails in channel competition, a station with a high priority, or a station with other characteristics, which will not be described in detail in this embodiment.

[0132] Specifically, the delayed signal is used to trigger other stations to wait for a second period of time before competing for the channel. For example, the other stations involved in this embodiment may be stations that can receive the delayed signal sent by the first station. It should be noted that the purpose of the first station sending the delayed signal in this embodiment is to allow other stations to wait for a period of time before competing for the channel, thereby increasing the probability of the first station successfully competing for the channel. The function of the delayed signal can be understood as triggering other stations that may receive the delayed signal to wait for a period of time before competing for the channel.

[0133] For example, the function of the delay signal may refer to the functional description of the above-mentioned Defer Signal, and this embodiment does not impose any limitation on the specific functional definition of the delay signal.

[0134] As a possible implementation manner, the delay signal in this embodiment is the Defer Signal shown above.

[0135] As another possible implementation, the delay signal is other signals that can implement the Defer Signal function.

[0136] In this implementation, the delayed signal may be a signal generated based on a MAC frame. For example, the delayed signal may be designed using the current CTS or Ack format.

[0137] Specifically, if the delay signal is generated based on a MAC frame, the values ​​of the scrambling seed, L-SIG, Duration field, and RA field included in the MAC frame are fixed. The fixed content included in the MAC frame can be understood as meaning that the MAC frame is predefined by the protocol or negotiated between stations. The content of the MAC frame does not vary between stations, meaning that the delay signal generated by different stations is the same.

[0138] In this implementation, since the delay signal is generated based on the MAC frame and the content of the MAC frame is certain, all stations that receive the delay signal can unify their response behavior to the delay signal and wait for a period of time before competing for the channel.

[0139] Optionally, the scrambling code seed may be a fixed scrambling code seed predefined in an existing standard or a future standard.

[0140] Optionally, the L-SIG includes a RATE field, a Reserved field, a LENGTH field, a Parity field, and a SIGNAL TAIL field. The Reserved field and the SIGNAL TAIL field are set to 0, and the Parity field is a check bit generated based on the field before the Parity field. As long as the RATE field and the LENGTH field are determined, the Parity field is also determined.

[0141] The RATA field must be fixed to a specific rate. For example, a RATA value of 1101 indicates the minimum rate of 6 Mbps. Alternatively, the RATA field can be fixed to other values ​​to indicate other rates. Furthermore, since the MAC frame is a fixed-length frame, no special convention is required for the LENGTH field.

[0142] Optionally, the Duration field is used to protect the delay signal for a period of time after the delay signal is transmitted, allowing multiple stations that transmit the delayed signal to back off. Since there are not many stations transmitting delayed signals simultaneously, a backoff window size of 7 or 3 can be selected. Thus, the Duration can be set to (7 + 1) * 9 microseconds = 72 microseconds, or (3 + 1) * 9 microseconds = 36 microseconds. 9 microseconds is the length of a time slot.

[0143] Optionally, the RA field indicates a broadcast address or a determined MAC address.

[0144] It should be understood that the above is merely an example, and the possible forms of the delayed signal in this embodiment do not limit the scope of protection of this application. This embodiment does not impose any restrictions on the specific form of the delayed signal. For example, when the delayed signal is generated based on a MAC frame, the content in the MAC frame may also be other internally determined content besides the content shown above.

[0145] Exemplarily, the first station may send the delay signal after the channel has been idle for a first period of time (e.g., DIFS). For example, the first station determines that the channel is idle by invoking a carrier sense mechanism, and sends the delay signal after the channel has been idle for DIFS. The method flow shown in FIG5 further includes:

[0146] Specifically, this embodiment does not impose any restrictions on how the first site determines whether the channel is idle. The judgment can be made through a carrier sensing mechanism. The process of judgment based on the carrier sensing mechanism can refer to the description of the site's judgment of whether the channel is idle or busy based on the carrier sensing mechanism in the current related technology, or refer to the carrier sensing process shown in Figure 6 below, which will not be described in detail here.

