CN107852769B - Link self-adaption method of W L AN and network equipment - Google Patents

Abstract

A link self-adapting method of W L AN and network equipment can improve the flexibility of channel information measurement and provide accurate link self-adaptation for users.

Description

A WLAN link adaptation method and network device

technical field

The present invention relates to the field of communication technologies, and in particular, to a WLAN link adaptation method and network equipment.

Background technique

In a wireless communication system, due to the influence of factors such as path loss, fading, or noise, the channel information of a wireless channel usually changes with time. Aiming at this time-varying characteristic of the channel, link adaptation technology has been introduced. The link adaptation technology refers to the behavior of the system adaptively adjusting the transmission parameters of the system according to the currently acquired channel information, so as to overcome or adapt to the influence of the current channel change. From the basic principle of link adaptation technology, it can be seen that the link adaptation technology mainly includes two aspects: on the one hand, the acquisition of channel information, that is, how to obtain the current channel condition accurately and effectively; on the other hand, the transmission parameters adjustment, such as MCS (Modulation and Coding Scheme, modulation and coding strategy), transmit power and time-frequency resources. At present, link adaptation technology is favored by its excellent performance in improving spectrum utilization and data transmission rate, and has been successfully applied in various mobile communication systems, becoming one of the key technologies to improve system performance.

In the link adaptation process of the existing WiFi (Wireless-Fidelity) standard, the mode of the probe PPDU used to measure the channel information is relatively simple. However, with the outdoor scene in the next-generation WiFi standard IEEE 802.11ax , the introduction of new features such as uplink multi-user transmission, it is difficult for a single mode of detection PPDU to adapt to the different needs of different application scenarios. Therefore, IEEE 802.11ax also puts forward higher requirements for the selection of detection PPDU in the process of link adaptation. .

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a WLAN link adaptation method and network device, which can improve the flexibility of channel information measurement and provide users with accurate link adaptation.

A first aspect of the embodiments of the present invention provides a WLAN link adaptation method, including:

The first network device acquires a target channel information measurement result, where the target channel information measurement result is a measurement result obtained by measuring the channel information according to the probing physical layer protocol data unit PPDU of the target mode;

The first network device performs link adaptive adjustment according to the target channel information measurement result.

With reference to the first aspect of the embodiment of the present invention, in a first implementation manner of the first aspect of the embodiment of the present invention, the acquisition of the target channel information measurement result by the first network device includes:

The first network device sends a first PPDU to the second network device, wherein the first PPDU indicates that the second network device needs to send a probe PPDU, and the first PPDU further includes a mode indication field, the mode indication field for instructing the second network device to generate a probe PPDU of the target mode;

receiving, by the first network device, a second PPDU sent by the second network device, where the second PPDU is a probe PPDU of a target mode generated by the second network device according to the mode indication field;

The first network device uses the second PPDU to measure channel information to obtain the target channel information measurement result.

With reference to the first aspect of the embodiment of the present invention, in a second implementation manner of the first aspect of the embodiment of the present invention, the acquisition of the target channel information measurement result by the first network device includes:

The first network device receives the PPDU sent by the second network device; wherein, the PPDU instructs the second network device to actively send the channel information measurement result, and the PPDU further includes a mode indication field, where the mode indication field is used to indicate the first 2. The mode of the probe PPDU used by the network device to measure the channel information;

The first network device determines a target channel information measurement result according to the mode indication field.

With reference to the first aspect of the embodiments of the present invention and any one of the first to second implementation manners of the first aspect, in the third implementation manner of the first aspect of the embodiments of the present invention, the mode of detecting the PPDU includes: At least one of the bandwidth information of the probe PPDU, the indoor mode or the outdoor mode of the probe PPDU, the Fourier transform order information of the long training field of the probe PPDU, and the guard interval information of the probe PPDU.

With reference to the first implementation manner of the first aspect of the embodiments of the present invention, in a fourth implementation manner of the first aspect of the embodiments of the present invention, the mode of detecting the PPDU includes detecting whether the PPDU adopts an indoor mode or an outdoor mode;

When the mode indication field instructs the second network device to generate an outdoor mode probe PPDU, the second PPDU is an enhanced probe PPDU generated by the second network device according to the mode indication field;

Wherein, the enhanced sounding PPDU refers to a sounding PPDU having at least one of the following formats:

At least one symbol of the preamble of the sounding PPDU is partially or completely copied in the time domain or frequency domain, the guard interval between some or all symbols of the sounding PPDU is greater than the first preset value, and the The modulation and coding mode MCS of at least one symbol satisfies a certain preset condition, and the Fourier transform order of at least one symbol of the probe PPDU is higher than a second preset value.

With reference to the first aspect of the embodiments of the present invention and any one of the first to fourth implementation manners of the first aspect, in a fifth implementation manner of the first aspect of the embodiments of the present invention, the channel information includes: Spread delay of the channel and/or delay between multiple users;

The link adaptation adjustment performed by the first network device according to the target channel information measurement result includes:

The first network device performs adaptive adjustment of the guard interval according to the target channel information measurement result.

With reference to the first aspect of the embodiments of the present invention and any one of the first to fourth implementation manners of the first aspect, in a sixth implementation manner of the first aspect of the embodiments of the present invention, the channel information includes: The signal-to-noise ratio (SNR) of the channel;

The link adaptation adjustment performed by the first network device according to the target channel information measurement result includes:

The first network device performs adaptive adjustment of the modulation and coding strategy MCS according to the target channel information measurement result.

A second aspect of the embodiments of the present invention provides a WLAN link adaptation method, including:

The second network device receives the first PPDU sent by the first network device; wherein, the first PPDU indicates that the second network device needs to send a probe PPDU, and the first PPDU further includes a mode indication field, and the mode indication field is used for for instructing the second network device to generate a probe PPDU of the target mode;

The second network device generates a probe PPDU of the target mode according to the mode indication field;

The second network device sends a second PPDU to the first network device, where the second PPDU is used by the first network device to measure channel information using the second PPDU to obtain the target channel information measurement As a result, link adaptive adjustment is performed according to the target channel information measurement result.

With reference to the second aspect of the embodiments of the present invention, in the first implementation manner of the second aspect of the embodiments of the present invention, the mode of detecting the PPDU includes detecting bandwidth information of the PPDU, detecting whether the PPDU adopts the indoor mode or the outdoor mode, and detecting the mode of the PPDU. At least one of Fourier transform order information of the long training field and guard interval information of the probe PPDU.

With reference to the second aspect of the embodiments of the present invention, in a second implementation manner of the second aspect of the embodiments of the present invention, the mode of detecting the PPDU includes detecting whether the PPDU adopts an indoor mode or an outdoor mode;

When the mode indication field instructs the second network device to generate the probe PPDU of the outdoor mode, the second network device generating the probe PPDU of the target mode according to the mode indication field includes:

generating, by the second network device, an enhanced probe PPDU according to the mode indication field;

Wherein, the enhanced sounding PPDU refers to a sounding PPDU having at least one of the following formats:

At least one symbol of the preamble of the sounding PPDU is partially or completely copied in the time domain or frequency domain, the guard interval between some or all symbols of the sounding PPDU is greater than the first preset value, and the The modulation and coding mode MCS of at least one symbol satisfies a certain preset condition, and the Fourier transform order of at least one symbol of the probe PPDU is higher than a second preset value.

With reference to the second aspect of the embodiments of the present invention and any one of the first to second implementation manners of the second aspect, in a third implementation manner of the second aspect of the embodiments of the present invention, the channel information includes Spread delay of the channel and/or delay between multiple users;

The second PPDU is used by the first network device to measure the spread delay of the channel and/or the delay between multiple users by using the second PPDU, and obtain the spread delay of the channel and/or the delay between multiple users according to the measurement Adaptive adjustment of guard interval is performed.

With reference to the second aspect of the embodiments of the present invention and any one of the first to second implementation manners of the second aspect, in the fourth implementation manner of the second aspect of the embodiments of the present invention,

The second PPDU is used by the first network device to measure the SNR of the channel by using the second PPDU, and perform adaptive adjustment of the MCS according to the measured SNR of the channel.

A third aspect of the embodiments of the present invention provides a WLAN link adaptation method, including:

The second network device generates a PPDU; wherein the PPDU instructs the second network device to actively send the channel information measurement result, and the PPDU further includes a mode indication field, where the mode indication field is used to indicate the second network device to use to measure the channel information The mode of the probe PPDU;

The second network device sends the PPDU to the first network device, where the PPDU is used by the first network device to determine the target channel information measurement result according to the mode indication field, and perform the target channel information measurement result according to the target channel information measurement result. Link adaptive adjustment.

With reference to the third aspect of the embodiments of the present invention, in the first implementation manner of the third aspect of the embodiments of the present invention, the mode of detecting the PPDU includes detecting the bandwidth information of the PPDU, detecting whether the PPDU adopts the indoor mode or the outdoor mode, and detecting the PPDU mode. At least one of Fourier transform order information of the long training field and guard interval information of the probe PPDU.

With reference to the third aspect of the embodiments of the present invention or the first implementation manner of the third aspect, in the second implementation manner of the third aspect of the embodiments of the present invention, the channel information includes the spreading delay of the channel and/or multiple delay between users;

The PPDU is used by the first network device to determine the target channel information measurement result according to the mode indication field, and to perform adaptive adjustment of the guard interval according to the target channel information measurement result.

With reference to the third aspect of the embodiments of the present invention or the first implementation manner of the third aspect, in a third implementation manner of the third aspect of the embodiments of the present invention, the channel information includes a signal-to-noise ratio SNR of the channel;

The PPDU is used by the first network device to determine a target channel information measurement result according to the mode indication field, and to perform adaptive adjustment of the MCS according to the target channel information measurement result.

A fourth aspect of the embodiments of the present invention provides a network device, including:

an acquisition unit, configured to acquire a target channel information measurement result, the target channel information measurement result being a measurement result obtained by measuring the channel information according to the probing physical layer protocol data unit PPDU of the target mode;

An adjustment unit, configured to perform link adaptive adjustment according to the target channel information measurement result.

