Communication method and communication device

Abstract

The invention provides a communication method, which can be applied to a WLAN (Wireless Local Area Network) system supporting an IEEE 802.11 be next generation, Wi-Fi 8 and other 802.11 series protocols, and can also be applied to a UWB (Ultra Wideband)-based wireless personal area network system and a sensing system. The method comprises: in a scene of channel competition, before a certain station sends a delay signal indicating that other stations wait for a period of time and then perform channel competition, a CFO is calibrated according to a first PPDU finally received before the delay signal is sent. According to the embodiment of the invention, the CFO is calibrated based on the finally received PPDU, so that a plurality of delay signals cannot be normally received by other stations due to overlarge CFO deviation in a scene that the plurality of stations all send the delay signals.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and more specifically, to a communication method and a communication device. Background Art

[0002] With the development of wireless local area network (WLAN), 802.11 is one of the current mainstream wireless access standards and has been widely used in commercial applications in the past decade. Its common basic architecture is that an access point (AP) accesses the Internet through wired or wireless, and the AP is associated with multiple stations (STA). The AP and the associated STAs communicate uplink and downlink through the 802.11 protocol. WLAN works on unlicensed spectrum, and multiple STAs need to share the same channel. In order to solve the channel access conflict problem between multiple STAs, a random backoff mechanism is introduced. However, if a STA continuously executes the backoff mechanism to avoid channel access conflicts, it will cause the STA's transmission delay to be too large.

[0003] In a current method for reducing latency, when a STA fails to send k times (for example, 4 times) in a row, the STA is allowed to send a delay signal (Defer Signal) after the channel is idle for a certain period of time to trigger other STAs to wait and achieve transmission on the channel. However, if multiple STAs send Defer Signals at the same time, other STAs may not be able to normally receive the Defer Signals sent by multiple STAs due to the deviation of the carrier frequency offset (CFO) between STAs, thus failing to reduce latency. Therefore, how to improve the performance of this method for reducing latency has become an urgent problem to be solved. Summary of the invention

[0004] The present application provides a communication method, which reduces latency by avoiding CFO deviations of different sites.

[0005] In a first aspect, a communication method is provided, which can be executed by a first site, or can also be executed by a component (such as a chip or circuit) of the first site, without limitation. For ease of description, the following description is based on the first site as an example.

[0006] The communication method includes: a first station sends a delay signal after a channel is idle for a first period of time, and 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 (physical protocol data unit, PPDU), and the first PPDU is the last PPDU received before sending the delay signal.

[0007] Based on the above technical solution, before sending the delay signal, the first station can calibrate the CFO according to the last received first PPDU. The delay signal is used to trigger other stations to wait for the second time period before competing for the channel, thereby increasing the probability of the first station successfully competing for the channel, in order to reduce the delay of the first station. In addition, in the technical solution, before sending the delay signal, the first station calibrates its own CFO according to the last received first PPD. In this way, in the scenario where multiple stations in the communication system send delay signals, the delay signals sent by multiple stations will not be unable to be normally received by other stations due to excessive CFO deviation, thereby ensuring the normal transmission of the delay signal and reducing the delay of the first station.

[0008] 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.

[0009] Based on the above technical solution, the above first PPDU may be a PPDU that meets certain conditions, for example, the first PPDU may be a PPDU that is successfully parsed by the first site. In this way, in a scenario where multiple sites in the communication system send delayed signals, it is possible to avoid different sites calibrating CFO based on different PPDUs (for example, due to interference between different sites or differences in the received signal-to-interference-noise ratio, some sites may have received frame parsing errors, which may cause different sites to calibrate CFO based on different PPDUs).

[0010] The frame carried in the first PPDU is a response frame or a frame that does not trigger a response frame. By stipulating that the frame used by the station to calibrate the CFO is a response frame or a frame that does not trigger a response frame, it is possible to avoid different stations calibrating the CFO based on different PPDUs in a scenario where multiple stations in the communication system send delayed signals (for example, due to different physical locations, different stations can receive different frames, which will cause different stations to calibrate the CFO based on different PPDUs).

[0011] In addition, after a site calibrates the CFO, the CFO will gradually increase over time. Therefore, in a scenario where multiple sites in a communication system send delay signals, even if multiple sites have performed CFO calibration based on the same PPDU, the calibration time cannot be too long from the time of sending the delay signal. In this technical solution, by limiting the time between the moment of calibrating the CFO and the moment of sending the delay signal to be less than or equal to the first threshold, it is avoided that the moment of calibrating the CFO is too long from the time of sending the delay signal.

[0012] In combination with the first aspect, in certain implementations of the first aspect, before the first station sends the delay signal, the method also includes: the first station 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.

[0013] Based on the above technical solution, before sending the delay signal, the first station determines that the state of the channel 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, a NAV timer is set, and then a 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 moment when different stations determine that the state of the channel is idle through the carrier sensing mechanism in the scenario where multiple stations in the communication system send delay signals, it can be set that the stations sending delay signals all use Duration to set NAV.

[0014] 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.

[0015] Based on the above technical solution, in order to avoid a large difference between the start times of sending delayed signals at different sites in a scenario where multiple sites in a communication system send delayed signals, the time synchronization function TSF value of the start time of sending the delayed signal can be set to an integer multiple of 9 microseconds to maximize the alignment of the start times of sending delayed signals at different sites.

[0016] 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.

[0017] Based on the above technical solution, in order to enable a site 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.

[0018] 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.

[0019] 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, and k is a positive integer.

[0020] In a second aspect, a communication method is provided, which can be executed by a first site, or can also be executed by a component (such as a chip or circuit) of the first site, without limitation. For ease of description, the first site is used as an example for description below.

[0021] 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 medium 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 before competing for the channel.

[0022] Based on the above technical solution, the first station determines that the state of the channel 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, a NAV timer is set, and then a countdown is performed until the countdown reaches 0. If the NAV value is not 0, the virtual carrier sensing is busy, and 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 continuous Duration field in the MAC frame header, the first station can send a delay signal after the channel has been 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 a delay signal cannot be sent, in order to avoid the situation where multiple stations in the communication system send delay signals. The time when different stations determine that the state of the channel is idle through the carrier sensing mechanism is too different.