[0147] In this embodiment, there is no limitation on which sites can receive the delayed signal. When the first site sends the delayed signal, it can send the delayed signal by broadcast, multicast or unicast. The first site may not be aware of which specific sites can receive the delayed signal. For the sake of convenience of description, this embodiment takes the example of the first site sending the delayed signal to the second site. The second site is any one of the at least one site that can receive the delayed signal.

[0148] As shown in Figure 4 above, the Defer Signal transmission process indicates that multiple stations are not scheduled by a trigger frame when sending Defer Signals. In this case, if multiple stations send Defer Signals independently without adjusting the CFO, the CFO deviation will be too large. According to standard protocol requirements, the center frequency deviation of station transmission in the 5GHz and 6GHz bands can reach ±20ppm. Calculated based on the 5GHz band, the CFO can reach ±100kHz, meaning the maximum absolute deviation can reach 200kHz. This is far greater than half of the subcarrier spacing of 312.5kHz. In this case, other stations will not be able to correctly receive Defer Signals sent simultaneously by more than two stations. As a result, the station sending the Defer Signal may not be able to trigger other stations to wait for a period of time before competing for the channel through the Defer Signal.

[0149] In this embodiment, to avoid the problem of excessive CFO deviation caused by multiple stations sending Defer Signals without adjusting the CFO as shown in FIG4 , the first station calibrates the CFO before sending the delayed signal. Therefore, the first station needs to calibrate the CFO before sending the delayed signal. That is, before the above-mentioned step S510, the method shown in FIG5 further includes:

[0150] S511: The first station calibrates the CFO according to the first PPDU.

[0151] The first PPDU is the last PPDU received before the delay signal is sent.

[0152] Exemplarily, in this embodiment, the first station calibrating the CFO based on the first PPDU can be understood as: the first station calibrating the CFO based on known information in a received signal carrying the first PPDU, such as an OFDM symbol. For example, the first station can calibrate the CFO using a signal carrying the Short Training Field (STF) and / or Long Training Field (LTF) field in a physical (PHY) frame header in the first PPDU, such as an OFDM symbol carrying these fields. In addition, a pilot in the data portion of the first PPDU can also be used for phase tracking and can also assist in CFO calibration.

[0153] Exemplarily, the first station calibrating its own CFO according to the first PPDU may be that the first station aligns its own CFO with the CFO of the station that sends the first PPDU.

[0154] For example, the first PPDU is a PPDU sent by site #2 to the first site. The CFO when site #2 sends the first PPDU is CFO#1. After the first site receives the first PPDU, it can determine that the CFO of site #2 is CFO#1 based on the first PPDU, and align its own CFO to CFO#1.

[0155] It should be noted that this embodiment does not limit how the last received PPDU is determined. For example, the first station can calibrate its CFO based on each received PPDU. In this way, before sending the delay signal, its CFO has already been calibrated based on the last received PPDU. Alternatively, in this embodiment, before sending the delay signal, the first station estimates the time to send the delay signal. Therefore, during a period of time before the time of sending the delay signal, the first station calibrates its CFO based on the reception of one or more PPDUs. CFO calibration is not required before this period of time.

[0156] For example, the first station estimates to send a delayed signal at time #1, and before time #1, the first station has received PPDU#1, PPDU#2 and PPDU#3 in succession, then PPDU#3 is the above-mentioned first PPDU.

[0157] Exemplarily, the first station calibrates the CFO according to the first PPDU, including: the first station calibrates the CFO according to at least one PPDU respectively, and the first PPDU is the last received PPDU in the at least one PPDU.

[0158] For example, the first site estimates that a delayed signal will be sent at time #1, and before time #1, the first site has successively received PPDU#1, PPDU#2, and PPDU#3. Then, the first site can calibrate CFO based on PPDU#1, calibrate CFO based on PPDU#2, and calibrate CFO based on PPDU#3, respectively.

[0159] In this embodiment, the first site calibrates the CFO based on the first PPDU. The first site may perform CFO calibration each time it receives a PPDU before sending the delay signal. Alternatively, the first site may determine, based on the estimated sending time of the delay signal, that a certain PPDU is the last PPDU received before sending the delay signal, and perform CFO calibration based on the PPDU.