With reference to the fourth aspect of the embodiment of the present invention, in a first implementation manner of the fourth aspect of the embodiment of the present invention, the obtaining unit includes:

A sending module, configured to send a first PPDU to a target network device, wherein the first PPDU indicates that the target network device needs to send a probe PPDU, and the first PPDU further includes a mode indication field, where the mode indication field is used to indicate The target network device generates a probe PPDU of the target mode;

a first receiving module, configured to receive a second PPDU sent by the target network device, where the second PPDU is a target mode probe PPDU generated by the target network device according to the mode indication field;

A first obtaining module, configured to use the second PPDU to measure channel information to obtain the target channel information measurement result.

With reference to the fourth aspect of the embodiment of the present invention, in a second implementation manner of the fourth aspect of the embodiment of the present invention, the obtaining unit includes:

The second receiving module is configured to receive the PPDU sent by the target network device; wherein, the PPDU indicates that the target network device actively sends the channel information measurement result, and the PPDU further includes a mode indication field, and the mode indication field is used to indicate the target network The mode of the probe PPDU used by the device to measure the channel information;

The second acquiring module is configured to determine the target channel information measurement result according to the mode indication field.

With reference to the fourth aspect of the embodiments of the present invention and any one of the first to second implementation manners of the fourth aspect, in the third implementation manner of the fourth aspect of the embodiments of the present invention, the mode of detecting the PPDU includes: At least one of the bandwidth information of the probe PPDU, the indoor mode or the outdoor mode of the probe PPDU, the Fourier transform order information of the long training field of the probe PPDU, and the guard interval information of the probe PPDU.

With reference to the first implementation manner of the fourth aspect of the embodiments of the present invention, in the fourth implementation manner of the fourth aspect of the embodiments of the present invention, the mode of detecting the PPDU includes detecting whether the PPDU adopts an indoor mode or an outdoor mode;

When the mode indication field instructs the target network device to generate an outdoor mode probe PPDU, the second PPDU is an enhanced probe PPDU generated by the target network device according to the mode indicator field;

Wherein, the enhanced sounding PPDU refers to a sounding PPDU having at least one of the following formats:

At least one symbol of the preamble of the sounding PPDU is partially or completely copied in the time domain or frequency domain, the guard interval between some or all symbols of the sounding PPDU is greater than the first preset value, and the The modulation and coding mode MCS of at least one symbol satisfies a certain preset condition, and the Fourier transform order of at least one symbol of the probe PPDU is higher than a second preset value.

With reference to the fourth aspect of the embodiments of the present invention and any one of the first to fourth implementation manners of the fourth aspect, in a fifth implementation manner of the fourth aspect of the embodiments of the present invention, the channel information includes: Spread delay of the channel and/or delay between multiple users;

The adjustment unit is specifically configured to perform adaptive adjustment of the guard interval according to the target channel information measurement result.

With reference to the fourth aspect of the embodiments of the present invention and any one of the first to fourth implementation manners of the fourth aspect, in the sixth implementation manner of the fourth aspect of the embodiments of the present disclosure, the channel information includes: SNR of the channel;

The adjustment unit is specifically configured to perform adaptive adjustment of the modulation and coding strategy MCS according to the measurement result of the target channel information.

A fifth aspect of the embodiments of the present invention provides a network device, including:

a receiving unit, configured to receive a first PPDU sent by a target network device; wherein, the first PPDU indicates that the network device needs to send a probe PPDU, and the first PPDU further includes a mode indication field, and the mode indication field is used for for instructing the network device to generate a probe PPDU of the target mode;

a generating unit, configured to generate a probe PPDU of the target mode according to the mode indication field;

a sending unit, configured to send a second PPDU to the target network device, where the second PPDU is used by the target network device to measure channel information using the second PPDU to obtain the target channel information measurement result, and Link adaptive adjustment is performed according to the target channel information measurement result.

With reference to the fifth aspect of the embodiments of the present invention, in the first implementation manner of the fifth aspect of the embodiments of the present invention, the mode of detecting the PPDU includes detecting the bandwidth information of the PPDU, detecting whether the PPDU adopts the indoor mode or the outdoor mode, and detecting the mode of the PPDU. At least one of Fourier transform order information of the long training field and guard interval information of the probe PPDU.

With reference to the fifth aspect of the embodiments of the present invention, in a second implementation manner of the fifth aspect of the embodiments of the present invention, the mode of detecting the PPDU includes detecting whether the PPDU adopts an indoor mode or an outdoor mode;

When the mode indication field instructs the network device to generate an outdoor mode probe PPDU, the generating unit is specifically configured to generate an enhanced probe PPDU according to the mode indication field;

Wherein, the enhanced sounding PPDU refers to a sounding PPDU having at least one of the following formats:

At least one symbol of the preamble of the sounding PPDU is partially or completely copied in the time domain or frequency domain, the guard interval between some or all symbols of the sounding PPDU is greater than the first preset value, and the The modulation and coding mode MCS of at least one symbol satisfies a certain preset condition, and the Fourier transform order of at least one symbol of the probe PPDU is higher than a second preset value.

With reference to the fifth aspect of the embodiments of the present invention and any one of the first to second implementation manners of the fifth aspect, in a third implementation manner of the fifth aspect of the embodiments of the present invention, the channel information includes Spread delay of the channel and/or delay between multiple users;

The second PPDU is used by the target network device to use the second PPDU to measure the spread delay of the channel and/or the delay between multiple users, and perform the measurement according to the measured spread delay of the channel and/or the delay between multiple users. Adaptive adjustment of guard interval.

With reference to the fifth aspect of the embodiments of the present invention and any one of the first to second implementation manners of the fifth aspect, in a fourth implementation manner of the fifth aspect of the embodiments of the present invention, the channel information includes: SNR of the channel;

The second PPDU is used by the target network device to measure the SNR of the channel by using the second PPDU, and perform adaptive adjustment of the MCS according to the measured SNR of the channel.

A sixth aspect of the embodiments of the present invention provides a network device, including:

A generating unit, configured to generate a PPDU; wherein the PPDU instructs the network device to actively send a channel information measurement result, and the PPDU further includes a mode indication field, where the mode indication field is used to indicate the network device to measure the channel information. The mode used to probe the PPDU;

A sending unit, configured to send the PPDU to a target network device, wherein the PPDU is used by the target network device to determine a target channel information measurement result according to the mode indication field, and perform chaining according to the target channel information measurement result Road adaptive adjustment.

With reference to the sixth aspect of the embodiments of the present invention, in the first implementation manner of the sixth aspect of the embodiments of the present invention, the mode of detecting the PPDU includes detecting the bandwidth information of the PPDU, detecting whether the PPDU adopts the indoor mode or the outdoor mode, and detecting the PPDU mode. At least one of Fourier transform order information of the long training field and guard interval information of the probe PPDU.

With reference to the sixth aspect of the embodiments of the present invention or the first implementation manner of the sixth aspect, in the second implementation manner of the sixth aspect of the embodiments of the present invention, the channel information includes the spreading delay and/or the channel information. delay between users;

The PPDU is used by the target network device to determine the target channel information measurement result according to the mode indication field, and to perform adaptive adjustment of the guard interval according to the target channel information measurement result.

With reference to the sixth aspect of the embodiments of the present invention or the first implementation manner of the sixth aspect, in a third implementation manner of the sixth aspect of the embodiments of the present invention, the channel information includes a signal-to-noise ratio SNR of the channel;

The PPDU is used by the target network device to determine the target channel information measurement result according to the mode indication field, and to perform adaptive adjustment of the MCS according to the target channel information measurement result.

In the technical solution provided by the embodiment of the present invention, the first network device obtains the target channel information measurement result, and the target channel information measurement result is the measurement result obtained by measuring the channel information according to the probing physical layer protocol data unit PPDU of the target mode; The link adaptive adjustment is performed on the target channel information measurement result. Therefore, compared with the prior art, the embodiment of the present invention can flexibly obtain the measurement result obtained by measuring the channel information using a probe PPDU in a specific mode, so as to adapt to different application scenarios. Different requirements, improve the flexibility of channel information measurement, so as to provide users with accurate link adaptation.

Description of drawings

Figure 1 is a schematic diagram of the format of a MAC frame in the IEEE 802.11n standard;

FIG. 2 is a schematic diagram of the format of the HT control field in the IEEE 802.11n standard;

3 is a schematic diagram of the format of the link adaptation control field in FIG. 2;

FIG. 4 is a schematic diagram of the format of the HT control field in the IEEE 802.11ac standard;

FIG. 5 is a schematic diagram of an embodiment of a link adaptation method for WLAN in an embodiment of the present invention;

FIG. 6 is a schematic diagram of another embodiment of a link adaptation method for WLAN in an embodiment of the present invention;

7 is a schematic diagram of a format of a detection PPDU in an embodiment of the present invention;

FIG. 8 is a schematic diagram of another embodiment of a link adaptation method for WLAN in an embodiment of the present invention;

FIG. 9 is a schematic diagram of another embodiment of a link adaptation method for WLAN in an embodiment of the present invention;

10 is a schematic diagram of a format of an HT control field in an embodiment of the present invention;

11 is a schematic diagram of another embodiment of a link adaptation method for a WLAN in an embodiment of the present invention;

FIG. 12 is a schematic diagram of another embodiment of a link adaptation method for WLAN in an embodiment of the present invention;

13 is a schematic diagram of another embodiment of a link adaptation method for WLAN in an embodiment of the present invention;

14 is a schematic diagram of another embodiment of a link adaptation method for WLAN in an embodiment of the present invention;

14a is a schematic diagram of another format of the HT control field in an embodiment of the present invention;

FIG. 15 is a schematic diagram of an embodiment of a network device in an embodiment of the present invention;

16 is a schematic diagram of another embodiment of a network device in an embodiment of the present invention;

17 is a schematic diagram of another embodiment of a network device in an embodiment of the present invention;

18 is a schematic diagram of another embodiment of a network device in an embodiment of the present invention;

FIG. 19 is a schematic diagram of another embodiment of a network device in an embodiment of the present invention.