[0023] 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 also includes: the first site sends the delayed signal after the channel is idle for a first period of time; before sending the delayed signal, the first site calibrates the carrier frequency offset CFO according to a first physical layer protocol data unit PPDU, and the first PPDU is the last PPDU received before sending the delayed signal.

[0024] Based on the above technical solution, before sending the delay signal, the first station can calibrate the CFO according to the last received first PPDU. The delay signal is used to trigger other stations to wait for the second time period before competing for the channel, thereby increasing the probability of the first station successfully competing for the channel, in order to reduce the delay of the first station. In addition, in the technical solution, before sending the delay signal, the first station calibrates its own CFO according to the last received first PPD. In this way, in the scenario where multiple stations in the communication system send delay signals, the delay signals sent by multiple stations will not be unable to be normally received by other stations due to excessive CFO deviations, thereby ensuring the normal transmission of the delay signal, thereby reducing the delay of the first station.

[0025] Exemplarily, the conditions satisfied by the first PPDU can refer to the description of the first PPDU in the first aspect above, which will not be repeated here. In addition, the delayed signal can be generated based on the MAC frame, and the conditions satisfied by the MAC frame can refer to the description of the delayed signal in the first aspect above, which will not be repeated here.

[0026] In combination with the second aspect, in certain 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.

[0027] Based on the above technical solution, in order to avoid a large difference between the start times of sending delayed signals at different sites in a scenario where multiple sites in a communication system send delayed signals, the time synchronization function TSF value of the start time of sending the delayed signal can be set to an integer multiple of 9 microseconds to maximize the alignment of the start times of sending delayed signals at different sites.

[0028] In a third aspect, a communication method is provided, which can be executed by a first site, or can also be executed by a component (such as a chip or circuit) of the first site, without limitation. For ease of description, the first site is used as an example for description below.

[0029] The communication method includes: a first station generates a delay signal based on a medium access control MAC frame, 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.

[0030] Based on the above technical solution, in order to enable a site 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.

[0031] 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.

[0032] 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.

[0033] 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, and the first PPDU is the last PPDU received before sending the delayed signal.

[0034] Based on the above technical solution, before sending the delay signal, the first station can calibrate the CFO according to the last received first PPDU. The delay signal is used to trigger other stations to wait for the second time period before competing for the channel, thereby increasing the probability of the first station successfully competing for the channel, in order to reduce the delay of the first station. In addition, in the technical solution, before sending the delay signal, the first station calibrates its own CFO according to the last received first PPD. In this way, in the scenario where multiple stations in the communication system send delay signals, the delay signals sent by multiple stations will not be unable to be normally received by other stations due to excessive CFO deviations, thereby ensuring the normal transmission of the delay signal, thereby reducing the delay of the first station.

[0035] 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.

[0036] 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.

[0037] Based on the above technical solution, before sending the delay signal, the first station determines that the state of the channel 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, a NAV timer is set, and then a 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 moment when different stations determine that the state of the channel is idle through the carrier sensing mechanism in the scenario where multiple stations in the communication system send delay signals, it can be set that the stations sending delay signals all use Duration to set NAV.

[0038] 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.

[0039] Based on the above technical solution, in order to avoid a large difference between the start times of sending delayed signals at different sites in a scenario where multiple sites in a communication system send delayed signals, the time synchronization function TSF value of the start time of sending the delayed signal can be set to an integer multiple of 9 microseconds to maximize the alignment of the start times of sending delayed signals at different sites.

[0040] In a fourth aspect, a communication device is provided, which is used to execute the method provided in the first to third aspects. Specifically, the device may include a unit and / or module, such as a processing unit and / or a communication unit, for executing the method provided in any one of the above implementations of the first to third aspects.

[0041] 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.

[0042] Exemplarily, when the communication device is the first station 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 medium 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 stations to wait for a second period of time to compete for the channel.

[0043] Exemplarily, when the communication device is the first station 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 stations to wait for a second period of time before competing 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 communication unit is used to send the delay signal after the channel is idle for a first period of time.

[0044] 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; 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.

[0045] Exemplarily, when the communication device is the first station in the above-mentioned first aspect, 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 stations 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.

[0046] Exemplarily, when the communication device is the first station 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 medium 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 stations to wait for a second period of time to compete for the channel.

[0047] 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 before competing 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 is used to send the delay signal after the channel is idle for a first period of time.

[0048] In another implementation, the device is a chip, a chip system or a circuit used in a terminal device. When the device is a chip, a chip system or a circuit used in a terminal device, the communication unit may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin or a related circuit on the chip, the chip system or the circuit; the processing unit may be at least one processor, a processing circuit or a logic circuit.

[0049] In a fifth aspect, a communication device is provided, comprising: 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 implementations of the first to third aspects, or a method provided by any one of the implementations of the second to third aspects.

[0050] In a sixth aspect, the present application provides a processor for executing the methods provided in the above aspects.

[0051] For the operations such as sending and acquiring / receiving involved in the processor, unless otherwise specified, or unless they conflict with their actual function or internal logic in the relevant description, they can be understood as operations such as processor output, reception, input, etc., or as sending and receiving operations performed by the radio frequency circuit and antenna, and this application does not limit this.

[0052] In a seventh aspect, a computer-readable storage medium is provided, which stores a program code for execution by a device, wherein the program code includes a method for executing any one of the above-mentioned implementations of the first to third aspects.

[0053] In an eighth aspect, a computer program product comprising instructions is provided. When the computer program product is run on a computer, the computer is enabled to execute the method provided in any one of the implementations of the first to third aspects.

[0054] In a ninth aspect, a chip is provided, the chip comprising 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.

[0055] Optionally, as an implementation method, the chip also includes a memory, in which a computer program or instructions are stored, and the processor is used to execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the processor is used to execute the method provided in any one of the above implementation methods.

[0056] 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

[0057] Figure 1 It is a schematic diagram of an application scenario applicable to the embodiment of the present application.

[0058] Figure 2 A schematic diagram of the structure of a device provided by the present application is shown.

[0059] Figure 3This is a schematic diagram of the PPDU format.