[0160] As a possible implementation, in this embodiment, the first station may perform CFO calibration immediately after receiving the first PPDU. For example, upon completing reception of the first PPDU, the first station may perform CFO calibration based on the first PPDU. For ease of understanding, in this embodiment, the first station performs CFO calibration immediately after receiving the first PPDU. Since the first PPDU has a certain transmission duration, the specific calibration time may be the time when the physical layer frame header (PHY Preamble) of the first PPDU is received or the time when the entire first PPDU is received, which is not limited in this application.

[0161] As another possible implementation, in this embodiment, the first station may perform CFO calibration some time after receiving the first PPDU and before sending the delay signal. For example, after receiving the first PPDU, the first station may record the first PPDU locally and calibrate the CFO based on the first PPDU when needed. In a scenario where multiple stations in a communication system all send delay signals, the last PPDU received by multiple stations in the system is likely to be the same PPDU. Therefore, if multiple stations perform CFO calibration based on the last received PPDU before sending delay signals, it can ensure to a certain extent that the CFO sizes of the multiple stations sending delay signals are similar. As a result, the delay signals sent by multiple stations will not be unable to be properly received by other stations due to excessive CFO deviations, ensuring the normal transmission of the delay signal. This allows the first station to trigger other stations to wait for a period of time before competing for the channel by sending the delay signal, thereby reducing the delay of the first station.

[0162] As a possible implementation method, in a scenario where multiple sites in a communication system all send delayed signals, some of the multiple sites may experience received frame parsing errors due to interference from the multiple sites sending delayed signals or differences in the received signal-to-interference-and-noise ratio. For example, site #1 among the multiple sites is unable to parse the last received PPDU due to interference, and thus is unable to perform CFO calibration based on the last received PPDU. If site #1 is unable to perform CFO calibration based on the last received PPDU, the CFO of site #1 may have a large CFO deviation from that of other sites among the multiple sites.

[0163] If the site #1 still sends the delayed signal, it may be that the CFO deviation is too large, causing the delayed signal transmission of other sites in the multiple sites to fail. In this case, site #1 is not allowed to send the delayed signal.

[0164] In this implementation, to prevent a station from failing to parse the last received PPDU, which could result in delayed signal transmission failure, the first PPDU in this embodiment is a PPDU that can be correctly parsed. A successfully parsed first PPDU indicates that the first station obtains the payload of the first PPDU and that the frame check sequence (FCS) of the payload of the first PPDU has successfully been verified.

[0165] As another possible implementation, after the first station calibrates the CFO, the CFO will gradually increase over time. Therefore, in a scenario where multiple stations in a communication system send delay signals, even if multiple stations perform CFO calibration based on the same PPDU, the calibration time cannot be too long after the delay signal is sent.

[0166] In this implementation, the time between the time of CFO calibration and the time of delay signal transmission can be limited to less than or equal to a first threshold, thereby preventing the time between the time of CFO calibration and the time of delay signal transmission from being too long. In other words, after exceeding this first threshold, the station is not allowed to transmit the delay signal. The value of the first threshold can be determined based on the frequency stability of the crystal oscillator used by the station, or the first threshold can be a value negotiated between stations, or the first threshold can be a predefined value. This embodiment does not limit the value of the first threshold.

[0167] As another possible implementation, different stations may receive different frames due to different physical locations. As shown in Figure 4, assuming STA#3 can receive A-MPDU1 but not BA1, STA#3 will calibrate the CFO based on the PPDU carried by A-MPDU1. STA#4 can receive BA1 but not A-MPDU1, so STA#4 will calibrate the CFO based on BA1. In other words, even if stations are required to calibrate the CFO based on the last PPDU received, different stations may receive different last PPDUs.

[0168] In this implementation, the frames carried in the first PPDU can be limited to response frames or frames that do not trigger response frames. By stipulating that the frames used by the station to calibrate the CFO are response frames or frames that do not trigger response frames, it is possible to avoid different stations calibrating the CFO based on different PPDUs in a scenario where multiple stations in the communication system all send delay signals. Among them, the response frame includes but is not limited to: a response frame (such as an ACK frame, a block acknowledgement (BA) frame, etc.) in response to a frame sent by the first station or other stations, and the frame that does not trigger a response frame includes but is not limited to: a frame sent by other stations received by the first station, which is a frame that does not require a response (such as a broadcast frame or other frame that does not require a response).