Detailed ways

Embodiments of the present invention provide a WLAN link adaptation method and network device, which can improve the flexibility of channel information measurement and provide users with accurate link adaptation, which will be described in detail below.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that the embodiments of the present invention are applied to an OFDMA communication system in a wireless local area network, where the OFDMA communication system includes a first network device and at least one second network device, wherein the at least one second network device wirelessly communicates with the The first network device is communicatively connected.

For example, the first network device may be an AP (Access Point, access point), then the second network device is a STA (Station, station), or, the first network device may also be a STA, then the second network device is an AP .

It should be noted that, in the following embodiments, only the link adaptation between the AP and the STA is used as a specific application scenario to exemplarily illustrate the principles and implementations of the present invention.

To facilitate understanding of the embodiments of the present invention, related technologies or terms that will be introduced in the description of the embodiments of the present invention are introduced below:

1. High throughput control field

The AP or the STA performs link adaptation through the HT (High Throughput, high throughput rate) control field in the MPDU (Medium Access Control Protocol Data Unit, medium access control protocol data unit, MAC frame for short).

As shown in FIG. 1 , it is a schematic diagram of the format of the MAC frame in the IEEE 802.11n standard. Among them, the HT control field is included in the frame header of the MAC frame and is used to indicate information such as link adaptation and calibration position. The HT control field generally exists in the Control Wrapper frame, or when the frame control field The sequence bit is set to 1 in the QoS data frame.

The format of the HT control field in some existing standards is briefly introduced below, for example: the HT control field of the HT variant in the IEEE 802.11n standard and the HT variant of the VHT (Very High Throughput) variant in the IEEE 802.11ac standard Control field.

As shown in FIG. 2, it is a schematic diagram of the format of the HT control field in the IEEE 802.11n standard (ie, the HT control field of the HT variant), wherein the link adaptation control field in the HT control field in FIG. The adaptation-related information is indicated, and FIG. 3 is a schematic diagram of the format of the link adaptation control field.

The following is a brief introduction to the link adaptation process of one of the MCS (Modulation and Coding Scheme, modulation and coding strategies) in the IEEE 802.11n standard, hereinafter referred to as TRQ (Training Request, probe request) mode: link The adaptation requester sends a PPDU (PhysicalLayer Protocol Data Unit, physical layer protocol data unit) including the HT control field of the HT variant to the responder, wherein TRQ is set to 1 to indicate that the responder needs to send a probe PPDU; the responder according to the above The HT control field of the HT variant generates a probe PPDU and sends the probe PPDU to the link adaptation requester; the link adaptation requester measures channel information according to the probe PPDU and performs link adaptation adjustment according to the channel information.

On the basis of the IEEE 802.11n standard, people have carried out a more comprehensive design of the HT control field of the VHT variant in the IEEE 802.11ac standard, as shown in Figure 4, which is the HT control field in the IEEE 802.11ac standard (that is, the Schematic diagram of the format of the HT control field). The HT control field of the VHT variant reuses the HT control field of the HT variant, wherein the first bit of the original reserved bit in the HT control field of the HT variant is used as the VHT bit, and the VHT bits are used to distinguish the two versions. When the bit is set to 0, it indicates that the current HT control field is the HT control field of the HT variant. When the VHT bit is set to 1, it indicates that the current HT control field is the HT control field of the VHT variant.

The following briefly introduces the link adaptation process of two MCSs in the IEEE 802.11ac standard, including the request-feedback mechanism and the unsolicited mode-feedback mechanism:

In a link adaptation process of the request-feedback mechanism, the link adaptation requester sends a probe PPDU to the responder, where VHT is set to 1 to indicate that the current HT control field is the HT control field of the VHT variant, and VHT is set to is 1, MRQ (MCS request) is set to 1 to indicate that the responder needs to perform MCS feedback; then the responder uses the above-mentioned probe PPDU to measure the channel information and feeds back the channel information measurement result to the link adaptation requesting end, so that the link adaptation requesting end Link adaptive adjustment is performed according to the channel information measurement result.

The non-request-feedback mechanism means that the active feedback end actively feeds back channel information measurement results for any frame or multiple frames of data previously sent by the communication opposite end when the communication opposite end does not send a feedback request. In a link adaptation process of the unsolicited-feedback mechanism, the active feedback end actively sends a PPDU including the HT control field of the VHT variant to its communication peer, where the VHT is set to 1 to indicate that the current HT control field is In the HT control field of the VHT variant, the Unsolicited MFB (Unsolicited MCS feedback indicator, unsolicited MCS feedback indicator) is set to 1 to indicate that the MCS feedback is unsolicited active feedback, and is carried in the MFB (MCS feedback, MCS feedback) field. Corresponding channel information measurement results, so that the communication peer can perform link adaptive adjustment according to the channel information measurement results.

It should be noted that some public information in the HT control field, such as MSI/STBC (MCS request sequence guide/space-time block coding) and other fields, are not introduced here. Those skilled in the art can refer to existing relevant standards and subsequent related stipulated in the standard.

2. Link adaptation

In this embodiment, the parameters adjusted by the link adaptation may include at least one of parameters such as MCS, GI (Guard Interval, guard interval), redundancy information, transmit power, and time-frequency resources. In this embodiment, the channel parameters used to measure the channel information may be determined according to the parameters adjusted by link adaptation, such as the SNR (Signal to Noise Ratio, signal-to-noise ratio) of the channel, the spreading delay of the channel, or the delay between multiple users, etc. Correspondingly, in the link adaptation process of the request-feedback mechanism and the non-request-feedback mechanism, the channel information measurement result obtained by measuring the channel information also includes various contents, such as MCS, GI, or antenna selection.

For example, the link adaptation of MCS, that is, when the parameter adjusted by the link adaptation is MCS, the channel information may include the SNR (Signal to Noise Ratio, signal-to-noise ratio) of the channel, and the corresponding channel information measurement results may include: The number of spatiotemporal streams, the proposed MCS, the bandwidth used by the proposed MCS, the average high-efficiency SNR, etc.

For example, link adaptation of GI, that is, when the parameter adjusted by link adaptation is MCS, the channel information may include channel spreading delay and/or multi-user delay, and the corresponding channel information measurement result may include suggested GI.

It should be noted that, in some of the following embodiments, the principle and implementation of the present invention are exemplified mainly by taking the link adaptation of the GI as a specific application scenario.

Referring to FIG. 5, an embodiment of a WLAN link adaptation method in the embodiment of the present invention includes:

501. A first network device acquires a target channel information measurement result;

The measurement result of the target channel information is a measurement result obtained by measuring the channel information according to the probe PPDU of the target mode. Therefore, step 501 can be specifically understood as: first, the first network device determines the probe PPDU of the target mode, and then obtains and uses the target mode. The target channel information measurement result obtained by measuring the channel information of the probing PPDU of the mode.

In this embodiment, the first network device may determine the probe PPDU of the target mode according to the application scenario, that is, in different application scenarios, select the probe PPDU corresponding to the adapted target mode, for example, the first network device may The scene is still an outdoor scene, the channel information to be measured, the accuracy requirements of the channel information, the feedback efficiency requirements, the busy status of the channels in the cell, etc. to determine the detection PPDU of the target mode. The selection rule of the detection PPDU mode is not limited here. .

It should be noted that, in this embodiment, the mode of detecting the PPDU may include detecting the bandwidth information of the PPDU, detecting whether the PPDU adopts the indoor mode or the outdoor mode, and detecting the Fourier change of the LTF (Long Training Field, long training field) of the PPDU. at least one of order information and guard interval information of the probe PPDU. Among them, the bandwidth information of the detection PPDU refers to which bandwidth is used for the detection PPDU; the Fourier transformation order information of the long training field of the detection PPDU refers to the FFT (Fast Fourier Transformation, Fast Fourier Transform) of which order is used to detect the PPDU. ), for example, a 64-point FFT, or a larger FFT such as a 128-point FFT or a 256-point FFT, etc.

It can be understood that, in this embodiment, in the link adaptation process of different mechanisms, the method of acquiring the measurement result of the target channel information will also be different. Specifically, how to acquire the measurement result of the target channel information will be followed later. Continue to describe in detail in the embodiment of .

502. The first network device performs link adaptive adjustment according to the target channel information measurement result;

In this embodiment, the channel information measurement result referenced for link adaptation adjustment is obtained by using the probe PPDU of the target mode to perform channel information measurement. Therefore, the channel information measurement result is more relevant to the current application scenario. Therefore, accurate link adaptation can be provided for users.

In the technical solution provided by the embodiment of the present invention, the first network device obtains the target channel information measurement result, and the target channel information measurement result is the measurement result obtained by measuring the channel information according to the probing physical layer protocol data unit PPDU of the target mode; The link adaptive adjustment is performed on the target channel information measurement result. Therefore, compared with the prior art, the embodiment of the present invention can flexibly obtain the measurement result obtained by measuring the channel information using a probe PPDU in a specific mode, so as to adapt to different application scenarios. Different requirements, improve the flexibility of channel information measurement, so as to provide users with accurate link adaptation.

A link adaptation process of the TRQ mode is introduced below from the perspective of the first network device. Referring to FIG. 6 , another embodiment of the link adaptation method of the WLAN in the embodiment of the present invention includes:

601. A first network device sends a first PPDU to a second network device;

In this embodiment, the first PPDU indicates that the second network device needs to send a probe PPDU. It can be understood that, in the actual application process, the first PPDU may indicate that the second network device needs to use its preamble field or the MPDU carried by it. Send the probe PPDU, which is not limited here.

In this embodiment, the first PPDU further includes a mode indication field, for example, denoted as a T-Mode (RequiredTraining PPDU mode, the mode of the required probing PPDU) field, and the T-Mode field is used to instruct the second network device to generate It can be understood that, in the actual application process, the T-Mode field may be included in the preamble field (for example, the SIG-B field) of the first PPDU, and may also be included in the MPDU of the first PPDU. , which is not specifically limited here.