[0060] Figure 4 This is a schematic diagram of sending a Defer Signal provided in an embodiment of the present application.

[0061] Figure 5 It is a schematic flow chart of a communication method provided in an embodiment of the present application.

[0062] Figure 6 It is a schematic flow chart of a communication method provided in an embodiment of the present application.

[0063] Figure 7 It is a schematic block diagram of a communication device provided in an embodiment of the present application.

[0064] Figure 8 It is a schematic diagram of another communication device provided in an embodiment of the present application.

[0065] Fig. 9 It is a schematic diagram of a chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0066] In order to facilitate understanding of the embodiments of the present application, the following points are first explained.

[0067] First, in this application, "used for indication" may include being used for direct indication and being used for indirect indication. When describing that a certain indication information is used for indicating A, it may include that the indication information directly indicates A or indirectly indicates A, but it does not mean that the indication information must carry A.

[0068] 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, the information to be indicated can be directly 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, the indication of specific information can also be achieved with the help of the arrangement order of each piece of information agreed in advance (for example, stipulated by the protocol), thereby reducing the indication overhead to a certain extent. At the same time, the common parts of each piece of information can also be identified and indicated uniformly to reduce the indication overhead caused by indicating the same information separately.

[0069] 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 inherent 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 interchanged in appropriate circumstances so as to be able to describe the schemes other than the embodiments of the present application. In addition, in the embodiments of the present application, words such as "S510" are only marks made for the convenience of description, and are not used to limit the order of execution steps.

[0070] Third, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0071] Fourth, the "storage" involved in the embodiments of the present application may refer to storage in one or more memories. The one or more memories may be separately set or integrated in an encoder or decoder, a processor, or a communication device. The one or more memories may also be partially separately set and partially integrated in a decoder, a processor, or a communication device. The type of memory may be any form of storage medium, which is not limited by the present application.

[0072] Fifth, in the implementation of this application, "protocol" may refer to a standard protocol in the communication field, for example, it may include the NR protocol and related protocols used in future communication systems, and this application does not limit this.

[0073] Sixth, in the embodiments of the present application, the terms “of”, “corresponding, relevant”, “corresponding” and “associate” 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.

[0074] 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 the same.

[0075] Eighth, the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0076] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0077] 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 802.11be next generation, 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. Among them, the 802.11n standard is called high throughput (HT), the 802.11ac standard is called very high throughput (VHT) standard, the 802.11ax standard is called high efficient (HE) standard, and the 802.11be standard is called extremely high throughput (EHT) standard. Among them, 802.11bf includes two major standards: low frequency (for example, sub7GHz) and high frequency (for example, 60GHz). The implementation of sub7GHz mainly relies on 802.11ac, 802.11ax, 802.11be and the next generation standards, and the implementation of 60GHz mainly relies on 802.11ad, 802.11ay and the next generation standards. Among them, 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.

[0078] Although the embodiments of the present application are mainly described by deploying a WLAN network, especially a network using the IEEE 802.11 system standard, it is easy for those skilled in the art to understand that the various aspects involved in the embodiments of the present application can be extended to other networks using various standards or protocols, such as a high performance radio local area network (HIPERLAN), a wireless wide area network (WWAN), a wireless personal area network (WPAN), or other networks known now or developed later. Therefore, regardless of the coverage range and wireless access protocol used, the various aspects provided in the embodiments of the present application can be applied to any suitable wireless network.

[0079] 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), worldwide 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.

[0080] The above-mentioned communication system applicable to the present application is only an example for illustration, and the communication system applicable to the present application is not limited to this. A unified description is given here and no further elaboration is given below.

[0081] Figure 1 Schematic diagram of an application scenario applicable to the embodiment of the present application. Figure 1As shown, 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 (non-AP STA), referred to as a non-AP station or STA. 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 also to data communication between APs (for example, data communication between AP1 and AP2), and data communication between non-AP STAs and non-AP STAs (for example, data communication between non-AP STA2 and non-AP STA3).

[0082] Among them, the access point can be a node for terminals (such as mobile phones) to enter the wired (or wireless) network. It is mainly deployed in homes, buildings and parks, with a typical coverage radius of tens to hundreds of meters. Of course, it can also be deployed outdoors. The access point is equivalent to a bridge connecting the wired network and the wireless network. Its main function is to connect various wireless network clients together and then connect the wireless network to the Ethernet.

[0083] 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., which is not limited in the embodiments of the present application. 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, 802.11ay, etc.

[0084] A non-AP site may be a wireless communication chip, a wireless sensor or a wireless communication terminal, etc., and may also be referred to as a user, user equipment (UE), an access terminal, a user unit, a user station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent or a 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 function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted 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, etc., and the embodiments of the present application are not limited to this. A non-AP site may be a device that supports the WLAN format. For example, the non-AP station may 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.

[0085] For example, non-AP sites can be mobile phones, tablet computers, set-top boxes, smart TVs, smart wearable devices, vehicle-mounted 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.

[0086] 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 respectively used for sending and receiving packet structures, 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.

[0087] For example, Figure 2 A communication device provided by the present application is shown. Figure 2 The device shown can be an AP or a non-AP site. Among them, the medium access control (MAC) layer processing module, the physical (PHY) layer processing module, the radio frequency / antenna, etc. are used to implement the relevant functions of the above-mentioned transmitter and receiver, such as Figure 2As shown, in addition to the MAC layer processing module, the PHY layer processing module, the RF / antenna, the memory, and the processor, the device may also include a controller and a scheduler.

[0088] It should be understood that Figure 2 This is only 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.

[0089] 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.

[0090] 1. Physical layer protocol data unit (PPDU): Figure 3 It is a schematic diagram of the PPDU format. PPDU includes Legacy Short Training Field (L-STF), Legacy Long Training Field (L-LTF), Legacy Signal Field (L-SIG), Repeat Legacy Signal Field (RL-SIG), Universal Signal Field (U-SIG), Extremely High Throughput Signal Field or Extremely High Throughput Signal Field (EHT-SIG), EHT Short Training Field (EHT-STF), EHT Long Training Field (EHT-LTF), Data Field and Package Extension Field (PE). Among them, L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-SIG, EHT-STF, EHT-LTF are partial structures in the physical layer header (or preamble) of PPDU.