[0169] S520: The second site analyzes the delayed signal.

[0170] Specifically, after receiving the delayed signal, the second station may trigger a wait time of a second duration based on the delayed signal before performing channel contention. For example, the second duration may be the EIFS described above.

[0171] It should be understood that the second duration that the second station waits for is related to the above-mentioned delayed signal. For example, it is assumed that the delayed signal includes a physical layer frame header (such as L-STF, L-LTF and L-SIG). After receiving the delayed signal, the second station believes that the delayed signal is a WLAN receive frame, but because it cannot parse out the correct payload part (such as the delayed signal may not have a payload part), the second station can treat the delayed signal as an erroneously received WLAN frame. The current protocol stipulates that when a station receives a WLAN frame but parses it incorrectly, it must wait until EIFS to avoid a conflict with a possible response frame of the frame. The duration of EIFS is equal to EIFS=aSIFSTime+AckTxTime+DIFS, where aSIFSTime is the inter-frame interval SIFS after the error frame, AckTxTime is the sending time of the confirmation frame for the error frame, and DIFS is the time it takes to wait for the channel to be continuously idle before competing for the channel again.

[0172] In the embodiment shown in FIG5 , before transmitting a delay signal, the first station can calibrate the CFO based on the last received first PPDU. The delay signal is used to trigger other stations to wait for a second duration before competing for the channel, thereby increasing the probability of the first station successfully competing for the channel and thereby reducing the first station's latency. Furthermore, in this technical solution, the first station calibrates its own CFO based on the last received first PPDU before transmitting the delay signal. This ensures that, in scenarios where multiple stations in the communication system transmit delay signals, the delayed signals transmitted by multiple stations will not be properly received by other stations due to excessive CFO deviations, ensuring normal transmission of the delayed signals and thus reducing the first station's latency.

[0173] The present application also provides a communication method, which can basically align the sending times of multiple sites that send delayed signals. The communication method is described in detail below in conjunction with Figure 6.

[0174] FIG6 is a schematic flow chart of a communication method provided in an embodiment of the present application, comprising the following steps:

[0175] S610: The first station determines that the channel status is idle according to physical carrier sensing and virtual carrier sensing.

[0176] In this embodiment, the first station may determine that the channel status is idle based on physical carrier sensing and virtual carrier sensing. Specifically, when both physical carrier sensing and virtual carrier sensing are idle, a station determines that the channel is idle.

[0177] Among them, physical carrier sensing is to directly monitor the received signal or energy level in the current channel.

[0178] Virtual carrier sense is to set the NAV timer after receiving a frame whose receiving address is neither the broadcast address nor its own MAC address, and then count down until the countdown reaches 0. If the NAV value is not 0, the virtual carrier sense is busy, and if the NAV value is 0, the virtual carrier sense is idle.

[0179] If multiple stations determine a channel is busy or idle through physical carrier sensing, they will determine the channel is busy or idle almost simultaneously. For example, if the communication distance between multiple stations is within tens of meters, the impact of propagation delay within this range is relatively small. For example, a distance difference of 30 meters only results in a difference of 0.1 microseconds, which is within the OFDM symbol guard interval (e.g., 0.4 microseconds or 0.8 microseconds).

[0180] The NAV value corresponding to the virtual carrier sensing can be set through the Duration field in the MAC frame header, and can also be set through the transmission opportunity TXOP subfield in the physical frame header.

[0181] Optionally, when the NAV value corresponding to virtual carrier sensing is set using the Duration field, the NAV granularity is 1 microsecond; if the NAV value corresponding to virtual carrier sensing is set using the TXOP subfield, the NAV granularity is 8 microseconds or 128 microseconds. If multiple stations set the NAV using different fields, the maximum error in determining the first idle time is much larger than the OFDM symbol guard interval. As a result, multiple stations that need to send delayed signals or defer signals will not be able to send them at the same time, and other stations will not be able to correctly receive the multiple delayed signals or defer signals sent by multiple stations.