The following describes in detail how the T-Mode field instructs the second network device to generate the probe PPDU of the target mode. The following examples illustrate:

(1) The first field;

For example, the first field is denoted as a BW (Bandwidth, bandwidth) field, and the BW field is used to indicate the bandwidth that the probe PPDU should use. which bandwidth.

(2) the second field;

For example, the second field is marked as the Indoor/Outdoor (Indoor mode or Outdoor mode, indoor/outdoor mode) field, and the Indoor/Outdoor field is used to indicate whether the detection PPDU should adopt the indoor mode or the outdoor mode, that is, the detection mode of the PPDU includes detection When the PPDU adopts the indoor mode or the outdoor mode, you can use the Indoor/Outdoor field to indicate whether the detection PPDU adopts the indoor mode or the outdoor mode.

(3) The third field;

For example, the third field is denoted as the NX_HE-LTF (N*64FFT of HE-LTF, FFT order of the high-efficiency long training field) field, and the NX_HE-LTF field is used to indicate the order of the FFT that should be used in the long training field of the sounding PPDU That is, when the mode of detecting the PPDU includes the Fourier transform order information of the long training field of the detecting PPDU, the NX_HE-LTF field can be used to indicate which order of FFT to use for detecting the PPDU. For example, in the actual application process, The current FFT order may be expressed as N times 64 based on 64 points, where N may be 1, 2, 4, or the like.

(4) the fourth field;

For example, the fourth field is denoted as the GI field, and the GI field is used to indicate the length of the guard interval that should be used for the detection PPDU, that is, when the mode of the detection PPDU includes the guard interval information of the detection PPDU, the GI field can be used to indicate which one to use for the detection PPDU. GI of length, for example, 0.4, 0.8us, or longer GI, such as 1.6, 2.4, or 3.2us, etc.

It can be understood that the mode of the probe PPDU may also include more information for describing the parameters of the probe PPDU, which is not specifically limited here. Correspondingly, a corresponding field may be set to indicate the relevant information.

602. The first network device receives the second PPDU sent by the second network device;

In this embodiment, the second PPDU is a probe PPDU of the target mode generated by the second network device according to the T-Mode field.

For example, when the Indoor/Outdoor field indicates that the probe PPDU should adopt the outdoor mode, the probe PPDU corresponding to the generated target mode (that is, the probe PPDU of the outdoor mode) is an enhanced probe PPDU, please refer to FIG. 7, the enhanced probe PPDU Refers to a probe PPDU having at least one of the following formats:

(1) Part or all of the at least one symbol of the preamble of the probe PPDU is copied in the time domain or the frequency domain;

That is, in the process of generating the probe PPDU, the second network device performs partial or full replication of a certain symbol in the preamble in the time domain or frequency domain. As shown in FIG. 7 , the L-SIG symbol is completely replicated.

(2) The GI between part or all of the detected PPDU symbols is greater than the first preset value;

That is, in the process of generating the probe PPDU, the second network device adopts a longer GI, and the first preset value can be set according to the actual scene, for example, it can be 0.8us, then the probe PPDU in the outdoor mode can use a longer GI than the traditional probe PPDU. Longer GI, such as 1.6, 2.4, 3.2us, etc. At this time, increasing the GI helps to resist the larger expansion delay in outdoor scenes.

(3) detecting that the MCS of at least one symbol of the PPDU satisfies a certain preset condition;

That is, when the second network device generates the probe PPDU, the MCS of at least one symbol of the probe PPDU is more robust, for example, the most robust MCS0 from MCS0 to MCS9, or the MCS10 in the IEEE 802.11ah standard, which The robustness is better than that of MCS0. Therefore, in the actual application process, the modulation and coding mode of MCS10 can be used for the signaling field or data field of the detection PPDU.

(4) The order of the FFT of at least one symbol of the probe PPDU is higher than the second preset value.

That is, when the second network device generates the probe PPDU, the probe PPDU can use a larger order FFT, such as a 128-point FFT or a 256-point FFT. At this time, a larger FFT can not only improve efficiency, but also reduce The effect of spreading delays.

It should be noted that the above only describes the format of the detection PPDU in the outdoor mode by way of example. In practical applications, the format of the detection PPDU in the outdoor mode can be used in combination with the above formats, and more For other formats, for example, an indication field can be introduced again to indicate the variable mode of the subsequent fields, for example, the GI information of the signaling field-B is indicated by a certain field in the signaling field-A, etc., The GI information of the data field and the like are indicated by a certain field of the signaling field-B.

603. The first network device uses the second PPDU to measure channel information to obtain a target channel information measurement result;

In this embodiment, the second PPDU is a probe PPDU of the target mode generated according to the T-Mode field. Therefore, by using the probe PPDU to measure channel information, a measurement result of the target channel information can be obtained.

604. The first network device performs link adaptive adjustment according to the target channel information measurement result;

Optionally, in this embodiment, the channel information includes the channel spreading delay and/or the delay between multiple users, and the corresponding target channel information measurement result is the target GI, then step 604 is specifically: the first network device according to the target GI Perform adaptive adjustment of GI.

Alternatively, in this embodiment, the channel information may also include the SNR of the channel, and the corresponding target channel information measurement result is the target MCS. Step 604 specifically includes: the first network device performs adaptive adjustment of the MCS according to the target MCS.

It can be understood that, in this embodiment, the channel parameters used for measuring the channel information may be determined according to parameters adjusted by link adaptation.

In the technical solution provided by the embodiment of the present invention, the first network device sends a first PPDU to the second network device, wherein the first PPDU indicates that the second network device needs to send a probe PPDU, and the first PPDU further includes a mode indication field, The mode indication field is used to instruct the second network device to generate a probe PPDU of the target mode; and receive a second PPDU, where the second PPDU is a probe PPDU of the target mode generated by the second network device according to the mode indicator field; and then use the first Two PPDUs measure channel information, obtain a target channel information measurement result, and perform link adaptive adjustment according to the target channel information measurement result. Therefore, compared with the prior art, the embodiment of the present invention also carries a mode indication field in the first PPDU to specify the mode of the probe PPDU, so that the probe PPDU of the corresponding mode can be used to measure the channel information, and the corresponding channel information measurement can be obtained. As a result, the embodiment of the present invention can flexibly acquire measurement results obtained by measuring channel information using a probe PPDU in a specific mode, so as to adapt to different requirements in different application scenarios, improve the flexibility of channel information measurement, and provide users Provides accurate link adaptation.

A link adaptation process of the TRQ mode is described below from the perspective of the second network device. Referring to FIG. 8 , another embodiment of the link adaptation method of the WLAN in the embodiment of the present invention includes:

801. The second network device receives the first PPDU sent by the first network device;

In this embodiment, the first PPDU indicates that the second network device needs to send a probe PPDU. It can be understood that, in the actual application process, the first PPDU may indicate that the second network device needs to use its preamble field or the MPDU carried by it. Send the probe PPDU, which is not limited here.

In this embodiment, the first PPDU further includes a mode indication field, and the mode indication field is used to instruct the second network device to generate a probe PPDU of the target mode. Specifically, for the description of the mode indication field, please refer to the implementation shown in FIG. 6 . The description of step 601 in the example is not repeated here.

802. The second network device generates a second PPDU of the target mode according to the mode indication field;

In this embodiment, after receiving the first PPDU sent by the first network device, the second network device reads the mode indication field therein, and generates a probe PPDU of the corresponding target mode according to the mode indication field, that is, the second PPDU .

803. The second network device sends a second PPDU to the first network device;

Wherein, the second PPDU is used by the first network device to use the second PPDU to measure channel information, obtain a target channel information measurement result, and perform link adaptive adjustment according to the target channel information measurement result.

Based on the embodiments shown in FIGS. 6 and 8 , taking the mode indication field included in the HT control field of the first PPDU as an example, a WLAN link adaptation method in the TRQ mode will be described in detail. Please refer to FIG. 9, another embodiment of the link adaptation method of the WLAN in the embodiment of the present invention includes:

901. A first network device sends a first PPDU to a second network device;

The first PPDU carries at least one MPDU, and the MPDU indicates that the second network device needs to send the probe PPDU. For example, in the actual application process, the TRQ bit can be set to 1 to indicate that the second network device needs to send the probe PPDU. Please refer to Figure 10 for details.

In this embodiment, the MPDU includes an HT control field, and the HT control field further includes a T-Mode field, where the T-Mode field is used to instruct the second network device to generate a probe PPDU of the target mode, as shown in FIG. 10 : the BW field, It is used to indicate the bandwidth that the probe PPDU should adopt; the Indoor/Outdoor field is used to indicate whether the probe PPDU should adopt the indoor mode or the outdoor mode, and the NX_HE-LTF field is used to indicate the order of the FFT that should be adopted in the long training field of the probe PPDU; The GI field is used to indicate the length of the guard interval that the probe PPDU should use.

It can be understood that the T-Mode field may further include more fields for indicating parameters of the probe PPDU, which is not specifically limited here.

In the actual application process, the T-Mode field can be set according to the application scenario to indicate the target mode for detecting the PPDU, wherein the application scenario includes an indoor scenario or an outdoor scenario, the channel information to be measured, and the accuracy of the channel information. requirements, feedback efficiency requirements, the busy status of channels in the cell, etc. The following examples illustrate:

If the first network device is an indoor scene, the Indoor/Outdoor field of the T-Mode field may be set to the indoor mode, thereby generating a probe PPDU in the indoor mode, and the GI of the probe PPDU is short, such as 0.8us, so as to ensure On the premise that the first network device obtains the channel information measurement result, the overhead caused by the second network device sending the probe PPDU is minimized.

If the channel information to be measured by the first network device is the extension delay, the GI field of the T-Mode field may be set to the longest GI to ensure that the GI length of the long training field of the probe PPDU is greater than the extension delay of the current channel, otherwise Signals on multiple paths of the channel will overlap, and even if the sounding PPDU is received, the spreading delay of the current channel cannot be measured correctly.