[0091] L-STF, L-LTF, and L-SIG can be understood as traditional preamble fields, which are used to ensure the coexistence of new devices and traditional devices. RL-SIG is used to enhance the reliability of traditional signaling fields.

[0092] U-SIG and EHT-SIG are signaling fields. U-SIG is used to carry some common information, such as information indicating the PPDU version, information indicating uplink / downlink, information indicating the frequency domain bandwidth of the PPDU, puncturing indication information, etc. EHT-SIG includes information indicating resource allocation and information indicating data demodulation, etc.

[0093] 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 examples. The various fields in the PPDU mentioned in the embodiments of the present application are not limited to the fields related to 802.11be, and the various fields in the PPDU mentioned in the embodiments of the present application may also be fields related to the standard version after 802.11be, including but not limited to the PPDU signaling field in the next generation protocol as ultra-high reliability signaling (UHR-SIG).

[0094] 2. Distributed coordination function (DCF): WLAN works on unlicensed spectrum, and multiple stations need to share the same channel. In order to solve the channel access conflict problem between multiple stations, a random backoff mechanism, namely the DCF mechanism, is introduced. Before a station wants to send data or management frames, it needs to call the carrier sensing (CS) mechanism to determine whether the channel status is idle or busy. When the channel status is busy, the station needs to postpone the channel access for a specific time.

[0095] 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).

[0096] Specifically, the durations of DIFS and EIFS are:

[0097] DIFS=aSIFSTime+2*aSlotTime;

[0098] EIFS=aSIFSTime+AckTxTime+DIFS.

[0099] In general, aSIFSTime is 16 microseconds and aSlotTime is 9 microseconds. Depending on the spectrum and protocol, their specific values ​​may also be different. The specific values ​​of aSIFSTime and aSlotTime are not limited in this application. AckTxTime is the transmission time of the acknowledgment (Ack) frame.

[0100] After the station waits for the channel to be idle for DIFS or EIFS, it must back off before sending data or management frames. For ease of description, the following explanation will take the specific time as DIFS as an example.

[0101] Exemplarily, a station performs the DCF mechanism as follows: the station randomly selects a backoff number from the window [0, contention window (CW)] as the counter value. After the station waits for the channel to be idle for DIFS, the counter value is reduced by 1 every time the channel is idle for aSlotTime. When the counter value is reduced to 0, the station sends data or management frames. The initial value of CW is the minimum contention window (CWmin). Wherein, [0, CW] indicates that the value range of the counter value is greater than or equal to 0 and less than or equal to CW.

[0102] 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.

[0103] If the station fails to send data or management frames, CW is set to 2*CW+1, and the counter value is randomly selected from [0, 2*CW+1] when the station competes for the channel next time.

[0104] If the station fails to send continuously, CW is set to CWmax and CW remains at CWmax until the sending is successful, at which time CW is set to CWmin.

[0105] From the above, it can be seen that in the scenario where multiple sites share the same channel, the DCF mechanism can be used to avoid channel access conflicts.

[0106] Optionally, two stations that generate the same random backoff counter value may back off to 0 at the same time, and then the two stations send data or management frames at the same time. At this time, the transmission of both stations will fail due to channel access conflict. After the transmission fails, the two stations will randomly select counter values ​​within a larger contention window for channel access, thereby reducing the probability of channel access conflict. The more stations that initiate contention at the same time, the greater the probability of channel access conflict, and the contention window will continue to increase. In other words, the actual contention window will be dynamically adjusted according to the contention stations, thereby supporting channel competition for different numbers of contention stations.

[0107] 3. Enhanced distributed channel access (EDCA): EDCA is derived from DCF.

[0108] In the DCF mechanism, one station corresponds to one contention queue, and the data to be sent by the station is cached in the same queue. In the EDCA mechanism, one station supports four access categories (AC) to distinguish data of different priorities. Each access category maintains an independent set of channel contention parameters. The four different access categories are AC_VO, AC_VI, AC_BE, and AC_BK from high to low priority.

[0109] During the random backoff process corresponding to each AC, instead of waiting for the DIFS duration, it waits for the Arbitration Interframe Space (AIFS) duration, AIFS[AC] = AIFSN[AC]*aSlotTime+aSIFSTime. Each AC also corresponds to different CWmin[AC] and CWmax[AC]. For high-priority access categories, smaller AIFSN, CWmin, and CWmax parameters can be allocated, and for low-priority access categories, larger AIFSN, CWmin, and CWmax parameters can be allocated, thereby increasing the sending opportunities of high-priority services and reducing the sending opportunities of low-priority services. The minimum value of AIFSN is 2.

[0110] 4. Defer Signal: When a station fails to send k times (for example, 4 times) in a row, the station is allowed to send a Defer Signal after the channel is idle for DIFS time.

[0111] An example of a Defer Signal is the use of a legacy preamble, that is, the Defer Signal includes the L-STF, L-LTF, and L-SIG fields. Since the Defer Signal has no payload, the station will treat the Defer Signal as an error frame after receiving it, thereby triggering the waiting time for the EIFS. Within the EIFS time, the station that sent the Defer Signal can initiate a backoff again, and the station that has completed the backoff can send data. Backoff can solve the collision problem after multiple stations send Defer Signals at the same time.

[0112] Combination of the above Figure 1The scenarios in which the communication method provided in the embodiments of the present application can be applied are briefly introduced, as well as the basic concepts that may be involved in the embodiments of the present application. The Defer Signal is introduced 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.

[0113] For ease of understanding, combined Figure 4 Describes how a site sends a Defer Signal.

[0114] When a transmission opportunity (TXOP) of a channel ends, other stations will determine when the previous TXOP ends based on physical carrier sensing and virtual carrier sensing. Figure 4 In this example, STA#1 obtains the previous TXOP (e.g. Figure 4 TXOP#1 shown in ), after the A-MPDU1 and BA1 frame exchanges, a period of time (such as Figure 4 The current TXOP ends at the start time of xIFS shown in . At this time, STA#3 and STA#4 have experienced several consecutive contention failures and meet the basic conditions for sending Defer Signal. STA#3 and STA#4 send Defer Signal after xIFS after the channel is idle. After receiving the Defer Signal, STA#1 and STA#2 regard the Defer Signal as an erroneous reception frame, and wait for EIFS time after receiving the Defer Signal before competing for the channel.