[0182] In this embodiment, in order to prevent a large difference in the time when different stations determine that the channel state is idle through the carrier sensing mechanism in a scenario where multiple stations in the communication system all send delayed signals, if the NAV based on which the first station performs virtual carrier sensing is set based on the duration field in the MAC frame header, then the first station can send the delayed signal after the channel is idle for a period of time; if the NAV based on which the first station performs virtual carrier sensing is set based on the TXOP field in the MAC frame header, then the first station determines that the delayed signal cannot be sent, and the method flow shown in FIG6 further includes:

[0183] S620, if the NAV value corresponding to the virtual carrier sensing is set based on the persistence field in the MAC frame header, the first site determines that a delay signal can be sent; or, if the NAV value corresponding to the virtual carrier sensing is set based on the transmission opportunity TXOP field in the MAC frame header, the first site determines not to send a delay signal.

[0184] It should be noted that even if the Duration in the MAC frame header is used to set the NAV value, the NAV values ​​set by different sites may deviate. Because the granularity of Duration is 1 microsecond, and the length of a frame is not always an integer multiple of microseconds, the NAV values ​​set by different sites may deviate by a few tenths of a microsecond. Furthermore, if the deviation is less than 1 microsecond after multiple accumulations, it may exceed 1 microsecond. For example, two sites that set NAV through Duration may have a time difference of microseconds or sub-microseconds if they set NAV through different frames (due to hidden node problems or one site missing some frames due to power saving). When this time difference is greater than the guard interval of the OFDM symbol, it may cause the third-party site to be unable to correctly receive the delayed signal.

[0185] This embodiment provides a method for determining the start time of sending a delayed signal, which can further reduce the deviation between the start times of sending delayed signals at different sites, even if there is a microsecond or sub-microsecond deviation between the channel idle times determined by different sites. Specifically, the time synchronization function TSF value of the start time of sending delayed signals at different sites is an integer multiple of 9 microseconds, that is, the start time of sending the delayed signal is aligned to the time point where the TSF value is an integer multiple of 9 microseconds, thereby aligning the sending time of the delayed signals at different sites. Specifically, one of upward, downward, or nearest alignment can be used to align the start time of sending the delayed signal with the time point where the TSF value is an integer multiple of 9 microseconds.

[0186] In the communication method shown in Figure 6, if the NAV on which the first station performs virtual carrier sensing is based on the Duration field setting in the MAC frame header, the first station can send a delayed signal after the channel has been idle for a period of time; if the NAV on which the first station performs virtual carrier sensing is based on the TXOP field setting in the MAC frame header, the first station determines that the delayed signal cannot be sent, so as to avoid large differences in the moments when different stations determine that the channel status is idle through the carrier sensing mechanism in the scenario where multiple stations in the communication system all send delayed signals.

[0187] In addition, it should be noted that the communication method shown in Figure 6 can be used in combination with the communication method shown in Figure 5. For example, in the communication method shown in Figure 5, the first station can determine the moment when the channel is idle and the moment when the delayed signal is sent based on the communication method shown in Figure 6 before sending the delayed signal; or, the communication method shown in Figure 6 can also be applied to any scenario in existing or future communication technologies that requires determining the moment when the channel is idle and / or the moment when the delayed signal is sent, and this is not limited in this application.

[0188] The present application also provides a method for designing a delayed signal, which can be applied to the communication method shown in Figure 5 above, or the method can be applied to any scenario in existing or future technologies that requires the design of a delayed signal. For example, in the communication method shown in Figure 5 above, the delayed signal sent by the first station is determined based on the design method of the delayed signal.

[0189] Specifically, the delay signal design method includes generating the delay signal based on a MAC frame, wherein the values ​​of the scrambling seed, L-SIG, Duration field, and RA field included in the MAC frame are fixed. The fixed content included in the MAC frame can be understood as meaning that the MAC frame is predefined by the protocol or determined by negotiation between stations. The content of the MAC frame does not change for different stations, i.e., the delay signal generated by different stations is the same.

[0190] In this implementation, since the delay signal is generated based on the MAC frame and the content of the MAC frame is certain, all stations that receive the delay signal can unify their response behavior to the delay signal and wait for a period of time before competing for the channel.

[0191] Optionally, the scrambling code seed may be a fixed scrambling code seed predefined in an existing standard or a future standard.