If the first network device has high requirements on the accuracy of the channel information, if you want to measure the channel information of all subcarriers, you can set the NX_HE-LTF field of the T-Mode field to 4X HE-LTF; If the channel correlation characteristics of the adjacent subcarriers are relatively high, the NX_HE-LTF field of the T-Mode field may be set to 1X HE-LTF or 2X HE-LTF. - Interpolate the channel measured by the LTF, and on the premise of obtaining channel information on all subcarriers, try to reduce the overhead caused by the second network device sending the probe PPDU.

For another example, according to the busy state of the channel in the cell, when a certain channel (such as 20M) has higher transmission efficiency, the BW field of the T-Mode field can be set to 20M bandwidth, so that the second network device The opportunity to transmit the probe PPDU can be acquired faster, so that the first network device can measure the channel information as soon as possible.

It should be noted that the above only describes the specific ways of setting the T-Mode field by the first network device with a few examples. In practical applications, the first network device can use the above setting methods in combination, and other settings can also be used. The specific setting method is not limited here.

Specifically, for the description of the T-Mode field here, reference may be made to step 601 in the embodiment shown in FIG. 6 . Based on this, the specific format of the T-Mode field is described in detail below:

First of all, it should be noted that in this embodiment, a new version identification field may be added to the MPDU in this embodiment of the present invention, for example, denoted as HE bit, and thus, the HT control field in this embodiment of the present invention can be understood HT control field for HE variants. In the actual application process, in order to realize the backward compatibility of the version, on the basis of the HT control field of the VHT variant, the HE bit is set at the bit position after the VHT bit. It can be understood that, in some specific application scenarios, the above-mentioned version identification field may not be included.

In this embodiment, the specific position and number of bits of the T-Mode field are not limited. For example, as shown in FIG. 10, the BW field may include 2 bits, the Indoor/Outdoor field may include one bit, and the NX_HE-LTF field 2 bits may be included, and the GI field may include 2 bits.

Optionally, in this embodiment, the MPDU may further include a fifth field, for example, denoted as a Required (Number of Training PPDU need to be transmitted, the number of probe PPDUs to be sent) field, the Required field is used to indicate the first Two network devices need to send the number of probe PPDUs. Of course, in some other embodiments, the Required field may also be included in other parts of the first PPDU, such as a preamble field.

Optionally, in this embodiment, the MPDU may include a Control Wrapper frame, a QoS data frame when the sequence bit of the frame control field is set to 1, a beacon frame, a probe response frame, or an association response frame, etc. . In the actual application process, some frames of other types may also be included, and the frame type of the MPDU is not limited here.

902. The second network device generates a second PPDU of the target mode according to the mode indication field;

In this embodiment, after receiving the first PPDU sent by the first network device, the second network device reads the T-Mode field therein, and generates a probe PPDU of the corresponding target mode according to the T-Mode field, that is, the first PPDU. Two PPDUs.

In this embodiment, corresponding to the Required field, the second PPDU may further include a sixth field, for example, denoted as Remaining (Number of Remaining Training PPDU need to be transmitted, the number of remaining probe PPDUs to be transmitted) field, the The Remaining field is used to indicate the number of probe PPDUs that the second network device will send later.

Specifically, for the description about the detection of the PPDU here, reference may be made to step 602 in the embodiment shown in FIG. 6 , and details are not repeated here.

903. The second network device sends a second PPDU to the first network device;

904. The first network device uses the second PPDU to measure channel information to obtain a target channel information measurement result;

905. The first network device performs link adaptive adjustment according to the target channel information measurement result;

Steps 904 to 905 in this embodiment are the same as steps 603 to 604 in the embodiment shown in FIG. 6 , and details are not repeated here.

For ease of understanding, a GI link adaptation process in the TRQ mode will be introduced in a specific application scenario with reference to the HT control field shown in FIG. 10 . Please refer to FIG. 11 . One embodiment of the adaptation method includes:

1101. The AP sends a first PPDU carrying the HT control field of the HE variant to the STA;

In this embodiment, both the VHT bit and the HE bit of the HT control field are set to 1 to indicate that the current HT control field is the HT control field of the HE variant; TRQ is set to 1 to indicate that the GI link in the TRQ mode will be automatically Adapt; then set the T-Mode field and the Required field.

1102. The STA generates a second PPDU in the target mode according to the first PPDU;

In this embodiment, the STA reads the MPDU, wherein, through TRQ, it learns that the probe PPDU needs to be sent, and further reads the T-Mode field to learn the mode of the probe PPDU to be sent, and reads the Required field to obtain the need to send. The number of probe PPDUs is determined, and a corresponding probe PPDU, that is, a second PPDU, is generated. In this embodiment, the second PPDU carries the HT control field, and both the VHT bit and the HE bit of the HT control field are set to 1 to indicate that the current HT control field is the HT control field of the HE variant, and then the Remaining field is set to Indicates the number of probe PPDUs that the STA will send later.

1103. The STA sends a second PPDU to the AP;

1104. The AP uses the second PPDU to measure the spread delay of the channel and/or the delay between multiple users to obtain the target GI;

Wherein, the AP measures the spreading delay and/or the delay between multiple users through the long training field of the second PPDU.

1105. The AP performs adaptive adjustment of the GI according to the target GI;

In this embodiment, after obtaining the target GI, the AP can perform adaptive adjustment of the GI according to the target GI.

A link adaptation process of the unsolicited-feedback mechanism is introduced below from the perspective of the first network device. Referring to FIG. 12 , another embodiment of the link adaptation method of the WLAN in the embodiment of the present invention includes:

1201. The first network device receives the PPDU sent by the second network device;

In this embodiment, the PPDU instructs the second network device to actively send the channel information measurement result to indicate that the link adaptation of the unsolicited-feedback mechanism will be performed. It can be understood that in the actual application process, the PPDU can pass its preamble field or the MPDU carried by it to instruct the second network device to actively send the channel information measurement result, which is not specifically limited here.

In this embodiment, the first PPDU further includes a mode indication field, for example, denoted as a T-Mode (Training PPDU mode, probing PPDU mode) field, where the T-Mode field is used to indicate the second network device to use for measuring the channel information It can be understood that in the actual application process, the T-Mode field may be included in the preamble field (for example, the SIG-B field) of the first PPDU, and may also be included in the MPDU of the first PPDU. , which is not specifically limited here.

The following describes in detail how the T-Mode field indicates the mode of the probe PPDU used by the second network device to measure the channel information. The following examples illustrate:

(1) The first field;

For example, the first field is denoted as a BW (Bandwidth, bandwidth) field, and the BW field is used to indicate the bandwidth used by the probe PPDU, that is, when the mode of the probe PPDU includes the bandwidth information of the probe PPDU, the BW field can be used to indicate whether the probe PPDU adopts the probe PPDU. which bandwidth.

(2) the second field;

For example, the second field is marked as an Indoor/Outdoor (Indoor mode or Outdoor mode, indoor/outdoor mode) field, and the Indoor/Outdoor field is used to indicate whether the detection PPDU adopts the indoor mode or the outdoor mode, that is, the detection PPDU mode includes the detection PPDU When the indoor mode or the outdoor mode is adopted, the Indoor/Outdoor field can be used to indicate whether the detection PPDU adopts the indoor mode or the outdoor mode.

(3) The third field;

For example, the third field is denoted as the NX_HE-LTF (N*64FFT of HE-LTF, the FFT order of the high-efficiency long training field) field, and the NX_HE-LTF field is used to indicate the order of the FFT adopted by the long training field of the sounding PPDU , that is, when the mode of detecting the PPDU includes the Fourier transform order information of the long training field of the detecting PPDU, the NX_HE-LTF field can be used to indicate which order of FFT is used for detecting the PPDU. For example, in the actual application process, The current FFT order may be expressed as N times 64 based on 64 points, where N may be 1, 2, 4, or the like.

(4) the fourth field;

For example, the fourth field is denoted as the GI field, and the GI field is used to indicate the length of the guard interval used for the detection PPDU, that is, when the mode of the detection PPDU includes the guard interval information of the detection PPDU, the GI field can be used to indicate which one is used for the detection PPDU. GI of length, for example, 0.4, 0.8us, or longer GI, such as 1.6, 2.4, or 3.2us, etc.

It can be understood that the mode of the probe PPDU may also include more information for describing the parameters of the probe PPDU, which is not specifically limited here. Correspondingly, a corresponding field may be set to indicate the relevant information.

It should be noted that, in the link adaptation process of the unsolicited-feedback mechanism, the second network device may actively send multiple PPDUs to the first network device, so as to actively feed back multiple channel information to the first network device without interruption. measurement results. It can be understood that, in an actual application process, the second network device may measure the channel information by probing PPDUs in any mode. For example, the second network device may measure the channel information by using the probing PPDUs in the outdoor mode, or the second network device may use The probe PPDU in the indoor mode (here, for the probe PPDU in the outdoor mode, refer to step 602 in the embodiment shown in FIG. 6 ) measures channel information, which is not specifically limited here.

1202. The first network device determines the target channel information measurement result according to the mode indication field;

In this embodiment, after receiving the PPDU, the first network device may learn, according to the mode indication field, which mode of the measurement result of the channel information indicated by the PPDU is obtained by using the probe PPDU measurement, and determine whether to select and use this mode The measurement result obtained by measuring the channel information of the probing PPDU is used as the channel information measurement result referenced by the subsequent link adaptive adjustment. If yes, the channel information measurement result is determined as the target channel information measurement result.

It can be understood that, in the link adaptation process of the unsolicited-feedback mechanism, the first network device can receive multiple PPDUs sent by the second network device, and learn the channel in each PPDU according to the indication of the mode indication field. The information measurement results are obtained by using which mode of probe PPDU measurement is used. Therefore, if the first network device wants to obtain the measurement result obtained by using a certain mode of probe PPDU measurement channel information, it only needs to perform the measurement according to the indication of the mode indication field. Select to suit different needs in different application scenarios.