[0115] In order to make STA#1 and STA#2 regard the Defer Signal as an erroneous reception frame, the physical layer frame header (i.e., L-STF, L-LTF, and L-SIG) is used as the Defer Signal. In this way, STA#1 and STA#2 will regard the Defer Signal as an erroneous frame because they cannot parse the payload part that was not originally sent. Since multiple stations may send Defer Signals at the same time, STA#3 and STA#4 cannot send immediately after sending the Defer Signal, but need to go through a backoff process (such as Figure 4 Backoff #1 and Backoff #2 shown in ) are used to avoid a collision between STA #3 and STA #4.

[0116] Figure 4 The Defer Signal sending process shown has the following problems:

[0117] 1) The carrier frequency offset CFO of each site is different. When multiple sites send Defer Signal at the same time, the third-party site may not be able to receive it normally due to excessive CFO deviation. For example, Figure 4 As shown in , if the CFO deviation between STA#3 and STA#4 is too large, the Defer Signal sent by STA#3 and STA#4 may not be received by STA#1 and STA#2.

[0118] 2) The channel idle time determined by different sites may be different, so the sending time of the Defer Signal cannot be aligned. For example, Figure 4 As shown in , if STA#3 and STA#4 need to confirm that the channel is idle before sending the Defer Signal, if the channel idle times determined by STA#3 and STA#4 are different, the Defer Signal sent by STA#3 and STA#4 may not be received by STA#1 and STA#2.

[0119] 3) When using L-STF, L-LTF and L-SIG as Defer signals, the behavior of traditional STAs after receiving them may be inconsistent. Some stations will no longer regard the Defer signal as a PPDU being received because there is no receiving energy after the Defer Signal, and will immediately initiate channel competition. For example, Figure 4 As shown in the figure, after receiving the Defer signal, STA#1 and STA#2 do not wait for the EIFS time to compete for the channel, but directly initiate the channel competition.

[0120] To solve Figure 4 The problem with the Defer Signal sending process shown is that the present application provides a communication method to reduce the delay by avoiding CFO deviation of different sites.

[0121] 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 Figure 1 The scenario shown is, but not limited to, that scenario.

[0122] 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 may 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.

[0123] 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 site and the second site as an example. The first site involved in the embodiment of the present application may be an access point AP, and the second site may be a non-access point non-AP (such as STA); or, the first site may be an access point STA, and the second site may be a non-access point AP; or, the first site and the second site are access points AP; or, the first site and the second site are non-access points non-AP.

[0124] Figure 5 It is a schematic flow chart of a communication method provided in an embodiment of the present application, comprising the following steps:

[0125] S510, the first site sends a delay signal.

[0126] The first station may be any station that needs to compete for a channel. For example, when the WLAN operates in an unlicensed spectrum, multiple stations need to share the same channel, and the first station is one of the multiple stations that need to share the same channel for transmission.

[0127] As a possible implementation, the first station may be a station that fails to send a wireless frame on the channel for k consecutive times, where k is a positive integer. When k is equal to 1, the first station fails to send a wireless frame on the channel for k consecutive times, which means that the first station fails to send a wireless frame on the channel once. In this embodiment, there is no limitation on the form of the wireless frame transmitted on the channel, which may be a data frame, a control frame, a management frame, etc.

[0128] As another possible implementation manner, the first site may be any site that needs to send a delayed signal.

[0129] It should be understood that in this embodiment, there is no limitation on the conditions for the first station to send the delay 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.

[0130] Specifically, the delayed signal is used to trigger other stations to wait for a second period of time before competing for the channel. Exemplarily, 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.

[0131] Exemplarily, 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.

[0132] As a possible implementation manner, the delay signal in this embodiment is the Defer Signal shown above.

[0133] As another possible implementation, the delay signal is other signals that can implement the Defer Signal function.

[0134] 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.

[0135] 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 determined. The content included in the MAC frame is determined, which can be understood as the MAC frame being predefined by the protocol or determined by negotiation between sites, etc. The content of the MAC frame does not change with different sites, that is, the delay signals generated by different sites are the same.

[0136] In this implementation, since the delay signal is generated based on the MAC frame and the content of the MAC frame is determined, 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.

[0137] Optionally, the scrambling code seed may be a fixed scrambling code seed predefined in an existing standard or a future standard.

[0138] Optionally, L-SIG includes a RATE field, a Reserved field, a LENGTH field, a Parity field, and a SIGNAL TAIL field, wherein the Reserved field and the SIGNAL TAIL field are set to 0, and the Parity field is a check bit generated according to the field before the Parity field. As long as the RATE field and the LENGTH field are determined, the Parity field is also determined.

[0139] The RATA field needs to be fixed to a rate, for example, the RATA field is 1101, indicating the minimum rate of 6 Mbps; or the RATA field is fixed to other values, indicating other rates. In addition, since the MAC frame is a fixed-length frame, the LENGTH field does not need to be specially agreed upon.

[0140] Optionally, the Duration field is used to protect a period of time after the delayed signal so that multiple stations that send delayed signals can back off. Since there are not many stations that send delayed signals at the same time, the back-off window size can be selected to be 7 or 3. In this way, the Duration can be set to (7+1)*9 microseconds = 72 microseconds, or (3+1)*9 microseconds = 36 microseconds. Among them, 9 microseconds is the length of a time slot.

[0141] Optionally, the RA field indicates a broadcast address or a determined MAC address.

[0142] It should be understood that the above is only an example, and the possible form of the delayed signal in this embodiment does not constitute any limitation on the protection scope of the present application, and the specific form of the delayed signal in this embodiment is not limited. For example, when the delayed signal is generated based on the MAC frame, the content in the MAC frame can also be other internally determined content in addition to the above.