[0192] Optionally, the L-SIG includes a RATE field, a Reserved field, a LENGTH field, a Parity field, and a SIGNAL TAIL field. The Reserved field and the SIGNAL TAIL field are set to 0, and the Parity field is a check bit generated based on the field before the Parity field. As long as the RATE field and the LENGTH field are determined, the Parity field is also determined.

[0193] The RATA field must be fixed to a specific rate. For example, a RATA value of 1101 indicates the minimum rate of 6 Mbps. Alternatively, the RATA field can be fixed to other values ​​to indicate other rates. Furthermore, since the MAC frame is a fixed-length frame, no special convention is required for the LENGTH field.

[0194] Optionally, the Duration field is used to protect the delay signal for a period of time after the delay signal is transmitted, allowing multiple stations that transmit the delayed signal to back off. Since there are not many stations transmitting delayed signals simultaneously, a backoff window size of 7 or 3 can be selected. Thus, the Duration can be set to (7 + 1) * 9 microseconds = 72 microseconds, or (3 + 1) * 9 microseconds = 36 microseconds. 9 microseconds is the length of a time slot.

[0195] Optionally, the RA field indicates a broadcast address or a determined MAC address.

[0196] The delayed signal involved in the delay signal design method can enable all sites that receive the delayed signal to have a unified response behavior to the delayed signal.

[0197] It should be understood that the size of the serial numbers of the above processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0198] It should also be understood that in the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0199] It should also be understood that in some of the above embodiments, devices in existing network architectures are mainly used as examples for illustrative purposes, and it should be understood that the embodiments of the present application do not limit the specific form of the devices. For example, devices that can achieve the same functions in the future are applicable to the embodiments of the present application.

[0200] It can be understood that in the above-mentioned various method embodiments, the methods and operations implemented by the device (such as the first site) can also be implemented by components that can be used in the device (such as chips or circuits).

[0201] It can also be understood that some optional features in the various embodiments of the present application may not depend on other features in certain scenarios, and may also be combined with other features in certain scenarios, without limitation.

[0202] The communication method provided in the embodiments of the present application is described in detail above in conjunction with Figures 5 and 6. The above communication method is mainly described from the perspective of the first site. It is understood that in order to implement the above functions, the first site includes the corresponding hardware structure and / or software modules for performing each function.

[0203] Those skilled in the art should be aware that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is performed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0204] The communication device provided in the embodiment of the present application is described in detail below with reference to Figures 7 to 9. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment. Therefore, for matters not described in detail, reference can be made to the method embodiment above. For the sake of brevity, some contents are not repeated here.

[0205] In the embodiment of the present application, the functional modules of the transmitting device or the receiving device can be divided according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation. The following is an example of dividing each functional module according to each function.

[0206] Figure 7 is a schematic block diagram of a communication device 10 provided in an embodiment of the present application. The device 10 includes a transceiver module 11 and a processing module 12. The transceiver module 11 can implement corresponding communication functions, and the processing module 12 is used to process data. In other words, the transceiver module 11 is used to perform operations related to receiving and sending, while the processing module 12 is used to perform operations other than receiving and sending. The transceiver module 11 can also be referred to as a communication interface or a communication unit.

[0207] Optionally, the device 10 may further include a storage module 13, which may be used to store instructions and / or data. The processing module 12 may read the instructions and / or data in the storage module so that the device implements the actions of the devices in the aforementioned method embodiments.

[0208] In one design, the device 10 may correspond to the first station in the above method embodiment, or a component (such as a chip) of the first station.

[0209] The device 10 can implement the steps or processes corresponding to those performed by the first site in the above method embodiment, wherein the transceiver module 11 can be used to perform the transceiver-related operations of the first site in the above method embodiment, and the processing module 12 can be used to perform the processing-related operations of the first site in the above method embodiment.

[0210] In one possible implementation, the processing module 12 is used to generate a delay signal, which is used to trigger other stations to wait for a second period of time to compete for the channel; the transceiver module 11 is used to send the delay signal after the channel is idle for a first period of time; before the transceiver module 11 sends the delay signal, the processing module 12 is used to calibrate the carrier frequency offset CFO according to the first PPDU, where the first PPDU is the last PPDU received before sending the delay signal.