1203. The first network device performs link adaptive adjustment according to the target channel information measurement result;

In this embodiment, the target channel information measurement result is a measurement result obtained by measuring channel information using a probe PPDU of a certain mode specified by the first network device, so that the first network device can flexibly select which mode of probe to use The measurement result obtained by measuring the channel information of the PPDU is subjected to link adaptive adjustment.

In the technical solution provided by the embodiment of the present invention, the first network device receives a PPDU sent by the second network device, wherein the PPDU instructs the second network device to actively send the channel information measurement result, and the PPDU further includes a mode indication field, the mode The indication field is used to indicate the mode of the probe PPDU used by the second network device to measure the channel information; the first network device determines the target channel information measurement result according to the mode indication field; and performs link adaptation adjustment according to the target channel information measurement result, In this way, the first network device can flexibly select which mode of the probing PPDU to use to measure the channel information for link adaptation adjustment. Therefore, compared with the prior art, the embodiment of the present invention also carries a mode indication field in the PPDU, so as to specify the mode of the probe PPDU used for measuring the channel information, so that the first network device can know which channel information measurement result is used. Therefore, the embodiment of the present invention can flexibly obtain measurement results obtained by measuring channel information using a probe PPDU of a certain mode, so as to adapt to different requirements in different application scenarios and improve the accuracy of channel information measurement. flexibility to provide users with accurate link adaptation.

A link adaptation process of the unsolicited-feedback mechanism is introduced below from the perspective of the second network device. Referring to FIG. 13 , another embodiment of the link adaptation method of the WLAN in the embodiment of the present invention includes:

1301. The second network device generates a PPDU;

In this embodiment, the PPDU instructs the second network device to actively send the channel information measurement result to indicate that the link adaptation of the unsolicited-feedback mechanism will be performed. It can be understood that in the actual application process, the PPDU can pass the The preamble field or the MPDU carried by the preamble field is used to instruct the second network device to actively send the channel information measurement result, which is not specifically limited here.

In this embodiment, the PPDU further includes a mode indication field, and the mode indication field is used to indicate the mode of the sounding PPDU used by the second network device to measure the channel information. Specifically, for the description of the mode indication field, please refer to FIG. 12 . The description of step 1201 in the embodiment is not repeated here.

It should be noted that, in the link adaptation process of the unsolicited-feedback mechanism, the second network device may actively send multiple PPDUs to the first network device, so as to actively feed back multiple channel information to the first network device without interruption. measurement results. It can be understood that, in an actual application process, the second network device may measure the channel information by probing PPDUs in any mode. For example, the second network device may measure the channel information using the probing PPDUs in the outdoor mode, or the second network device may use The probe PPDU in the indoor mode (here, for the probe PPDU in the outdoor mode, refer to step 602 in the embodiment shown in FIG. 6 ) measures channel information, which is not specifically limited here.

1302. The second network device sends a PPDU to the first network device;

In this embodiment, the PPDU is used by the first network device to determine the target channel information measurement result according to the mode indication field, and to perform link adaptive adjustment according to the target channel information measurement result. Specifically, for the process of determining the target channel information measurement result according to the mode indication field by the first network device, and performing link adaptation adjustment according to the target channel information measurement result, reference may be made to steps 1202 and 1203 in the embodiment shown in FIG. 12 . .

On the basis of the embodiments shown in FIGS. 12 and 13 , the mode indication field is included in the HT control field of the PPDU as an example to describe in detail a WLAN link adaptation method using an unsolicited-feedback mechanism. Referring to FIG. 14, another embodiment of the WLAN link adaptation method in the embodiment of the present invention includes:

1401. The second network device generates a PPDU;

In this embodiment, the PPDU carries at least one MPDU, and the MPDU instructs the second network device to actively send the channel information measurement result to indicate that link adaptation of the unsolicited-feedback mechanism will be performed. It can be understood that the MPDU also carries the channel information measurement result. For example, in the actual application process, the Unsolicited MFB (Unsolicited GI Feedback, unsolicited GI Feedback) field may be set to 1 to instruct the second network device to actively send the channel information measurement result, where the channel information measurement result is carried in the GFB ( GI Feedback) field to indicate a suitable GI to the first network device, please refer to FIG. 14a for details.

In this embodiment, the MPDU includes an HT control field, and the HT control field further includes a T-Mode field, where the T-Mode field is used to indicate the mode of the probe PPDU used by the second network device to measure the channel information, as shown in FIG. 14a : The BW field is used to indicate the bandwidth used by the probe PPDU; the Indoor/Outdoor field is used to indicate whether the probe PPDU adopts the indoor mode or the outdoor mode, and the NX_HE-LTF field is used to indicate the FFT order used in the long training field of the probe PPDU ; The GI field is used to indicate the length of the guard interval used by the probe PPDU.

It can be understood that the T-Mode field may further include more fields for indicating parameters of the probe PPDU, which is not specifically limited here. Specifically, for the description of the T-Mode field here, reference may be made to step 1201 in the embodiment shown in FIG. 12 . In this embodiment, the specific position and the number of bits of the T-Mode field are not limited. For details, reference may be made to step 901 in the embodiment shown in FIG. 9 here.

Optionally, in this embodiment, the MPDU may include a control wrapper (Control Wrapper) frame, a QoS data frame when the sequence bit of the frame control field is set to 1, a probe request frame or an association request frame, and the like. In the actual application process, some frames of other types may also be included, and the frame type of the MPDU is not limited here.

1402. The second network device sends a PPDU to the first network device;

1403. The first network device determines the target channel information measurement result according to the mode indication field;

1404. The first network device performs link adaptive adjustment according to the target channel information measurement result;

Steps 1403 to 1404 in this embodiment are the same as steps 1202 to 1203 in the embodiment shown in FIG. 12 , and are not repeated here.

The link adaptation method of the WLAN in the embodiment of the present invention is described above, and the network device in the embodiment of the present invention is described below. Referring to FIG. 15, an embodiment of the network device in the embodiment of the present invention includes:

The network device in the embodiment of the present invention can implement the process of the embodiment shown in FIG. 5 , and the network device includes:

an obtaining unit 1510, configured to obtain a target channel information measurement result, where the target channel information measurement result is a measurement result obtained by measuring the channel information according to the probing physical layer protocol data unit PPDU of the target mode;

The adjustment unit 1520 is configured to perform link adaptation adjustment according to the target channel information measurement result.

For ease of understanding, the following takes a specific application scenario as an example to describe the internal operation process of the network device in this embodiment:

The acquiring unit 1510 acquires the measurement result of the target channel information, the measurement result of the target channel information is the measurement result obtained by measuring the channel information according to the probing physical layer protocol data unit PPDU of the target mode; the adjusting unit 1520 performs chaining according to the measurement result of the target channel information. Road adaptive adjustment.

In the technical solution provided by the embodiment of the present invention, the obtaining unit 1510 of the network device obtains the target channel information measurement result, and the target channel information measurement result is the measurement result obtained by measuring the channel information according to the probing physical layer protocol data unit PPDU of the target mode; and The adjustment unit 1520 performs link adaptive adjustment according to the measurement result of the target channel information. Therefore, compared with the prior art, the embodiment of the present invention can flexibly obtain the measurement result obtained by measuring the channel information using the probe PPDU of a certain mode, so as to adapt to the target channel information. It can match different requirements in different application scenarios, improve the flexibility of channel information measurement, and provide users with accurate link adaptation.

A network device in the TRQ mode is described below. For details, please refer to FIG. 16. Another embodiment of the method for the network device in the embodiment of the present invention includes:

The network device in the embodiment of the present invention can implement the process of the embodiment shown in FIG. 6 , and the network device includes:

The sending module 1611 is configured to send a first PPDU to the target network device, wherein the first PPDU indicates that the target network device needs to send a probe PPDU, and the first PPDU further includes a mode indication field, where the mode indication field is used for Instruct the target network device to generate a probe PPDU of the target mode;

a first receiving module 1612, configured to receive a second PPDU sent by the target network device, where the second PPDU is a target mode probe PPDU generated by the target network device according to the mode indication field;

a first obtaining module 1613, configured to use the second PPDU to measure channel information to obtain the target channel information measurement result;

An adjustment unit 1620, configured to perform link adaptation adjustment according to the target channel information measurement result.

Optionally, in this embodiment, the mode of detecting the PPDU includes bandwidth information of the detecting PPDU, detecting whether the PPDU adopts the indoor mode or the outdoor mode, detecting the Fourier transform order information of the long training field of the detecting PPDU, and detecting the guard interval of the PPDU. at least one of the information.

Optionally, in this embodiment, the mode of detecting the PPDU includes detecting whether the PPDU adopts the indoor mode or the outdoor mode; when the mode indication field instructs the target network device to generate the detection PPDU in the outdoor mode, the second PPDU is the enhanced probe PPDU generated by the target network device according to the mode indication field;

Wherein, the enhanced sounding PPDU refers to a sounding PPDU having at least one of the following formats:

At least one symbol of the preamble of the sounding PPDU is partially or completely copied in the time domain or frequency domain, the guard interval between some or all symbols of the sounding PPDU is greater than the first preset value, and the The modulation and coding mode MCS of at least one symbol satisfies a certain preset condition, and the Fourier transform order of at least one symbol of the probe PPDU is higher than a second preset value.

Optionally, in this embodiment, the channel information includes channel spreading delay and/or multi-user delay;

The adjusting unit 1620 is specifically configured to perform adaptive adjustment of the guard interval according to the target channel information measurement result.

Optionally, in this embodiment, the channel information includes the SNR of the channel;

The adjusting unit 1620 is specifically configured to perform adaptive adjustment of the modulation and coding strategy MCS according to the target channel information measurement result.