[0143] Exemplarily, the first station may send the delay signal after the channel is idle for a first time (eg, 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 is idle for DIFS. Figure 5 The method flow shown also includes:

[0144] Specifically, in this embodiment, there is no limitation on how the first station determines whether the channel is idle, and the judgment can be made through a carrier sensing mechanism. The process of judging based on the carrier sensing mechanism can refer to the description of the station judging whether the channel is idle or busy based on the carrier sensing mechanism in the current related technology, and can also refer to the following Figure 6 The carrier sensing process shown in is not described in detail here.

[0145] 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.

[0146] From the previous article Figure 4It can be seen from the Defer Signal sending process shown that when multiple sites send Defer Signals, they are not scheduled by a trigger frame. At this time, multiple sites send DeferSignals without adjusting CFO, which will cause the CFO deviation to be too large. According to the requirements of the standard protocol, the center frequency deviation of the site in the 5GHz and 6GHz bands can reach ±20ppm. According to the calculation of the 5GHz band, the CFO can reach ±100kHz, that is, the maximum absolute deviation can reach 200kHz. It is much larger than half of the subcarrier spacing of 312.5kHz. In this case, other sites will not be able to correctly receive the Defer Signals sent by more than two sites at the same time. As a result, the site sending the Defer Signal may not be able to trigger other sites to wait for a period of time before competing for the channel through the Defer Signal.

[0147] In this embodiment, in order to avoid Figure 4 The multiple sites shown in the figure each send DeferSignal without adjusting CFO, which will lead to the problem of excessive CFO deviation. Before sending the delayed signal, the first site will calibrate the CFO. Therefore, the first site needs to calibrate the CFO before sending the delayed signal, that is, before the above step S510, Figure 5 The method flow shown also includes:

[0148] S511: The first station calibrates the CFO according to the first PPDU.

[0149] The first PPDU is a PPDU received last before the delay signal is sent.

[0150] Exemplarily, in this embodiment, the first station calibrates the CFO according to the first PPDU, which can be understood as: the first station performs CFO calibration according to the known information in the received signal carrying the first PPDU, such as the OFDM symbol. For example, the first station can calibrate the CFO by carrying the signal of the short training field (STF) and / or the long training field (LTF) field in the physical (Physical, PHY) frame header in the first PPDU, such as the OFDM symbol carrying these fields. In addition, the pilot in the data part of the first PPDU can also be used for phase tracking, and can also assist in CFO calibration.

[0151] Exemplarily, the first station calibrating its own CFO according to the first PPDU may be that the first station aligns its own CFO to the CFO of the station that sends the first PPDU.

[0152] For example, the first PPDU is a PPDU sent by site #2 to the first site. The CFO of site #2 when sending 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.

[0153] It should be noted that this embodiment does not limit how to determine the last received PPDU. For example, the first site can calibrate its own CFO based on each received PPDU, so that before sending the delay signal, it has naturally calibrated its own CFO based on the last received PPDU. Alternatively, in this embodiment, before sending the delay signal, the first site estimates the time of sending the delay signal. Therefore, within a period of time before the time of sending the delay signal, the first site calibrates its own CFO based on the reception of one or more PPDUs. CFO calibration may not be performed before this time period.

[0154] For example, the first site estimates to send a delayed signal at time #1, and before time #1, the first site has received PPDU #1, PPDU #2 and PPDU #3 successively, then PPDU #3 is the above-mentioned first PPDU.

[0155] Exemplarily, the first site calibrates the CFO according to the first PPDU, including: the first site 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.

[0156] For example, the first site estimates that a delayed signal will be sent at time #1, and before time #1, the first site has received PPDU#1, PPDU#2, and PPDU#3 successively. 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.

[0157] In this embodiment, the first site calibrates the CFO according to the first PPDU. The first site may perform CFO calibration once for each PPDU received 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.

[0158] As a possible implementation method, in this embodiment, the first station can perform CFO calibration immediately after receiving the first PPDU. For example, when the first station completes receiving the first PPDU, it can 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 can be the time of receiving the physical layer frame header (PHYPreamble) of the first PPDU or receiving the entire first PPDU, and this application does not limit this.

[0159] As another possible implementation, in this embodiment, the first station may perform CFO calibration before sending a delay signal after a period of time after receiving the first PPDU. For example, the first station may record the first PPDU locally after receiving the first PPDU, and calibrate the CFO according to the first PPDU when needed. In a scenario where multiple stations in a communication system 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 multiple stations sending delay signals are similar, so that the delay signals sent by multiple stations will not be unable to be normally received by other stations due to excessive CFO deviations, ensuring the normal transmission of delay signals, so that the first station can trigger other stations to wait for a period of time before competing for channels by sending delay signals, thereby reducing the delay of the first station.

[0160] 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 that send delayed signals or differences in the received signal-to-interference-noise ratio. For example, site #1 among the multiple sites is unable to parse the last received PPDU due to interference problems, 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 other sites among the multiple sites.

[0161] If the site #1 still sends the delayed signal, it may be that the CFO deviation is too large, causing the delayed signal transmission failure of other sites among the multiple sites. In this case, site #1 is not allowed to send the delayed signal.

[0162] In this implementation, in order to avoid a delayed signal transmission failure due to a certain station being unable to parse the last received PPDU, the first PPDU mentioned in this embodiment is a PPDU that can be correctly parsed. The first PPDU being a successfully parsed PPDU indicates that the first station obtains the payload part of the first PPDU, and the frame check sequence (FCS) of the payload part of the first PPDU is successfully checked.

[0163] 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 the communication system send delay signals, even if multiple stations have performed CFO calibration based on the same PPDU, the calibration time cannot be too long from the time of sending the delay signal.

[0164] In this implementation, the time between the time of calibrating the CFO and the time of sending the delay signal can be limited to be less than or equal to the first threshold, so as to avoid the time between the time of calibrating the CFO and the time of sending the delay signal being too long. That is, after exceeding the first threshold, the site is not allowed to send the delay signal. The size of the first threshold can be determined according to the frequency stability of the crystal oscillator used by the site, or the first threshold is a value negotiated between sites, or the first threshold is a predefined value, and this embodiment does not limit the value of the first threshold.