[0211] In another possible implementation, the processing module 12 is used to determine that the state of the channel is idle based on physical carrier sensing and virtual carrier sensing; if the network allocation vector NAV value corresponding to the virtual carrier sensing is set based on the duration field in the medium access control MAC frame header, the processing module 12 is used to determine to send a delay signal after the channel is idle for a first period of time; or, if the NAV value corresponding to the virtual carrier sensing is set based on the transmission opportunity TXOP field in the MAC frame header, the processing module 12 is used to determine not to send the delay signal, and the delay signal is used to trigger other stations to wait for the first period of time to compete for the channel.

[0212] In another possible implementation, the processing module 12 is used to generate a delay signal based on the medium access control MAC frame, and the delay signal is used to trigger other stations to wait for a second period of time to compete for the channel. The values ​​of the scrambling code seed, the traditional signaling field L-SIG, the continuous Duration field and the receiving address RA field of the MAC frame are determined; the transceiver module 11 is used to send the delay signal after the channel is idle for a first period of time.

[0213] When the device 10 is used to execute the method in FIG5 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as step S510 , and the processing module 12 may be used to execute the processing steps in the method, such as step S511 .

[0214] When the device 10 is used to execute the method in FIG6 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, and the processing module 12 may be used to execute the processing steps in the method, such as steps S610 and S620 .

[0215] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0216] It should also be understood that the device 10 here is embodied in the form of a functional module. The term "module" here may refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a dedicated processor or a group processor, etc.) and memory for executing one or more software or firmware programs, a combined logic circuit and / or other suitable components that support the described functions. In an optional example, those skilled in the art will understand that the device 10 may be specifically the mobile management network element in the above-mentioned embodiment, and may be used to execute the various processes and / or steps corresponding to the mobile management network element in the above-mentioned method embodiments; or, the device 10 may be specifically the terminal device in the above-mentioned embodiment, and may be used to execute the various processes and / or steps corresponding to the terminal device in the above-mentioned method embodiments. To avoid repetition, it will not be described here.

[0217] The apparatus 10 of each of the above-described solutions has the function of implementing the corresponding steps performed by the device (e.g., the first station) in the above-described method. This function can be implemented by hardware, or by hardware executing corresponding software implementations. The hardware or software includes one or more modules corresponding to the above-described functions; for example, the transceiver module can be replaced by a transceiver (e.g., the transmitting unit in the transceiver module can be replaced by a transmitter, and the receiving unit in the transceiver module can be replaced by a receiver), and other units, such as the processing module, can be replaced by a processor to respectively perform the transceiver operations and related processing operations in each method embodiment.

[0218] In addition, the transceiver module 11 may also be a transceiver circuit (for example, may include a receiving circuit and a sending circuit), and the processing module may be a processing circuit.

[0219] FIG8 is a schematic diagram of another communication device 20 provided in an embodiment of the present application. Device 20 includes a processor 21, which is configured to execute computer programs or instructions stored in memory 22, or read data / signaling stored in memory 22, to perform the methods described in the above method embodiments. Optionally, there may be one or more processors 21.

[0220] Optionally, as shown in FIG8 , the apparatus 20 further includes a memory 22 for storing computer programs or instructions and / or data. The memory 22 may be integrated with the processor 21 or may be separately provided. Optionally, there may be one or more memories 22 .

[0221] Optionally, as shown in Figure 8, the device 20 further includes a transceiver 23, which is used to receive and / or send signals. For example, the processor 21 is used to control the transceiver 23 to receive and / or send signals.

[0222] As a solution, the device 20 is used to implement the operations performed by the first station in each of the above method embodiments.

[0223] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0224] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory and / or a non-volatile memory. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM includes the following forms: static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0225] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) can be integrated into the processor.

[0226] It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0227] 9 is a schematic diagram of a chip system 30 provided in accordance with an embodiment of the present application. The chip system 30 (or also referred to as a processing system) includes a logic circuit 31 and an input / output interface 32 .