In the technical solution provided by the embodiment of the present invention, the sending module 1611 of the network device sends a first PPDU to the target network device, where the first PPDU indicates that the target network device needs to send a probe PPDU, and the first PPDU further includes a mode indication field, The mode indication field is used to instruct the target network device to generate a probe PPDU of the target mode; and the first receiving module 1612 receives a second PPDU, where the second PPDU is a probe PPDU of the target mode generated by the target network device according to the mode indicator field ; Then the first acquisition module 1613 uses the second PPDU to measure the channel information to obtain the target channel information measurement result, and the adjustment unit 1620 performs link adaptive adjustment according to the target channel information measurement result. Therefore, compared with the prior art, the embodiment of the present invention also carries a mode indication field in the first PPDU to specify the mode of the probe PPDU, so that the probe PPDU of the corresponding mode can be used to measure the channel information, and the corresponding channel information measurement can be obtained. As a result, the embodiment of the present invention can flexibly acquire measurement results obtained by measuring channel information using a probe PPDU in a specific mode, so as to adapt to different requirements in different application scenarios, improve the flexibility of channel information measurement, and provide users Provides accurate link adaptation.

Another network device in the TRQ mode is described below, with reference to FIG. 17 for details. Another embodiment of the method for the network device in the embodiment of the present invention includes:

The network device in the embodiment of the present invention can implement the process of the embodiment shown in FIG. 8 , and the network device includes:

A receiving unit 1710, configured to receive a first PPDU sent by a target network device; wherein the first PPDU indicates that the network device needs to send a probe PPDU, and the first PPDU further includes a mode indication field, the mode indication field for instructing the network device to generate a probe PPDU of the target mode;

a generating unit 1720, configured to generate a probe PPDU of the target mode according to the mode indication field;

a sending unit 1730, configured to send a second PPDU to the target network device, wherein the second PPDU is used by the target network device to measure channel information using the second PPDU to obtain the target channel information measurement result, And perform link adaptive adjustment according to the target channel information measurement result.

Optionally, in this embodiment, the mode of detecting the PPDU includes bandwidth information of the detecting PPDU, detecting whether the PPDU adopts the indoor mode or the outdoor mode, detecting the Fourier transform order information of the long training field of the detecting PPDU, and detecting the guard interval of the PPDU. at least one of the information.

Optionally, in this embodiment, the mode of detecting the PPDU includes detecting whether the PPDU adopts the indoor mode or the outdoor mode; when the mode indication field instructs the target network device to generate the detection PPDU in the outdoor mode, the second PPDU is the enhanced probe PPDU generated by the target network device according to the mode indication field;

Wherein, the enhanced sounding PPDU refers to a sounding PPDU having at least one of the following formats:

At least one symbol of the preamble of the sounding PPDU is partially or completely copied in the time domain or frequency domain, the guard interval between some or all symbols of the sounding PPDU is greater than the first preset value, and the The modulation and coding mode MCS of at least one symbol satisfies a certain preset condition, and the Fourier transform order of at least one symbol of the probe PPDU is higher than a second preset value.

Optionally, in this embodiment, the channel information includes channel spreading delay and/or multi-user delay;

The second PPDU is used by the target network device to use the second PPDU to measure the spread delay of the channel and/or the delay between multiple users, and perform the measurement according to the measured spread delay of the channel and/or the delay between multiple users. Adaptive adjustment of guard interval.

Optionally, in this embodiment, the channel information includes the SNR of the channel;

The second PPDU is used by the target network device to measure the SNR of the channel by using the second PPDU, and perform adaptive adjustment of the MCS according to the measured SNR of the channel.

A network device of the unsolicited-feedback mechanism is described below. For details, please refer to FIG. 18. Another embodiment of the method for the network device in the embodiment of the present invention includes:

The network device in the embodiment of the present invention can implement the process of the embodiment shown in FIG. 12 , and the network device includes:

The second receiving module 1811 is configured to receive the PPDU sent by the target network device; wherein, the PPDU indicates that the target network device actively sends the channel information measurement result, and the PPDU further includes a mode indication field, which is used to indicate the target The mode of the probe PPDU used by the network device to measure the channel information;

a second obtaining module 1812, configured to determine the target channel information measurement result according to the mode indication field;

An adjustment unit 1820, configured to perform link adaptation adjustment according to the target channel information measurement result.

Optionally, in this embodiment, the mode of detecting the PPDU includes bandwidth information of the detecting PPDU, detecting whether the PPDU adopts the indoor mode or the outdoor mode, detecting the Fourier transform order information of the long training field of the detecting PPDU, and detecting the guard interval of the PPDU. at least one of the information.

Optionally, in this embodiment, the channel information includes channel spreading delay and/or multi-user delay;

The adjusting unit 1820 is specifically configured to perform adaptive adjustment of the guard interval according to the target channel information measurement result.

Optionally, in this embodiment, the channel information includes the SNR of the channel;

The adjusting unit 1820 is specifically configured to perform adaptive adjustment of the modulation and coding strategy MCS according to the target channel information measurement result.

In the technical solution provided by the embodiment of the present invention, the second receiving module 1811 of the network device receives a PPDU sent by the target network device, where the PPDU instructs the target network device to actively send the channel information measurement result, and the PPDU further includes a mode indication field, The mode indication field is used to indicate the mode of the probe PPDU used by the target network device to measure the channel information; and the second acquisition module 1812 determines the target channel information measurement result according to the mode indication field; and then the adjustment unit 1820 measures the target channel information according to the mode indication field. As a result, the link adaptive adjustment is performed, whereby the network device can flexibly select which mode of the probing PPDU measurement channel information is used to perform the link adaptive adjustment. Therefore, compared with the prior art, the embodiment of the present invention also carries a mode indication field in the PPDU, so as to specify the mode of the probe PPDU used to measure the channel information, so that the network device can know which channel information measurement result is used. Therefore, the embodiment of the present invention can flexibly obtain measurement results obtained by measuring channel information using a probe PPDU of a certain mode, so as to adapt to different requirements in different application scenarios and improve the accuracy of channel information measurement. flexibility to provide users with accurate link adaptation.

Another network device of the unsolicited-feedback mechanism is described below. For details, please refer to FIG. 19. Another embodiment of the method for the network device in the embodiment of the present invention includes:

The network device in the embodiment of the present invention can implement the process of the embodiment shown in FIG. 13 , and the network device includes:

A generating unit 1901, configured to generate a PPDU; wherein the PPDU instructs the network device to actively send a channel information measurement result, the PPDU further includes a mode indication field, and the mode indication field is used to instruct the network device to measure the channel information The mode of the probe PPDU used;

The sending unit 1902 is configured to send the PPDU to the target network device, wherein the PPDU is used by the target network device to determine the target channel information measurement result according to the mode indication field, and perform the measurement according to the target channel information measurement result. Link adaptive adjustment.

Optionally, in this embodiment, the mode of detecting the PPDU includes bandwidth information of the detecting PPDU, detecting whether the PPDU adopts the indoor mode or the outdoor mode, detecting the Fourier transform order information of the long training field of the detecting PPDU, and detecting the guard interval of the PPDU. at least one of the information.

Optionally, in this embodiment, the channel information includes channel spreading delay and/or multi-user delay;

The PPDU is used by the target network device to determine the target channel information measurement result according to the mode indication field, and to perform adaptive adjustment of the guard interval according to the target channel information measurement result.

Optionally, in this embodiment, the channel information includes a signal-to-noise ratio SNR of the channel;

The PPDU is used by the target network device to determine the target channel information measurement result according to the mode indication field, and to perform adaptive adjustment of the MCS according to the target channel information measurement result.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above may refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

The integrated unit, if implemented in the form of a software functional unit and sold or used as an independent product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: U disk, removable hard disk, Read-Only Memory (ROM, Read-Only Memory), Random Access Memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program codes.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: The technical solutions described in the embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (38)

1. A method for link adaptation in a W L AN, comprising:

a first network device receives a physical layer protocol data unit (PPDU) sent by a second network device; the PPDU comprises information indicating that the second network device actively sends a channel information measurement result, and a mode indication field, where the mode indication field is used to indicate a mode of a target sounding PPDU used by the second network device to measure channel information, and the PPDU further comprises the channel information measurement result;

the first network equipment acquires the channel information measurement result, wherein the channel information measurement result is obtained by the second network equipment according to the target detection PPDU measurement;

and the first network equipment performs link self-adaptive adjustment according to the channel information measurement result.

2. The method of claim 1, wherein the channel information measurement results comprise: a proposed number of space-time streams, a proposed modulation and coding scheme, MCS, and a bandwidth employed by the proposed MCS.

3. The method of claim 1, wherein the instructing the second network device to actively send the information of the channel information measurement result specifically comprises: the Unsolicited MCS feedback in the PPDU directs an unoiled MFB field to set 1, indicating that the second network device actively sends the channel information measurement result.

4. The method of claim 1, wherein the PPDU further comprises a bandwidth BW field for indicating a bandwidth of the target sounding PPDU.

5. The link adaptation method of the W L AN of claim 1, wherein the mode of the sounding PPDU comprises at least one of whether the sounding PPDU employs AN indoor mode or AN outdoor mode, fourier transform order information of a long training field of the sounding PPDU, and guard interval information of the sounding PPDU.

6. The link adaptation method of W L AN according to any one of claims 1 to 5, wherein the channel information includes AN extended delay of a channel and/or a delay between multiple users;

the first network device performing link adaptive adjustment according to the channel information measurement result includes:

and the first network equipment performs self-adaptive adjustment of the guard interval according to the channel information measurement result.

7. The link adaptation method of W L AN according to any one of claims 1 to 5,

the first network device performing link adaptive adjustment according to the channel information measurement result includes:

and the first network equipment carries out the self-adaptive adjustment of the modulation and coding strategy MCS according to the channel information measurement result.