[0165] As another possible implementation, different stations may receive different frames due to different physical locations. Figure 4 As shown in the figure, assuming that STA#3 can receive A-MPDU1 but cannot receive BA1, STA#3 will calibrate CFO based on the PPDU carried by A-MPDU1, and STA#4 can receive BA1 but cannot receive A-MPDU1, then STA#4 will calibrate CFO based on BA1. In other words, even if the station is required to calibrate CFO based on the last PPDU received, the last PPDU received by different stations may be different.

[0166] 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 according to different PPDUs in a scenario where multiple stations in the communication system send delayed signals. Among them, response frames include but are not limited to: response frames in response to frames sent by the first station or other stations (such as ACK frames, block acknowledgement (BA) frames, etc.), and frames that do not trigger response frames include but are not limited to: frames sent by other stations received by the first station, which are frames that do not require response (such as broadcast frames or other frames that do not require response).

[0167] S520, the second site analyzes the delayed signal.

[0168] Specifically, after receiving the delayed signal, the second station may trigger, based on the delayed signal, waiting for a second time period before performing channel contention. For example, the second time period may be the EIFS shown above.

[0169] It should be understood that the second duration that the second station waits for is related to the above-mentioned delayed signal. Exemplarily, 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 considers that the delayed signal is a WLAN receive frame, but because the correct payload part cannot be parsed (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 for EIFS to avoid conflicts with possible response frames 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 required to wait for the channel to be continuously idle before channel competition again.

[0170] Figure 5In the embodiment shown, before sending the delay signal, the first station can calibrate the CFO according to the last received first PPDU. The delay signal is used to trigger other stations to wait for the second time period before competing for the channel, thereby increasing the probability of the first station successfully competing for the channel, in order to reduce the delay of the first station. In addition, in the technical solution, before sending the delay signal, the first station calibrates its own CFO according to the last received first PPDU. In this way, in the scenario where multiple stations in the communication system send delay signals, the delay signals sent by multiple stations will not be unable to be normally received by other stations due to excessive CFO deviation, thereby ensuring the normal transmission of the delay signal, thereby reducing the delay of the first station.

[0171] The present application also provides a communication method, which can make the sending time of multiple sites sending delayed signals basically aligned. Figure 6 This communication method is described in detail.

[0172] Figure 6 It is a schematic flow chart of a communication method provided in an embodiment of the present application, comprising the following steps:

[0173] S610: The first station determines that the state of the channel is idle according to physical carrier sensing and virtual carrier sensing.

[0174] In this embodiment, the first station may determine that the state of the channel is idle according to physical carrier sensing and virtual carrier sensing. Specifically, when the physical carrier sensing and virtual carrier sensing are both idle, a station determines that the channel is idle.

[0175] Among them, physical carrier sensing is to directly monitor the received signal or energy size in the current channel.

[0176] Virtual carrier sensing 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 sensing is busy, and if the NAV value is 0, the virtual carrier sensing is idle.

[0177] If multiple stations determine that a channel is busy or idle through physical carrier sensing, the multiple stations determine that the channel is busy or idle at almost the same time. For example, the communication distance between multiple stations is within a few tens of meters, and the impact of propagation delay within a few tens of meters is small. For example, a distance difference of 30 meters only brings a difference of 0.1 microseconds, which is within the OFDM symbol guard interval (for example, the OFDM symbol guard interval is 0.4 microseconds or 0.8 microseconds).

[0178] 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.

[0179] Optionally, when the NAV value corresponding to the virtual carrier sensing is set using the Duration field, the granularity of the NAV is 1 microsecond; if the NAV value corresponding to the virtual carrier sensing is set using the TXOP subfield, the granularity of the NAV is 8 microseconds or 128 microseconds. If multiple stations set the NAV through different fields, the maximum error in determining the first idle time is much larger than the OFDM symbol protection interval, which will cause multiple stations that need to send delayed signals or Defer Signals to be unable to send them at the same time, so that other stations cannot correctly receive multiple delayed signals or Defer Signals sent by multiple stations.

[0180] In this embodiment, in order to prevent the time when different stations determine that the state of the channel is idle through the carrier sensing mechanism from being too different in the scenario where multiple stations in the communication system all send delay 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 a delay signal after the channel has been 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 delay signal cannot be sent, then Figure 6 The method flow shown also includes:

[0181] 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 station 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 station determines not to send a delay signal.

[0182] It should be noted that even if the NAV value is set using the Duration in the MAC frame header, 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, it may exceed 1 microsecond after being accumulated multiple times. 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 misses some frames due to power saving). When the time difference is greater than the protection interval of the OFDM symbol, it may cause the third-party site to be unable to correctly receive the delayed signal.

[0183] 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, so that the sending time of the delayed signals at different sites is aligned. 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.

[0184] Figure 6 In the communication method shown, if the NAV on which the first station performs virtual carrier sensing is based on a setting of the duration field in the MAC frame header, the first station can send a delay 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 a setting of the TXOP field in the MAC frame header, the first station determines that a delay signal cannot be sent, in order to avoid a scenario in which multiple stations in the communication system send delay signals, thereby avoiding large differences in the moments when different stations determine that the channel state is idle through the carrier sensing mechanism.

[0185] In addition, it should be noted that Figure 6 The communication method shown can be used with Figure 5 The communication methods shown are used in conjunction with, for example, Figure 5 In the communication method shown, the first station can send a delay signal based on Figure 6 The communication method shown determines the time when the channel is idle, and determines the time when the delay signal is sent; or, Figure 6 The communication method shown 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 a delayed signal is sent, which is not limited in this application.

[0186] The present application also provides a method for designing a delayed signal, which can be applied to the above Figure 5 Alternatively, the method can be applied to any scenario where a delay signal needs to be designed in existing or future technologies, for example, Figure 5 In the communication method shown, the delayed signal sent by the first station is determined based on a design method of the delayed signal.

[0187] Specifically, the design method of the delay signal includes: generating a delay signal based on a MAC frame, wherein the values ​​of the scrambling code seed, L-SIG, Duration field, and RA field included in the MAC frame are determined. The content included in the MAC frame is determined, which can be understood as the MAC frame is predefined by the protocol or determined by negotiation between sites, and the content of the MAC frame does not change with different sites, that is, the delay signals generated by different sites are the same.

[0188] In this implementation, since the delay signal is generated based on the MAC frame and the content of the MAC frame is determined, 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.