[0228] The logic circuit 31 may be a processing circuit in the chip system 30. The logic circuit 31 may be coupled to a storage unit and call instructions in the storage unit so that the chip system 30 can implement the methods and functions of the various embodiments of the present application. The input / output interface 32 may be an input / output circuit in the chip system 30, outputting information processed by the chip system 30 or inputting data or signaling information to be processed into the chip system 30 for processing.

[0229] As a solution, the chip system 30 is used to implement the operations performed by the first site in each of the above method embodiments.

[0230] For example, the logic circuit 31 is used to implement the processing-related operations performed by the first site in the above method embodiment; the input / output interface 32 is used to implement the sending and / or receiving-related operations performed by the terminal device in the above method embodiment.

[0231] An embodiment of the present application further provides a computer-readable storage medium on which computer instructions for implementing the methods executed by the device in the above-mentioned method embodiments are stored.

[0232] For example, when the computer program is executed by a computer, the computer can implement the method performed by the first site in each embodiment of the above method.

[0233] An embodiment of the present application further provides a computer program product comprising instructions, which, when executed by a computer, implement the method performed by the first station in each of the above method embodiments.

[0234] An embodiment of the present application also provides a communication system, including the aforementioned first site.

[0235] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0236] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0237] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state disk (SSD)). For example, the aforementioned available medium includes, but is not limited to, various media that can store program code, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0238] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: The method comprises: The first station sends a delay signal after the channel is idle for a first time period, and the delay signal is used to trigger other stations to wait for a second time period before competing for the channel; Before sending the delayed signal, the first station calibrates the carrier frequency offset CFO according to a first physical layer protocol data unit PPDU, where the first PPDU is a PPDU received last before sending the delayed signal.

2. The method according to claim 1, characterized in that The first PPDU is a successfully parsed PPDU; and / or, The duration between the moment of calibrating the CFO and the moment of sending the delay signal is less than or equal to a first threshold; and / or, The frame carried in the first PPDU is a response frame or a frame that does not trigger a response frame.

3. The method according to claim 1 or 2, characterized in that: Before the first station sends the delayed signal, the method further includes: The first station determines that the channel is idle according to physical carrier sensing and virtual carrier sensing, and a network allocation vector NAV value corresponding to the virtual carrier sensing is set based on a duration field in a medium access control MAC frame header.

4. The method according to any one of claims 1 to 3, characterized in that The time synchronization function TSF value of the start time of sending the delay signal is an integer multiple of 9 microseconds.

5. The method according to any one of claims 1 to 4, characterized in that The delay signal is generated based on a medium access control MAC frame, and the values ​​of a scrambling code seed, a traditional signaling field L-SIG, a continuous Duration field, and a receiving address RA field of the MAC frame are determined.

6. The method according to claim 6, characterized in that: The rate RATA field in the L-SIG indicates 6 megabits per second Mbps; and / or, The Duration field indicates 72 microseconds or 36 microseconds; and / or, The RA field indicates a broadcast address or a determined MAC address.

7. The method according to any one of claims 1 to 6, characterized in that The first station is a station that fails to send wireless frames on the channel for k consecutive times, where k is a positive integer.

8. A communication device, characterized in that: include: Transceiver unit and processing unit, The sending unit is used to send the delay signal after the channel is idle for a first time period, and the delay signal is used to trigger other stations to wait for a second time period before competing for the channel; Before the sending unit sends the delayed signal, the processing unit is used to calibrate the carrier frequency offset CFO according to a first physical layer protocol data unit PPDU, where the first PPDU is a PPDU received last before sending the delayed signal.

9. The device according to claim 8, characterized in that Before the sending unit sends the delayed signal, the processing unit is further used to determine that the channel is idle based on physical carrier sensing and virtual carrier sensing, and the network allocation vector NAV value corresponding to the virtual carrier sensing is set based on the Duration field in the media access control MAC frame header.

10. A communication device, characterized in that: include: A processor, configured to execute a computer program stored in a memory, so that the apparatus performs the method according to any one of claims 1 to 7.

11. The device according to claim 10, characterized in that The apparatus also includes the memory.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 7.

13. A computer program product, characterized in that The computer program product comprises instructions for performing the method of any one of claims 1 to 7.

14. A communication system, characterized in that: include: A first node, wherein the first node is configured to execute the method according to any one of claims 1 to 7.

Images