8. A method for link adaptation in a W L AN, comprising:

the second network equipment receives a physical layer protocol data unit (PPDU) sent by the first network equipment; wherein the PPDU indicates that the second network device needs to send a sounding PPDU, and the PPDU further includes a mode indication field, and the mode indication field is used for indicating the second network device to generate a sounding PPDU of a target mode;

the second network equipment generates a detection PPDU of a target mode according to the mode indication field;

and the second network equipment sends the detection PPDU in the target mode to the first network equipment, wherein the detection PPDU in the target mode is used for the first network equipment to measure channel information by using the detection PPDU in the target mode to obtain a channel information measurement result, and performs link self-adaptive adjustment according to the channel information measurement result.

9. The link adaptation method of a W L AN of claim 8, wherein the mode of the sounding PPDU comprises at least one of bandwidth information of the sounding PPDU, whether the sounding PPDU employs AN indoor mode or AN outdoor mode, fourier change order information of a long training field of the sounding PPDU, and guard interval information of the sounding PPDU.

10. The link adaptation method of the W L AN of claim 8, wherein the mode of the sounding PPDU includes whether the sounding PPDU employs AN indoor mode or AN outdoor mode;

when the mode indication field indicates that the second network device generates a sounding PPDU in an outdoor mode, the second network device generating a sounding PPDU in a target mode according to the mode indication field includes:

the second network equipment generates an enhanced detection PPDU according to the mode indication field;

wherein the enhanced sounding PPDU refers to a sounding PPDU having at least one of the following formats:

at least one symbol of a preamble of the sounding PPDU is partially or completely copied in a time domain or a frequency domain, a guard interval between partial or all symbols of the sounding PPDU is larger than a first preset value, a Modulation and Coding Scheme (MCS) of at least one symbol of the sounding PPDU meets a certain preset condition, and a Fourier change order of at least one symbol of the sounding PPDU is higher than a second preset value.

11. The link adaptation method of W L AN according to any one of claims 8 to 10, wherein the channel information includes AN extended delay of a channel and/or a delay between multiple users;

and the target mode sounding PPDU is used for the first network equipment to measure the extension delay of the channel and/or the delay among multiple users by using the target mode sounding PPDU, and to perform the self-adaptive adjustment of the guard interval according to the measured extension delay of the channel and/or the delay among multiple users.

12. The method of any one of claims 8 to 10, wherein the channel information measurement result comprises: a proposed number of space-time streams, a proposed modulation and coding scheme, MCS, and a bandwidth employed by the proposed MCS.

13. A method for link adaptation in a W L AN, comprising:

the second network equipment generates a physical layer protocol data unit PPDU; the PPDU comprises information indicating that the second network equipment actively sends a channel information measurement result, and further comprises a mode indication field, wherein the mode indication field is used for indicating a mode of a target sounding PPDU used by the second network equipment for measuring the channel information;

and the second network equipment sends the PPDU to the first network equipment, wherein the PPDU comprises the channel information measurement result, the channel information measurement result is obtained by the second network equipment according to the measurement of the target detection PPDU, and the channel information measurement result is used for the first network equipment to carry out link self-adaptive adjustment.

14. The method of claim 13, wherein the channel information measurement result comprises: a proposed number of space-time streams, a proposed modulation and coding scheme, MCS, and a bandwidth employed by the proposed MCS.

15. The method of claim 13, wherein the information instructing the second network device to actively send channel information measurement results comprises: and setting 1 in an unoiled MFB field in the PPDU, and indicating the second network equipment to actively send the channel information measurement result.

16. The method of claim 13, wherein the PPDU further comprises a BW field for indicating a bandwidth of the target sounding PPDU.

17. The link adaptation method of a W L AN of claim 13, wherein the mode of the sounding PPDU comprises at least one of whether the sounding PPDU employs AN indoor mode or AN outdoor mode, fourier transform order information of a long training field of the sounding PPDU, and guard interval information of the sounding PPDU.

18. The link adaptation method of W L AN of claim 13, wherein the channel information includes AN extended delay of a channel and/or a delay between multiple users;

and the PPDU is used for the first network equipment to determine a channel information measurement result according to the mode indication field and to perform self-adaptive adjustment of a guard interval according to the channel information measurement result.

19. The link adaptation method of W L AN of claim 13, wherein the PPDU is used by the first network device to determine a channel information measurement result according to the mode indication field and to perform adaptive adjustment of MCS according to the channel information measurement result.

20. A network device, comprising:

the receiving module is used for receiving a physical layer protocol data unit PPDU sent by target network equipment; the PPDU includes information indicating that the target network device actively sends a channel information measurement result, and a mode indication field, where the mode indication field is used to indicate a mode of a target sounding PPDU used by the target network device to measure channel information, and the PPDU also includes the channel information measurement result;

an obtaining module, configured to obtain the channel information measurement result, where the channel information measurement result is obtained by the target network device according to the target sounding PPDU;

and the adjusting unit is used for carrying out link self-adaptive adjustment according to the channel information measurement result.

21. The network device of claim 20, wherein the channel information measurement results comprise: a proposed number of space-time streams, a proposed modulation and coding scheme, MCS, and a bandwidth employed by the proposed MCS.

22. The network device of claim 20, wherein the information instructing the target network device to actively send the channel information measurement result specifically comprises: the unsolicited MCS feedback in the PPDU directs the UnsulcittedMFB field to set 1, indicating that the target network device is actively sending the channel information measurement result.

23. The network device of claim 20, wherein the PPDU further comprises a bandwidth BW field for indicating a bandwidth of the targeted sounding PPDU.

24. The network device of claim 20, wherein the mode of the sounding PPDU comprises at least one of whether the sounding PPDU employs an indoor mode or an outdoor mode, fourier transform order information of a long training field of the sounding PPDU, and guard interval information of the sounding PPDU.

25. The network device according to any of claims 20 to 24, wherein the channel information comprises an extension delay of a channel and/or a delay between multiple users;

the adjusting unit is specifically configured to perform adaptive adjustment of a guard interval according to the channel information measurement result.

26. The network device according to one of claims 20 to 24, wherein the adjusting unit is specifically configured to perform adaptive adjustment of a modulation and coding scheme, MCS, according to the channel information measurement result.

27. A network device, comprising:

a receiving unit, configured to receive a physical layer protocol data unit PPDU sent by a target network device; the PPDU indicates that the network equipment needs to send a sounding PPDU, and the PPDU further comprises a mode indication field, wherein the mode indication field is used for indicating the network equipment to generate a sounding PPDU in a target mode;

a generating unit, configured to generate a sounding PPDU of a target mode according to the mode indication field;

and a sending unit, configured to send the sounding PPDU in the target mode to the target network device, where the sounding PPDU in the target mode is used by the target network device to measure channel information using the sounding PPDU in the target mode to obtain a channel information measurement result, and perform link adaptive adjustment according to the channel information measurement result.

28. The network device of claim 27, wherein the mode of the sounding PPDU comprises at least one of bandwidth information of the sounding PPDU, whether the sounding PPDU employs an indoor mode or an outdoor mode, fourier transform order information of a long training field of the sounding PPDU, and guard interval information of the sounding PPDU.

29. The network device of claim 27, wherein the mode of the sounding PPDU comprises whether the sounding PPDU employs an indoor mode or an outdoor mode;

when the mode indication field indicates that the network device generates a sounding PPDU in an outdoor mode, the generating unit is specifically configured to generate an enhanced sounding PPDU according to the mode indication field;

wherein the enhanced sounding PPDU refers to a sounding PPDU having at least one of the following formats:

at least one symbol of a preamble of the sounding PPDU is partially or completely copied in a time domain or a frequency domain, a guard interval between partial or all symbols of the sounding PPDU is larger than a first preset value, a Modulation and Coding Scheme (MCS) of at least one symbol of the sounding PPDU meets a certain preset condition, and a Fourier change order of at least one symbol of the sounding PPDU is higher than a second preset value.

30. The network device according to any of claims 27 to 29, wherein the channel information comprises an extension delay of a channel and/or a delay between multiple users;

the target mode of the sounding PPDU is used for the target network device to measure the extension delay of the channel and/or the delay among multiple users by using the target mode of the sounding PPDU, and the self-adaptive adjustment of the guard interval is carried out according to the measured extension delay of the channel and/or the delay among multiple users.

31. The network device of any of claims 27 to 29, wherein the channel information measurement result comprises: a proposed number of space-time streams, a proposed modulation and coding scheme, MCS, and a bandwidth employed by the proposed MCS.

32. A network device, comprising:

a generating unit, configured to generate a physical layer protocol data unit PPDU; the PPDU comprises information indicating that the network equipment actively sends a channel information measurement result, and further comprises a mode indication field, wherein the mode indication field is used for indicating a mode of a target sounding PPDU used by the network equipment for measuring the channel information;

a sending unit, configured to send the PPDU to a target network device, where the PPDU includes the channel information measurement result, the channel information measurement result is obtained by the network device according to the target sounding PPDU, and the channel information measurement result is used for performing link adaptive adjustment by the target network device.

33. The network device of claim 32, wherein the channel information measurement result comprises: a proposed number of space-time streams, a proposed modulation and coding scheme, MCS, and a bandwidth employed by the proposed MCS.

34. The network device of claim 32, wherein the information instructing the network device to actively send channel information measurements comprises: and setting 1 in an unoiled MFB field in the PPDU, and indicating the network equipment to actively send a channel information measurement result.

35. The network device of claim 32, wherein the PPDU further comprises a BW field indicating a bandwidth of the targeted sounding PPDU.

36. The network device of claim 32, wherein the mode of the sounding PPDU comprises at least one of whether the sounding PPDU employs an indoor mode or an outdoor mode, fourier transform order information of a long training field of the sounding PPDU, and guard interval information of the sounding PPDU.

37. The network device of claim 32, wherein the channel information comprises an extended delay of a channel and/or a delay between multiple users;

and the PPDU is used for the target network equipment to determine a channel information measurement result according to the mode indication field and to perform self-adaptive adjustment of a guard interval according to the channel information measurement result.

38. The network device of claim 32, wherein the PPDU is configured for the target network device to determine a channel information measurement result according to the mode indication field and to perform adaptive adjustment of an MCS according to the channel information measurement result.

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