[0189] Optionally, the scrambling code seed may be a fixed scrambling code seed predefined in an existing standard or a future standard.

[0190] Optionally, L-SIG includes a RATE field, a Reserved field, a LENGTH field, a Parity field, and a SIGNAL TAIL field, wherein the Reserved field and the SIGNAL TAIL field are set to 0, and the Parity field is a check bit generated according to the field before the Parity field. As long as the RATE field and the LENGTH field are determined, the Parity field is also determined.

[0191] The RATA field needs to be fixed to a rate, for example, the RATA field is 1101, indicating the minimum rate of 6 Mbps; or the RATA field is fixed to other values, indicating other rates. In addition, since the MAC frame is a fixed-length frame, the LENGTH field does not need to be specially agreed upon.

[0192] Optionally, the Duration field is used to protect a period of time after the delayed signal so that multiple stations that send delayed signals can back off. Since there are not many stations that send delayed signals at the same time, the back-off window size can be selected to be 7 or 3. In this way, the Duration can be set to (7+1)*9 microseconds = 72 microseconds, or (3+1)*9 microseconds = 36 microseconds. Among them, 9 microseconds is the length of a time slot.

[0193] Optionally, the RA field indicates a broadcast address or a determined MAC address.

[0194] 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.

[0195] It should be understood that the sequence numbers of the above processes do 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.

[0196] 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.

[0197] It should also be understood that in some of the above embodiments, the devices in the existing network architecture are mainly used as examples for exemplary description, 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 function in the future are applicable to the embodiments of the present application.

[0198] 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).

[0199] It can also be understood that some optional features in the embodiments of the present application may not depend on other features in some scenarios, or may be combined with other features in some scenarios, without limitation.

[0200] Above, combined Figure 5 and Figure 6 The communication method provided by the embodiment of the present application is described in detail. The above communication method is mainly introduced from the perspective of the first site. It can be understood that the first site, in order to implement the above functions, includes hardware structures and / or software modules corresponding to executing various functions.

[0201] 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.

[0202] The following, combined Figures 7 to 9 The communication device provided in the embodiment of the present application is described in detail. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment, so the contents not described in detail can be referred to the method embodiment above, and some contents will not be repeated for the sake of brevity.

[0203] The embodiment of the present application can divide the functional modules of the transmitting end device or the receiving end device according to the above method example. For example, each functional module can be divided corresponding to each function, or two or more functions can be integrated into one processing module. The above integrated module 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 corresponding to each function.

[0204] Figure 7 1 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 perform data processing, or in other words, the transceiver module 11 is used to perform operations related to receiving and sending, and the processing module 12 is used to perform other operations besides receiving and sending. The transceiver module 11 can also be called a communication interface or a communication unit.

[0205] 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.

[0206] In one design, the device 10 may correspond to the first site in the above method embodiment, or may be a component (such as a chip) of the first site.

[0207] The device 10 can implement the steps or processes executed by the first station in the above method embodiment, wherein the transceiver module 11 can be used to perform the transceiver-related operations of the first station in the above method embodiment, and the processing module 12 can be used to perform the processing-related operations of the first station in the above method embodiment.

[0208] In one possible implementation, the processing module 12 is used to generate a 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; 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, and the first PPDU is the last PPDU received before sending the delay signal.

[0209] 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 a certain period of time before competing for the channel.

[0210] 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 before competing 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.

[0211] When the device 10 is used to perform Figure 5 When the method is performed, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as step S510, and the processing module 12 can be used to execute the processing steps in the method, such as step S511.

[0212] When the device 10 is used to perform Figure 6 When the method is performed, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, and the processing module 12 can be used to execute the processing steps in the method, such as steps S610 and S620.

[0213] 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.

[0214] 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 a memory for executing one or more software or firmware programs, a merged logic circuit and / or other suitable components that support the described functions. In an optional example, those skilled in the art may understand that the device 10 may be specifically a 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 a 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 repeated here.

[0215] The apparatus 10 of each of the above schemes has the function of implementing the corresponding steps performed by the device (such as the first station) in the above method. The function can be implemented by hardware, or by hardware executing the corresponding software implementation. The hardware or software includes one or more modules corresponding to the above functions; for example, the transceiver module can be replaced by a transceiver (for example, the sending 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.

[0216] 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.

[0217] Figure 8 2 is a schematic diagram of another communication device 20 provided in an embodiment of the present application. The device 20 includes a processor 21, and the processor 21 is used to execute a computer program or instruction stored in a memory 22, or read data / signaling stored in the memory 22 to execute the method in each method embodiment above. Optionally, there are one or more processors 21.

[0218] Alternatively, if Figure 8 As shown, the device 20 also includes a memory 22, which is used to store computer programs or instructions and / or data. The memory 22 can be integrated with the processor 21, or can also be separately set. Optionally, the memory 22 is one or more.

[0219] Alternatively, if Figure 8As shown, the device 20 further includes a transceiver 23, and the transceiver 23 is used for receiving and / or sending signals. For example, the processor 21 is used to control the transceiver 23 to receive and / or send signals.

[0220] As a solution, the device 20 is used to implement the operations performed by the first station in each of the above method embodiments.

[0221] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or 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. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0222] 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).

[0223] 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.

[0224] 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.

[0225] Fig. 9 Schematic diagram of a chip system 30 provided in 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.

[0226] Among them, the logic circuit 31 can be a processing circuit in the chip system 30. The logic circuit 31 can be coupled to the storage unit and call the instructions in the storage unit so that the chip system 30 can implement the methods and functions of each embodiment of the present application. The input / output interface 32 can 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.

[0227] 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.

[0228] 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.

[0229] An embodiment of the present application also 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.

[0230] 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.

[0231] An embodiment of the present application also provides a computer program product, comprising instructions, which, when executed by a computer, implement the method performed by the first station in the above-mentioned method embodiments.

[0232] An embodiment of the present application also provides a communication system, including the aforementioned first site.

[0233] 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.

[0234] In the several embodiments provided in the present 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. There may be other division methods in actual implementation, 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.

[0235] 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 devices. 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 site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. 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 contains 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 codes, 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.

[0236] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope 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.

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